Chapter 5 The Endocrine System

Question 1

What are the three classifications of hormones?

Answer 1

1. Peptide hormones (can travel thru blood)
2. Amino acid derivatives
3. Steroids (cannot travel thru blood on own)

Question 2

What is a direct hormone?

Answer 2

A direct hormone is a hormone that directly stimulates a physiological change and act directly on a target tissues. This is in contrast to tropic hormones.

Question 3

What is a tropic hormone?

Answer 3

A tropic hormone is a hormone that acts as a second messenger which goes on to stimulate other hormones.

Question 4

What are the 8 endocrine glands?

Answer 4

The hypothalamus, the pituitary, the pineal, thyroid, parathyroid, adrenal, pancreas, and the gonads.

Question 5

What are the two divisions of the pituitary?

Answer 5

The anterior (front) and posterior pituitary (back)

Question 6

The hypothalamus and pituitary are connected by what “system”?

Answer 6

The hypophyseal portal system, which is within the pituitary stalk.

Question 7

What are the 4 hormones released by the hypothalamus intended for the anterior pituitary?

Answer 7

1. Thyroid Releasing Hormone (TRH)
2. Gonadotropin-releasing hormone (GnRH)
3. Growth hormone-releasing hormone (GHRH)
4. Corticotropin

Question 8

When stimulated by the hypothalamus, the posterior pituitary releases what two hormones?

Answer 8

1. Oxytocin

2. Antidiruetic Hormone (ADH)

Question 9

What is the goal of ADH (Antidiuretic Hormone)

Answer 9

The goal of this is to reserve water and decrease release via the kidneys. This increases blood osmolarity (more water in blood).

Question 10

What are the 7 hormones released by the anterior pituitary? (FLATPEG)

Answer 10

Follicle stimulating hormone (FSH)
Lutenizing Hormone
Adrenocorticotropic Hormone (ACTH)
Thyroid stimulating hormone (TSH)

Prolactin
Endorphins
Growth Hormone (GH)

Question 11

What does Prolactin do?

Answer 11

Prolactin stimulates milk production in the mammary glands. This is a unique hormone in that dopamine release decreases prolactin secretion.

Question 12

What are endorphins?

Answer 12

Endorphins mask the perception of pain

Question 13

What hormone contributes to gigantism and dwarfism?

Answer 13

Growth Hormone is the cause of both of these conditions. Too much GH pre-puberty will result in gigantism and too little will cause dwarfism.

Question 14

What are the Thyroid’s 2 main functions?

Answer 14

1. Setting Basal Metabolic Rate

2. Maintaining Calcium Homeostasis

Question 15

What hormones are release by the thyroid and what do they do?

Answer 15

1. T3 and T4 - Increased amounts = increase cell. respiration
2. Calcitonin - increased amounts = less blood calcium

Question 16

What does T3 and T4 do?

Answer 16

T3 and T4 speeds up BOTH degradation and synthesis of fatty acids and proteins

Question 17

T3 and T4 work by negative feedback. If there are high amounts of T3 and T4, what hormone(s) would you expect to be inhibited?

Answer 17

1. TRH (from hypothalamus)

2. TSH (from pituitary)

Question 18

Calcitonin released by the thyroid gland does what 3 things to control calcium levels?

Answer 18

1. Induces calcium secretion in kidneys
2. Inhibits calcium uptake in gut
3. Increase calcium storage in bone

Question 19

The parathyroid gland’s goal is to what?

Answer 19

The goal is to INCREASE blood calcium levels by doing quite the opposite of what the thyroid gland does.

Question 20

What hormone is released by the parathyroid gland to maintain increased blood calcium levels?

Answer 20

Parathyroid Hormone (PTH)

Question 21

What 3 classes of hormones are released by the adrenal Cortex?

Answer 21

1. Glucocorticoids
2. Mineralocorticoids
3. Cortical sex hormones

Question 22

What are the main glucocorticoids and what do they do?

Answer 22

The main ones are cortisol and cortisone. These both increase blood glucose levels AND regulate protein synthesis. They do this via increasing gluconeogenesis and decreasing protein synthesis.

Question 23

What upstream hormones control the adrenal cortex’s release of glucocorticoids?

Answer 23

The hypothalamus releases Corticotropin relasing factor (CRF) which stimulates the pituitary to release ACTH (AdrenoCorticotropic Hormone) which stimulates adrenal cortex production of the glucs.

Question 24

What is the main mineralcorticoid hormone released by the adrenal cortex, and what does it do?

Answer 24

Aldosterone; this hormone controls blood volume & pressure - note that this hormone only increases volume and does not change blood osmolarity, that is, it does not change the molarity of sodium/other ions in the blood.

Question 25

What are the cortical sex hormones released by the adrenal cortex?

Answer 25

Androgens and estrogens

Question 26

The adrenal glad has two divisions, the cortex and the medulla. What hormones are released by the medulla?

Answer 26

Epinephrine and norepinephrine

Question 27

What do epinephrine and norepinephrine do?

Answer 27

Both increase heart rate and shunt blood where it is needed most during a fight/flight response. Norepinephrine increases blood glucose levels by stimulating gluconeogenesis.

Question 28

The pancreas has groups of hormone-releasing cells; what are these groupings called?

Answer 28

Islets of Langerhans

Question 29

Islets of Langerhans house 3 types of cells. What are the 3 types and what exactly do they release?

Answer 29

Alpha Cells- Glucagon
Beta cells- Insulin
Delta cells - somatostatin

Question 30

Glucagon induces what effect?

Answer 30

Glucagon stimulates glucose production and glucose release from gylcogen.

Question 31

What does the hormone Somatostatin do?

Answer 31

This hormone inhibits BOTH insulin and glucagon