9.1.2 - Hormone Action

Question 1

Where are the pituitary gland and hypothalamus located?

Answer 1

The brain

Question 2

What is the name of the cells on the hypothalamus and what do they do?

Answer 2

Neurosecretory cells
Produce secretions from the axons.

Question 3

What do neurosecretory cells 1 do?

Answer 3

produce substances that stimulate or inhibit the release of hormones from the anterior pituitary.

Question 4

What are 2 names that neurosecretory cells 1 can be given depending on their role?

Answer 4

Releasing factors - if they stimulate
Release-inhibiting factors - if they inhibit.

Question 5

What do neurosecretory cells 2 do?

Answer 5

Produce secretions that are stored in the posterior pituitary and are later released as hormones.

Question 6

How many hormones does the pituitary gland produce and where do they get produced?

Answer 6

8
6 from anterior lobe
2 from posterior lobe

Question 7

What are two ways hormones can act?

Answer 7

Release of a second messenger
Hormone enters the cells

Question 8

What happens when a hormone undergoes the second messenger route?

Answer 8

Hormone binds to a receptor on the target cell membrane as it is unable to enter as it isn’t lipid soluble so can’t cross the membrane.
This triggers a series of intracellular membrane-bound reactions.
This stimulates the release of a second messenger.
The second messenger activates enzymes to alter the metabolism of the cell.

Question 9

Adrenalin undergoes the second messenger route.
Explain this process.

Answer 9

Adrenalin binds to a receptor.
This activates an enzyme called adenyl cyclase which converts ATP to cyclic AMP (cAMP)
cAMP acts as a second messenger.
It triggers different responses in the cell, increased respiration for muscle contraction.

Question 10

Explain how a hormone affects a cell when it enters inside the cell?

Answer 10

Hormones pass through the membrane and bind to a receptor inside the cell.
They form a hormone-receptor complex which passes into the nucleus and acts as a transcription factor to regulate gene expression.

Question 11

Name 3 hormones produced by the pituitary gland.

Answer 11

LH
FSH
GH
Prolactin
Oytocin

Question 12

What does oxytocin do?

Answer 12

Stimulates muscles of the uterus to contract during labour.

Question 13

What does prolactin do?

Answer 13

Maintains the production of mill on mammary glands.