The adrenals and their hormones

Question 1

Where does the left adrenal vien drain into?

Answer 1

Renal vien

Question 2

Where does the right adrenal vein drain into?

Answer 2

Inferior Vena Cava

Question 3

How many veins do both adrenal glands have?

Answer 3

1

Has 1 vein and many arteries

Question 4

List the zones of the adrenal cortex and recall the products of the adrenal cortex and medulla

Answer 4

Question 5

List the zones of the adrenal cortex?

Answer 5

Question 6

What does the adrenal medulla produce?

Answer 6

Catecholamines

Question 7

What type of hormones does the adrenal cortex produce?

Answer 7

Corticosteriods

Question 8

All the blood diffuses down the cortex into the medulla. As the corticosteriods diffuse down the cortex into the medulla it eventually reaches the central vien. The Corticosteriods have a beneficial effect on promoting adrenaline and noraadrenaline production

Answer 8

Question 9

What cells in the adrenal medulla produce Catecholamines?

Answer 9

Chromaffin Cells

80%-Adrenaline

20%-Noradrenaline

Evens produces a small amount of dopamine

Question 10

List the types of Corticosteriods produced by the adenal cortex and give examples of each?

Answer 10

Mineralocorticoids-Aldosterone

Glucocorticoids- Cortisol

Question 11

What other hormones besides Mineralocorticoids and Glucocorticoids can the adrenal cortex produce?

Answer 11

Sex steriods

Androgens and Oestrogens

Question 12

What zone or zones in the adrenal cortex produces Aldosterone?

Answer 12

Zona Glomerulosa

Question 13

What zone is Cortisol and Androgens produced in?

Answer 13

Zona Fasciculata

Zona Reticularis

Question 14

Why are the adrenal cortex hormones also known as C21 steriods

Answer 14

21 Carbons in Mineralcorticoids and Glucocorticoids

Cholesterol has 27 carbons

Question 15

State the steps for synthesis of genral steriod hormones

Answer 15

LDLs are delivered to the cell and are stored as Fatty Acid Esters (seen as fat droplets)

To synthesise steroid hormones you need to break down the fatty acid esters to liberate cholesterol

Esterase enzymes break down the fatty acid esters

STEROID HORMONES ARE MADE IN THE MITOCHONDRIA

Cholesterol gets into the mitochondrion via StAR Proteins (Steroidogenic Acute Regulatory Protein)

This is one of the rate limiting steps in steroid hormone production

The more StAR proteins you have, the more cholesterol you can get into the mitochondrion and the more steroid hormone you can produce

When cholesterol enters the mitochondrion, there are lots of enzymes that allows the step-wise conversion of the cholesterol into the steroid hormone of choice

The enzymes present in certain cells determines the final steroid hormone product (e.g. adrenal cortical cells have a set of enzymes that produced cortisol)

Question 16

Recall the synthesis for Cortisol?

Answer 16

Sequence of addition and subtraction

Question 17

List the steps for aldosterone synthesis?

Answer 17

NO P450c17 ENZYME

Question 18

Recall the steps for sex hormone synthesis in the adrenal cortex

Answer 18

NO need to remember enzymes

Remember some important intermediate molecules

Question 19

What is the difference between glomerulosa and the FASCICULATA?

Answer 19

NO p450c17 in glomerulosa

Glomerulosa has Aldosterine synthase

Question 20

What proportion of aldosterone is free, bound to CBG ( corticosteroid-binding globulin) or bound to Albumin?

Answer 20

40% free

15%- CBG

45%- Albumin

Question 21

What proportion of Cortisol is free, bound to CBG ( corticosteroid-binding globulin) or bound to Albumin?

Answer 21

10%- Free

80%- CBG

10%- Albumin

Question 22

Test: Cortisol binds to the glucocorticoid receptor (GR) whereas aldosterone binds to the mineralocorticoid receptor (MR).

Only free unbound hormone can access tissues and bind to relevant receptors.

Is a 5% displacement of hormone (cortisol/aldosterone) from binding proteins going to cause a greater increase in % GR binding or MR binding?

Answer 22

Cortisol

Question 23

By how much is there a difference in the concentrations of Cortisol and Aldosterone?

Answer 23

1000 x

Question 24

What is the name of the receptor or receptors that cortisol can bind to?

Answer 24

Glucocorticoid Receptor

Aldosterone Receptor (MR)

Question 25

What is the major implication of the data below?

Answer 25

Cortisol can bind to and aggrevates the MR just as effectively as Aldosterone and is 1000x more. So what is the point of aldosterone. There is certain tissue that excludes cortisol by making it inactive :11b-hydroxysteriod dehydrogenase 2. So aldosetrone is needed because in certain tissue aldesterone can bind to MR receptor whilst cortisol can't. An example of this tissue is the kidney- This is the target organ for aldosterone and cortisol cant enter the kidney unless it has very high concentration. The 11b-hydroxysteriod dehydrogenase 2 is found in such tissuess. This enzyme is also in the placenta to prevent maternal cortisol for reaching the baby because cortisol is growth inhibitory.

