An
Outline
of
Histology
Department of Anatomy, Histology & Embryology
Peking Union Medical College
2009.5
Contents
Epithelium .................................................................................................. 1
Connective Tissue (CT) ............................................................................. 4
Cartilage and Bone ..................................................................................... 8
Blood and Hemopoiesis ............................................................................11
Muscle Tissue ........................................................................................... 15
Nervous Tissue ......................................................................................... 18
The Circulatory System ........................................................................... 21
Immune System........................................................................................ 24
The Endocrine System ............................................................................. 28
Skin .......................................................................................................... 32
Oral Cavity and Salivary Glands ............................................................. 35
Digestive Tract ......................................................................................... 37
Digestive Glands ...................................................................................... 41
The Respiratory System ........................................................................... 45
The Urinary System ................................................................................. 48
The Male Reproductive System ............................................................... 53
The Female Reproductive System ........................................................... 57
The Eye and the Ear ................................................................................. 61
Epithelium
1. Components of epithelium
2. Characteristics of epithelium
(1) Many cells with little intercellular substances
(2) Shows polarity-nucleus position and shape, and special locations of
organelles and inclusions
(3) Rest on a basement membrane
(4) Avascular
3. Classification:
Covering epithelium
Gland epithelium
4. Functions
(1) Form a selective barrier
(2) Protection
(3) Absorption
(4) Excretion
(5) Digestion
(6) Secretion
(7) Sensation
5. Classification of covering epithelium
A. Cell shape
B. Number of layers
Simple --- cells in a single layer
Stratified --- cells in two or more layers
(1) Simple squamous
Very flattened cells presenting a minimal barrier to the passage of
material, e.g. oxygen, through them.
Cytoplasm is very hard to see with LM.
The very similar endothelium and mesothelium, line blood and lymph
vessels, and serous cavities, respectively.
(2) Simple cuboidal
Cell height and width are equal
(3) Simple columnar
Cell height exceeds width
Cells have three surfaces and sealed at the top of their sides by
encircling junctional complexes.
Cells have three surfaces: free/luminal, lateral and basal; each may
have membrane specializations, e.g. cilia at free, desmosomes at
lateral, and infoldings at basal surfaces.
(4) Pseudostratified columnar --- ciliated; non ciliated
Nuclei lie at different levels suggesting stratified, but all cells are in
contact with the basement membrane.
1
Two or more cell types are present: short basal, tall columnar
(5) Stratified squamous
Many cells, thick.
Basal most cells are cuboidal or columnar and divide.
Cells above the base become polyhedral and are held on this protective
epithelium
Underside of the epithelium is indented by vascular papillae of
connective tissue, except in the cornea.
(6) Keratinized stratified squamous
Similar in its basal and middle layers to (5), but the uppermost
epithelium has granular cells concerned with forming special, dead
cells solidly packed together as a surface keratin layer for greater
protection.
(7) Stratified cuboidal
(8) Stratified columnar
Surface cells are cuboidal or columnar in shape, basal most cells are
low columnar, and between them are polyhedral cells.
(9) Transitional epithelium
Several cells, thick, the surface cells vary from cuboidal in the relaxed
condition to squamous in the distended condition.
Basal layer are cuboidal or low columnar, intermediate layers are
polyhedral. Cells of the superficial layer are often binucleate.
6. Cell adhesion in the epithelial cells’ membrane
(1) Tight or occluding junction - outer parts of two cells’ membranes are
fused together thereby occluding the intercellular cleft.
(2) Adhering junctions - zonula adherens: macula adherens
Filaments of the terminal web in each cells apical cytoplasm fasten to
the complex.
Desmosomes are disc-like structure scattered on cells’ surfaces; each
is contributed to by membranes of two cells; cytoplasmic
tonofilaments converge on and insert into thickened cell membranes.
(3) Hemidesmosome - for better adhesion of the cell membrane to the
basal lamina.
(4) Gap junction - where two cells’ membranes come closely together
with only a 2-nm gap, and the permeability to ions increases for
electrical conductivity (electronic coupling).
(5) Terminal bar (LM) = Junctional complex (EM).
7. Surface specialization in epithelium
(1) Microvilli - on apical cell surface formed by tube-like evaginations of
apical plasma membrane with a core of cytoplasm containing
microfilaments of actin.
(2) Stereocilia - as long slender processes of the apical surface that are
nonmotile.
(3) Cilia - as fine, hair-like processes of the free apical surface, which are
2
motile.
8. Basal specializations in epithelium
(1) Basement membrane
(2) Basal membrane infoldings --- formed by infoldings of the basal
plasma membrane
9. Gland epithelium
Unicellular gland --- goblet cell
Multicellular gland
10. Types of glands
exocrine gland
endocrine gland
11. Classification of the exocrine glands
(1) Shape of the secretory unit - tubular, acinar, tubuloalveolar
(2) Duct system --- Simple --- nonbranching duct
Compound --- duct branched (intercalated, intralobular,
interlobular, and lobar duct).
(3) Duct epithelium --- low cuboidal, columnar, pseudostratified
columnar, and stratified.
(4) Manner of secretion --- holocrine, apocrine, merocrine.
12. Endocrine gland
(1) Cell arrangement - cords, clumps type, follicles.
(2) Rich of capillaries.
3
Connective Tissue (CT)
Introduction:
1. Origin: derived from mesenchyme
2. Components: cells + extracellular matrix (intercellular substances)
3. Characteristics:
(1) relative few cells with more extracellular matrix
(2) cells arranged loosely
(3) cells without polarity
(4) rich in blood vessels.
4. Classification:
Loose CT
Dense CT
CT Proper
Adipose CT
Mature CT
Regular Dense CT
Irregular Dense CT
Elastic Tissue
White (Yellow) adipose CT
Brown adipose CT
Reticular CT
Specialized CT
Cartilage
Bone
Blood & lymph
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage
mesenchyme
Embryonic CT mucous CT
5. Functions: connecting, supporting, defense, nutrition, and repair.
Loose Connective Tissue (areolar tissue)
1. Extracellular matrix
(1) Ground substance:
1) Compositions:
multiadhesive glycoproteins
glycosaminoglycans (GAGs)
proteoglycans
a. Multiadhesive glycoproteins: fibronectin, laminin, chondronectin.
b. Glycosaminoglycans (GAGs)
 type of GAGs: hyaluronic acid, chondroitin sulfate, dermatan sulfate,
keratan sulfate, heparan sulfate, etc.
 characteristics of GAGs: linear polymers of repeating disaccharide
units composed of a hexosamine and an
uronic acid, intensely hydrophilic.
c. Proteoglycans:
glycosaminoglycans (GAG) + core protein → proteoglycan molecular +
4
link proteins + hyaluronic acid → proteoglycan aggregates
2) Functions: Molecular sieve:
a. Exchange medium
b. Reservoir of hormones
c. Resistance to compression
d. Gel - like barrier
(2) Tissue fluid:
Equilibrium between formation and absorption
Edema
(3) Fibers:
Formed by collagen or elastin
1) Types of collagen: type I、II、III、IV、V etc.
2) Formation of collagen fibril：
Amino acid (e.g. glycine, proline, hydroxyproline, hydroxylysine) → a
polypeptide chain × 3→ procollagen molecule → → tropocollagen
molecule → fibril
64-nm periodicity transverse striation
3) Classification:
a. Collagen fibers: “white” fibers
 Components: type I collagen
collagen fibrils → collagen fibers → collagen bundles
 Characteristics: having great tensile strength and resistance to
stretching
b. Reticular fibers: argyrophilic fibers
 Components: type III collagen
 Characteristics: stained black by silver salts impregnation;
PAS-positive
c. Elastic fibers: “yellow fibers”
 Components: elastin core + microfibrils sheath
 Characteristics: high elasticity
2. Cells
Resident cell population (permanent residents)
Wandering or transient cell population
(1) Fibroblasts:
1) Morphology:
LM:
EM:
Fibroblasts
↔
Fibrocytes
2) Function: synthesis of fibers and ground substances
(2) Macrophages:
1) Origin:
2) Morphology:
LM:
EM:
3) Functions:
a. Phagocytosis:
 Amoeboid mobility: chemotactic factors
 Recognition and binding antigens
5
 Ingestion: forming phagosome
 Digestion: proteolytic enzymes
b. Secretion:
c. Participating and regulating immunological reaction:
Antigen-presenting cell
4) Mononuclear phagocyte system:
a. Monocytes in the blood
b. Macrophages in the CT
c. Kupffer's cells in the liver
d. Osteoclasts in the bone
e. Microglia in the CNS
f. Langhans cells in the skin
g. Dendritic cell in the LN
h. Alveolar macrophages in the lung
i. Epithelioid cells & Multinuclear giant cells
(3) Plasma cells:
1) Origin:
2) Morphology:
LM: cartwheel or clock-face nucleus
EM:
3) Function: synthesis of antibody (Ab)
(4) Mast cells:
1) Morphology:
LM: metachromasia granules
EM:
2) Function:
Storage of chemical mediators of the inflammatory response, including:
heparin, histamine, eosinophil chemotactic factor of anaphylaxis
(ECF-A).
Leukotrienes
Mediating the allergic reactions.
(5) Adipose cells (adipocytes, fat cells):
1) Origin:
2) Morphology:
a. Unilocular adipocytes: one large fat vacuole, “signet ring cells”
b. Multilocular adipocytes: many small fat vacuoles and mitochondria
3) Function:
a. Unilocular adipocytes:
energy storage, insulation and
cushioning of vital organs.
b. Multilocular adipocytes: a source of heat.
(6) Leukocytes:
(7) Undifferentiated mesenchymal cells
Dense Connective Tissue
1. Regular Dense CT
2. Irregular Dense CT
3. Elastic Tissue
6
Adipose Connective Tissue
1. White adipose CT
2. Brown adipose CT
Reticular Tissue
Reticular cells + reticular fibers + ground substance
Constituting the architectural framework of the lymphatic and hemopoietic
organs
Embryonic Connective Tissue
1. Mesenchyme
2. Mucous Connective Tissue
Umbilical cord
7
Cartilage and Bone
I. Cartilage
1. Structure of cartilage
1) Perichondrium dense C.T.
outer fibrous layer
inner cellular layer
2) Cartilage tissue
(1) Chondrocyte
young ~ : elliptic, singly
mature ~ : round isogenous group
LM:
EM:
Function:
lacunae
cartilage capsule
(2) Cartilage matrix
fibers: type II collagen fibrils / elastic fibers / type I collagen fibers
ground substance: (GAG rich)
proteoglycans aggregates: chondroitin sulfate, keratan sulfate
glycoprotein: chondronectin
rich in water
3) Properties
avascular, no lymphatic vessels or nerves
nourished by diffusion
2. Types of Cartilage
1) Hyaline cartilage
(1) Location
(2) Structure
perichondrium (except articular cartilage)
chondrocytes
cartilage matrix: type II collagen fibrils
2) Elastic cartilage
(1) Location: external ear, auditory tube, epiglottis et al.
