L26

Question 1

What sits below the hypothalamus

Answer 1

The pituitary gland

Question 2

Organs within the torso

Answer 2

Visceral organs

Question 3

What is the hypothalamus the connection between?

Answer 3

Neural and hormonal pathways

Question 4

What is the pituitary gland made of

Answer 4

Two lobes: posterior and anterior
Anterior has a different attachment to the hypothalamus

Question 5

How does the hypothalamus control hormone secretion of the pituitary?

Answer 5

When activated by neural input, the hypo stimulates pituitary to secrete hormones

Excitatory APs from hypo travel down the axon or secrete hormones in that area

Question 6

What do pituitary hormones do?

Answer 6

Some pituitary hormones stimulate target cells and some stimulate the secretion of hormones by other endocrine glands

Question 7

Where are the hormones secreted by the posterior pituitary gland produced?

Answer 7

Cell bodies of Hypothalamus
* It is secreted into the blood

Question 8

Where are the hormones stored and how are they released?

Answer 8

In the vesicles after travelling down the axons

The hypo uses neural comms to signal to the pituitary to release the hormones into the blood

Question 9

Two types of hormones released by the posterior pituitary

Answer 9

ADH (Antidiuretic hormone aka Vasopressin) and Oxytocin

Question 10

What does ADH do?

Answer 10

It prevents urine from being made by encouraging the kidneys to reabsorb filtered H2O to conserve H2O when the body is dehydrated or to increase blood volume

Question 11

Oxytocin

Answer 11

*Stimulates contraction of uterine muscles during childbirth when baby applies pressure (+ve feedback loop)
*Love hormone
*Stimulates release of milk while breastfeeding

Question 12

How are hormones released from the anterior pituitary?

Answer 12

Neural stimulus in hypo –> Releasing/inhibiting hormones made by hypo travel down short axons and released into AP (portal blood vessels) which then activate certain areas of the AP by binding to their plasma mem receptors to release diff hormones which are then released into the blood

Question 13

What kind of hormones stored in the cells of the AP

Answer 13

Peptide, H2O soluble and hence stored in vesicles

Question 14

What do each type of AP cell has

Answer 14

Its own kind of hypothalamic hormone receptor

Question 15

Another word for the portal blood vessels

Answer 15

Median eminence

Question 16

Feedback regulation of AP

Answer 16

Hypo releases hypothalamic hormone –> AP releases pituitary hormone –> reaches target hormone which releases its own hormone that has the desired effect but also feedbacks to the hypothalamus to stop producing hypothalamic releasing hormones

Question 17

GH-RH

Answer 17

Growth hormone - releasing hormone

Question 18

GH-IH

Answer 18

Growth hormone - inhibiting hormone

Question 19

Another word for Growth hormone - releasing hormone

Answer 19

SS or somatostatin

Question 20

Pathway of GH-RH/GH-IH

Answer 20

Either –> Affects growth hormone release (AP) –> travels through systemic circulation and affects Liver –> IGF -1 –> effects but also inhibit GH-RH

Question 21

Another name for IGF- 1

Answer 21

Somatomedin C

Question 22

What else does the growth hormone effect

Answer 22

Indirectly affects the muscles and fat and direct effects through IGF -1

Question 23

Direct effects of GH

Answer 23

*Muscles - protein synthesis (long term) and inhibits cellular uptake of glucose (short term), have glucose taken up where needed during growth/repair
*Liver - glucose synthesis
*Fats - triglyceride breakdown in adipose tissue i.e free fatty acids to make new glucose (short term)

Question 24

Indirect effects of GH

Answer 24

Promotes growth of bones, muscles and tissues –> releases IGC-1, promotes cell divison (long term)

Long term effects on growth and short term effects on metabolism

Question 25

When is most growth hormone is released?

Answer 25

During sleep and puberty