Unit 1 - A & P Module - Different Types of Cellular Communication

Question 1

Most long-distance communication between cells is accomplished via chemicals known as autocrines and paracrines. True or false?

Answer 1

True

Question 2

Autocrine signals __________.

Answer 2

act on the same cell that secreted them

Question 3

__________ are substances that are released from neurosecretory cells but travel through the bloodstream to target tissues.

Answer 3

Neurohormones

Question 4

Put the following events in the correct order:

a. Chemical messenger binds to receptor on the target cell.
b. A response occurs in the target cell.
c. Chemical messenger is secreted.
d. Signal transduction occurs in the target cell.

Answer 4

c, a, d, b

Question 5

Due to the similarities in chemical structure of dopamine, epinephrine, and norepinephrine, they can all be classified as __________.

Answer 5

amines and catecholamines

Question 6

When calcium enters a cell through ligand-gated channels, it may __________.

Answer 6

interact with proteins, induce muscle contractions, or act as a second messenger

Question 7

The fastest-acting membrane-bound receptors are __________.

Answer 7

proteins that contain both the receptor and the channel

Question 8

A cell that responds to a chemical messenger secreted by another cell is called the ____________.

Answer 8

target cell

Question 9

__________ are ligands that bind to receptors but do not produce a response.

Answer 9

Antagonists

Question 10

Paracrines and autocrines ________.

Answer 10

both depend on diffusion as a means to reach their target cell and differ primarily in their targets

Question 11

Steroid hormones are __________.

Answer 11

membrane permeable and synthesized on demand from cholesterol in the smooth endoplasmic reticulum and released immediately

Question 12

The term used to describe the minimum stimulus to trigger a response in a feedback loop is __________.

Answer 12

threshold

Question 13

Responses to chemical messengers produced by target cells vary in magnitude according to __________.

Answer 13

number of receptors present for the chemical messenger to bind, the volume of messenger present, and the affinity of the receptor to bind with the messenger

Question 14

Which of the following statements about G proteins are true?

Answer 14

All answers are true.

1. G proteins can be stimulatory or inhibitory
2. Alpha subunits can interact with effector proteins
3. Beta-gamma subunits can interact with effector proteins
4. G proteins are also enzymes