(2) Structure
perichondrium
chondrocytes
cartilage matrix : elastic fiber + type II collagen fibrils
3) Fibrocartilage
transitional type
(1) Location: intervertebral disks, symphysis pubis, et al.
(2) Structure
perichondrium: no
chondrocytes: small, often arrange in long row
8
cartilage matrix: type I collagen fibers, less ground substance
3. Histogenesis and growth of cartilage
1) Histogenesis
mesenchymal cells  chondroblasts + perichondrium
2) Growth
(1) Interstitial (endogenous) growth
from inside
(2) appositional (perichondrium) growth from outside
II. Bone
Functions:
Preparations:
ground bone, decalcified bone
1. Structure of bone tissue
1) Bone matrix
(1) Organic matrix: (35%)
fibers: type I collagen fibers
proteoglycan aggregates
structural glycoproteins: osteocalcin, osteonectin, et al.
(2) Inorganic salts: (65%)
hydroxyapatite crystals
osteoid → calcified → bone matrix
2) Bone cell
(1) Osteoprogenitor cell: stem cell
LM:
(2) Osteoblast: bone- forming cell
LM: single layer, polygonal shape, basophilic cytoplasm
EM: rER, Golgi complex, matrix vesicle
(3) Osteocytes
lacunae
canaliculi
LM: slender processes
EM:
Function: maintain the bone matrix; maintain the homeostasis of blood
Ca2+
(4) Osteoclast: bone reabsorbing cell
Howship’s lacunae
LM: multinucleated large cell, acidophilic cytoplasm
EM: ruffled border, clear zone, lysosome, mitochondria, endocytic
vesicles
2. Architecture of Long Bone
1) Compact bone
(1) Outer and inner circumferential lamellae
(2) Haversian systems (osteon):
cylindrical unit, supporting
Haversian canal + concentric lamellae + osteocytes
cementing substance
9
(3) Interstitial lamellae
(4) Volkmann’s canal (perforating canal)
2) Spongy (cancellous) bone
trabeculae: parallel lamellae + osteocytes
3) Periosteum & endosteum
(1) Periosteum
outer fibrous layer
inner osteogenic layer
Sharpey’s fibers (perforating fiber)
(2) Endosteum
osteogenic cells
3. Histogenesis of bone
1) Intramembranous ossification
• mesenchymal cell → osteoprogenitor cell → osteoblast→ osteocyte
• mesenchymal sheet → primary ossification center → primary spongy
bone → primary compact bone
• mesenchymal sheet → periosteum, endosteum, bone marrow
2) Endochondral ossification
(1) Cartilage model formation
mesenchymal cell → chondrocyte & perichondrium
cartilage growth
(2) Bone collar formation and Cartilage degeneration
perichondrium → vascularization → periosteum
osteoprogenitor cell → osteoblast → osteocyte
bone collar
chondrocyte hypertrophied, calcified, degenerated
(3) Primary ossification center formation
periosteal bud (blood vessels, osteoprogenitor cells, osteoclasts)
primary ossification center
marrow cavity
(4) Secondary ossification center formation
Epiphyseal plate
zone of epiphyseal cartilage
A. zone of reserve cartilage
B. zone of proliferation
C. zone of hypertrophy and calcification
D. zone of ossification
(5) Remodeling
primary bone tissue (woven bone)
secondary bone tissue (lamellar bone)
10
Blood and Hemopoiesis
Blood
male: 4.1-6 × 1012 /L
Erythrocytes
female: 3.9-5.5× 1012 /L
Granular ~
Formed element
Leukocytes
~ 45%
6-10× 109 /L
Neutrophils
60-70%
Eosinophils
2-4%
Basophils
<1%
Lymphocytes 20-30%
Agranular ~
Monocytes
3-8%
Platelets
(100-300)×109 /L
Plasma ~ 55%
Hematocrit:
40-50% in man & 35-45% in woman
I. Plasma: yellowish & translucent
1. Compositions:
Plasma proteins: albumin, ,,-globulin, clotting protein (prothrombin,
fibrinogen, etc.), complement protein (C1-C9), lipoproteins (chylomicrons,
VLDL, LDL, HDL).
2. Functions: transportation, regulation & defense.
3. Serum:
II. Formed element:
Smear and sectioned slide
Wright & Giemsa stain
(azures)
1. Erythrocytes (Red Blood Cell, RBC)
(1) Structure:
“Histologic ruler”
Biconcave disc, d  7-8m, anucleate, no organelles, acidophilic, rich in
hemoglobin & deformable membrane.
Erythrocyte rouleaux (stacked coins)
1) Hemoglobin (Hb): globin + iron-containing heme
male: 120-150g/L & female: 105-135g/L,
HbA & HbF
Oxyhemoglobin ↔ carbaminohemoglobin
carboxyhemoglobin
11
2) Cell membrane: flexible & deformable
a. Peripheral membrane proteins: spectrin, actin, and ankyrin etc. serving
as a membrane skeleton.
b. Integral membrane proteins: Na+-K+ pump, Ca++ pump, and glucose
transport protein, band 3 protein, and glycophorins etc.

Blood group, transfusion and hemolytic transfusion reaction
ABO group & Rh group:
(2) Function: Transporting O2 and CO2
(3) Change of RBC
1) Physical adaptation:
2) Pathological changes:
d > 9m, macrocytes;
d < 6m, microcytes;
anisocytosis:
12
Anemia: RBC < 3 × 10 /L, Hb < 100g/L
Iron-deficiency ~, Sickle cell ~, Mediterranean ~ etc
(4) Osmotic equilibrium between RBC and plasma
Hemolysis:
blood shadow or blood ghost
Isoosmotic solution:
Hyperosmotic solution:
Hypoosmotic solution:
(5) Reticulocyte:
0.5~1.5% of RBC
Anucleate, contain some organelles, e.g.: ribosomal RNA (rRNA), and
demonstrated by brilliant cresyl blue methods
(6) Life span: about 120days
2. Leukocytes (White Blood Cell, WBC)
Inactive WBC in circulating blood → Active WBC in connective tissue
diapedetis
(1) Introduction:
1) Granular leukocytes
a. Azurophilic granules: staining purple, lysosomes, containing acid
phosphatase, myeloperoxidase, etc.
b. Specific granules:
c. Types: Neutrophils, Eosinophils & Basophils
2) Agranular leukocytes (mononuclear leukocytes)
a. Azurophilic granules
b. Types: Lymphocytes & Monocytes
3) Life span: variable
(2) Classification:
1) Neutrophils: 12-15m
a. Structure:
 Nucleus: band-form nucleus or lobulated, 2-5 lobes
Sex chromosome: drumstick-like appendage of nucleus in 3% of
neutrophils in female in LM
 Specific granules: neutrophilic granules:
12
Small, barely visible in LM, containing alkaline phosphatase,
collagenase and lysozyme etc.
b. Functions:
 Chemotaxis:
 Phagocytosis and destruction of microorganisms, especially bacteria.
Pus & pyocyte
2) Eosinophils: 12-15m
a. Structure:
 Nucleus: bilobed
 Specific granules: eosinophilic granules
Large, staining orange-pink, elongated, crystalline core, refractile, and
containing major basic protein, histaminase, myeloperoxidase, etc.
b. Functions:
 Chemotaxis:
 Phagocytosis of Ag-Ab-complexes and destruction of parasites.
3) Basophils: 12-15m
a. Structure:
 Nucleus: lobed, S-shaped, or irregular, often masked by the
overlying specific granules
 Specific granules: basophilic granules:
metachromasia, staining blue purple and containing heparin,
histamine, and eosinophil chemotactic factor of anaphylaxis
(ECF-A).
leukotriene
b. Functions: mediating the allergic reactions.
Anaphylatic shock
4) Lymphocytes:
a. Structure:
 Small lymphocytes: 6-8m, nucleus: cytoplasm ≈ 9:1
Deeply-stained spherical nucleus, sometimes with an indentation,
located eccentrically; cytoplasm is basophilic, sky-blue, contains
fine azurophilic granules.
 Medium-sized lymphocytes: 9-12m
 Large lymphocytes: 13-18m
b. Classification and functions:
 B-Lymphocytes: 20-30%, responsible for antibody - mediated
(humoral) immunity.
 T-Lymphocytes: 70-80%, responsible for cell - mediated immunity.
 Natural killer cells:
5) Monocytes: 12-20m
a. Structure: oval, kidney- or horseshoe - shaped nucleus, eccentric
position; cytoplasm is basophilic, bluish-gray, and contains
fine azurophilic granules.
b. Functions: precursor cells of the mononuclear phagocyte system
13
3. Platelets: (Thrombocytes)
2-4m
(1) Structure: often in clumps
1) non-nucleate, biconvex round or ovoid discs.
2) Hyalomere: peripheral clear zone
Dense tubular system, open canalicular system & microtubules
3) Granulomere: central darker zone
, ,  granules
(2) Functions: promote blood clotting & controlling hemorrhage
(3) Origin:
Protoplasmic discs derived from bone marrow megakarocytes.
(4) Life span: ~ 10 days.
Thrombocytopenic purpura
Hemopoiesis (Blood Cell Formation)
I. Hemopoietic Organ:
1. Mesoblastic phase: yolk sac
3w
2. Hepatic phase:
6w - end of gestation
3. Splenic phase:
4m - end of gestation
4. Myeloid phase: bone marrow > 6m
Red Bone Marrow
↔
Yellow Bone Marrow
Structure of Red Bone Marrow
(1) Stroma:
reticular tissue
(2) Hemopoietic cord: hemopoietic cells & macrophages

Pluripotential hemopoietic stem cells  progenitor cells (committed stem cells)
[Colony-forming cells (CFC) or colony-forming units (CFU)]  precursor
cells (blasts)

Growth Factors, colony-stimulating factors (CSF) or hematopoietins, e.g.:
Erythropoietin (EPO), G-CSF, GM-CSF etc.
