Chapter 32 Hypothalamus & Pituitary

Question 1

What are some functions that the pituitary has control over?

Answer 1

-Reproductive function (including milk synthesis and lactation)

-Stress response

-Somatic growth

-Metabolism

-Body fluid homeostasis

Question 2

What is the optic nerve important for?

Answer 2

Vision

Question 3

What are the roles of both Anterior and Posterior pituitary?

Answer 3

Anterior portion is a collection of endocrine cells that produce and secret hormone then release them into the blood circuit and the posterior portion is a collection of neurons where the hormones are stored and released when it gets the signals

Question 4

What are the 5 cell types and what hormones do each of them produce?

Answer 4

Corticotroph produces Adrenocorticotropin(ACTH)

Thyrotroph produces Thyroid stimulating hormone (TSH)

Gonadotroph produces Luteinizing hormone (LH) and Follicle stimulating hormone (FSH)

Somatotroph produces Growth Hormone (GH)

Mammotroph (Lactotoroph) produces Prolactin

Question 5

Describe the hypothalamic regulation of each anterior pituitary hormone

Answer 5

They all start with the hypothalamus which releases TRH and stimulates the anterior pituitary to release TSH and stimulate thyroid gland to release thyroid hormone and then which reaches the final target organ and causes the biological effect

Question 6

During which time of day and night is the Growth hormone secretion the highest ?

Answer 6

During our sleep

Question 7

Where are negative feedbacks sent when you have high levels of IGF-1 and high levels of Growth Hormone

Answer 7

For IGF-1 it sends a negative feedback to the anterior pituitary to decrease GH secretion and it also sends a negative feedback to the Hypothalamus to reduce GHRH secretion and increase the Somatostatin secretion which will help inhibit GH secretion

For Growth hormone it only sends a negative feedback to the hypothalamus to increase somatostatin and reduce GHRH secretion to inhibit the GH secretion

Question 8

What are some biological factors that could effect the regulation of GH secretion ?

Answer 8

things like exercise, stress and sleep can help stimulate GH secretion

things like Glucose can inhibit GH secretion

Question 9

What is the Hypopheseal portal vein responsible for? and what is it important for?

Answer 9

To transport hypothalamic hormones from the hypothalamus to the anterior pituitary.

Important to communicante between the hypothalamus and the pituitary gland

Question 10

Describe the regulation pathway of the anterior pituitary hormone secretion by hypothalamic hormones

Answer 10

There are 5 different endocrine cell types that secrete 6 different types of hormones that are controlled by the neurons in the hypothalamus the go on into the blood flow. then the blood flows to the capillaries then go to form the hypophyseal portal vein and then transported to the anterior pituitary gland.

Question 11

Describe the regulation pathway of the posterior pathway

Answer 11

There are large size neurons called Magnocellular neurons that connect from the hypothalamus and connect to the posterior pituitary gland which connect to the blood flow and it contains the posterior pituitary hormones.

Question 12

Where is the Thyroid stimulating hormone(TSH) released from and what does it effect and help stimulate?

Answer 12

It is released from the Anterior Pituitary Thyrotroph and effects the thyroid gland to help stimulate thyroid development and secretion of thyroid hormone

Question 13

Where is the Adrenocorticotropic hormone(ACTH) released from and what does it effect and help stimulate?

Answer 13

It is released from the Anterior Pituitary Corticotroph and effects the Adrenal cortex to stimulate secretion of glucocorticoids (such as cortisol)

Question 14

Where are the Luteinizing hormone (LH) and Follicle stimulating hormone(FSH) aka Gonadotropins released from and what do they effect ?

Answer 14

It is released from the Anterior pituitary Gonadotroph and they both have an effect on ovary and testis

Question 15

Where is the Prolactin released from and what does it effect and help stimulate ?

Answer 15

It is released from the Anterior Pituitary Mammotroph and it effects the mammary gland and helps promote milk production in lactating females

Question 16

How is the prolactin secretion regulated and what helps it inhibit it and how?

Answer 16

The hypothalamus releases the prolactin releasing factor to effect the pituitary which then produces prolactin to effect mammary glands and gonads but if there is too much the dopamine has a inhibition feedback loop that inhibits prolactin secretion

Question 17

Where is the Growth Hormone (GH) released from and what does it effect and help stimulate ?

Answer 17

It is released from the Anterior Pituitary Somatotroph and it has effect on most tissues and it helps to promote growth and regulate metabolism

Question 18

What are the differences between the direct and indirect mechanisms of the growth hormone ?

Answer 18

In the direct the growth hormone it gets released by the anterior pituitary somatotrophs and it effects the target organ leading to a biological effect

In the indirect the growth hormone gets released from the Anterior pituitary somatotrophs which act on the tissues in the liver which then stimulate and production of the IGF-1 which is the released in the blood circulation which reaches the target organ and then leads to a biological effect

It is considered indirect because it is caused by another hormone stimulated by the growth hormone

Question 19

What are the metabolic effects for growth hormone on lipid metabolism ?

Answer 19

Increase in lipolysis (lipid break down)
Decrease in lipid synthesis and storage

Question 20

What are the metabolic effects for growth hormone on carbohydrate metabolism ?

Answer 20

It increase blood glucose in two ways
-Increase in Gluconeogenesis (glucose production) in the liver
-Decrease in glucose uptake in tissues such as muscle

Question 21

What are the metabolic effects for growth hormone on protein metabolism ?

Answer 21

increase in protein synthesis in many tissues