Week 12: Endocrine

Question 1

Hormones are transported primarily via what?

Answer 1

The bloodstream

Question 2

Where do hormones bind?

Answer 2

Receptors on target cells

Question 3

What do endocrine glands do?

Answer 3

They secrete their hormones directly into the surrounding fluid.

Question 4

Describe the three types of stimuli for hormone releases?

Answer 4

1. Neural: Parasympathetic NS (ACh/Insulin), sympathetic NS (ACh, epinephrine), posterior pituitary hormones
2. Hormonal: Hypothalamic/anterior pituitary pathways
3. Humora: Ions/molecules in the environment, high glucose/insulin, low glucose/glucagon

Question 5

Hormones are released into the blood and only travel to target cells in the body. True or false?

Answer 5

False. They travel to all cells, but only target cells (with a specific hormone receptor) respond.

Question 6

What two things dictate the response of a target cell?

Answer 6

1. The specific type of receptor
2. The specific intracellular signaling pathways

Question 7

Response levels depend on what?

Answer 7

The level of the hormone

(Response decreases as hormone is cleared from body)

Question 8

Where is the receptor for steroids?

Answer 8

The cytoplasm or nucleus

Question 9

Where is the receptor for proteins and amine?

Answer 9

The cell membrane

Question 10

What kind of signaling pathways are initiated by steroids?

Answer 10

Activation of genes for transcription and translation

Question 11

What kind of signaling pathways are initiated by proteins and amines?

Answer 11

Activation of second messenger systems

Question 12

What is the half-life length of steroids, proteins, and amines?

Answer 12

Steroids: Long
Proteins: Short
Amines: Short

Question 13

What is the stimuli for cortisol?

Answer 13

Circadian rhythm and stress

Question 14

Where does cortisol come from?

Answer 14

The adrenal cortex

Question 15

What are cortisol’s four targets and actions?

Answer 15

1. Immune system: Suppressed
2. Liver: Gluconeogenesis
3. Muscle: Protein catabolism
4. Adipose tissue: Lipolysis

Question 16

What are whole body level responses to cortisol?

Answer 16

Increases available energy and prioritizes energy use for stress response

Question 17

What is the hormone that is reponsible for ecdysis (extrusion from exoskeleton) in crustaceans?

Answer 17

Edysone

Question 18

What types of hormones are involved in the molting process?

Answer 18

Neural and hormonal

Question 19

MIH inhibits the release of ecdysone from the Y organ. True or false?

Answer 19

True

Question 20

When MIH levels in the plasma of a crustacean are high, ecdysone levels tend to be low. True or false?

Answer 20

True; MIH inhibits ecdysone

Question 21

MIH receptors in molting crustaceans are located on the X organ.

Answer 21

False. They’re located on the Y organ.

Question 22

Cortisol inhibits the release of ACTH from the hypothalamus. True or false?

Answer 22

False.
Cortisol inhibits the release of ACTH from the anterior pituitary.
CRH comes from the hypothalamus.

Question 23

In humans, cortisol receptors are found in the hypothalamus and liver. True or false?

Answer 23

True

Question 24

When CRH levels in the plasma of a human are high, ACTH levels will be low. True or false?

Answer 24

False. ACTH levels will be high.

Question 25

Suppose a human had high (excess) levels of cortisol. What would be the levels of CRH and ACTH in their plasma.

Answer 25

Low plasma CRH and low plasma ACTH. Cortisol inhibits both.