H/E Lecture 12

Question 1

What are the two types of transport between a lumen and CT?

Answer 1

Paracellular: between cells, passive process, small solutes, water, ions
Intracellular: through the cell, active

Question 2

What are the proteins used in tight junctions and what are they called when they join between cells?

Answer 2

occludin and claudin

They meet in ICS to form junctional strands

Question 3

What is the junctional complex?

Answer 3

Orderly series of Tight Junctions, Adherens Junctions, and Desmosomes

Question 4

What are terminal bars?

Answer 4

Same as junctional complexes. They appear as bars or dots along the luminal surface of cells.

Question 5

Which of the adhesion-type junctions are unique to epithelium?

Answer 5

Hemidesmosomes

Question 6

Which of the non-adhesion junctions is unique to epithelium?

Answer 6

Tight junctions. Gap junctions are in other cells as well.

Question 7

What are the three cellular features that increase the surface area of a cell?

Answer 7

Lateral folds: hold cells together, aid trans-cellular transportation
Basal folds: for active transport, many mitochondria also present
Microvilli: for absorption and secretion, includes glycocalyx

Question 8

What makes up microvilli?

Answer 8

Actin filaments through the core and a terminal web in the cell.

Question 9

Describe cilia.

Answer 9

9+2 arrangement of microtubule doublets in cilium body, 9 triplets in the basal body, synchronized movement

Question 10

What are the atypical forms of cilia and microvilli?

Answer 10

Cilia: single long cilia are kinocilium in the inner ear, and flagellum in sperm
Microvilli: Sterocilia in male reproductive tract