4.03 Epithelium

Question 1

Variation in morphology in epithelia depends on:

Answer 1

function and position in the body

Question 2

Seven functions of epithelium

Answer 2

protection
absorption
secretion
excretion
sensory receptors
filtration
lubrication

Question 3

T/F. The epithelium is derived solely from the ectoderm.

Answer 3

False. It is derived from all three germ layers.

Question 4

T/F. The epidermis is derived solely from the ectoderm.

Answer 4

True.

Question 5

T/F. Epithelia are vascular, because we bleed when we are cut.

Answer 5

False.

Question 6

What is the purpose of microvilli?

Answer 6

To increase surface area for absorption

Question 7

What is the difference between cilia and stereocilia?

Answer 7

The former is motile, while the latter is nonmotile

Question 8

These operate as communication channels governing functions such as growth and cell division

Answer 8

cell junction

Question 9

Three types of cell junctions

Answer 9

Tight junctions or zonula occludens
Adhering junctions or desmosomes, zonula adherens
Communication junctions or nexus junctions

Question 10

What is the purpose of tight junctions?

Answer 10

block passage of molecules between adjacent cells

Question 11

Purpose of adhering junctions

Answer 11

strong attachment in between cells, link the intermediate filaments to form robust structural framework for the entire epithelium

Question 12

Purpose of communication junctions

Answer 12

provide a conduit for the passage of small molecules directly between adjacent cells; signaling; coordinate and synchronize functions of the epithelium

Question 13

Kind of epithelium present in surfaces where the exchange of substances occurs

Answer 13

simple squamous

Question 14

Kind of epithelium lining the intestines and the gall bladder

Answer 14

Simple columnar

Question 15

Surface epithelium in tubules of kidneys, covering of the ovary, choroid plexus, capsule of lens.

Answer 15

Simple cuboidal

Question 16

When the epithelium is keratinized, what happens to the cells?

Answer 16

The lose their nucleus and organelles

Question 17

Kind of epithelium where all the cells are attached to the basal lamina, but not all of them reach the level of the lumen

Answer 17

pseudostratified columnar

Question 18

Intermediate or transitional from between stratified squamous and columnar epithelia; this is characteristic of which organ system? hence what is it called?

Answer 18

transitional epithelium; urinary; uroepithelium

Question 19

Epithelium composed of cells specialized in producing a secretion that differs in composition from blood or from intracellular fluid

Answer 19

Glandular epithelium

Question 20

Glands that release their products into blood or lymph system for transport to target cells in another part of the body

Answer 20

Endocrine

Question 21

Glands that take advantage of the principle of diffusion

Answer 21

Paracrine

Question 22

Gland whose secretions is NOT discharged from the cell producing it

Answer 22

Accrine gland

Question 23

1. secretion released through the cell membrane with the cell remaining intact
2. involves loss of a part of the apical cytoplasm
3. release of the whole cell into the excretory ducts

Answer 23

1. merocrine
2. apocrine
3. holocrine

Question 24

1. secretion is thin and watery
2. secretion is thick and viscous
3. mixture of 1 and 2
4. secretion of cells

Answer 24

1. serous
2. mucous
3. mixed
4. cytogenic

Question 25

Morphological classification of epithelium that cannot be found in humans

Answer 25

simple alveolar

Question 26

morphological classification of glands in the eyelids

Answer 26

simple branched alveolar

Question 27

morphological classification of glands in the intestines

Answer 27

simple tubular

Question 28

morphological classification of glands in the oral cavity, cardiac glands in the stomach, Brunner’s glands, bulbourethral glands

Answer 28

compound tubular

Question 29

morphological classification of glands in the pancreas, esophageal glands, glands in the respiratory passages, mammary glands

Answer 29

compound tubule-alveolar