Lecture 2 - Epithelium

Question 1

Epithelia are avascular i.e. lack a direct blood and lymphatic supply .Nutrients are delivered by ______

Answer 1

Diffusion

Question 2

Domain of epithelium

has structures important for protection and absorption microvilli , Cilia and stereo cilia

Answer 2

Apical Domain

Question 3

Domain of epithelium
have structures needed to anchor epithelial cells to each other e.g. Occluding Junctions, Desmosomes and Cell – Cell attachment.

Answer 3

Lateral Domain

Question 4

Domain of epithelium
have structures needed to anchor cells to basement membrane e.g. cell to extracellular matrix junctions and basal cell membrane infoldings

Answer 4

Basal Domain

Question 5

• increase the surface area for absorption / secretion and are found in cells lining stomach and intestines.
• In the small intestines , they are densely packed and have a uniform height –brush border or striated border .

Answer 5

Microvili

Question 6

-transport matter along the cell surface and are found on columnar cells lining the oviduct , bronchi.
They are long , highly motile apical structures

Answer 6

Cilia

Question 7

-chronic respiratory infections ( lack of cleansing action of cilia , infertility ( immotile spermatozoa)

Answer 7

Kartagener,s syndrome

Question 8

________are specialized proteins in the plasma membranes of adjacent cells.

They “stitch together” adjacent cells to form a tight cellular connection.

They are designed to restrict movement of material between the cells they link.

Answer 8

Tight junctions

Question 9

________ are specialized connection protein complexes in cells that “rivet” cells together. They are attached to the intermediate fibers of adjacent cells.
The anchoring proteins can also be used to communicate between cells

Answer 9

Desmosomes

Question 10

_______are holes lined with specialized proteins that create cytoplasmic communication bridges between cells allowing for chemical and electrical signals to be passed rapidly.

Answer 10

Gap junctions

Question 11

Many agents such as cytomegalovirus and cholera toxin cause junctional complexes to become permeable.
__________ disrupt zonula occludens of stomach epithelial cells

Answer 11

Helicobacter pylori

Question 12

Locations of simple squamous epithelium

Functions of simple squamous epithelium

Answer 12

• Blood vessels ( endothelium)
• Body cavities ( mesothelium)
• Bowman’s capsule of the kidneys
• Alveoli of lungs
• Fluid transport ( e.g. kidney)
• Gas Exchange ( lung alveolus)
• Lubrication ( e.g. mesothelium)

Question 13

Locations of simple cuboidal epithelium

Functions of simple cuboidal epithelium

Answer 13

• small ducts of exocrine glands
• Most of the kidney tubules.
• Thyroid Follicles
• Protection
• Absorption
• Secretion
• Conduit

Question 14

Locations of simple columnar epithelium

Functions of simple columnar epithelium

Answer 14

lining the stomach , intestines , gall bladder uterus , oviducts .

• protection , secretion, absorption and transport .
• Simple columnar epithelial cells have specialized projections on apical surface , namely microvilli or cilia.

Question 15

Type of Stratified squamos epithelium

found lining moist cavities e.g. oral cavity , esophagus , vagina and anal canal. Primary function is to provide a protective barrier

Answer 15

Nonkeratinized

Question 16

Type of Stratified squamos epithelium

found in the epidermis of thick and thin skin and consist of surface layers of dead cells filled with keratin and no nucleus .

Answer 16

Keratinized

Question 17

Epithelium found lining sweat glands

Answer 17

Stratified Cuboidal Epithelium

Question 18

Epithelium found conjunctiva of the eye and ducts of some large glands.

Answer 18

Stratified Columnar Epithelium

Question 19

Location of pseudo stratified epithelium with cilia

Answer 19

many portions of respiratory tract e.g. trachea , primary bronchi and nasal cavity.

Question 20

Location of pseudo stratified epithelium without cilia

Answer 20

is found in ducts of male urethra and epididymis

Question 21

Function of pseudo stratified epithelium

Answer 21

protection , motility , and sensory perception

Question 22

Composed of 2-6 layers of cells , found exclusively in the portions of urinary system , where it lines the urinary bladder , ureter and parts of urethra.

Answer 22

Transitional epithelium
(Lower cell layers are cuboidal  but apical layers  can be variable in shape . When the bladder is distended the apical cells are flattened , however when the bladder is empty these cells have rounded)

Question 23

Function of transitional epithelium

Answer 23

Protective by forming a barrier between the urine and underlying tissue . The apical cells have unique intracellular plaques which effectively form a physical shield. Also possesses distensible property

Question 24

Reversible conversion of one type of epithelial cells into another
An adaptive response to stress , chronic inflammation etc.
The most common epithelial metaplasia is columnar to squamous

Answer 24

Epithelial Metaplasia

Question 25

Gland that

remain connected to the surface by an excretory duct that transports the secretory product to the outside.

Answer 25

Exocrine glands

Question 26

Gland that

lack an excretory duct and their product is released into blood circulation

Answer 26

Endocrine glands