Epithelium

Question 1

What separates epithelial tissue from underlying connective tissue?

Answer 1

Basement membrane

Question 2

What is a consequence of losing basement membrane integrity?

Answer 2

Longer healing time

Question 3

What does the term pseudostratified mean?

Answer 3

While all cells rest on a basement membrane, not all reach the free surface or the lumen

Question 4

Where is simple squamous epithelium found?

Answer 4

Serosal surfaces (outside surface of organs)

Question 5

What is a potential space?

Answer 5

A space that doesn’t really exist, but will become a space if it fills with fluid in times of disease

Question 6

Where is keratinizing stratified squamous epithelium found?

Answer 6

Skin (epidermis) - ONLY LOCATION

Question 7

Why is some epithelium labeled as transitional?

Answer 7

The structure is an intermediate between stratified squamous and columnar

Question 8

Where is transitional epithelium found?

Answer 8

Urinary tract - ONLY LOCATION

Question 9

Cilia can be present in epithelium (ciliated pseudostratified columnar). What is cilia important for?

Answer 9

Movement of fluid - unidirectional

Question 10

Where is ciliated pseudostratified columnar epithelium found?

Answer 10

Trachea, bronchial tree, and efferent ductules of epididymis

Question 11

What are glandular epithelial cells?

Answer 11

Epi cells specialized for secretion

Question 12

How does endocrine glandular epithelium secrete molecules?

Answer 12

Secretes them into the surrounding CT

Question 13

Hormones are released from endocrine glandular epithelium. What happens after the hormone is secreted into the surround CT?

Answer 13

The molecules diffuse into the blood vessels and are carried by the blood to the site of action.

Question 14

How does exocrine glandular epithelium secrete molecules?

Answer 14

Either directly onto a free epithelial surface or through a hollow duct to the site of action.

Question 15

What are the 3 modes of secretion for exocrine glandular epithelium?

Answer 15

Merocrine, Apocrine, and Holocrine

Question 16

Serous membranes line serosal cavities (mesothelium), do not contain glandular epi, and are covered by a watery fluid. What does the serous membrane include?

Answer 16

Mesothelium and underlying CT

Question 17

What is the stroma of epi tissue?

Answer 17

The supporting tissue or matrix of an organ (e.g. CT)

Question 18

What is the parenchyma of epi tissue?

Answer 18

Essential or functional elements of an organ (e.g. secretory unit, duct)

Question 19

Is disease of the stroma or disease of the parenchyma in epi tissue more likely to spread to other organs?

Answer 19

Stroma, since the tissue connects. Parenchyma might only affect the organ it’s with.

Question 20

What is the difference between mucus and serous?

Answer 20

Mucus is high in polysaccharides but low in protein.

Serous is low in polysaccharides but high in protein.

Question 21

What is a secretory unit?

Answer 21

The basic cluster of secretory cells in the gland

Question 22

What is the function of mucous glands?

Answer 22

Protection, capturing particles, and lubrication

Question 23

What is the function of serous secretory glands?

Answer 23

Produce enzymes and is antibacterial. Aids in protein function

Question 24

On the apical surface of epithelium there are microvilli, which are finger-like projections. What is the main structural component of microvilli?

Answer 24

Actin microfilaments

Question 25

What is the function of microvilli located on the epi apical surface?

Answer 25

Increase SA to facilitate absorption (e.g. brush border in intestine and nephron-view of many microvilli with LM)

Question 26

What are the microvilli connected to on the epi tissue?

Answer 26

The cytoskeleton (AKA terminal web)

Question 27

In addition to microvilli, there is also a presence of stereocilia on the apical surface of epi. What is the structural element of stereocilia?

Answer 27

Actin

Question 28

What is the classic place we will find stereocilia?

Answer 28

The epididymis. Also on sensory cells of inner ear

Question 29

What is the motor protein that aids in cilia motility?

Answer 29

Dyein protein

Question 30

What is the function of motile cilia?

Answer 30

Move fluid in one direction. It's unidirectional

Question 31

What is the structural unit of cilia?

Answer 31

Tubulin

Question 32

What are the two main functions of primary, immotile cilia?

Answer 32

Chemosensory and mechanosensory

Question 33

What are some functions of the basement membrane?

Answer 33

Barrier for epi, anchor for epi to the supporting stroma, and controls growth and differentiation

Question 34

To see the BM with LM we use H&E stain. What of the BM is visible using LM?

Answer 34

Only a single layer is visible in the trachea and occasionally can be seen in the ureters and urinary bladder

Question 35

If we use TEM to visualize the BM, what will we be able to see?

Answer 35

Three layers: lamina lucida, lamina densa, and lamina fibroreticularis

Question 36

On what surfaces of the cell will cellular adhesions form?

Answer 36

Basal and lateral portions

Question 37

What is purpose of having cellular adhesions?

Answer 37

To anchor cells, to compartmentalize the apex/lumen from the base, to stabilize the layer, and to provide communication between cells in the layer.

Question 38

What, specifically, about cellular adhesions helps to anchor the cell? What does this job?

Answer 38

Hemidesmosomes and focal adhesions

Question 39

What, specifically, in the cellular adhesion compartmentalizes the apex and lumen from the base?

Answer 39

Tight junction (zonula occludens)

Question 40

What provides communication between cells in the same epi layer?

Answer 40

Gap junctions