CHAPTER 3 – PART 2
Body Tissues
TISSUE
Histology
4
Tissue Types:
1.
Epithelial – (covering)
2. Connective – (support)
3. Muscle – (movement)
4. Nervous – (control)
EPITHELIAL TISSUE
 Lining,
covering, & glandular
 Functions:
Protections, absorption,
filtration, & secretion
EPITHELIAL TISSUE, CONT’D…
Special
Characteristics:
Cells
fit closely together to form sheets
Has a free surface (apical surface)
Lower surface – (basement
membrane)
Epithelial
Avascular
to connective
– no direct blood supply
Diffusion
Regenerate
easily
EPITHELIAL TISSUE, CONT’D…
Classification
of epithelium
Named
according to # of layers &
shape of cells at the free surface
Layers:
Simple
(1 layer)
Stratified (2 or more layers)
Shape:
Squamous
– flat
Cuboidal – cube shaped
Columnar – taller than wide
EPITHELIAL TISSUE, CONT’D…
Simple
Epithelium: absorption,
secretion, & filtration
 Simple Squamous Epithelium – forms
serous membranes (serosae - fluid)
 Lines
body cavities & organs
EPITHELIAL TISSUE, CONT’D…Simple Epithelium, cont’d…
Simple
Cuboidal – glands & ducts
EPITHELIAL TISSUE, CONT’D…Simple Epithelium, cont’d…
Simple
columnar epithelium – forms
mucus membranes (mucosae).
Lines
cavities open to exterior
Ex. Respiratory Tracts, Digestive Tracts
EPITHELIAL TISSUE, CONT’D…Simple Epithelium, cont’d…
Pseudostratified
Lines
Columnar Epithelium
Respiratory Tract
Ciliated
EPITHELIAL TISSUE, CONT’D…
Stratified
Epithelia–layered; protects
 Stratified
Squamous Epithelium – most
common; high abuse & friction.
 Ex.
Skin, mouth, esophagus
EPITHELIAL TISSUE, CONT’D…Stratified Epithelia, cont’d…
Stratified
Rare;
Cuboidal & Stratified Columnar:
large ducts
EPITHELIAL TISSUE, CONT’D…Stratified Epithelia, cont’d…
Transitional
Epithelia: function is stretching
EPITHELIAL TISSUE, CONT’D…
Glandular
Epithelia: glands; produces
& secretes
 2 types:
 1. Endocrine Glands (ductless)
 Directly
into the blood stream
 Hormones (ovaries, testes, adrenal)
 2.
Exocrine Glands (ducts)
 Sweat,
 Liver
oil
Answers:
A - simple columnar epithelium.
B - simple columnar epithelium with cilia.
C - stratified squamous epithelium.
D - simple squamous epithelium.
E - transitional epithelium.
F - pseudostratified epithelium.
G - stratified squamous epithelium.
H - choanocytes
I - stratified columnar epithelium with cilia.
CONNECTIVE TISSUE
Functions:
protection, support, &
binding together
Most abundant tissue type
Found everywhere in the body
CONNECTIVE TISSUE, CONT’D…
COMMON CHARACTERISTICS:
 Some
vascular
 Some avascular (cartilage) – heals slowly
 Many different types of cells
 Extracellular Matrix: non-living substance
outside of cell; can be liquid, semisolid or
gel-like, or very hard
 Examples:
 Tissue
Fat (soft); Bone (hard)
can bear weight, withstand stretching
& abrasions.
CONNECTIVE TISSUE, CONT’D…
TYPES OF CONNECTIVE TISSUE:
Bone
Bone
(osseous tissue) – vascular
cells surrounded by hard
matrix of calcium salts & collagen
fibers
Function: protect & support other
organs
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
Cartilage
Less
– avascular
hard/more flexible than bone
Hyaline cartilage- voice box; covers
end of bone; attaches ribs to sternum;
skeleton of fetus
Elastic cartilage- more elasticity. Ex:
ears, nose
Fibrocartilage- highly compressible
and cushion-like; between vertebrae
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
Dense
Connective Tissue
(fibrous tissue)
Mostly
collagen fibers
Forms strong, rope-like structures
Ex: Tendons; Ligaments
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
 Loose
Connective Tissue- Softer & fewer fibers
Areolar
Tissue
Soft, pliable tissue that protects &
wraps body organs
Universal packing tissue & connective
tissue glue that helps hold internal
organs together
Edema- areolar tissue soaks up fluid
in inflamed area; swells & becomes
puffy
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
LOOSE CONNECTIVE TISSUE, CONT’D
Adipose
Tissue – “fat”
Forms subcutaneous layer below
skin; insulates & protects from heat
& cold.
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
Reticular
Delicate
Connective Tissue
network of fibers
Found in lymph nodes
Ex: Spleen and bone marrow.
CONNECTIVE TISSUE, CONT’D…TYPES, CONT’D…
Blood
– “vascular tissue”
Blood
cells surrounded by blood
plasma
Protein fibers in blood
Blood
clotting
MUSCLE TISSUE
 Specialized
to contract or shorten
 Muscle Cells (muscle fibers)
MUSCLE TISSUE, CONT’D…
TYPES OF MUSCLE TISSUE (3 TYPES)
 Skeletal
Muscle- (striated muscle)
Attached
to skeleton; forms flesh
Voluntary
Cells
are long, cylindrical, multinucleate,
& striated
MUSCLE TISSUE, CONT’D…TYPES, CONT’D…
 Cardiac
Has
Muscle- (heart only)
striations, uninucleate; fit tightly
together; gap junctions
Involuntary
MUSCLE TISSUE, CONT’D…TYPES, CONT’D…
 Smooth
No
Muscle- (visceral)
striations, single nucleus & spindleshaped (pointed at both ends)
Found in walls of stomach, bladder, uterus
& blood vessels (hollow organs)
Contracts slowly
Peristalsis – wave-like motion through
small intestine
Involuntary
IV. NERVOUS TISSUE
Cells
= Neurons
Function = Irritability & Conductivity
A. Tissue Repair (Wound Healing)
-
-
Defense at tissue level – skin,
mucous membranes, cilia, and acid
in stomach glands.
Inflammation – body response to
prevent further injury.
IV. NERVOUS TISSUE….CONT’D
-
-
Immune Response – specific to
invaders
2 Ways tissue repairs (depends on
tissue type and severity of injury)
-
-
Regeneration: replacement of destroyed
tissue by same kinds of cells
Fibrosis: repair by dense connective
tissue (fibrous) – forms scar tissue
IV. NERVOUS TISSUE….CONT’D
-
Process of tissue repair:
1. Capillaries become
permeable/allows clotting fibers to
seep to injury (bleed)
2. Blood Clot forms/then scab
3. Granulation tissue forms (new skin)
4. Epithelium regenerates/scab falls
off (healed)
**Scar Tissue cannot function as
original cells.
 Growth
through cell division  puberty
 Replacement of tissue exposed to
friction  lifetime
 Epithelial Tissue – Mitotic
 Connective Tissue – Mitotic (forms scar
tissue)
 Muscle Tissue – Amitotic after puberty
 Nervous Tissue – Amitotic shortly after
birth
 Aging
– Caused by chemical and physical
exposures and genetics, and stress
 Neoplasm: abnormal Cell division – multiply
wildly – benign or malignant (tumor)
 Hyperplasia: enlarged tissue due to local
irritant or condition
Ex. Anemia/Bone marrow undergoes
hyperplasia to produce more red blood
cells
Ex. Breast enlargement during pregnancy
 Atrophy:
decrease in size – loss of
stimulation
Ex. Muscle reduction from wearing a
cast