(3) Sinusoids:
Bone marrow aspiration
II. Erythropoiesis
~7d
Proerythroblast  basophilic erythroblast  polychromatophilic
erythroblast  orthochromatophlic erythroblast (normoblast) 
reticulocyte  erythrocyte

Major morphological changes:
(1) Cell volume: 
(2) Cytoplasm: basophilic  acidophilic
(3) Nucleus:  disappear; nucleoli: disappear; chromatin condensation
III. Granulopoiesis
~11d
Granules
Myeloblast  promyelocyte  myelocyte  metamyelocyte 
granulocyte
IV. Thrombopoiesis
Megakaryoblast  promegakaryocyte  megakaryocyte  platelet
14
Muscle Tissue
I. Introduction
1. Composition
• Muscle fibers: specialized contractile cells
• Extracellular matrix
2. Function
Movement
3. Classification
skeletal muscle
voluntary
striated
cardiac muscle
involuntary
smooth
smooth muscle
II. Skeletal Muscle
1. Organization of skeletal muscle
Epimysium
Perimysium
Endomysium
Myotendinous junction
2. Structure of skeletal muscle fiber
Terminology
muscle fiber = muscle cells, sarcolemma = plasmalemma
sarcoplasm = protoplasm, sarcoplasmic reticulum = sER
1) Morphology
long, cylindrical, multinucleated cell with cross-striation
2) Nuclei
100-1000 nuclei per cell, located peripherally, ovoid & flattened.
3) Sarcoplasm:
(1) Myofibrils:  =1-2 m
• long cylindrical filamentous bundles consisting of stacks of
sarcomeres
• A band, I band, Z line, H band, M line
• sarcomere: functional unit of contraction
1/2 I band + A band + 1/2 I band
• thin filament
15
actin (G-actin, F-actin), tropomyosin, troponin (TnT, TnC, TnI)
thick filament:
myosin: 2 heavy chains + 4 light chains
rod-like portion
globular head: actin binding sites, ATP binding sites, ATPase activity
• cross-bridge
• muscle contraction:
sliding filament mechanism
(2) Membrane system
• transverse (T) tubule system
• sarcoplasmic Reticulum
• triad = T tubule + 2 terminal cisternae
at A-I junction
(3) Other components
mitochondria, glycogen, lipid droplet, myoglobin, ribosome
•
3. Types of skeletal muscle fiber
red fibers (type I fibers), white fibers (type II B fibers), intermediate fibers
(type II A fibers)
Characteristics
Red fiber
White fiber
Fiber diameter
smaller
larger
Vascular supply
rich
poorer
Myoglobin
rich
poor
Sarcoplasmic reticulum
not extensive
extensive
Glycogen
poor
rich
Mitochondria
numerous
few
Metabolism
aerobic
anaerobic
Contraction
slow, not easily fatigued,
Fast, easily fatigued,
weaker contraction
stronger contraction
4. Innervation
motor end-plate (myoneural junction)
Sensitive nerves: muscle spindles
5. Development and regeneration
1) Development: myoblast  myotubes  myocytes
2) Regeneration: satellite cell
III. Cardiac Muscle
1. Organization of cardiac muscle
2. Structure of the cardiac muscle fiber
1) Morphology:
cross-striated, elongated, branched cell
2) Nuclei: 1 or 2 centrally
3) Sarcoplasm
(1) Myofibrils:
thinner, branched
16
(2) Membrane system
• T tubule: numerous, larger
• Sarcoplasmic reticulum: less developed
• diads:
Z disk level
(3) Other components
numerous mitochondria, lipid droplets, glycogen, lipofuscin, et al.
4) Intercalated disk
transverse portion: zonula adherens, desmosomes
lateral portion: gap junction
3. Types of cardiac muscle cell
1) Myoendocrine cells: atrial natriuretic factor (atriopeptin)
2) Impulse-generating & conducting system
4.
Regeneration
IV. Smooth Muscle
1. Organization
2. Structure of smooth muscle cell
1) Morphology: nonstriated, fusiform
2) Nucleus: single, centrally
3) Sarcoplasm
(1) Cytoskeleton
dense body and dense patch
intermediate filaments: desmin, vimentin
(2) Myofilament unit
• thin filaments: actin, tropomyosin, calmodulin, caldesmon
• thick filaments: myosin
• thick filaments : thin filaments = 1:12
• contraction
(3) Membrane system
caveolae, rudimentary SR
(4) Other components
(juxtanuclear region)
rER, Golgi complex, ribosome, et al.
3. Innervation
• Autonomic nervous system
• Hormone regulation
4. Regeneration
active
17
Nervous Tissue
The Neuron
I. The structure of the neuron
A. The Cell body
1. Cell membrane
2. Nucleus, Nucleolus
3. Cytoplasm, Perikaryon
(1) Golgi Apparatus
(2) Mitochondria
(3) Microtubules, 20-26nm diameter
(LM, neurofibril)
(4) Neurofilaments, 8-10nm diameter
(5) Lysosomes
(6) Nissl body (rough ER and free ribosomes)
B. Dendrites
1. Nissl body
2. Purkinje’s 250μm2~27,000μm2
3. Mitochondria
4. Microtubules
5. Neurofilaments
6. Dendritic spine
C. Axons
1. Axon hillock
2. Collateral branch
3. Terminal arborization
4. Axolemma
5. Axoplasm (few microtubules, mitochondria, neurofilaments)
6. Axoplasmic flow
II. Classification of the neuron
A. Multipolar neurons: motor neurons from the spinal cord
B. Bipolar neurons: olfactory cells
C. Pseudounipolar neurons: central process, peripheral process, spinal
ganglia
III. Synapses Specialized Structures
A. Types: axodendritic synapse, axosomatic synapse, axoaxonal synapse,
dendrodendritic synapse
B. Boutons terminaux
C. Structure
1. Presynaptic element, membrane, neurotransmitters
2. Synaptic cleft, 15-30nm width
18
3. Postsynaptic element, membrane, receptor
4. Synaptic vesicle
D. Chemical synapse: neurotransmitter
E. Electrical synapse: gap junction
Neuroglia Cell
I. CNS
A. Astrocyte --- fibrous, protoplasmic types
1. Nucleus: oval, large and less dense than oligodendrocyte nucleus
2. Stellate projections
3. Perivascular feet
4. Comparison
Distribution
Processes
Glial filament
Fibrous Astrocyte
white matter
long, slender,
abundant
smooth, a few
branches
Protoplasmic
gray matter
short, thick, rough
few
Astrocyte
many branches
Glial fibrillary acidic protein (GFAP)
B. Oligodendrocyte
1. Nucleus: small, dark
2. Myelin in CNS --- Each oligodendrocyte myelinates many internodes
of different axons
C. Microglia (gray matter)
1. Nucleus: smaller, dark, elongated shape
2. Short processes: thorny spines
3. Engulfing function: mononuclear phagocyte system in nervous tissue
D. Ependymal cell
1. Line ventricular system and central canal
2. Cuboidal, columnar
3. Apical surface: microvilli, cilia
II. PNS
A. Schwann cells
1. Make PNS myelin
2. One Schwann cell myelinates one internode
B. Satellite cells
Nerve fibers
I. Myelinated fibers
1. Myelin sheath
Lipoprotein
19
Neurokeratin
Schmidt - Lanterman’s clefts
Neurolemma - plasma membrane and basement membrane of
Schwann cell
2. Initial Segment
3. Node of Ranvier
4. Internode
5. Schwann cells make PNS myelin
6. Oligodendrocytes make CNS myelin
II. Unmyelinated fibers
1. No myelin sheath, No node of Ranvier
2. Axons are embedded in the cytoplasm of a Schwann cell
Nerve Ending
I. Sensory nerve ending
1. Free nerve ending
2. Tactile corpuscle (Meissner’s corpuscle)
3. Lamellar corpuscle (Pacinian corpuscle)
4. Muscle spindle - intrafusal muscle fiber
II. Motor nerve ending
1. Motor end- plate, neuro-muscular junction
2. Visceral motor nerve ending
varicosity
Ganglia
Nerve ganglion: An aggregation of nerve cell bodies outside the central
nervous system
1. Spinal ganglia
Pseudounipolar neurons, satellite cell
2. Cranial ganglia
3. Autonomic ganglia multipolar neurons
Peripheral Nerve
1. Endoneurium
2. Perineurium
3. Epineurium
20
The Circulatory System
Blood vascular system + Lymphatic vascular system
artery
heart
capillary ↔ tissue fluid ↔ cell
lymph
vein
lymphatic vascular system
I. Blood vascular system
heart + arteries + capillaries + veins
1. General structure of blood vessels --- 3 concentric layers
(1) Tunica intima
1) Endothelium + basal lamina
 Weibel-Palade granules (W-P bodies):
especially in the endothelial cells of elastic arteries, rod-shaped, having
dense matrix housing parallel tubular elements, containing Von
Willebrand’s factor (factor VIII).
2) Subendothelial layer --- loose connective tissue
3) Internal elastic lamina --- a fenestrated sheet of elastin
Myoendothelial junctions
(2) Tunica media
1) Various numbers of smooth muscle cell layers intermingled with
fibroelastic C.T.
2) External elastic lamina
(3) Tunica adventitia
fibroelastic C.T.
Vasa vasorum:
Lymphatic vessel & innervation
2. Specific structure of blood vessels
(1) Capillaries
1) Composition:
a. Pericytes:
 Morphology: having long processes, basal lamina fusing with that of
endothelial cells
 Functions: contractility & participating in regeneration
b. Endothelial cells + basal lamina
Morphology: LM:
EM:
2) Ultrastructure and classification of the capillaries
a. Continuous Capillaries
 Morphology: continuous endothelium, tight junctions, continuous
basal lamina, pinocytotic vesicles.
 Distribution: muscle, C.T., exocrine gland, lung, CNS, etc.
b. Fenestrated capillaries
 Morphology: fenestrates (pores) with or without diaphragm,
continuous basal lamina.
21
 Distribution: stomach, intestine, endocrine gland, kidney, etc.
c. Discontinuous sinusoidal capillaries (sinusoids)
 Morphology: enlarged diameter, gaps, large fenestrates without
diaphragm, discontinuous or absent basal lamina.
