Lecture 34: Pituitary glands

Question 1

Where is the pituitary gland located?

Answer 1

At the base of the brain

-attached to the hypothalamus which controls the secretion of pituitary hormones

Question 2

What are the two hypothalamus nuclei?

Answer 2

• Paraventricular

- Supraoptic

Question 3

What hormones does the posterior pituitary secrete?

Answer 3

Antidiuretic hormone ADH

Oxytocin

Question 4

What effect does oxytocin have on the body?

Answer 4

• stimulates contraction of uterine muscles

- stimulates milk ejection reflex - milk release in breastfeeding

Question 5

What effect does ADH have on the body?

Answer 5

• stimulates the kidneys to reabsorb water

Question 6

What hormones do the anterior pituitary secrete?

Answer 6

Growth Hormone
Prolactin
TSH
ACTH

Question 7

What effect does growth hormone have on the body?

Answer 7

INDIRECT =
Promotes growth of bone, tissue & muscles
DIRECT=
Metabolism

Question 8

What effect does prolactin have on the body?

Answer 8

• stimulates production of milk after birth of baby

- development of breast at puberty & during pregnancy

Question 9

How is the hypothalamus connected to the posterior pituitary gland?

Answer 9

• via neurons
• cell body in hypothalamus
• axon terminates in posterior lobe

Question 10

How is the hypothalamus connected to the anterior pituitary gland?

Answer 10

connected via blood vessels

Question 11

Where are posterior pituitary hormones made?
Are they stored?
When are they released?

Answer 11

• Hormones are made in the hypothalamus
• travel down axon
• Stored at the axon ending until required
• AP’s stimulate the release of specific stored hormones

Question 12

Where are anterior pituitary hormones made?

Answer 12

Hormones are made in gland

Question 13

How does the hypothalamus control the release of hormones from the anterior pituitary?
* look at diagram

Answer 13

1. Hypothalamus releases either a releasing hormone or inhibitory hormones
2. Hormone travels to anterior lobe via blood vessel
3. Hormone binds to specific cell membrane receptor
4. Hormone receptor binding stimulates the release of specific hormone which travels to target organ
5. hormone influences activity of target cel

Question 14

What causes the release of prolactin?

- release is mainly inhibitory

Answer 14

• dopamine acts as an inhibitory hormone which is released by the hypothalamus
• TRH from the hypothalamus can stimulate prolactin secretion

Question 15

What hormones does the hypothalamus release into the anterior pituitary gland?

Answer 15

Releasing or inhibitory hormones are released into the medial eminence - which bind to receptors in and anterior pituitary causing peptide hormone release