Hypothalamic Pituitary Adrenal Pathway

Question 1

What is the hypothalamic pituitary adrenal axis?

Answer 1

The interaction between the hypothalamus, pituitary gland and the adrenal gland

Question 2

What are the steps of the hypothalamic pituitary adrenal axis?

Answer 2

• Hypothalamus detects stimulus and releases CRH
• The anterior pituitary is activated by CRH to release ACTH
• The adrenal gland is activated by ACTH and the zona fasciculata produces cortisol

Question 3

Where is the pituitary gland?

Answer 3

In a protected pocket of bone directly connected to the pituitary gland

Question 4

What is the innfundibulum?

Answer 4

The stalk that connects the pituitary to the brain

Question 5

What is the posterior pituitary?

Answer 5

An extension of the neural tissue

Question 6

What is the anterior pituitary?

Answer 6

A true endocrine gland

Question 7

What does CRH stand for?

Answer 7

Corticotrophin Releasing Hormone

Question 8

What does ACTH stand for?

Answer 8

Adrenocorticotrophic Hormone

Question 9

What are tropic hormones?

Answer 9

Hormones which activate another endocrine gland

Question 10

What are non-tropic hormones?

Answer 10

Hormones which target cells or organs

Question 11

How are the hormones regulated in HPA?

Answer 11

Either long loop negative feedback or short loop negative feedback

Question 12

What does ACTH do?

Answer 12

Acts on the adrenal cortex to promote the synthesis and release of cortisol

Question 13

How does cortisol influence the negative feedback loop?

Answer 13

It inhibits ACTH secretion

Question 14

What does cortisol do?

Answer 14

Activates the liver to produce glucose via gluconeogenesis

Question 15

What does CRH do?

Answer 15

The anterior pituitary is activated to produce ACTH

Question 16

Where is the adrenal gland?

Answer 16

On the kidney

Question 17

What are the two parts of the adrenal gland?

Answer 17

Outer cortex and inner medulla

Question 18

What is the largest part of the adrenal gland?

Answer 18

The cortex

Question 19

How many zones is the cortex divided into?

Answer 19

3

Question 20

Where is cortisol produced?

Answer 20

In the zona fasciculata in the cortex of the adrenal gland

Question 21

What does the adrenal medulla do?

Answer 21

Secrets catecholamines

Question 22

What are catechomalines?

Answer 22

Adrenaline, noradrenaline and dopamine

Question 23

What does cortisol increase?

Answer 23

• Appetite
• Blood pressure
• Insulin resistance
• Gluconeogenesis

Question 24

What does cortisol decrease?

Answer 24

• Wound healing
• Inflammatory activity
• Bone formation

Question 25

What is the usual pattern of cortisol levels?

Answer 25

Highest at the beginning of the day and slowly decreasing until the lowest at the end of the day returning to highest during night

Question 26

What is hyper-cortisolism?

Answer 26

Production of too much cortisol

Question 27

What can cause hyper-cortisolism?

Answer 27

- Cushing's syndrome - Tumors on the adrenal gland or pituitary - Exogenous administration

Question 28

What does exogenous administration mean?

Answer 28

Something taken in from outside an organism ie medication, insulin, vitamins

Question 29

What is hypo-cortisolism?

Answer 29

Not enough production of cortisol

Question 30

What can cause hypo-cortisolism?

Answer 30

Addison's disease Congenital adrenal hyperplasia

Question 31

What is cushing's disease?

Answer 31

When cortisol levels are constantly elevated

Question 32

What impacts does cushing's disease have?

Answer 32

- Severe muscle, bone and skin breakdown - Dampens the inflammatory and immune response - Increases blood pressure, blood glucose and obesity

Question 33

What are some signs and symptoms of cushing's disease?

Answer 33

- Weight gain - Slow healing cuts - Increased risk of infections - Fatigue - Glucose intolerance