 Distribution: liver, spleen, bone marrow, etc.
3) Functions:
a. Permeability
exchange vessels
b. Metabolic functions
 Activation
angiotensin I  angiotensin II
 Inactivation
bradykinin, serotonin, etc.
 Lipolysis
lipoproteins
 Production of vasoactive factors
e.g., endothelins & NO
c. Antithrombogenic function
4) Microcirculation:
a. Composition:
precapillary sphincters
Arterioles  metarterioles  capillaries  postcapillary venules
Arteriovenous anastomosis
Metarterioles: with a discontinuous smooth muscle layer
b. Functions: blood pressure & blood flow regulation, and thermoregulation
in particular areas.
(2) Arteries
1) Arterioles (Peripheral resistance vessels)
Diameter < 0.5 mm (including all 3 layers)
1-2 concentric smooth muscle layers in media, thin adventitia
2) Muscular arteries
a. Small arteries d < 1mm (Peripheral resistance vessels)
b. Medium - sized arteries (Distributing Arteries)
Prominent internal elastic lamina, 3-40 concentric smooth muscle layers
in media, external elastic lamina usually visible, adventitia equal in
thickness to media
3) Elastic Arteries (Conducting Arteries)
yellowish color
Relatively thick intima, 40-70 elastic laminae in media, thin adventitia
4) Specialized arteries and age changes in arteries:
Atherosclerosis
 Specific receptors:
a. Carotid bodies & aortic bodies: chemoreceptors, sensing O2 and CO2
tension & pH.
b. Carotid sinuses: baroreceptors, sensing blood pressure.
(3) Veins (Capacitance vessels)
Comparing with their corresponding arteries, veins have valves and
squashed, larger lumen, thinner wall, and poorly demarcated layers.
1) Venules
diameter < 1mm
22
pericytes in postcapillary venules, discontinuous or no smooth muscle in
media
Permeability
2) Small to medium-sized veins
diameter: 1-9mm
2-4 1ayers of smooth muscle cells in media, intermixed with fibroelastic
C.T., thicker adventitia with or without some longitudinal arranged
smooth muscle cells. One - way valves in veins > 2mm diameter
Venous valves: paired, semilunar folds of the intima
3) Large veins
relatively thin media, thickest adventitia with many longitudinal bundles
of smooth muscles.
(4) Heart
1) Tunics:
a. Endocardium
 Endothelial cells + basal lamina
 Subendothelial layer
 Subendocardial layer
Branches of Purkinje fibers in it
b. Myocardium
c. Epicardium (Visceral pericardium): CT + mesothelium
Subepicardial layer
Visceral pericardium
2) Fibrous skeleton (cardiac skeleton)
Including annuli fibrosi, the trigona fibrosa & septum membranaceum.
3) Valves
Tricuspid, mitral valves & semilunar valves
A central core of dense C.T., lined on both sides by endothelial layers
4) Impulse Conducting System
a. Sinoatrial (SA) node: pacemaker, in subepicardial layer
b. Atrioventricular node (AV), in subendocardial layer
c. AV Bundle of His, in subendocardial layer
Purkinje cell: specialized cardiac muscle cells, one or two nuclei, paler
cytoplasm; clear (glycogen storage) area forms “halo”
around nuclei, reduced number of myofibrils.
B. Lymphatic Vascular System
1. Lymphatic capillaries
Blind ended vessels, endothelial cells have no fenestrate, no tight junction,
and little or no basal lamina.
2. Lymphatic vessels
3. Main lymphatic trunks
23
Immune System
Lymphoid Tissue
Reticular cell, Reticular fiber
I. Diffuse lymphoid tissue
II. Lymphoid nodule (Lymphoid follicle)
1. Germinal center
2. Aggregated lymph nodule (Peyer’s Patches)
Lymphoid Organ
I. Central lymphoid Organ
1. Thymus (thymus dependent lymphocyte)
2. Bursa equivalent - fetal liver, bone marrow
3. Bursa of Fabricius
II. Peripheral lymphoid organ
1. Lymph Nodes
2. The spleen
3. Tonsils
Thymus
I. The Structure of the thymus
A. Capsule, interlobular septum, lobule
B. Cortex
1. Thymocyte, large lymphocytes, medium - sized lymphocytes, small
lymphocytes
2. Epithelial - reticular cell
(1) Morphology: large nuclei, many processes, desmosome,
tonofilament
(2) Function
a. microenvironment
b. support
c. secretion
C. Medulla
Thymus corpuscle (Hassall’s corpuscle):
30-150μm in diameter, consisting of concentric layers of epithelial reticular cells
D. Blood circulation and blood - thymus barrier
1. Postcapillary venule
2. Blood - thymus barrier
(1) Endothelial cell of continuous capillary
24
(2) Basement membrane of the endothelial cell
(3) Pericapillary space, Macrophages
(4) Basement membrane of the epithelial - reticular cell
(5) Processes of the epithelial - reticular cell
II. Function of the thymus
1. Cultivating T lymphocytes, P.V.
2. Secretion of hormone, thymosin
Lymph Nodes
I. The structure of lymph nodes
A. Capsule related structures
1. Capsule
2. Trabecula
3. Afferent lymphatic vessel
4. Hilus
5. Efferent lymphatic vessel
B. Cortex
1. Lymphoid nodule
(1) Germinal center --- cap, light zone, dark zone
(2) Dendritic cell --- Cytoplasm branches into numerous process
2. Paracortical zone (Thymus-dependent zone)
(1) Location
(2) Postcapillary venule
a. Exhibit an unusual endothelial lining consisting of cuboidal
cells.
b. Lymphocytes are capable of traveling into and between the
endothelial cells of this vessel
C. Medulla
1. Medullary cord: mainly consisting of B lymphocytes
2. Medullary sinus
D. Lymphoid sinus and lymph circulation
1. Subcapsular sinuses
Cortical Sinuses
2. Peritrabecular sinuses
3. Medullary sinuses
4. Lymph circulation
II. Recirculation of lymphocyte
1. Postcapillary venule
2. Lymphocyte recirculating pool
B, T lymphocyte, 18-30hrs/round
25
III. Function
1. Filtering lymph
2. Immune
The Spleen
I. The Structure of the spleen:
A. Capsule and trabecula
1. Mesothelium
2. Some smooth muscle cells
B. White pulp
1. Periarterial lymphatic sheath
mainly consisting of T lymphocytes, thymus - dependent zone,
interdigitating cell
2. Lymphoid nodule
mainly consisting of B lymphocytes, cap, light zone, dark zone
C. Marginal zone
1. Many B lymphocytes and macrophages
2. The path of lymphocytes from blood flow entering lymphoid tissues
3. Playing a significant role in filtering the blood and launching an
immune response
D. Red pulp
1. Splenic blood sinusoid
(1) They have a dilated, large, irregular lumen
(2) Spaces between lining endothelial cells
(3) Reticular fibers forming barrel hoop - like rings
2. Splenic cord
Reticular cells and reticular fibers macrophages engulf old RBCs and
platelets
II. Blood circulation
capillaries
Splenic artery  trabecular artery  central artery  penicillar arterioles 
pulp arteriole  sheathed arteriole  arterial capillaries  sinusoid  pulp
vein  trabecular vein  splenic vein
III. Function
1. Filtration of blood: marginal zone, splenic cord, macrophages
2. Production of blood
3. Blood storage. 40ml, (splenic cord, splenic blood sinusoid)
4. Immune. B lymphocyte 55%
T lymphocyte 45%
Macrophages
26
Tonsils
Palatine Tonsils
1. Crypts 10-30
2. Lymphoid nodule
3. Infiltrated epithelium
Mononuclear Phagocyte System and Reticulo-endothelial System
Promonocytes 
monocytes

macrophages
(bone marrow)
(blood)
(tissues and organs)
27
The Endocrine System
I. Introduction
Terminology
endocrine cells, endocrine, paracrine, autocrine, target cells / organs,
hormones: steroid hormones & inclusive nitrogen hormones
1. Ultrastructure of endocrine cells
1) Peptide - secreting cell
EM: rER, Golgi complex, membrane - bound vesicles
2) Steroid-secreting cell
EM: lipid droplets, Mit. (tubular & vesicular cristae), sER
2. Distribution of the endocrine cells
• dispersed endocrine cells
• endocrine tissues
• endocrine glands
3. Characteristics of endocrine gland
• ductless glands
• cells arrange in cords, clumps or follicles
• highly vascularized by fenestrated capillaries (sinusoids)
• delicate C.T.
II. Pituitary gland (hypophysis)
1. Embryogenesis
adenohypophysis: oral ectoderm (Rathke’s pouch)
neurohypophysis: neural ectoderm (diencephalon)
2. Gross structure
adenohypophysis
pars distalis
pars tuberalis
pars intermedia
anterior lobe
posterior lobe
pars nervosa
neurohypophysis
infundibular stem
infundibulum
median eminence
3. Adenohypophysis
1) Pars distalis
arranged in cords
fenestrated cap.
28
(1) Chromophils
Stain affinity
Acidophils
35-40%
Basophils
10-15%
Cell type
somatotropic cells
mammotropic cells
thyrotropic cells
corticotropic cells
gonadotropic cells
Hormone
growth hormone
prolactin (PRL)
thyrotropin (TSH)
corticotropin (ACTH)
follicle stimulating hormone (FSH)
luteinizing hormone (LH)
(2) Chromophobes 50%
degranulated chromophils
undifferentiated cells
follicular cells
2) Pars intermedia
follicles & cords
chromophobes & basophils
3) Pars tuberalis
abundant longitudinal blood vessels
cell arranged in cords
basophils: may secrete gonadotropins
4. Neurohypophysis
1) Unmyelinated nerve fibers
2) Pituicytes: neuroglial cells
3) fenestrated capillaries
4) Herring bodies
5. Blood supply
hypophyseal portal system
superior
hypophyseal A.
inferior
hypophyseal A.


primary
capillary plexus
(infundibulum)
capillaries
(pars nervosa)

portal veins
(pars
tuberalis)


secondary
capillary plexus
(pars distalis)

hypophyseal
veins
6. Hypothalamo - hypophyseal system
1) the hypothalamus and adenohypophysis
neuroendocrine cells in tuberal nuclei, etc (releasing hormones, RH &
releasing inhibiting hormones, RIH  the portal system  the endocrine
cells in pars distalis  target cells in other organs
2) the hypothalamus and neurohypophysis
neuroendocrine cells in supraoptic and paraventricular nuclei
secrete oxytocin & antidiuretic hormone (ADH, vasopressin)
29
III. Thyroid gland
1. Gross structure
2. Microscopic structure
capsule, lobules
fenestrated capillaries, C.T.
