Tissue: Fabric of
Life
Read & Review Chapter 4
Body Tissues
 Histologytissues
study of biology of tissues
are cells organized for a specific
function
Development of Tissues
Primary Germ Layers
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the process of forming 3 germ layers is
called gastrulation
the process of the germ layers
differentiating into tissues is called
histogenesis
Tissue development
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Endoderm – innermost
layer
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Mesoderm - middle layer
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ex. Lining of digestive and
respiratory organs, thyroid
ex. muscle, skeleton, blood,
skin, connective tissue,
excretory and reproductive
organs
Ectoderm – outermost
layer
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ex. skin, nervous, epidermis
tissue
Tissues
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Groups of cells that are similar in structure and
function
Four primary tissue types
1. Epithelial
Covering
Support
2. Connective
3. Muscle
Movement
4. Nervous
Control
II. Epithelial Tissues
A. 2 Main Types
1. Membranous epithelium- lining/ covering
2. Glandular epithelium- secreting
Epithelial: Functions
1.
2.
3.
4.
5.
Protection- ex. skin
Sensory- ex. skin, nose, eye, ear
Secretion- ex. hormones, digestive
juices, sweat
Absorption- ex. small intestine, lungs
Excretion- ex. urine, sweat
C. Characteristics
1. limited extracellular space (matrix); cells appear
tightly packed
2. apical surface (free surface exposed to the body
exterior or the cavity of an internal organ) &
basement membrane (bottom surface connected to
connective tissue)
Characteristics-(Continued)
3. avascular- no blood vessels; uses diffusion
instead
4. innervated- contains nerve fibers
5. origin is ectodermal, mesodermal, endodermal
6. high regeneration capacity
D. Classification of membranous epithelial
1. Cell Shapes
a. Squamous- flat, round
b. Cuboidal- cubed
c. Columnar- narrow
cylinder
d. Pseudostratified- one
layer of odd-shaped
columnar cells; appears
to be more than one
layer
Layers of Cells
Layers of Cells
a. Simple- single layer
b. Stratified- more than
one layer
3. Cell Shapes & Layers of Cells
a. simple squamousex. alveoli in lungs
b. simple cuboidalex. glands, kidney
c. simple columnarex. golbet cells, cilia,
microvilli
Simple Squamous Epithelium
 Absorption
 Secretion
 Filtration
Simple Cuboidal
Epithelium
Glands, ducts
 Walls of the kidney
tubules
 Surface of the
ovaries

Simple Columnar Epithelium
Goblet cells secrete mucus
that aids in the function of
respiratory system
Pseudostratified columnar
ex. goblet cells, respiratory
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All the cells rest on the
basement membrane
Since some of the cells are
shorter then others, the
nuclei appear at different
heights
Stratified Squamous (keratinized and
non-keratinized)
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Stratified Squamous
Epithelium: Most common
stratified epithelium in the
body
Squamous at the free edge
and columnar or cuboidal at
the basement membrane
Sites of abuse or friction:
esophagus, mouth and outer
portion of the skin, the outer
surface of skin is keratinized
(surface cells contain keratin,
Keratinized vs. Nonkeratinized
Stratified Cuboidal
Stratified Cuboidal
and Columnar
Epithelium usually
just two cell layers
 Fairly rare in the
body; mainly ducts
of large glands
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Sweat glands
Mammary glands
Transitional Epithelium

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highly modified stratified
squamous: urinary
bladder, ureters, urethra.
All these organs are part
of the urinary system
and are subject to
considerable stretching
Section 2 vocab: common suffixes
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-ac, -al, -ary, -ic, -tic, -ous:
pertaining to/related to
-ad: derived from
-algia: pain
-cele: hernia
-centesis: puncturing
-ectomy: cutting out
-iasis: a process or its results
-itis: inflammation
-ium: diminuitive, small
-ize: to make into
-lysis: break down
-oid: resembling, like
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-oma: tumor/cancer
-osis: denotes states or
condition
-ous: possessing, full of
-plasty: molding, forming
-rrhea: flow
-sect: to cut, divide
-sia, -sis, -tion, -y:
action/condition
-stomy: make an artificial
opening
-tomy: to cut
Three Week Schedule
9/8- Gladular Epithelial tissue; Scope Work
9/9- Quiz (Epithelial tissue); Connective Tissue & Muscle tissue
9/10- Scope Work (Sub day)
9/11- Nervous Tissue; Scope Work
9/12- Vocab quiz (2); Microscope work (no lecture)
9/15- Integumentary Notes, Scope work
9/16- Integ. Notes, Tissues Review, Scope work
9/17- Tissue Practicum Quiz, Tissue Packet Due
9/18- Finish Integ Notes; Lab activity
9/19- Vocab Quiz (3), Disease & Disorder Lecture (End 1st 6 wks)
9/22- Review for Test
9/23- Tissue/IntegumentaryTest
9/24- Bones/Skeletal Lecture
9/25- Bones Discussion and Identification
9/26- Vocab Quiz (5), Bones Lab
Glandular Epithelium
 Gland:
one or more cells that
make and secrete a product
 Secretion: protein molecule in
aqueous fluid [some secrete a
lipid or steroid rich secretion]
Classification of glandular epithelial tissue
1. Cell Number
a. Unicellular glands- single cells
ex. goblet cells- mucus
b. multicellular glands- clusters of cells;
ex. mammary ducts- milk
Classification of glandular epithelial tissue
2. Discharge method
a. Exocrine glands – secrete into duct
ex. saliva, sebaceous, mammary, sweat
b. Endocrine glands - ductless; secrete
hormones into bloodstream
ex. pituitary gland, thyroid, ovary, testes, adrenal,
pancreas
Glandular Epithelium
 Endocrine:
( internal
secreting)
ductless;
all hormone
secretions directly into
the blood or
lymphatics (secrete
by the process of
exocytosis)
 thyroid;
pituitary
adrenals;
Multicellular Exocrine Glands
 Two
basic parts:
Duct
Secretory unit
that consists of
secretory cells
called acini
Modes of secretion
Merocrine glandsexocytosis
(pancreas, salivary
glands, sweat glands)
 Holocrine Glandsrupture
(Sebaceous oil glands
of the skin)

Epithelial tissue overview
Epithelial
Simple
Squamous
Cubodial
Stratified
Columnar
Pseudostratified
transitional
ciliated
cubodial
nonciliated
columnar
ciliated
squamous
keratinized
nonkeratinized
nonciliated