Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrine > The adrenal gland poster > Flashcards

The adrenal gland poster Flashcards

1
Q

Where is the adrenal gland located?

A

Retroperitoneal- on the superior aspect of the kidneys.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What two glands can the adrenal gland be divided into?

A

The medulla and the cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

From superficial to deep-name the four layers of the cortex

A

Connective tissue
Zona glomerulosa
Zona fasciculata
Zona reticularis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the zona reticularis secrete and what regulates it?

A

It secretes adrenal androgens such as DHEA (sex hormones) and is regulated by ACTH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the zona fasciculata secrete and what controls its secretion

A

It secretes glucocorticoids such as cortisol and is regulated by ACTH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the zona glomerulosa secrete and what is it regulated by?

A

Secretes mineralocorticoids such as aldosterone.

Regulated by K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the medulla secrete?

A

Catecholamines such as adrenaline and noradrenaline.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When is aldosterone released?

A

When there is a fall in NaCl, blood pressure or extracellular fluid volume.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can the zona glomerulosa secrete more aldosterone?

A

Stimulus means cell growth occurs releasing more hormone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Conns syndrome?

A

Primary aldosteronism. An adenoma in the zona glomerulosa resulting in increased aldosterone secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the NaCl, water, potassium, renin and aldosterone levels in Conns syndrome

A

NaCl in high concentrations because it is being reabsorbed.
Water also in high concentrations.
Pottasium in low concentrations (hypokalaemia)
Renin will be low because it is trying to inhibit the release of aldosterone. Aldosterone will be high.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is adrenal hyperplasia?

A

Presents the same as Conns syndrome causing secondary hypertension however it is bilateral.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How would you diagnose someone with Conns syndrome or adrenal hyperplasia?

A

Renin- Aldosterone ratio.
If it is greater than 750 then need to do a saline suppression test.
Give 4L of saline over two hours. Then record renin and aldosterone levels. Would expect renin to fall and aldosterone to fall. Needs to decrease by 50% to be deemed normal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Treatment of Conns syndrome and adrenal hyperplasia

A

Conns syndrome- surgery

Adrenal hyperplasia- can’t remove both glands therefore have to give an aldosterone receptor blocker (spiranolactone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is the release of cortisol stimulated?

A

By ACTH from the anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the regulation of cortisol

A

The hypothalamus releases corticotrophin releasing hormone (CRH) which stimulates the anterior pituitary to release ACTH. ACTH then stimulates the adrenals to release cortisol.
Stress/illness and diurnal rhythm also stimulate the hypothalamus to release CRH.
The release of cortisol has a negative feedback system which inhibits the release of ACTH from the anterior pituitary and CRH from the hypothalamus.

17
Q

What are the functions of cortisol?

A

It increases lipolysis increasing plasma free fatty acids.
It decreases glucose uptake within tissues (except the brain)
Increases gluconeogenesis in the liver.
It also acts on the muscle increasing proteolysis meaning there is an increase in the plasma amino acids.

18
Q

Why does the body need glucocorticoids?

A

When the body is stressed these provide it with energy sources from carbs, fats and proteins.
Cortisol also increases the bodies responsiveness to adrenaline therefore preventing shock and helps with circulation.
It is also an anti-inflammatory and immunosuppressive at high levels.

19
Q

What would you expect from cortisol hyper secretion?

A

Decreased protein synthesis therefore muscle wasting
Increased lipolysis meaning there is an increase in free fatty acids that become centrally distributed around the body.
Macrophage activity and cytokine production decrease in the body (immunosuppression)
Cardiac output and blood flow increase due to the increased sensitivity to adrenaline
Reduces osteoblast activity in bone and decreases collagen formation.

20
Q

Symptoms of cortisol hyper secretion

A 
Moon face- due to redistribution of fat
Central obesity for the same reason
Easy bruising and slow healing
Purpura striae 
Muscle wasting 
Polyuria and polydipsia due to the increase in plasma glucose levels
Osteoporosis
Sense of euphoria.
21
Q

What is Cushings syndrome?

A

Hypersecretion of cortisol. Many causes- ACTH dependent, ACTH independent or ectopic cancers.

