Epithelial tissue

Question 1

Features of epithelium

Answer 1

Covers and lines outer & inner body e.g organs, cavities and ducts
Selective barriers

Question 2

Features of Glandular epithelium

Answer 2

Forms glands

Function: secretes hormones and other substances into ducts, surfaces or blood

Question 3

Features of epithelial tissue

Answer 3

All epithelial tissue are avascular (not associated with or supplied by blood vessels)
Rely on the blood supply of the connective tissues
Exchange of nutrients and waste takes place by diffusion from vessels in connective tissue.

Question 4

Structure of basement membrane

Answer 4

Found between epithelial tissue and connective tissue.
Basal Lamina
Secreted by the epithelial cells
Contains collagen, laminin, other proteoglycans, glycoproteins etc.
Reticular Lamina
Produced by cells of the underlying connective tissue (fibroblasts)
Contains fibrous proteins e.g. fibronectin, collagen

Question 5

Function of basement membrane

Answer 5

Supports overlying epithelium
Provides a surface along which epithelial cells migrate during growth & wound healing
Acts as a physical barrier
Participates in the filtration of substances in the kidney

Question 6

epithelial tissue classifications: shape

Answer 6

Squamous 
Fast absorption 
Flat (squashed) cell
Flat nucleus
Easy for materials to move across i.e oxygen
Cuboidal 
Absorb nutrients
Produce secretion
Height & width about the same (cube)
Circular nucleus
Columnar
Absorb nutrients 
Produce secretion
Tall and thick
Cushions underlying tissues
Transitional 
Cells change shape depending on organ
Example: urinary bladder allows stretching when needed

Question 7

epithelial tissue classifications: arrangement

Answer 7

Simple 
One layer of cells
Stratified 
Multiple layers of cells on top of each other 
Pseudostratified
Mostly one layer
Cells are different shapes and sizes
Nuclei at different levels