1) Thyroid follicles
simple cuboidal epithelium
colloid within the lumen
(1) Follicle cells
LM:
EM:
Functions: secrete the thyroid hormone (T3 & T4)
(2) Mechanism of synthesis and secretion of T3 & T4
a. synthesis of thyroglobulin
b. uptake of iodide & activation
c. iodination of thyroglobulin
d. reuptake of colloid stimulated by TSH
e. digestion of iodinated thyroglobulin
f. release of T3 & T4
(3) Functions of the thyroid hormone
2) Parafollicular cells
Location:
LM:
EM:
Functions: secrete calcitonin
IV. Parathyroid glands
1. Gross structure
2. Microscopic structure
cells arrange in cords
1) Chief cell
LM:
EM:
Functions: secrete parathyroid hormone
2) Oxyphil cells
LM: acidophilic
EM: many mitochondria
Function is unknown
V. Adrenal (suprarenal) glands
1. Gross structure
dense collagenous C.T. capsule
cortex:
medulla:
2. Microscopic structure of cortex
1) Cortex
30
(1) Zona glomerulosa 15%
small cells arranged in rounded or arched cords
secrete mineralocorticoids (aldosterone)
(2) Zona fasciculate 78%
arranged in straight cords
cells contain many lipid droplets
secrete glucocorticoids (cortisol & corticosterone)
(3) Zona reticularis 7%
arranged in anastomosing network
cells contain lipofuscin
secrete androgens, glucocorticoids
2) Medulla
(1) Medullary cells (chromaffin cells):
modified sympathetic postganglionic neurons
LM:
EM:
Functions: secrete epinephrine & norepinephrine
(2) Ganglion cells
3. Blood supply
31
Skin
16% body weight, total area 1.2-2.0m2
1300 nerve endings / inch2
The Structures of the skin
Average thickness 1 - 4mm, the most thick 1.5mm
Epidermis
A. The structures
Keratinocyte
Nonkeratingzing cell- Melanocyte, Langerhan’s cell, Merkel cell
1. Stratum basale (Stratum germinativum)
(1) Basal cell: intense mitosis
basophilic cytoplasm
tonofibril
(2) Ultrastructure
a. tonofilament: 10nm, keratin filament
b. extensive desmosomes on apical and lateral surface
c. hemidesmosomes basally
d. numerous ribosomes
2. Stratum spinosum
(1) Several layers of polygonal to slightly flattened cells
Spinous cells: spiny projections, intercellular bridges
(2) Mitosis observed; involucrin
(3) Ultrastructure
a. more tonofilaments
b. desmosomes cover entire surface
c. first appearance of membrane coating granules, 0.1-0.3μm in
diameter, lamellar granules
3. Stratum granulosum
(1) Several layers of flattened cells
(2) Ultrastructure
a. more membrane coating granules and they release content into
intercellular space by exocytosis
b. appearance of keratohyalin granules, non - membrane limited,
basophilic granules
4. Stratum lucidum
(1) Most pronounced in thick skin
(2) Flattened, non - nucleated cells
keratohyalin in cytoplasm
5. Stratum corneum
(1) Terminal differentiated population
32
(2) Layers of flattened, non-nucleated cells which are totally keratinized
(called horny cells)
Their cytoplasm is full of keratin
(3) Ultrastructure
a. no organelles left
b. tonofilaments
c. plasma membrane: extensively thickened
d. desmosomes
B. Nonkeratingzing cells
1. Melanocytes
(1) neural crest origin and invade epidermis at 12-14 weeks embryo
(2) unicellular exocrine glands which synthesize and secrete melanin
absorbs UV
(3) dopa reaction
(4) ultrastructure
a. all organelles for synthetic function: abundant ribosomes, prominent
Golgi apparatus, lots of rough ER
b. no desmosomes
c. no tonofilaments
d. contain developmental gradient of melanosomes with ultimate
maturation to melanin granules
2. Langerhans cells
(1) very visible with
ATPase
gold chloride impregnation
(2) ultrastructure
a. no desmosomes
b. no tonofilaments
c. tennis racquet granules (Birbeck granules)
Dermis
average thickness 1-2mm
I. Papillary layer
Dermal papillae
abundant capillaries
Meissner’s corpuscle
II. Reticular layer
Contains vessels, hair follicles, sweat glands, sebaceous glands, nerves,
Pacinian corpuscle
Hypodermis
Consisting of loose connective tissue and adipose tissue
33
Hair
1. Hair Shaft - Portion above epidermis
2. Hair Root - Portion embedded in skin
3. Hair Bulb - Basal portion of root penetrated by hair papilla rich in
capillaries, hair matrix, scattered melanocytes
4. Hair Follicle - epidermal and connective tissue sheaths around root
(1) Internal root sheath
(2) External root sheath
5. Glassy Membrane
6. Arrector pili muscle
Sebaceous Gland
1.
2.
Located in dermis
Acinus composed of two cell types:
(1) Undifferentiated basal cells
Proliferate and differentiate into acinar cells
(2) Acinar cells
Holocrine
Sebum
Sweat Glands
I. Merocrine sweat glands
1. Exocytosis
2. Clear cells: large, acidophilic
3. Dark cells: small, basophilic
4. Myoepithelial cells:
Long flat nuclei lying at the base of epithelial cells of the glands just
inside the basement membrane
5. Ducts:
Contain 2-3 layers of cuboidal or low columnar cells
II. Apocrine sweat glands
1. Secretory part
2. Ducts
34
Oral Cavity and Salivary Glands
Oral Cavity
I. Organization
II. General structure of oral mucosa
Stratified squamous epithelium
Lamina propria
III. Tongue
1. Epithelium
2. Lamina propria
3. Skeletal muscle
4. Lingual papillae
Table 1. Main Features of Lingual Papillae
Papillae
Shape
Number
Filiform ~
elongated conical
Numerous
Fungiform ~
mushroomlike
a few
Circumvallate ~
large circular
10-14
papillae,
gland of von Ebner
Foliate ~
leaf-like
5.Taste bud: specialized gustatory structures
taste pore
Type II, taste cells: taste hair, pale staining
Type I, supporting cells: spindle shape, dark staining
basal cells: conical shape, mitotic pool
Salivary Glands
I. Structure: compound tubuloalveolar glands
A. General organization
1. Stroma: CT, septa, lobules
2. Parenchyma: secretory alveoli & intralobular ducts
B. Alveoli
Single layer of cuboidal or pyramidal cells
Myoepithelial cells
1. Serous alveoli
(1) basal RER, apical secretory granules
(2) basal junctional complexes
2. Mucous alveoli
35
Taste buds
no
scattered
many
many
(1) flattened basal nuclei, mucigen granules, cytoplasm looks foamy
or empty, HE. pale staining
(2) Basal junctional complexes
3. Mixed alveoli: Mixed seromucous alveoli, serous demilune
C. Duct System
1. Intercalated duct:
Squamous or low cuboidal epithelium
myoepithelial cells
2. Striated (secretory) duct
Intralobular
simple columnar cells
the basal cytoplasm membrane infoldings with longitudinally
arranged mitochondria
3. Interlobular duct
Pseudostratified columnar epithelium
4. Main duct
Scattered goblet cells, stratified squamous epithelial
II. Differentiation of the three major salivary glands
Table 2. Main Features and Functions of Major Salivary Glands
Gland
alveoli
intercalated
striated
secretions
ducts
ducts
parotid
pure serous
long
present
amylase, a
~
little mucus
Submandibular
mixed,
short
long
mucus, a
~
mostly
little amylase
serous
Sublingual
mixed,
none
a few short
mainly
~
mostly
mucus
mucous with
some serous
demilune
III. Function
1. Moistening, lubricating
2. Digestions
3. Immunoglobulins - sIgA
36
Digestive Tract
I. General structure
1. Mucosa
(1) Epithelium
stratified squamous ~ / simple columnar ~
(2) Lamina propria
loose C.T.
glands
gut - associated lymphatic tissue (GALT)
(3) Muscularis mucosae
smooth muscle
inner circular layer, outer longitudinal layer
2. Submucosa
dense C.T.
submucosal (Meissner’s) nerve plexus
lymphoid tissue
submucosal glands
3. Muscularis
skeletal muscle / smooth muscle
inner circular layer, outer longitudinal layer
myenteric (Auerbach’s) nerve plexus
Enteric Nervous System
4. Adventitia
serosa：mesothelium + C.T.
fibrosa (adventitia): C.T.
