Characteristics of Epithelial Tissues III

Question 1

True or False:

Microvilli are motile.

Answer 1

False –> microvilli are non-motile

Question 2

What is the primary function of microvilli?

Answer 2

Primarily function is to increase the surface area of absorption.

Question 3

Name two areas in the body that you would find simple columnar epithelium with microvilli on the apical surface.

Answer 3

Intestinal epithelium and parts of the renal tubule.

Question 4

What are microvilli?

Answer 4

Microvilli are finger-like projections of the apical cell membrane supported by cross-linked actin bundles.

Question 5

What protein regulates the assembly of the actin filaments at the barbed ends?

Answer 5

Formin

Question 6

What two proteins cross-link the actin filaments in the core of the microvilli?

Answer 6

Villin and Fimbrin

Question 7

True of False:

Stereocilia are non-motile.

Answer 7

True

Question 8

How many protofilaments make-up the alpha tubule of a doublet?

Answer 8

13 protofilaments

Question 9

How many protofilaments make-up the beta tubule of a doublet?

Answer 9

10-11 protofilaments

Question 10

What transport protein gives cilia the ability to move?

Answer 10

Dynein

Question 11

What is the principal functions of the inner sheath and radial spokes of the axoneme?

Answer 11

They stabilize the axonemal bending.

Question 12

Is the B tubule a complete protofilament.

Answer 12

No

Question 13

How many protofilaments does each microtubule have?

Answer 13

13 protofilaments each