This document discusses different types of epithelia, including stratified cuboidal epithelium, stratified columnar epithelium, transitional epithelium, and the basement membrane. It provides examples of where each type is found in the body and their functions. The main functions of epithelium are listed as protection, secretion, absorption, excretion, and transport.

1. Maryam Fida (o-1827)
EPITHELIUM

2.  STRATIFIED CUBOIDAL EPITHELIUM
 STRATIFIED COLUMNAR EPITHELIUM
 TRANSITIONAL EPITHELIUM
 BASEMENT MEMBRANE
 FUNCTIONS OF EPITHELIUM

3. Stratified cuboidal epithelium
 It consists of two or three
layers of cuboidal cells
 Rarely distributed
throughout the body
 Examples includes lining
of the ducts of some
exocrine glands like
pancreas, salivary glands
& sweat glands
 Not involved in absorptive
or secretory activity

4. Stratified columnar epithelium
 Consists of columnar
surface cells resting on
one or more layers of
cuboidal cells
 Rarely distributed
throughout body
 Examples include lining
of conjunctiva of eye &
some parts of the male
urethra

5.  Unlike the stratified squamous epithelium
 the surface cells of stratified cuboidal and
stratified columnar epithelium are not
continuously replaced by mitosis at basal
cell layer and no progress of cells from the
base to surface.

6. Transitional epithelium
 A special type of stratified
epithelium  lines the urinary
tract
 Specially designed for stretch
produced by storing & passing
of urine
 It prevents reabsorption of urine
 Lines renal calyces, renal
pelvis, ureters, urinary
bladder & proximal part of
male & female urethra

7. BASEMENT MEMBRANE or BASAL
LAMINA
 A thin layer of extracellular material present between
epithelial cells and the underlying connective tissue
 It consist of:
 Collagen type IV
 Glycoproteins
 Functions of basement membrane:
 Binds epithelial cells
 Provides support to epithelial cells
 Diffusion occurs through it  leading to
nourishment of epithelial cells

8. FUNCTIONS OF EPITHELIUM
1. PROTECION
 Function of all
 Most marked in stratified squamous
epithelium
2. SECRETION
 Goblet cells
3. ABSORPTION
 Lining of small intestine
 Epithelial cells of kidney tubules

9. 4. EXCRETION
 Urine & Sweat
5. TRANSPORT
 Cilia  transport of mucus & ovum