Chapter 4 - Epithelial Tissues

Question 1

What are the major transmembrane link proteins in tight junctions?

Answer 1

occludins, claudins, and ZO proteins

Question 2

What are the major transmembrane link proteins in adherens juctions?

Answer 2

e-cadherin and catenin complexes

Question 3

What are the major transmembrane link proteins in desmosomes?

Answer 3

cadherin family proteins

Question 4

What are the major transmembrane link proteins in hemidesmosomes?

Answer 4

integrins

Question 5

What are the major transmembrane link proteins in gap junctions?

Answer 5

connexin

Question 6

What are the cytoskeletal components present in tight junctions?

Answer 6

actin filaments

Question 7

What are the cytoskeletal components present in adherens junctions?

Answer 7

actin filaments

Question 8

What are the cytoskeletal components present in tight junctions?

Answer 8

actin filaments

Question 9

What are the cytoskeletal components present in desmosomes?

Answer 9

intermediate filaments (keratins)

Question 10

What are the cytoskeletal components present in hemidesmosomes?

Answer 10

intermediate filaments

Question 11

What are the cytoskeletal components present in gap junctions?

Answer 11

none

Question 12

What are the major functions of a tight junction?

Answer 12

1- seals adjacent cells to one another
2- controls the passage of molecules between cells
3- separates apical and basolateral membrane domains

Question 13

What are the major functions of an adherens junction?

Answer 13

1- provides points linking the cytoskeletons of adjacent cells
2- strengthens and stabilizes nearby tight junctions

Question 14

What are the major functions of a desmosome?

Answer 14

provides points of strong intermediate filament coupling between adjacent cells, strengthening the tissue

Question 15

What are the major functions of hemidesmosomes?

Answer 15

anchors cytoskeleton to basal lamina

Question 16

What are the major functions of gap junctions?

Answer 16

allows the direct transfer of small molecules and ions from one cell to another

Question 17

What are the main functions of simple squamous epithelia?

Answer 17

1- Mesothelium: facilitates the movement of the viscera
2- Mesothelium: secretes biologically active molecules
3- Mesothelium and endothelium: active transport by pinocytosis

Question 18

What are the main functions of simple cuboidal epithelia?

Answer 18

1- Covering
2- Secretion

Question 19

What are the functions of simple columnar epithelia?

Answer 19

1- Protection
2- Lubrication
3- Absorption
4- Secretion