Lecture 27

Question 1

Where are the adrenal glands?

Answer 1

Superior to each kidney, they are lateral to the spinal cord and blood vessels.

Question 2

What are the two seperate glands?

Answer 2

Adrenal cortex and adrenal medulla

Question 3

What do the 3 layers of adrenal cortex release?

Answer 3

Outermost layer secretes mineral corticoids like aldosterone, middle layer secretes cortisol, the inner layer produces androgens

Question 4

What does the adrenal medulla produce and where is it?

Answer 4

It is in the middle of the adrenal gland and produces adrenaline

Question 5

When is cortisol produced?

Answer 5

It is produced when required

Question 6

How does it get around the body?

Answer 6

Carried in the blood bound to a carrier protein

Question 7

What are the steps of cortisol binding, and response in the cell?

Answer 7

• It travels to the target cell and passes through the cell membrane
• Then binds to a specific receptor
• Moves into the nucleus
• Activates specific genes
• mRNA to form protein
• Protein has effect on the cell
• It takes a long time to effect

Question 8

What can cortisol release?

Answer 8

Stress or non-stress/ neural inputs

Question 9

What does the hypothalamus secrete when under stress or non stress neural inputs

Answer 9

Corticotropin releasing hormone (CRH)

Question 10

CRH causes the anterior pituitary gland to secrete what?

Answer 10

adrenocorticotropic hormone (ACTH)

Question 11

What does the adrenal cortex secrete after being signaled by ACTH?

Answer 11

Cortisol

Question 12

What response does cortisol have on muscles?

Answer 12

An increase in protein breakdown and a decrease in glucose uptake

Question 13

What response does cortisol have on fats?

Answer 13

Increases fat breakdown and decreases glucose uptake

Question 14

What response does cortisol have on liver?

Answer 14

Glucose synthesis

Question 15

What are some other effects that occur from cortisol?

Answer 15

Helps one to cope with stress but in the long-term is suppresses immune system, it is also essential for maintaining normal blood pressure

Question 16

Cortisol secretion is controlled by what feedback?

Answer 16

Negative feedback (EXCEPT during the stress response)

Question 17

When do you get a peak in cortisol?

Answer 17

In the mornings/ upon wakening

Question 18

What happens when there is a disturbance in normal sleep patterns?

Answer 18

It affects the cortisol pathway can lead to issues in the immune-system

Question 19

What is the function of cortisol?

Answer 19

Increases blood glucose levels, increasing fat, protein and carbohydrate metabolism to maintain blood glucose, up regulating immune responses, promoting anti-inflammatory actions, increasing blood pressure, increasing heart and blood vessel tone and contraction and activation of the central nervous system.

Question 20

What is Addison’s disease?

Answer 20

Lowered secretion of both cortisol and aldosterone

Question 21

What happens when there is low cortisol concentration?

Answer 21

It leads to ACTH secretion, its similar to hormone involved in stimulation of melatonin production which binds to the receptors of melatonin receptors.

Question 22

What are other symptoms of Addison’s disease?

Answer 22

Low blood pressure and weakness from lack of fuel, brain is weak, issues with blood potassium and much more

Question 23

What happens when you have Cushing’s syndrome?

Answer 23

Too much cortisol, which causes depositions of fats in certain areas. You get fats on the back of your neck, on face and stomach.

Question 24

What are other symptoms of Cushing’s syndrome

Answer 24

High blood pressure and weakness causing muscles to waste away.

Question 25

How is the adrenal medulla activated?

Answer 25

By the sympathetic pre-ganglionic fibre

Question 26

Why is noradrenaline secreted?

Answer 26

It is secreted as a part of the sympathetic nervous systems response to stress

Question 27

How does noradrenaline travel through the body?

Answer 27

Action potentials travel down the pre sympathetic fibres which then cause a release in acetyl choline causing another action potential to be sent down the post ganglionic chain then the release of the noradrenaline at the target tissue

Question 28

How does adrenaline travel through the body?

Answer 28

Action potential released down the pre ganglionic neuron from the hypothalamus, then it causes a response within the adrenal medulla, that action potential releases hormone into the blood and acts on the same cells that the sympathetic nervous system acts on, by doing that it can extend and prolong the actions of the CNS. This is called flight, fight or fright response.

Question 29

What does an increase in adrenaline cause?

Answer 29

It makes the actions from the sympathetic nervous system last longer particularly in times of stress

Question 30

Why is the adrenaline feed straight into the blood?

Answer 30

Because it needs to be a fast response

Question 31

What type of hormone is adrenaline?

Answer 31

Catecholamines still water soluble

Question 32

Is adrenaline an amplified response?

Answer 32

Yes as the second messenger doubles

Question 33

Stress causes the hypothalamus to do what?

Answer 33

Send action potentials down to the pre ganglionic fibres to act on the adrenal medulla which causes a release in adrenaline.

Question 34

What affects does adrenaline have?

Answer 34

Forces us to use our stored glucose in the skeletal muscles and liver. In fats it increases breakdown of fat to fatty acids

Question 35

What are some other affects on the SNS from adrenaline?

Answer 35

Some systems are activated for physical activity and systems not crucial for short-term survival are shut down.

Question 36

What is stress?

Answer 36

Its a stimuli that activates the hypothalamus

Question 37

What does the hypothalamus activate when under stress?

Answer 37

The hypothalamus activates the adrenal glands, sympathetic nervous system and posterior lobe of the pituitary gland

Question 38

How does your body responds to the stress signal?

Answer 38

Same response no matter what the stimulus was or is

Question 39

What affect does stress have on the hypothalamus which in turn has an affect on sympathetic nervous system? and so on

Answer 39

It stimulates the SNS to send action potentials down the sympathetic pre ganglionic fibres, then stimulates the adrenal medulla to secrete adrenaline which then increases blood glucose, heart rate and blood pressure.

Question 40

What affect does stress have on the hypothalamus which in turn has an effect on the anterior pituitary gland? and so on

Answer 40

Causes the hypothalamus to secrete CRH, which then causes the anterior pituitary gland to secrete ACTH, which then causes the adrenal cortex to secrete and SYNTHESIS cortisol and therefore increases the blood glucose and blood pressure.

Question 41

What affect does stress have on the hypothalamus which in turn has an effect on the posterior pituitary? and so on

Answer 41

The hypothalamus to send action potentials down to the posterior pituitary to release the ADH and therefore causes an effect in the kidneys and causes a decrease in water excretion and an increase in blood volume and blood pressure.