Lecture 33: The Pituitary Gland and the Hypothalamus: What is the Connection?

Question 1

The pituitary gland is broken up into two parts:

Answer 1

• Anterior lobe
• Posterior lobe
• They both secrete their own hormones

Question 2

Pituitary Hormones:

Answer 2

- Anterior:
Growth hormone
ACTH
Thyroid-regulating ormone
Gonadotropic (sex) hormones
Prolactin ; tropic and have their own effects
- Posterior
Antidiuretic / vasopressin hormone
Oxytocin

Question 3

Different anterior pituitary hormonal pathways:

Answer 3

- Hypothalamus Pituitary Gonadal Axis:
GnRH
FSH + LH
Gonads
Estrogen + testosterone secretion
- Hypothalamus Pituitary Adrenal Axis:
CRH
ACTH
Adrenal cortex
Cortisol secretion
- PRH / PIH
- Prolactin + / -
- Breast development and milk production
- TRH effects prolactin output
- TSH
- Thyroid Gland
- T3, T4 secretion
- GHRH
- Growth Hormone
- Nutrient metabolism and tissue growth
- SS negatively effects growth hormone and TSH

Question 4

Releasing hormone = ?

Answer 4

• Hormones come from hypothalamus

Question 5

How does information get to the posterior pituitary lobe?

Answer 5

• Axon terminals ending in posterior lobe of the pituitary gland, cell bodies in hypothalamus
• Neural communication

Question 6

Hormones released by the posterior pituitary:

Answer 6

• Antidiuretic hormone : stimulates the kidneys to reabsorb water
• Oxytocin : uterine musles & milk release
• Both hormones are made in the hypothalamus and stored in the pituitary glands

Question 7

What does ADH do?

Answer 7

• If it’s absent we have a large volume of dilute urine

- If it’s present, water is reabsorbed by the kidneys

Question 8

Oxytocin is a form of…

Answer 8

• Positive feedback