Epithelium

Question 1

What type of junction prevents passage of substances between the cells?

Answer 1

Occluding (tight) junctions

Question 2

What is the main function of stratified squamous epithelium?

Answer 2

Protection of the skin under mechanical and thermal stress, as well as desiccation.

Question 3

Where can simple squamous epithelium commonly be found?

Answer 3

Alveoli, blood vessels (endothelium), body cavities (mesothelioma), Bowman’s capsule (kidney).

Question 4

What are two main functions of simple squamous epithelium?

Answer 4

• Easy gas exchange
• Fluid circulation (i.e. thin layer of cells)

Question 5

Where is simple cuboidal epithelium commonly found?

Answer 5

Glands, small ducts (exocrine glands), surface of ovary.

Question 6

What are two main functions of simple cuboidal epithelium?

Answer 6

Absorption and secretion.

Question 7

Where can stereo cilia be found?

Answer 7

Ear hairs (immotile microvilli).

Question 8

Where can microvilli be found?

Answer 8

Small intestine (increases surface area for absorption).

Question 9

Where can cilia be found?

Answer 9

Respiratory system and GI system (trap bacteria, and move mucus & fluid).

Question 10

What 3 structures project from the plasma membrane and are 1st to contact harmful substances?

Answer 10

Cilia, microvilli, and stereo cilia.

Question 11

The apical surface always faces the ____.

Answer 11

Lumen.

Question 12

What are the four types of cell morphology?

Answer 12

Squamous, cuboidal, columnar, and transitional.

Question 13

What are the two main classification criteria for epithelium?

Answer 13

Cell number & cell morphology.

Question 14

The epithelium arises from which 3 embryonic layers?

Answer 14

Ectoderm, mesoderm, and endoderm.

Question 15

Where do mucous glands come from?

Answer 15

Salivary glands, surface cells of stomach.

Question 16

Where do serous glands come from?

Answer 16

The pancreas.

Question 17

What are the two materials of secretion we have learned about?

Answer 17

Serous and mucous.

Question 18

Epithelium lies on what membrane?

Answer 18

Basal membrane.

Question 19

The 3 embryonic origins are closely _____ & _____ to one another.

Answer 19

Apposed & adherent.

Question 20

What junction attaches basal surface of epithelial cells to Basal membrane?

Answer 20

Hemidesmosomes (anchoring junction).

Question 21

Where can simple columnar epithelium be found?

Answer 21

Small intestines, colon, stomach, gastric glands.

Question 22

Where can transitional epithelium be found?

Answer 22

URINARY TRACT ONLY, bladder, urethra, ureters.

Question 23

What is the main function of stratified cuboidal epithelium?

Answer 23

Barrier (NOT COMMON).

Question 24

Which epithelium can be between simple and cuboidal stratified epithelium?

Answer 24

Transitional epithelium.

Question 25

What is the main function of pseudostratified columnar?

Answer 25

Secretion and absorption.

Question 26

What is the embryonic origin of mesoderm?

Answer 26

Mesothelium and Endothelium.

Question 27

What kind of epithelia would you find lining body cavities?

Answer 27

Mesothelium (simple squamous).

Question 28

What kind of epithelia would you find in blood vessels?

Answer 28

Endothelium (simple squamous epithelia).

Question 29

What is found in the respiratory system & GI system and can move mucus and fluid?

Answer 29

Cilia.

Question 30

What is found in the small intestine and increases surface area for absorption?

Answer 30

Microvilli.

Question 31

Where do both serous and mucosa secretion get secreted from?

Answer 31

Submandibular glands.

Question 32

Where does serous secretion come from?

Answer 32

The pancreas.

Question 33

What are the two materials of secretion?

Answer 33

Serous (low glycoprotein) and Mucus (glycoprotein, viscous).

Question 34

Where does mucus secrete from?

Answer 34

Salivary glands and surface cells of the stomach.

Question 35

What type of gland is a cluster of glandular cells considered to be?

Answer 35

A multicellular gland.

Question 36

The thymus, thyroid gland, and pancreas are all considered to be what?

Answer 36

Endocrine glands (organs).

Question 37

What type of gland is individual exocrine cells among other nonsecretory cells considered to be?

Answer 37

A unicellular gland.

Question 38

What type of secretion is characterized by product-filled apical areas of cells being extruded?

Answer 38

Apocrine secretion.

Question 39

What type of secretion involves terminally differentiated cells undergoing complete disruption?

Answer 39

Holocrine secretion.

Question 40

What are the three types of exocrine secretion?

Answer 40

Merocrine secretion, Holocrine secretion, and Apocrine secretion.

Question 41

What type of secretion involves exocytosis of membrane-bound vesicles/secretory granules?

Answer 41

Merocrine secretion.

Question 42

How does paracrine secretion release its products?

Answer 42

Individual cells secrete a substance that doesn't reach the bloodstream but affects other cells within the same epithelium.

Question 43

What is the 3rd main type of secretion besides endocrine and exocrine?

Answer 43

Paracrine.

Question 44

Which gland does NOT have direct contact with apical surface, nor a duct system?

Answer 44

Endocrine gland.

Question 45

Which gland has direct contact with apical surface via ducts?

Answer 45

Exocrine gland.

Question 46

Where/how is glandular epithelium formed?

Answer 46

Derives from a covering epithelium and gains glandular function.

Question 47

Epithelium is avascular tissue but needs an underlying or adjacent ______ conjunctive tissue.

Answer 47

Vascularized.

Question 48

Is epithelium capable of self renewal?

Answer 48

Yes.

Question 49

What is glandular epithelium?

Answer 49

Cells arising from epithelium which have secretory function.

Question 50

What type of junction allows passage of small molecules between adjacent cells?

Answer 50

Gap (communicating junctions).

Question 51

What type of junction seals gap between epithelial cells?

Answer 51

Occluding (tight).

Question 52

What type of junction connects cell-cell & cell-ECM?

Answer 52

Zonula Adheren (anchoring junction).

Question 53

What junction connects cytoskeleton to inner cytoplasmic domain?

Answer 53

Desmosomes (adherent anchoring junction).

Question 54

What are epithelial cells?

Answer 54

Cells that are closely apposed and adherent to one another with specialized junctions.

Question 55

What are cell junctions?

Answer 55

A communication between cells, creating mechanical links, receptor-ligand interactions.

Question 56

What is simple epithelium?

Answer 56

Epithelium that is only one cell layer thick.

Question 57

What is epithelium?

Answer 57

An avascular tissue composed of cells covering the surface of the body and organs.

Question 58

Examples of transient cells?

Answer 58

Neutrophils, eosinophils, basophils, lymphocytes, monocytes.

Question 59

Where can you find keratinized and non-keratinized epithelium?

Answer 59

Stratified squamous.

Question 60

Examples of non-keratinized epithelium?

Answer 60

Skin, esophagus.

Question 61

Non-keratinized epithelium has?

Answer 61

A nucleus.

Question 62

Example of keratinized epithelium?

Answer 62

Skin, hair, nails.

Question 63

Keratinized epithelium has?

Answer 63

No nucleus.

Question 64

What cytoskeleton components can produce apical projections such as cilia, microvilli, and stereo cilia?

Answer 64

Microtubules and actin filament.

Question 65

What are the two kinds of proteins microtubules have and what directions do they travel in?

Answer 65

Kinesin - anterograde (- to +) and Dyneins - retrograde (+ to -).

Question 66

Are microtubules polar or non-polar?

Answer 66

Polar.

Question 67

What are microtubules composed of?

Answer 67

Tubulin dimers.