Hypothalamic-Anterior Pituitary System

Question 1

If the connection between hypothalamus and anterior pituitary is severed all hormones from anterior pituitary decrease, except? Why?

Answer 1

• prolactin ⬆️

- ⬇️ PIF (from hypothalamus) ▶️ maintain inhibition prolactin release

Question 2

Why hormone from hypothalamus in high concentration may stimulate production of prolactin?

Answer 2

TRH

Question 3

Most common tumor affecting the hypothalamic-pituitary system in children

Answer 3

Craniopharyngioma

Question 4

Defective GnRH synthesis ▶️ ⬇️ LH,FSH, sex steroids

Answer 4

Kallman syndrome

Question 5

Ischemic necrosis in the pituitary causing by a arteriolar spasm in response a severe blood loss during delivery in pregnancy ▶️ hypopituitarism, how does it call? What is the most strong sign of some grade of pituitary damage?

Answer 5

• Sheehan syndrome
• failure to resume normal menstrual cycle after weaning

*symptoms variable depend of extent and location of the damage

Question 6

Most common cause of hypothalamic-pituitary dysfunction and most common manifestation of it

Answer 6

• Pituitary adenomas ▶️ microadenomas ▶️ prolactinoma (60%) ▶️ hyperprolactinemia
• Hypogonadism, galactorrhea, no period 🚺, no erection 🚹

Question 7

What is difference between kallman and klinefelter syndromes as cause of Hypogonadism?

Answer 7

• kallman: ⬇️ gonatropins

- klinefelter: ⬆️ gonatropins

Question 8

How does the GnRH prevent the downregulation of their receptors at gonadotrophs cells?

Answer 8

Pulsatile release