Tissues Flashcards
Cells work together in functional group called
Tissues
How many types of tissues
4 type of Tissues
Epithelial tissue
Covers a body surface or lines a body cavity
Function of epithelial tissue
Protection
Absorption & Secretion
Filtration
Forms slippery surf
Factors holding epithelial cells together
Adhesion proteins link plasma membranes of
adjacent cells
Contours of adjacent cell membranes
Special cell junctions
◼ Tight Junctions
◼ Gap Junctions
◼ Desmosomes
Classifications & Naming of Epithelia
First name of tissue indicates number of
layers
Simple– one layer of cells
Stratified– more than one
layer of cell
Last name of tissue describes shape of
cells
Squamous– cells wider
than tall (plate or “scale” like)
Cuboidal– cells are as wide
as tall, as in cubes
Columnar– cells are taller than
they are wide, like colu
Tight junctions
close off intercellular
space
Found at apical region of most epithelial types
Desmosomes
two disc-like plaques
connected across intercellular space
Plaques of adjoining cells are joined by
proteins called cadherins
Gap junctions
– passageway between two
adjacent cells
Let small molecules move directly between
neighboring cells
Simple Squamous Epithelium
single layer of flat cells with disc shaped nuclei
Passage of materials by passive diffusion and
filtration
Secretes lubricating substances in serosae
Simple Cuboidal Epithelium
single layer of cube-like cells with large, spherical central nuclei
secretion and absorption
Simple Columnar Epithelium
single layer of column-shaped (rectangular)
cells with oval nuclei
◼ Some bear cilia at their apical surface
◼ May contain goblet cells
Simple Columnar Epithelium
Non-ciliated form
◼ Lines digestive tract,
gallbladder, ducts of
some glands
Pseudostratified Columnar Epithelium
All cells originate at basement membrane
Only tall cells reach the apical surface
May contain goblet cells and bear cilia
Nuclei lie at varying heights within cells
◼ Gives false impression of stratificat
Stratified Epithelia
Contain two or more layers of cells
◼ Regenerate from below
◼ Major role is protection
◼ Are named according to the shape of cells
at apical laye
Stratified Squamous Epithelium
Many layers of cells – squamous in shape
Deeper layers of cells appear cuboidal or
columnar
Thickest epithelial tissue – adapted for protection
Glandular Epithelium
Ducts carry products of exocrine glands to
epithelial surface
Unicellular Exocrine Glands
(The Goblet Cell)
◼ Goblet cells produce
mucin
◼ Mucin + water →
mucus
◼ Protects and lubricates
many internal body
surfaces
Multicellular Exocrine Glands
Classified by structure (branching
& shape) of duct
◼ Can also be classified by mode or
type of secretion
Connective Tissue
Most diverse and abundant tissue
◼ Main classes
Connective tissue proper
Blood – Fluid connective tissue
Cartilage
Supporting connective tissues Bone tissue
Connective Tissue Proper -
Classifications
Loose Connective Tissue
◼ Dense Connective Tissue
◼ Adipose Tissue
◼ Cartilage
◼ Bone
◼ Blood
Muscle Tissue
◼Types
Skeletal muscle tissue
Smooth muscle tissue
Cardiac muscle tissue
Skeletal Muscle Tissue
Characteristics
Long, cylindrical cells
Multinucleate
Obvious striations
◼ Function
Voluntary movement
Manipulation of
environment
Facial expression
Smooth Muscle Tissue
◼ Characteristics
Spindle-shaped cells with
central nuclei
Arranged closely to form
sheets
No striations
◼ Function
Propels substances along
internal passageways
Involuntary control