Hypothalamus And Pituitary Glands

Question 1

What is the pituitary stalk called? What does it connect?

Answer 1

Infundibulum

Connects the hypothalamus and the pituitary glands

Question 2

What does the pituitary gland sit in?

Answer 2

The sella turcica (socket of bone)

Question 3

Name some processes that the hypothalamus and pituitary glands modulate

Answer 3

Body growth
Reproduction 
Adrenal gland function 
Water homeostasis 
Milk secretion
Lactation
Thyroid gland function
Puberty

Question 4

Where does the anterior pituitary originate from?

Answer 4

Oral ectoderm (rathke’s pouch)

Question 5

Where does the posterior pituitary gland originate from?

Answer 5

Neuroectoderm (Primitive brain tissue)

Question 6

Why is the posterior pituitary gland incorrectly named?

Answer 6

It does not synthesis hormones, it only stored and releases them therefore it is technically not a gland

Question 7

What two hormones are released by the posterior pituitary gland?

Answer 7

Oxytocin and antidiurectic hormone

Question 8

Where are oxytocin and antidiurectic hormones produced?

Answer 8

Supraoptic and paraventricular nuclei of the hypothalamus (both secrete both hormones)

*transported down infundibulum by neurocrine secretion

Question 9

What kind of hormones does the hypothalamus produce?

Answer 9

Tropic hormones- their function is to control the synthesis and release of hormones in the pituitary glands

Question 10

How do hormones travel from the hypothalamus to the anterior pituitary gland?

Answer 10

Transported down axons and stored in median eminence before release into the hypophyseal portal system

Travel in the hypophyseal portal system to the anterior pituitary gland

Question 11

What kind of signalling functions does the anterior pituitary gland have?

Answer 11

Neurocrine (how the anterior pituitary gland itself is stimulated)

Endocrine

Autocrine + paracrine

Question 12

The hormones produced by nerve cells in the hypothalamus act via two distinct neurocrine pathways, what are they?

Answer 12

1. Direct effects on distant target tissue via oxytocin and ADH from the posterior pituitary
2. Hormones secreted exclusively into hypophyseal portal system affect endocrine cells within the anterior pituitary

Question 13

What function does OT (oxytocin) serve?

Answer 13

Milk let down

Uterus contractions during birth

Question 14

There are 6 tropic hormones produced by the hypothalamus. These have direct effects on the releases of anterior pituitary hormones. What are they?

Answer 14

1. TRH-thryotropin releasing hormone
2. PIH - prolactin release-inhibiting hormone (/dopamine)
3. CRH- corticotropin releasing hormone
4. GnRH - gonadotropin releasing hormone
5. GHRH- growth hormone releasing hormone
6. GHIH - growth hormone inhibiting hormone (somatostatin)

Question 15

What does TRH (thyrotropin releasing hormone) do?

Answer 15

Causes the release of TSH / thyroid stimulating hormone

Question 16

What does PIH (prolactin release-inhibiting hormone) do?

Answer 16

Inhibits release of prolactin

Question 17

What does CRH (corticotropin releasing hormone) ?

Answer 17

Causes the release of ACTH (adrenocorticotropic hormone)

Question 18

What doe GnRH (gonadotropin releasing hormone) do?

Answer 18

Causes the release of LH (luteinising hormone)and FSH (follicle stimulating hormone)

Question 19

What does GHRH (growth hormone releasing hormone)do?

Answer 19

Stimulates the release of growth hormone

Question 20

Name the 6 hormones produced by the anterior pituitary gland and state what they do

Answer 20

1. TSH (thyroid stimulating hormone): secretion of thyroid hormone
2. ACTH (adrenocorticotropic hormone): secretion of hormones from adrenal cortex
3. LH (luteinising hormone): ovulation and secretion of sex hormones
4. FSH (follicle stimulating hormone): development of eggs and sperm
5. PRL (prolactin): mammary gland development and milk secretion
6. GH (growth hormone): growth ad energy metabolism. Stimulates IGFs