II. Esophagus
1. Mucosa
1) Nonkeratinized stratified squamous epithelium
2) Lamina propria
esophageal cardiac glands
3) Muscularis mucosae:
single longitudinal layer
2. Submucosa
esophageal glands: mucus-secreting glands
3. Muscularis
skeletal muscle / smooth muscle
4. Fibrosa / serosa
III. Stomach
Rugae, Gastric pits
1. Mucosa
1) Simple columnar epithelium
surface mucous cells:
37
LM:
EM: tight junction
Function: secrete insoluble mucus
2) Lamina propria
Gastric glands
(1) Fundic glands
isthmus, neck, base region
a. Mucous neck cells
Location:
LM:
EM:
Function:
b. Parietal (oxyntic) cells
Location:
LM:
EM: resting phase, active phase
intracellular canaliculus, tubulovesicular system, mitochondria
Function: secret HCl, intrinsic factor
c. Chief (zymogenic) cells
Location:
LM:
EM:
Functions: secrete pepsinogen
d. Enteroendocrine cells
e. Stem cells
Protective mechanism:
• mucous-HCO3- barrier
• tight junction
• rapid renewal
(2) Cardiac glands
shallow pits, coiled terminal portions, wide lumens
secrete mucus
(3) Pyloric glands:
deep pits, shorter coiled secretory portions
secrete mucus
3) Muscularis mucosae
2. Submucosa
3. Muscularis
inner oblique layer, middle circular layer, outer longitudinal layer
pyloric sphincter
4. Serosa
IV. Small Intestine
1. Special structures
1) Plicae circulares (Kerckring’s valves)
mucosa + submucosa
2) Intestinal villi and intestinal gland (crypts, glands of Lieberkühn)
epithelium + lamina propria
3) Microvilli
cell membrane + microfilaments
38
2. Mucosa
1) Simple columnar epithelium
(1) Absorptive cells (enterocytes)
Location:
LM: striated border
EM: junctional complex, glycocalyx coat
Functions: digestion, absorption, secretion
(2) Goblet cells
(3) Enteroendocrine cells (basal granular cell)
Location:
LM: open type, closed type
EM:
Function: secrete gut hormone
(4) Paneth’s cells
Location:
LM: acidophilic granules
EM: lysozyme, defensin
Functions: regulate intestinal flora
(5) Undifferentiated cells
stem cell
2) Lamina propria
(1) Central lacteals (lymphatic capillary)
(2) Lymphoid tissue
• solitary nodules: duodenum, jejunum
• aggregated nodules (Peyer’s patches ): ileum
• microfold (M) cells
Location:
LM:
EM:
Functions:
(3) Muscularis mucosae
3. Submucosa
duodenal (Brunner’s) glands
secrete alkaline mucus, EGF
4. Muscularis
5. Fibrosa / Serosa
V. Large Intestine
1. Cecum and colon
taeniae coli, haustra coli, appendices epiploicae
no villi, crypts packed closely
1) Mucosa
(1) Simple columnar epithelium
absorptive cells, numerous goblet cells, no Paneth’s cell
(2) Lamina propria
rich in lymphoid tissue
(3) Muscularis mucosae
2) Submucosa
3) Muscularis
taeniae coli
4) Fibrosa / Serosa
39
2. Appendix
small, narrow, and irregular lumen
1) Mucosa
simple columnar epithelium
fewer & shorter intestinal gland
numerous lymphoid nodules
muscularis mucosae incomplete
2) Submucosa
3) Muscularis
4) Serosa
3. Rectum and anal canal
1) Mucosa
simple columnar epithelium / stratified squamous epithelium
muscularis mucosae terminate at anal valves
2) Submucosa
vein plexus
3) Muscularis
internal anal sphincter: inner circular layer, smooth muscle
external anal sphincter: skeletal muscle
4) Fibrosa
40
Digestive Glands
Liver
I. General Structure
1. Stroma
(1) fibroconnective tissue capsule (of Glisson) collagen fibers, elastic
fibers, serosa
(2) lobules
(3) reticular fibers
2. Parenchyma
II. The liver lobule
Essential structural units
Prismatic polygonal units, 2×1mm
Hepatic plate
Central vein
Sinusoid
Hepatic cord
Bile Canaliculus
A. Hepatocyte
1. General considerations
80%, 20μm in diameter, round central nuclei, eosinophilic cytoplasm,
hepatic plate (single layer), 6-8 surfaces
2. Organelles
(1) Mitochondria 1,000-2,000 / cell, 20%
(2) Lysosomes
many, store iron
(3) Peroxisomes
1,000 / cell
Peroxidase catalase
Peroxides
free radicals
(4) Golgi complexes 50 / cell
(5) Rough Endoplasmic Reticulum
RER Synthesizes blood albumin, fibrinogen
Prothrombin
(6) Smooth Endoplasmic Reticulum
Bile Synthesis
Lipids metabolism
Biological transformation
Detoxification (glucuronyl transferase)
(7) Inclusion
Lipid droplets, Glycogen, Pigment
3. Three plasma membrane regions
Blood-sinusoid
41
Bile Canaliculi
Cell junction surface: *gap junction
B. Hepatic Sinusoid
1. Structure
(1) discontinuous endothelial cells
(2) 9-12 μm
(3) micropinocytotic vesicles, a few organelles
(4) Gaps, no diaphragm, no BM, reticular fibers
(5) Macromolecules - chylomicron, VLDL
2. Kupffer cells
They phagocytize blood cells, iron & debris
C. Space of Disse
Perisinusoidal space
microvilli
Reticular fibers
Fat-storing cells (store fat and Vitamin A)
D. Bile canaliculi (Silver stain, ATPase)
Tubular space, junction complex
microvilli
III. Portal areas
Interlobular vein
Interlobular Artery
Interlobular bile duct
Portal triad
IV. Biliary Passages
Central
peripheral ductules
interlobular
Canaliculi
(Hering’s canals)
bile ducts
Right & Left
common
common
Hepatic ducts
hepatic duct
bile duct
Cystic duct
V. Hepatic blood circulation
Hepatic
Artery
IA, THA
Liver
Sinusoids
Portal
Vein
Central
vein
sublobular
vein
IV, TPV
Hepatic
inferior
vein
vena cava
THA: Terminal Hepatic Arteriole
TPV: Terminal Portal Venule
42
VI. Lobulation
1. The classic lobule
2. Portal lobule
3. Liver acinus
VII. Functions
1. Synthesis and store
2. Secreting bile
3. Detoxification
4. Immune
5. Hemopoiesis
Gallbladder
I. Mucosa
Folds, Simple columnar epithelium, microvilli
II. Muscularis
III. Serosa
Pancreas
I. General Features
Stroma: thin CT capsule, lobules, septa
Parenchyma: exocrine and endocrine cells
II. The Exocrine Portion
A. Acini
11m2
1. compound tubuloacinar glands
2. a single layer of pyramidal cells
3. size of the central lumen
4. centroacinar cell (flattened, pale staining) cuboidal
5. typical serous cell: Basal basophilic, apical acidophilic
6. EM findings: Basal RER
Free ribosome
Longitudinal arranged mitochondria
Zymogen granules (0.6μm)
7. No myoepithelial cell
8. trypsin inhibitor, acute pancreatitis
B. Duct
1. Intercalated duct
2. Low cuboidal epithelium, centroacinar cell
3. No striated duct!
4. Intralobular duct: simple cuboidal epithelium
5. Interlobular duct: simple columnar epithelium
6. Main duct: simple high columnar epithelium
43
goblet cell
enteroendocrine cell
C. Secretion
1. Merocrine secretion
2. Regulation
(1) Neural control: vagus nerve 
(2) Hormonal control:
a. Secretin: bicarbonate and water
b. Pancreozymin (cholecystokinin)
Pancreatic enzyme
3. Enzymes:
proteases (e.g. trypsin)
amylase
lipases
RNAases
DNAases
III. The Endocrine Portion
A. Islets of Langerhans: 1.5% of total volume one million islets
Rich fenestrated capillaries  loose reticular fibers
B.
Cell type
Distribution
Percentage
Hormone
Function
A (alpha) ~
periphery
20%
glucagons
blood sugar
glycogenolysis
B (beta) ~
center
70%
insulin
blood sugar
Diabetes
Mellitus
D (delta) ~
scattered
5%
somatostation
inhibition,
paracrine
(A&B cells)
PP ~
scattered
a few
pancreatic
Pancreatic
polypeptide
juice,
gastroenteric
motility
44
The Respiratory System
External respiration & internal respiration
The respiratory system has two parts:
1. Conducting Portion：Nose → → → Terminal Bronchiole
Functions:
(1) Conducting air
(2) Conditioning air: cleansing, moistening & warming air
(3) Olfaction
(4) Phonation
2. Respiratory Portion: Respiratory Bronchiole → → → Alveoli
Function: Gas exchange
I. Introduction:
Respiratory epithelium: pseudostratified ciliated columnar epithelium
Ciliated column cells
Mucous goblet cells
Basal cells
Brush cells: sensory receptors
Small granule cells: neuroendocrine cells
II. Nasal cavity:
Median nasal septum and superior, middle & inferior conchae
1. Vestibule:
anterior
Epithelium posterior
Mucosa
Lamina propria:
2. Respiratory Portion：pink
Epithelium:
Mucosa
Lamina propria: rich in venous plexuses & mixed glands
Countercurrent heat-exchange system
3. Olfactory Potion：yellowish brown
Epithelium*: pseudostratified columnar epithelium
Mucosa
Lamina propria: serous glands of Bowman
Supporting (Sustentacular) cells:
* Basal cells:
Olfactory (Sensory) cells: bipolar neurons, have olfactory vesicle &
olfactory cilia
Paranasal sinuses:
45
III. Nasopharynx：
Epithelium:
Mucosa
Lamina propria
IV. Larynx：
Epithelium:
Mucosa
Lamina propria:
V. Trachea and Bronchi：
Epithelium:
1. Mucosa
Lamina propria:
2. Submucosa：mixed glands in C.T.
SIgA
3. Adventitia：“C” shaped or irregular hyaline cartilage and smooth muscles,
fibroelastic C.T.
VI. Lungs：
1. Bronchial Tree & Pulmonary lobule:
d  1mm
d  0.5 mm
Primary Bronchi   Bronchioles  Terminal Bronchioles  Respiratory
Bronchioles  Alveolar Ducts  Alveolar Sacs  Alveoli
2. Conducting Portion:
(1) Cavity and wall: 
(2) Epithelium: 
(3) Goblet Cells: 
(4) Glands: 
(5) Cartilage: 
(6) Smooth Muscle: 
(7) Elastic fibers: 
 Terminal Bronchioles:
Clara cells: dome-shaped apex, secretory granules
Ciliated cells:
3. Respiratory Portion:
Respiratory Bronchioles  Alveolar Ducts  Alveolar Sacs  Alveoli
 Alveoli Epithelium:
(1) Type I Cells (Squamous Alveolar Cells)
LM: squamous and thin
EM: pinocytotic vesicle, junctional complex
Functions:
(2) Type II Cells (Great Alveolar Cell)
LM: cuboidal cells, spherical nucleus & foamy cytoplasm
46
EM: lamellar bodies
Functions：Synthesize and secrete pulmonary surfactant.
Respiratory distress syndrome (hyaline membrane disease)
(3) Blood-Air Barrier:
Surfactant + Type I Alveolar cells + Basal Lamina
Interstitial Space
Capillary's Basal lamina + Endothelium
(4) Alveolar Septum: C.T., rich in capillary and elastic fibers.
