lecture 26 - pituitary, hypothalamus & growth hormone

Question 1

Where is the pituitary gland located?

Answer 1

At the base of the brain, attached to the hypothalamus.

Question 2

How is the pituitary gland stimulated to produce hormones?

Answer 2

Activated by the hypothalamus by neural and hormonal imput.

Question 3

What are the 2 key parts of the pituitary gland?

Answer 3

Anterior lobe and Posterior lobe

Question 4

How is the posterior lobe of the pituitary connected to the hypothalamus?

Answer 4

By neurons, which have their cell bodies in the hypothalamus, and axon terminals in the posterior lobe

Question 5

Where are posterior pituitary hormones made?

Answer 5

In the cell body of neurons that connect the hypothalamus to the posterior lobe

Question 6

Where are posterior pituitary hormones stored?

Answer 6

At the axon endings of the neurons that connect the hypothalamus and posterior pituitary.

Question 7

What type of hormone are posterior pituitary hormones, and in what medium are they soluble?

Answer 7

Peptide hormones (water soluble)

Question 8

What are the hormones released by the posterior pituitary?

Answer 8

(ADH) Antidiuretic hormone, oxytocin

Question 9

What is the rate of the release of posterior pituitary hormones dependent on?

Answer 9

The rate of action potentials fired by the hypothalamus.

Question 10

What is ADH (hormone)?

Answer 10

Antidiuretic hormone

Question 11

What is the function of ADH?

Answer 11

Antidiuretic - stimulates the kidneys to reabsorb and conserve water, rather than releasing it as urine

Question 12

What hormone acts on the kidneys, causing them to reabsorb water?

Answer 12

ADH - antidiuretic hormone

Question 13

What are the key functions of oxytocin?

Answer 13

Stimulate the contraction of uterine muscles during childbirth and stimulate the milk ejection reflex during breast feeding

Question 14

How is the anterior pituitary connect to the hypothalamus?

Answer 14

Via a portal vessel network

Question 15

How does the hypothalamus signal to the anterior pituitary?

Answer 15

Via releasing hormones, released from neurosecretory neurons in the hypothalamus and transported via portal vessels to the anterior lobe.

Question 16

What type of hormone are releasing hormones released by the hypothalamus?

Answer 16

peptide hormones

Question 17

How do releasing hormones trigger the release of anterior pituitary hormones?

Answer 17

The peptide hormones bind to target cell membrane receptors, which triggers the secretion of a specific anterior pituitary hormone into the bloodstream.

Question 18

Where is growth hormone secreted from?

Answer 18

The anterior pituitary

Question 19

What triggers the release of growth hormone from the anterior pituitary?

Answer 19

GH-RH - growth hormone releasing hormone

Question 20

What inhibits the release of growth hormone from the anterior pituitary?

Answer 20

GH-IH - growth hormone inhibiting hormone

Question 21

What is the target gland of growth hormone?

Answer 21

The liver

Question 22

What is PIH (hormone)?

Answer 22

Prolactin inhibiting hormone

Question 23

What is PRH (hormone)?

Answer 23

Prolactin releasing hormone.

Question 24

What does prolactin inhibiting hormone (PIH) inhibit?

Answer 24

Prolactin release and TSH release from the anterior pituitary

Question 25

What does the anterior pituitary hormone prolactin (PRL) do?

Answer 25

Stimulates the mammary gland to secrete breast milk

Question 26

What are the direct, long term effects of growth hormone on muscles?

Answer 26

Stimulates protein synthesis

Question 27

What are the direct, short term effects of growth hormone on muscles?

Answer 27

Inhibits cellular uptake of glucose

Question 28

What are the short term effects of growth hormone on the liver?

Answer 28

Stimulates glucose synthesis (gluconeogenesis)

Question 29

What are the short term effects of growth hormone on fat/adipose tissue?

Answer 29

Increase triglyceride/fat breakdown

Question 30

What are the indirect effects of growth hormone on the body?

Answer 30

Promotes cell division in bones, muscles and other tissues, by releasing Somatomedin C

Question 31

What is the other name for Somatomedin C?

Answer 31

IGF -1 (insulin growth factor 1)

Question 32

What is the function of Somatosedin C?

Answer 32

Promotes cell division for growth in the long term

Question 33

When are GH concentrations in the body highest?

Answer 33

During the night/when asleep

Question 34

In a negative feedback loop, the increase of what hormones will lead to the release of GH-IH and therefore a decrease in the release of growth hormone from the anterior pituitary?

Answer 34

Somatomedins

Question 35

Where are somatomedins released from, and in response to what stimulus?

Answer 35

The liver - in response to growth hormone acting on target tissue

Question 36

Where are the axon terminals of hypothalamus neurons that secrete anterior pituitary releasing hormones found?

Answer 36

Median eminence