22
Q

What is ACTH dependent cushings syndrome?

A

Most commonly -When there is a pituitary adenoma that secretes ACTH. This then stimulates the adrenal glands to secrete cortisol. The ACTH will not be suppressed by negative feedback because there is just too much being released.

23
Q

What is ACTH independent Cushings syndrome?

A

Hypersecretion of cortisol from the zona fasciculata. Meaning that ACTH levels will be low but cortisol will still be high.
Could be due to
Adrenal adenoma, adrenal carcinoma or nodular hyperplasia.
Most commonly is adenoma.

24
Q

Ectopic cancers and cushings syndrome

A

Ectopic cancers produce ACTH from elsewhere in the body. Means that the adrenal glands are stimulated.
Most commonly cancers in the lung, the thymus or the pancreas.

25
Q

Complications of Cushings syndrome

A

Due to the zona reticularis also being regulated by ACTH- an increase in production of sex hormones will occur.
Dehydroepiandosterone (DHEA) is a pro hormone to the sex steroids- therefore increasing amounts of testosterone will be present.

26
Q

How will increased sex hormone release affect patients?

A

Women will present with acne, amenorrhoea, frontal balding and facial hair growth.
Men will have lack of libido and impotence and acne.

27
Q

How do you diagnose cushings syndrome?

A

Low dose dexamethasone test.

28
Q

What is dexamethasone? And how will it effect people without cushings?

A

A very potent glucocorticoid that is not naturally produced by the body.
Cortisol levels should decrease when a normal person gets this due to it suppressing the release of ACTH.

29
Q

Describe the processes of a low dose dexamethasone test and a high dose dexamethasone test.
Include the results you’d expect from someone with Cushings.

A

Low dose- 2mg a day for two days of dexamethasone.
Measure cortisol levels (need to be less than 50nmol/litre to be clear
High dose- 2mg/6 hourly. If cortisol isn’t suppressed then it would either be an ectopic cancer or an ACTH independent tumour.

30
Q

Why can high dose dexamethasone tests differ between ACTH dependent and ACTH independent?

A

Giving high levels of dexamethasone should suppress the ACTH released from the tumour as well as the functioning pituitary gland. So if cortisol is not suppressed after this you know it is not a pituitary adenoma.

31
Q

Treatment of Cushings disease?

A

Metyrapone- stops the secrete of cortisol. Is a 1-1-beta hydroxylase inhibitor.
Ketoconazole- works in the same way
Surgery- once the cortisol is under control you would ideally do surgery. If pituitary adenoma- transsphenoidal approach. If adrenal hyperplasia- bilateral adrenolectomy.

32
Q

Which cells release adrenaline in the medulla?

A

Chromaffin cells.

33
Q

Effects of adrenaline on the body.

A

Increase heart rate and force (beta 1)
Peripheral vasoconstriction (alpha 1)
Cause vasodilation of skeletal muscle (beta 2)
Cause decreased insulin secretion from islet cells (alpha 2)
Increase gluconeogenesis and glucogenolysis (alpha 1 and beta 1)

34
Q

What would a patient with hyper secretion of adrenaline present with?

A

Increased heart rate and force- tachycardic
Pallor or excessively flushed
Excessive sweating
Hypertension
Constipation- fight or flight doesn’t include digestion
Palpitations
Polydipsia and polyuria (due to no insulin secretion and high levels of glucose)

35
Q

What is the classic triad of features of adrenaline hypersecretion?

A

Hypertension
Sweating
Headaches

36
Q

What is a pheochromocytoma?

A

A tumour of the sympathetic ganglia cells that secrete catecholamines.

37
Q

Where do pheochromocytomas usually occur?

A

In the adrenal gland.

If they are outside the adrenal gland it is called a paraganglioma.

38
Q

Why is it called the 10% tumour?

A 
10% extra-adrenal
10% malignant
10% bilateral
10% in children
10% hereditary (MEN2)
39
Q

How would you diagnose a pheochromocytoma?

A

Measure urinary catecholamines. If raised then do a MRI or CT scan.
MIBG scan is more specific

Endocrine (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions