Epithelial tissues

Question 1

What are the 2 major categories of epithelia?

Answer 1

Membranous, glandular

Question 2

What are 2 ways in which membranous epithelia are further described?

Answer 2

1. Number of layers (simple, stratified, pseudostratified)

2. Cell shape (squamous, cuboidal, columnar)

Question 3

What is a simple epithelium?

Answer 3

ONE cell layer thick, resting on a basement membrane. Mononucleated.

Question 4

Describe simple squamous epithelia.

Answer 4

Single layer of cells that are much flatter than they are tall.

Question 5

What is mesothelium?

Answer 5

Simple squamous epithelium that covers the outer surface of organs.

Question 6

What cell type makes up the amnion?

Answer 6

Simple cuboidal

Question 7

What do intestinal goblet cells do?

Answer 7

Secrete mucin

Question 8

What are the primary cells of the lining of the gut?

Answer 8

Simple columnar

Question 9

What are stratified epithelia and how are they named?

Answer 9

Two or more layers of cells, with the deep layers usually different than the surface. **Named for the most superficial layer!

Question 10

Where do stratified squamous NONkeratinized epithelia exist? What are some examples?

Answer 10

Moist surfaces of the body that require special protection against abrasive forces. e.g. lining of esophagus, parts of oral cavity, epiglottis, vagina, etc.

Question 11

How do cells move through the stratified squamous epithelium?

Answer 11

Cells are generated in the basal layer of the epithelium and become flattened as they are pushed toward the luminal surface by cells below. They change from columnar basal to squamous.

Question 12

Do keratinized cells have nuclei?

Answer 12

No! Replaced with keratin

Question 13

What cells line glands and ducts?

Answer 13

Stratified cuboidal epithelium

Question 14

What cell type defines respiratory epithelium?

Answer 14

Ciliated pseudostratified epithelium

Question 15

What makes something pseudostratified?

Answer 15

All cells touch/reside on the basement membrane but reach different heights to that they appear almost multi-layered.

Question 16

Where do you find transitional epithelia?

Answer 16

Bladder

Question 17

What cell type is characteristic of transitional epithelia? What defines it?

Answer 17

Binucleated umbrella cells, defined by a chance in appearance when stretched; usually stratified.

Question 18

What is adluminal?

Answer 18

Toward the lumen

Question 19

What is abluminal?

Answer 19

Away from the luminal (attached to the underlying surface)

B = base!

Question 20

What is the basement membrane?

Answer 20

Any interface of epithelia and connective tissue. Connected via integrins

Question 21

What are 5 common characteristics of epithelia?

Answer 21

1. Form surface-parallel sheets
2. Sheet and individual cells are polarized
3. Cells are tightly apposed to each other
4. Avascular
5. Dynamic

Question 22

What is metaplasia?

Answer 22

Epithelia produce progeny that are specialized, but not what is normally found in that location.

Question 23

What is dysplasia?

Answer 23

Abnormal differentiation results in altered size, shape, and organization of mature cells; may preclude neoplasia.

Question 24

What is neoplasia?

Answer 24

Cancer. Occurs if cell proliferation is not controlled and results in an abnormal mass of proliferating cells ( a tumor). Benign (non-cancerous, localized) vs malignant (cancerous, metastatic).

Question 25

What type of fiber can be tissue-specific?

Answer 25

Intermediate fibers

Question 26

What germ layer makes up the CNS?

Answer 26

Ectoderm

Question 27

To transport material across and epithelium, cells use ______.

Answer 27

Caveolae

Question 28

What are basal enfoldings/striations?

Answer 28

Epithelial cells that actively transport something (e.g. sodium) outside of a cell WITHOUT processing (transcellular transport!)