Question 26

What 3 things causes renin release?

Answer 26

RENIN IS AN ENZYME **-Decreased renal perfusion pressure (normally associated with decreased arteriole blood pressure)** - **Increased renal sympathetic activity- flight or fight response** - The JGA (juxta-glomerular apparatus) has sympathetic innervation - The sympathetic system is activated when the blood pressure falls - This leads to renin release **Decreased Na+ load dilivered to the distal tube -**This load is measured by the **macula densa** (Na+ sensor) of the juxtaglomerular apparatus. Sodium diffuses out of the macula cells causing them to shrink which causes Renin production. Decreased sodium concentration at the top of the loop of Henle This leads to activation of JGA and the release of renin

Question 27

Draw a diagram showing the renin angiotensin system?

Answer 27

Question 28

What does Angiotensin II stimulate?

Answer 28

ANGIOTENSIN II stimulates the zona glomerulosa to produce aldosterone

Question 29

Low Na+ in blood and high K+ in blood stimulates aldosterone production- not as much as angiotensin II

Answer 29

Question 30

Draw the Adrenal gland – hypothalamo-pituitary-adrenocortical axis

Answer 30

A key stmuli for cortisol production is Stress- any stress

Question 31

Describe your cortisol levels throughout the day

Answer 31

Higher when sleeping

Question 32

Where are the target cells for aldosterone located

Answer 32

target cells for aldosterone are located in the distal tubule and cortical collecting duct,

Question 33

What are the actions of aldosterone?

Answer 33

**Stimulates Na+ reabsorption in the distal convoluted tubule and cortical collecting duct** This is particularly important in the kidneys but is also important in sweat glands, gastric glands and colon) **Stimulates K+ and H+ secretion in the distal convoluted tubule and cortical collecting duc**t So it will have an effect on pH regulation of the blood

Question 34

Draw a diagram shoing the effects of aldosterone inside a cell

Answer 34

Question 35

What is cortisol mechanism of action inside a cell? Draw a diagram

Answer 35

Question 36

For normal physiological effects of cortisol, what ratio of MR to GR receptor stimulation do you need?

Answer 36

Maximal MR stimulation ( MR most important for normal cortisol physiollogical response) excluding the tissue with enzyme protection and Little stimulation of GR

Question 37

What effects on the body does very high levels and low levels of cortisol have on the body ( chronic- for a long time )? List 9 for each

Answer 37

Question 38

When you are stressed, what happens to the proportion of GR to MR stimulation?

Answer 38

The are both highlt stimulated GR drives your stress response

Question 39

What effects does cortisol have in the liver?

Answer 39

Stimulate Glycolysis Stimulate Gluconeogenesis Increase blood glucose conc

Question 40

What effect does cortisol have on skeletal muscle and adipose cells?

Answer 40

Decreases bloodflow to skeletal muscle and Fat Decrase the transporters that causes glucose to enter the cells **CORTISOL WANTS TO INCREASE BLOOD GLUCOSE CONCENTRATION**

Question 41

What effect does cortsiol have on memory function?

Answer 41

Dantate Gyrus- large pink, green and yellow area- important area Seratonin and cortisol in the hippocampus work together Seratonin promotes granular cell (have a role in memory formation) proliferation Cortisol increases the sensitivity of the hippocampus to seratonin Acute stress response- help with memory- that is why most of your first memories are stressful

Question 42

What effects does high conc of cortisol like substances have?

Answer 42

If you use high dose of cortisol like substances it has a powerful anti-inflammatory and immunosuppressive efffects At normal physiological levels it supports the immune system- more research is needed in this level That is why during exam period you are more likely to get ill

Question 43

What effect does alcohol and caffine have on cortisol production?

Answer 43

Caffine and Alcohol increase cortisol Alcohol is more powerful then caffine

Question 44

If you are chronically stressed how does it effect memory?

Answer 44

Memory gets much worse due to GR receptor having the main effect and bring the major activator. Example of this is PTSD

Question 45

Test: What effect would supraphysiological levels of cortisol have on blood pressure? Hint – 11 beta HSD II

Answer 45

Normally you have the enzyme barrier in the kidney- high levels can pass the enzyme barrier and has the same effect as aldosteron whilst in the kidney- this causes an increase in blood pressure?

Question 46

In which zone is Adrenal androgens synthesised?

Answer 46

Zona reticularis

Question 47

Dehydroepiandrosterone (DHEA) This is a very weak androgen Precursor for androgens and oestrogens Converted to active hormones within target cells (which have appropriate enzymes) Peak serum levels at 20-30 years, then decreasing steadily with increasing age Particularly important in post-menopausal women as a precursor for oestrogen (and androgen) synthesis by target tissue in the absence of ovarian steroids

Answer 47

Question 48

What effects on the body does angiotensin 2 have?

Answer 48

Potent vasoconstrictor