Ch. 17 Functional Organization of Endocrine System

Question 1

When comparing the endocrine system and the nervous system, the endocrine system generally:

1. is faster-acing than the nervous system
2. produces effects that are of shorter duration
3. uses blood-borne chemical messengers
4. produces more localized effects
5. relies less on chemical messengers

Answer 1

3. uses blood-borne chemical messengers

Question 2

Given this list of molecule types, which could be hormone molecules?

1. nucleic acid derivatives
2. fatty acid derivatives
3. peptides
4. proteins
5. phospholipids

Answer 2

2. fatty acid derivatives
3. peptides
4. proteins

Question 3

*** Which of these can regulate the secretion of a hormone from an endocrine tissue?

1. other hormones
2. negative-feedback mechanisms
3. humoral substances in blood
4. the nervous system
5. all of the above

Answer 3

5. all of the above
6. other hormones
7. negative-feedback mechanisms
8. humoral substances in blood
9. the nervous system

Question 4

Hormones are released into the blood

1. at relatively constant levels
2. in large amounts in response to a stimulus
3. in an episodic fashion
4. all of these are correct

Answer 4

4. all of these are correct
5. at relatively constant levels
6. in large amounts in response to a stimulus
7. in an episodic fashion

Question 5

Lipid-soluble hormones readily diffuse through capillary walls, whereas water-soluble hormones, such as proteins, must

1. pass through capillary endothelium
2. pass through capillary cells
3. be moved out of the capillary by active transport
4. remain in the blood
5. be broken down to amino acids before leaving the blood

Answer 5

1. pass through capillary endothelium

Question 6

Concerning the half-life of hormones

1. lipid-soluble hormones generally have a longer half life
2. hormones with a shorter half-life regulate activities with a slow onset and long duration
3. hormones with a shorter half-life are maintained at more constant levels in the blood
4. lipid-soluble hormones are degraded rapidly by enzymes in the circulatory system

Answer 6

1. lipid-soluble hormones generally have a longer half life

Question 7

Given these observations, which of these observation can be explained by the characteristics of hormone receptors?

1. a hormone affects only a specific tissue (not all tissues)
2. a tissue can respond to more than one hormone
3. some tissues respond rapidly to a hormone, whereas others take many hours to respond

Answer 7

1. a hormone affects only a specific tissue (not all tissues)
2. a tissue can respond to more than one hormone
3. some tissues respond rapidly to a hormone, whereas others take many hours to respond

Question 8

Which of these is NOT a means by which hormones are eliminated from the circulatory system?

1. excreted into urine or bile
2. bound to binding proteins
3. enzymatically degraded in the blood
4. actively transported into cells
5. conjugated with sulfate or glucuronic acid

Answer 8

2. bound to binding proteins

Question 9

*** Down-regulation

1. produces a decrease in the number of receptors in the target cell
2. produces an increase in target cells’ sensitivity to a hormone
3. is found in target cells that respond to hormones that are maintained at constant levels
4. occurs partly because of an increase in receptor synthesis by the target cell
5. all of these are correct

Answer 9

1. produces a decrease in the number of receptors in the target cell

Question 10

*** Activated G proteins can

1. cause ion channels to open or close
2. activate adenylate cyclase
3. inhibit the synthesis of cAMP
4. alter the activity of IP
5. all of these are correct

Answer 10

5. all of these are correct
6. cause ion channels to open or close
7. activate adenylate cyclase
8. inhibit the synthesis of cAMP
9. alter the activity of IP

Question 11

Given these events, list the order in which the events occur after a hormone binds to a membrane bound receptor.

1. GTP is converted to GDP
2. the subunit separates from the B and y units
3. GDP is released from the a subunit

Answer 11

3. GDP is released from the a subunit
4. GTP is converted to GDP
5. the subunit separates from the B and y units

Question 12

Which of these can limit a cell’s response to a hormone?

1. phosphodiesterase
2. coverting GTP to GDP
3. decreasing the number of receptors
4. blocking binding sites
5. all of these are correct

Answer 12

5. all of these are correct
6. phosphodiesterase
7. coverting GTP to GDP
8. decreasing the number of receptors
9. blocking binding sites

Question 13

Given these events, choose the arrangement that lists the evens in the order they occur after a hormone binds to a receptor on a smooth muscle cell.

1. the a subunit of a G protein interacts with Ca2+ channels
2. calcium ion diffuse into the cell
3. the a subunit of a G protein is activated

Answer 13

3. the a subunit of a G protein is activated
4. the a subunit of a G protein interacts with Ca2+ channels
5. calcium ion diffuse into the cell

Question 14

*** Given these events, choose the arrangement that lists the events in the order they occur after a hormone binds to a receptor.

1. cAMP is synthesized
2. the a subunit of G protein is activated
3. phosphodiesterase breaks down cAMP

Answer 14

2. the a subunit of G protein is activated
3. cAMP is synthesized
4. phosphodiesterase breaks down cAMP

Question 15

When a hormone binds to a nuclear receptor,

1. DNA produces mRNA
2. G proteins are activated
3. the hormone-receptor complex causes ion channels to open or close
4. the cell’s response is faster than when a hormone binds to a membrane bound receptor
5. the hormone is usually a large, water-soluble molecule

Answer 15

1. DNA produces mRNA

Question 16

Given these events, which of these events can occur when a hormone binds to a nuclear hormone receptor?

1. activation of cAMP
2. activation of genes
3. alteration of enzyme activity

Answer 16

2. activation of genes

3. alteration of enzyme activity