Histology of the Epithelium

Question 1

Epithelium that changes its appearance based on the presence of fluid is called?

Answer 1

Transitional Epithelium

Question 2

Describe the term pseudostratified

Answer 2

Epithelium in which all cells touch the basal membrane, but not all reach the apical surface/lumen.

Question 3

Multiple layers of epithelial cells is described as…

Answer 3

Stratified

Question 4

One layer of epithelial cells is described as…

Answer 4

Simple

Question 5

An epithelial cell that is taller than it is wide is described as…

Answer 5

Columnar

Question 6

An epithelial cell that is as tall as it is wide is described as…

Answer 6

Cuboidal

Question 7

A flat epithelial cell is described as…

Answer 7

Squamous

Question 8

Describe a Goblet Cell.

Answer 8

A specialized unicellular exocrine gland that excretes mucin onto the surface of the epithelium in a mechanism similar to an apocrine gland. Exist in the gut and respiratory tract.

Question 9

How does an apocrine gland excrete products

Answer 9

The product pinches off the apical surface (top) directly into the lumen.

Question 10

This gland excretes products via apoptosis once the cell has fully matured.

Answer 10

Holocrine gland

Question 11

Describe the mechanism of a merocrine gland.

Answer 11

Products are excreted via membrane-bound vesicles.

Question 12

Name the three types of exocrine glands.

Answer 12

Merocrine, Holocrine, Aprocine

Question 13

What is the difference between exocrine and endocrine glands?

Answer 13

Exocrine glands release products via a surface duct. Endocrine glands lack a surface duck and release products into the connective tissue to be taken up into the blood stream.

Question 14

Desmolgeins make up what structure(s)?

Answer 14

Desmosomes/Macula Adherens/Spot Junctions

Question 15

What structures make up tight junctions?

Answer 15

claudin and occludin

Question 16

What proteins makes up zonula adherens?

Answer 16

e-cadherin cantenin complex

Question 17

What is connexin?

Answer 17

The structure that makes up gap junctions.

Question 18

What is the function of Zonula Occludens?

Answer 18

A tight junction that forms a seal between cells and the lumen, thus restricting fluid movement between cells.

Question 19

In which domain are gap junctions are present? Why?

Answer 19

Lateral Domain to enable cell-to-cell communication

Question 20

Name the anchoring junctions of epithelial cells.

Answer 20

Zonula Adherens & Macula Adherens

Question 21

What structure is impacted by cholera toxins, thus causing diarrhea and dehydration?

Answer 21

Zonula Occludens

Question 22

This specialized structure is composed of microtubule bundles in a 9+2 arrangement. They extend from the plasma membrane and assist with the movement of substances.

Answer 22

Motile Cilia

Question 23

This specialize structure is made of long bundled actin. They serve as mechanoreceptors in the inner ear and increase absorption in the epidyimus.

Answer 23

Stereocilia

Question 24

These specialized extensions are made of actin and serve to increase the surface area of epithelial cells. They are most commonly found in the GI tract and nephron tubules.

Answer 24

Microvilli

Question 25

What structures are found in the apical domain of epithelial cells?

Answer 25

Microvilli, Cilia, Stereocilia

Question 26

What are the six characteristics of epithelial tissues?

Answer 26

Derived from all 3 germ layers, Cover all spaces, Regenerative, Undergo Mitosis, Densely Packed - Little interstitial space, Polar - Top, Bottom, Sides