Briefly discuss cell to cell adhesions.

Question 1

Question 1: What are the three different means by which cells are linked together to form tissues and organs?

A. Enzymatic reactions, cellular junctions, and the extracellular matrix
B. Cell adhesion molecules, extracellular matrix, and specialized cell junctions
C. Cytoskeleton, receptor proteins, and gap junctions
D. Fibrous structural proteins, elastin, and proteoglycans

Answer 1

B. Cell adhesion molecules, extracellular matrix, and specialized cell junctions

Question 2

Question 2: Which macromolecule within the extracellular matrix provides tensile strength or resistance to longitudinal stress?

A. Adhesive glycoproteins
B. Collagen
C. Elastin
D. Proteoglycans

Answer 2

B. Collagen

Question 3

Question 3: What is the role of fibronectin in the extracellular matrix?

A. It forms cable-like fibers for tensile strength.
B. It provides resistance to longitudinal stress.
C. It promotes cell adhesion and anchorage.
D. It is responsible for the passive recoil of the lungs.

Answer 3

C. It promotes cell adhesion and anchorage.

Question 4

Question 4: Which type of cell junction is a barrier to diffusion, preventing the movement of substances through transport proteins in the plasma membrane?

A. Tight junctions
B. Adherens junctions
C. Desmosomes
D. Gap junctions

Answer 4

A. Tight junctions

Question 5

Question 5: What is the function of gap junctions?

A. They provide a tight seal between adjacent cells.
B. They offer strong mechanical attachments.
C. They allow small ions and molecules to pass directly from one cell to another.
D. They maintain polarity across the apical and basal aspects of individual epithelial cells.

Answer 5

C. They allow small ions and molecules to pass directly from one cell to another.

Question 6

Question 6: How does gating regulate the permeability of the junctional complex in response to injured cells?

A. It increases the permeability of the junctional complex.
B. It decreases the permeability of the junctional complex.
C. It has no effect on the permeability of the junctional complex.
D. It depends on the type of junctional complex.

Answer 6

B. It decreases the permeability of the junctional complex.