(5) Alveolar Pore:
(6) Pulmonary Macrophage: alveolar macrophage
dust cell & heart failure cell
4. Blood Vessels:
Pulmonary Circulation: functional circulation
Bronchial Circulation: nutritional circulation
5. Pleura
47
The Urinary System
Kidney
I. Gross structure of the kidney
1. Renal capsule
2. Cortex (outer) dark brown and granular structure
Cortical labyrinths + renal columns (of Bertin)
3. Medulla (inner) pale and radially striated structure
Medullary pyramids + medullary rays
• Renal lobe: medullary pyramid + renal column
• Renal lobules: medullary ray + cortical labyrinths
II. Histological structure of the kidney
1. Introduction:
• Uriniferous tubules:
Nephrons + Collecting tubules
• Nephrons:
Renal corpuscle + Tubule system
• Renal corpuscle
Glomerulus + Bowman’s capsule
• Tubule system
Proximal tubule + Thin limb + Distal tubule
• Henle’s Loop:
straight portion of the proximal tubule or thick descending limb
the thin limb
the distal straight tubule or thick ascending limb
• Cortical nephrons
• Juxtamedullary nephrons
juxtamedullary nephron
cortical nephron
location
adjacent to medulla
size
larger
outer
cortex
smaller
number
loop
few
(15%)
long
numerous
(85%)
short
function
urine concentration
reabsorption
48
2. Nephrons
structural and functional unit
1) Renal corpuscle
(1) Structure:
Glomerulus + Bowman’s capsule + Bowman's space (urinary space)
Vascular pole & Urinary pole
a. Glomerulus (glomerular capillaries; glomerular tuft)
 Fenestrated capillaries
Afferent arteriole  Fenestrated capillaries  Efferent arteriole
 Mesangium
mesangial matrix
intraglomerular mesangial cells
Location:
Function: supporting, producing mesangial matrix, phagocytosing,
contracting, secreting chemical mediators
b. Bowman’s capsule: double - walled epithelial capsule
 Parietal layer
Visceral layer: modified
Podocytes:
Location:
LM:
EM: primary processes, secondary processes (pedicels),
filtration slits and slits membrane
Function:
(2) Function of renal corpuscle:
Filtration barrier (membrane):
 Structure
• filtration slits diaphragm
• Glomerular basement membrane (GBM):
Lamina Rare Interna: fibronectin, proteoglycans (heparin sulfate)
Lamina Densa : type IV collagen, laminin
Lamina Rare Externa : fibronectin, proteoglycans
• endothelium
 Function : selective filter (physical barrier, charge barrier)
2) Proximal Tubule
Convoluted : in cortical labyrinths (CL)
Straight : in medullary rays (MR) or medullary pyramids (MP)
LM: small, uneven lumen, large acidophilic cuboidal cells, brush border
EM: microvilli, canaliculi, lateral processes, membrane infoldings,
large amount of Mit.
Function: reabsorption, secretion
3) Thin limbs
(1) Structure: simple squamous epithelium
(2) Function:
4) Distal tubule
Straight : in MR or MP
Convoluted : in CL
49
LM: shorter, larger lumen, smaller, lighter cells
EM: lack brush border, (Tamm-Harsfal protein)
Function:
regulated by Aldosterone & ADH
LM
number
lumen
simple cuboidal
epithelium
spherical nucleus
cytoplasm
EM
brush border
lateral boundary of the
cell
basal vertical striation
apical microvilli
apical canaliculi and
vesicle
lateral cell processes
basal cell membrane
infoldings
Proximal tubule
abundant
smaller, irregular
higher
Distal tubule
few
larger, regular
lower
large, located centrally
acidophilic, densely
staining
obvious
invisible
small, located near
the lumen
acidophilic, lighter
staining
absent
visible
faint
long, abundant
numerous
prominent
short, few
absent
extensive
deeply
few
more deeply
numerous
more numerous
elongated
mitochondria
Function
3. Collecting tubules and ducts
collecting tubules  cortical collecting ducts  medullary collecting
ducts  papillary ducts
cuboidal.  columnar
1) Structure:
pale-staining cytoplasm, lateral boundary of adjacent cells is clearly
visible
2) Function: urine concentration
Regulated by Aldosterone & ADH
4. Intrarenal collecting system
Renal papilla  minor calyx  major calyx  renal pelvis
transitional epithelium
C.T.
smooth muscle
50
5. Juxtaglomerular apparatus (Juxtaglomerular complex)
1) Structure
(1) Macula densa
• Structure:
in the distal convoluted tubule
tall, narrow cells, densely staining nuclei closely packed together
• Function: sensor of [Na+]
(2) Extraglomerular mesangial cell (polar cushions)
• Structure:
• Function: signal transduction
(3) Juxtaglomerular cells:
• Structure:
modified smooth muscle cells
large cuboidal cells with secretory granules
• Function:
secretion of renin (vasoconstrictor)
renin angiotensin converting enzyme (ACE)
angiotensinogen
angiotensin I
angiotensin II
2) Function:
regulate blood pressure
6. The renal interstitium
Interstitium: fibroblast, collagen, proteoglycan
Interstitial cells:
synthesis of prostaglandins, prostacyclin, Erythropoietin (EPO)
7. Vascular supply
vasa recta (arteriolae rectae )
renal A.
renal V.
interlobar A.
interlobar V.
arcuate A.
straight v.
arcuate V.
interlobular A.
straight a.
interlobular V.
peritubular cap. network
afferent arteriole
glomerulus
cap. network in capsule & outer cortex
51
efferent arteriole
stellate V.
Ureters, Bladder, Urethra
1. Mucosa
1) Epithelium:
Ureters, Bladder： transitional epithelium layers ↑
Urethra： transitional epithelium → stratified squamous epi.
2) Lamina propria
2. Muscularis
Ureters
upper 2/3: inner longitudinal, outer circular
lower 1/3: inner longitudinal, middle circular and outer longitudinal
Urinary bladder:
thick, helical arrangement
3. Adventitia
52
The Male Reproductive System
I. Introduction:
II. Testis
Migration of primordal germ cells (PGCs) & Descent of testis
Cryptorchidism
Structure of testis:
1. Testicular capsule:
(1) tunica vaginalis: surrounding the anterolateral aspect of each testis
(2) tunica albuginea
mediastinum testis
lobuli testis
(3) tunica vasculosa
2. Seminiferous tubule
total length is nearly 0.5 km
(1) tunica propria
muscle-like myoid cells
(2) basal lamina
(3) seminiferous (or germinal) epithelium stratified epithelium
1) Spermatogenic cells
Spermatogenesis & meiosis
a. Spermatogonia: located in basal compartment,
mitosis
Dark type A spermatogonia: heterochromatin
Pale type A spermatogonia: euchromatin
Type B spermatogonia:
b. Primary spermatocyte: the largest male germ cells, having
chromosome within their nuclei.
c. Secondary spermatocytes: short-lived cells
d. Spermatid
 Spermiogenesis: round spermatids  elongated spermatids, through
shedding of much of their cytoplasm, rearrangement of their organelles,
and formation of flagella
 Nucleus becomes condensed and elongated  sperm head
 Golgi apparatus  acrosome (acrosomal cap) (a specialized lysosome)
proacrosomal granules  acrosomal granule within a acrosome vesicle
 Centriole  flagellum
 Mitochondria  mitochondrial sheath
 Microtubuli  manchette (caudal tube)
 Residual bodies are shed, and phagocytosed by Sertoli cell
e. Spermatozoon morphologically mature
 Head
 Neck
 Tail: middle piece, principal piece, end piece
 Clonal nature of the germ cells
53
Cytoplasmic bridges & Syncytium of germ cells
The cycle of seminiferous epithelium
The waves of seminiferous epithelium
2) Sertoli cells
a. Structure:
LM: tall columnar cell; a large, pale, oval or irregular shaped nucleus
with a prominent nucleolus; invisible lateral cellular limits.
EM: lateral and apical cell membrane & nucleus with infoldings; many
organelles; tight junctions & gap junctions.
 Blood-testis barrier
 Basal compartment
 Adluminal compartment
b. Functions:
 Support, protection and nutrition of developing germ cells.
 Phagocytosis of residual bodies.
 Secretion. e.g.: androgen-binding protein (ABP), anti-müillerian
hormone & inhibin, and a fructose - rich medium.
 Formation of blood-testis barrier.
 Regulation the release of spermatozoa
3. Interstitial tissue
(1) Interstitial cell (Leydig cell):
1) Structure:
LM: always in clusters; large, polyhedral cells, acidophilic cytoplasm,
central located nucleus.
EM: typical steroid-producing cells, containing large amounts of sER,
mitochondria with tubular cristae, and numerous of lipid droplets.
2) Function: secretion of testosterone.
(2) Others: including C.T., nerve, blood & lymphatic vessels.
4. intratesticular genital ducts:
(1) tubuli recti (straight tubules):
Lined by Sertoli cells in proximal half and simple cuboidal epithelium in
distal half, supported by loose C.T.
(2) Rete testis:
A system of labyrinthine spaces housed within the mediastinum testis,
lined by simple low cuboidal epithelium, supported by vascular C.T.
(3) Ductuli efferentes:
Undulated lumen lined by pseudostratified columnar E., supported by
loose C.T., forming the head of the epididymis.


III. Extratesticular genital ducts
1. Ductus epididymidis
Forming the body and tail of the epididymis
Lined by pseudostratified columnar epithelium of uniform height,
composed of basal cells and tall principal cells, the latter have many long
54
stereocilia and are actively reabsorptive. Epithelium is supported by loose
C.T. and abundant circularly arranged smooth muscles.
2. Ductus deferens (Vas deferens)
A narrow lumen and a thick-walled tube lined by pseudostratified
columnar epithelium with stereocilia, and surrounded by 3 layers of
smooth muscle: inner and outer longitudinal layers and middle circular
layer.
Ampulla
 Spermatic cord: passes through the inguinal canal, including arteries,
veins and ductus deferens.
 Pampiniform plexus
Countercurrent heat-exchange system
3. Ejaculatory duct
Lined by a simple columnar epithelium, and supported by loose C.T.
4. Urethra
(1) Prostatic urethra
Transitional E.
(2) Membranous urethra
Pseudostratified columnar E.
(3) Spongious part (bulbous part and pendulous part)
Pseudostratified columnar E.
Glands of Littre
IV. Accessory sex glands
1. Seminal vesicles
Highly coiled tubuli, lined by pseudostratified columnar epithelium, and
supported by fibroelastic C.T. and smooth muscles, producing fructose rich seminal fluid that is energy source for sperm motility.
2. Prostate gland
An collection of branched tubuloalveolar glands, the epithelium ranges
from simple cuboidal - columnar to pseudostratified columnar depending
on the man's hormonal states, and the glands are embedded within a
fibromuscular stroma. Three groups of glands concentrically arranged
around the urethra:
(1) Mucosal glands (central zone)
(2) Submucosal glands (transition zone)
(3) Main glands (peripheral zone)
Prostatic concretions (corpora amylacea)
3. Bulbourethral glands
Tubuloalveolar, mucus-secreting glands, lined by a simple cuboidal or
columnar epithelium.
V. Penis
1. Structure:
Each of three columns of erectile tissue, which is encircled by tunica
albuginea, has large venous sinuses separated by trabeculae.
(1) Corpora cavernosa of the penis: Paired, located dorsally.
55
Helicine arteries & Intimal cushion
(2) Corpus cavernosum of the urethra (corpus spongiosum): ventrally located,
containing penile urethra.
2. Functions:
(1) Urination
(2) Copulation organ
Penile erection: a hemodynamic event
56
The Female Reproductive System
I. Ovary
1. Oogenesis: miosis of oocyte
oogonia  primary oocytes ①secondary oocytes ② ovum
+
+
polar body
polar body
 stopped in prophase of meiosis I, completed before ovulation
 stopped in metaphase of meiosis II, completed when fertilization taken
place
2. General structures
1) Ovarian surface epithelium:
simple squamous/cuboidal epithelium
2) Tunica albuginea
dense C.T.
3) Cortex
stroma: C.T., stromal cells, smooth muscle
gamete - producing structures & derivatives
4) Medulla:
loose C.T.
5) Hilum
hilus cells: secrete androgen
3. Structures in cortex
1) Follicular growth
follicle: an oocyte + follicular cells
basement membrane surround the follicles
growing follicles
(1) Primordial follicles
primary oocyte + a single layer of flattened follicular cells
(2) Primary follicles
• primary oocyte: growth rapidly
• granulosa cells (follicular cells)
flattened  cuboidal, unilaminar  multilaminar
• zona pellucida
structures: ZP1, ZP2, ZP3
functions:
(3) Secondary follicles
• follicular cavity (antrum): follicular fluid
• cumulus oophorus: primary oocyte + corona radiata
• stratum granulosum
• basement membrane
57
•
theca folliculi:
theca interna: theca cells, cap.
theca externa: C.T., smooth muscle cells
• estrogen produced: theca interna – follicular cell synergism
(4) mature (Graafian) follicles
oocyte: primary  secondary
granulosa layer: proliferation decreased
2) Ovulation
after LH surge
Process:
stigma
secondary oocyte + zona pellucida + corona radiata
3) Corpus luteum
(1) Formation
(2) Structure
granulosa lutein cells: centrally located, numerous, large, acidophilic
theca lutein cells: peripherally located, smaller
(3) Function
secrete progesterone, estrogen
(4) Types
• corpus luteum of menstruation
• corpus luteum of pregnancy
relaxin
4) Corpus albicans
5) Follicular atresia
oocyte  degeneration, granulosa cells  degeneration
happened at any stage of follicle
interstitial glands
structure:
hormones:
4. Function of ovary
• produce ovum
• secrete female sexual hormone
II. Oviducts (Uterine Tubes)
1. Gross structure
Infundibulum, Ampulla, Isthmus, Intramural Portion
2. Microscopic Structure
1) Mucosa
simple columnar epithelium
hormone sensitively
• ciliated cell
• secretory cells (peg cells)
lamina propria
2) Muscularis
inner circular layer, outer longitudinal layer
58
3) Serosa
longitudinal folds
smooth muscle
infundibulum:
fimbriae
ampulla:
isthmus:
intramural portion:
III. Uterus
body (corpus), fundus, cervix
1. Structure of uterine body
1) Perimetrium serosa
2) Myometrium
3 layers: inner longitudinal layer, middle circular layer, outer longitudinal layer
large blood vessels in middle layers
bundles of smooth muscle fibers + C.T.
3) Endometrium
(1) Simple columnar epithelium
ciliated cells, secretory cells
(2) Lamina propria:
stromal cell
uterine glands:
(3) Basalis
• the closed tips of the uterine glands
• straight arteries
• not shed
(4) Functionalis
• cyclic changes
• hormone responsive
• spiral arteries
2. Cyclic changes in the endometrium
Menstrual cycle
menstrual
proliferative phase
secretory
phase
phase
time (day)
1-4
5-14
15-28
ovary phase
follicular phase
luteal phase
hormone
reduction
estrogen
progesterone
estrogen
spiral A.
elongated
elongated
constricted  relaxed
coiled
highly coiled
 broken
uterine glands
broken
straight
highly coiled
epithelial cells
necrosis
proliferated
secreting
glycogen
stroma cells
necrosis
proliferated
differentiated
functionalis
detached
regenerated
edema
59
3. Uterine Cervix
1) Mucous
(1) Epithelium not desquamate
cervical canal: simple columnar epithelium
protio vaginalis: stratified squamous epithelium
(2) Cervical glands
2) Myometrium
few smooth muscle fibers , mainly C.T.
3) Adventitia
IV. Vagina
fibromuscular tubular structure
1. Mucosa
1) Epithelium
stratified squamous nonkeratinized epithelium
glycogen → lactic acid
2) lamina propria
loose C.T., rich in elastic fibers, highly vascular
2. Muscularis
3. Adventitia
dense C.T.,
rich in elastic fibers
V. Mammary Glands
dense C.T. + adipose tissue + compound tubuloalveolar glands
1. Structures:
1) Compound tubuloalveolar glands
alveoli  intralobular ducts  interlobular ducts  lactiferous ducts
 lactiferous sinuses  opening
simple cuboidal epithelium  simple columnar  stratified
cuboidal/columnar  stratified squamous epithelium
2) Alveoli
secreting cell: milk secretion
myoepithelial cells
2. Different state of mammary gland
1) Inactive (resting) mammary gland
inactive duct system
2) Active mammary gland
pregnancy: alveoli proliferate
lactation: milk secretion & accumulation
60
The Eye and the Ear
Eye
The Eyeball
I. The wall of eyeball
A. Tunica fibrosa (external layer)
Cornea
limbus cornea
sclera
1. Cornea:
(1) Epithelium: stratified squamous non - keratinizing epithelium
(2) Bowman’s membrane (anterior limiting membrane)
(3) Stroma (substantia propria)
collagen fibers, chondroitin sulfate, keratan sulfate
(4) Descemet’s membrane (posterior limiting membrane)
collagen fibrils
(5) Endothelium: simple squamous epithelium
2. Limbus cornea
trabecular meshwork, sinus venosus sclerae (canal of Schlemm)
3. Sclera
many bundles of collagen fibers
scleral spur
lamina cribrosa
B. Uveal coat (vascular layer)
iris
ciliary body
choroids
1. Iris:
pupil, anterior chamber, posterior chamber
(1) Anterior border layer: fibroblasts & melanocytes
(2) Iris stroma: blood vessels, melanocytes
(3) Epithelial layer
a. The anterior layer:
dilator pupillae muscle (sympathetic)
sphincter pupillae muscle (parasympathetic)
b. The posterior layer: pigmented epithelial layer cuboidal epithelial
cells
2. Ciliary body
(1) Ciliary muscle:
(2) Vascular layer
(3) Ciliary epithelium
a. The outer layer: pigmented, simple cuboidal epithelium
b. The inner layer: nonpigmented, simple cuboidal epithelium
secreting aqueous humor forming ciliary zonule
61
3. Choroid
(1) The outer layer: large vessels, melanocytes
(2) The middle layer: choriocapillary layer
(3) The inner layer: glassy or Bruch’s membrane
C. Retina
Retina
ora serrata
double - layered epithelium
1. Pigment epithelium
melanin, lamellar debris, vitamin A, rhodopsin
2. Photoreceptors:
(1) Rods: 120milion
a. The outer segment: membranous discs
11-cirretinae + opsins
rhodopsin
b. The inner segment: M, rER, ribosomes
(2) Cones: 700milion
a. The membranous discs are continuous
b. Visual pigments (blue, green, red)
c. enriched in fovea
3. Bipolar cells: synapses
4. Ganglion cells: synapses
5. Ten layers
(1) Pigment epithelial layer *
(2) Layer of rods & cones *
(3) Outer limiting membrane
(4) Outer nuclear layer *
(5) Outer plexiform layer
(6) Inner nuclear layer *
(7) Inner plexiform layer
(8) Ganglion cell layer *
(9) Nerve fiber layer
(10) Inner limiting membrane
6. Macula lutea: 3-4mm, fovea centralis only cones
7. Optic disc and Optic nerve
Papilla of optic verve
II. The Refractive Media
A. Lens
1. Lens capsule: collagen fibrils
2. Lens epithelium: simple cuboidal epithelium
3. Lens fibers: hexagonal prismatic
4. Accommodation
B. Aqueous humor
1. Production
2. Drain passage
C. Vitreous body
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1. Hyaluronic acid, vitrein, collagen fibrils
2. Hyalocyte
III. Light conducting passage
Accessory Organs of the Eye
I. Eyelids
A. Skin: eyelash, glands of Zeis
glands of Moll
B. Hypodermis
C. Muscular layer: Orbicularis oculi muscle
Palpebralis
Palpebral muscle
D. Tarsal plates: tarsal (Meibomian) glands
E. Conjunctiva
II. Lacrimal gland
The Ear
I. External ear
A. Auricle
B. External auditory meatus: ceruminous gland
C. Tympanic membrane
II. Middle ear
A. Tympanic cavity: malleus, incus, stapes
Simple squamous or low cuboidal epithelium
B. Eustachian tube
III. Internal ear
A. Osseous labyrinth
1. Vestibule and semicircular canals:
Oval window, Round window
2. Cochlea
modiolus, scala vestibuli & scala tympani Helicotrema, cochlear duct
B. Membranous labyrinth
1. Membrane semicircular canals, Utricle, Saccule
simple squamous or cuboidal epithelium
(1) Macula utriculi and macula sacculi
a. Supporting cells
b. Hair cells: stereocilia, kinocilium
c. Otolithic membrane, otoliths
(2) Crista ampullaris: Cupula
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2. Cochlear duct
(1) Vestibular membrane
(2) Spiral ligament, stria vascularis (endolymph)
(3) Osseous spiral lamina
Membranous spiral lamina (Basilar membrane)
Auditory string
(4) Tectorial membrane
(5) Organ of Corti (spiral organ)
a) Pillar cell
b) Phalangeal cell
c) Hair cell
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