Adrenal glands

Question 1

The adrenal gland is made up of…

Answer 1

• capsule
• outer cortex
• medulla

all of seperate embyrological origins

Question 2

What are the layers of the cortex?

Answer 2

zona glomerulosa
zona fasciculata
zona reticularis

Question 3

The adrenal cortex contains triglyceride droplests, what is the purpose of this?

Answer 3

they are used for steroid production

Question 4

The cortex is regulated by…

Answer 4

hypothal and pituitary hormones

Question 5

What are the characteristics of the adrenal medulla?

Answer 5

• made up of chromaffin cells
• no lipids
• stimulated by sympathetic nervous system

Question 6

What hormones are produced in the zona glomerulosa? What is the function of these hormones

Answer 6

• mineralcorticoids- aldosterone
• regulate electrolyte homeostasis; kidney- blood pressure

Question 7

What hormones are produced in the zona fasciculata? What is the function of these hormones

Answer 7

• glucocorticoids cortisol
• regulates glucose homeostasis

Question 8

What hormones are produced in the zona reticularis? What is the function of these hormones

Answer 8

• androgens
• regulates male characteristics

secondary sex hormones

Question 9

What hormones are produced in the adrenal medulla? What is the function of these hormones?

Answer 9

catecholamines- adrenaline, noradrenaline
fight or flight response

Question 10

Why is cortisol able to stimulate mineralcorticoid receptors?

Answer 10

this is because they share similar strutures and all cells in the adrenal glands start with the base raw material of cholesterol

Question 11

Aldosterone is stimulated by the ______ pathway

Answer 11

RAA - renin- angiotensin aldosterone pathway

Question 12

What is the function of aldosterone?

Answer 12

• increases sodium reabsorption at the kidney (therefore water reabsorption)
• promotes potassium exctretion at kidney
• increases blood volume and thus blood pressure

Question 13

Briefly describe the RAA pathway

Answer 13

• renin released by kidneys when there is a drop in blood pressure and volume
• renin acts on angiotensinogen to form angiotensin I
• ACE released from the lungs converts angiotensin I to angiotensin II
• angiotensin II has a direct impact on the blood vessels, stimulating vasoconstriction; increasing blood pressure
• angiotensin II acts on adrenal glands and stimulated release of aldosterone from ZG; aldosterone acts on distal convoluted tubules and increased Na2+, Cl- reabsorption; thus increases water reabsorption and causes an increase in blood volume

Question 14

The production of cortisol in the ZF is stimulated by… produced by the __________

Answer 14

Adrenocorticotrophic hormone (ACTH)
anterior pituitary gland

Question 15

The functions of cortisol are __________ and __________

Answer 15

• metabolic and immunologic (immunosuppresant, anti-inflammatory)

Question 16

What are the functions of cortisol ?

Answer 16

• promote fat breakdown- adipose tissue
• cortisol counteracts insulin to increase blood glucose levels- pancrease
• decreases amino acid uptake by muscle
• glucose generation in the liver
• reduces bone formation

Question 17

Plasma cortisol vary according to a diurnal rhythm, briefly describe normal plasma cortisol levels throughout the day?

Answer 17

• plasma cortisol levels are greatest in the morning
• lower at night

Question 18

The purpose of cortisol is…

Answer 18

to help the body cope with emotional and physical stress

Question 19

Briefly outline the substrates used in production of mineralcorticoids

Answer 19

Cholesterol —> Prenenolone —>progesterone –> 11 deoxy-corticosterone –> corticosterone –> 18-OH corticosterone –> aldosterone

Question 20

Briefly outline the substrates used in production of glucocorticoids

Answer 20

Cholesterol –> prenenolone –> 17-hdroxyprenenolone –>17-hydroxyprogesterone –> 11-deoxycortisol —> cortisol

Question 21

Briefly outline the substrates used in production of sex hormones

Answer 21

Cholesterol –> Prenenolone –> 17-hydroxyprenenolone–> DHEA –>androstenedione –> testosterone –> dihydrotestosterone (DHT)

Question 22

What is the main androgen in men?

Answer 22

testosterone

Question 23

_________ are precursors to oestrogen in women

Answer 23

Androgens

Question 24

What is the function of androgens?

Answer 24

development and maintenance of male charatceristics

Question 25

The release of catecholeamines from the adrenal medulla is stimulated by ...

Answer 25

sympathetic preganglionic neurones

Question 26

What is the function of catecholamines released by adrenal medulla?

Answer 26

* increases plasma glucose- glycogen broken down by liver, stimulates glucagon release, inhibition of insulin releae * promotes lipolysis in adipose tissue * increases metabolic rate * increases cardiac output (increases contractility and HR; inotropy) * relaxation of peripheral smooth muscles (bronchodilation, increased muscle blood glow, decreased GIT activity) bronchodilation- lungs more open; allows breathing | GIT- gastrointestinal tract

Question 27

What is the effect of the stress response on visceral effector tissue ?

Answer 27

* increased heart rate and force of beat * constriction of blood vessels most near the skin and viscera * dilation of blood vessels of heart, brain, lungs and skeletal muscles * contraction of spleen * conversion of glycogen into glucose in liver * dilation of airways * decrease digestive activities * water retention and elevated blood pressure

Question 28

What is Cushings disease?

Answer 28

a disease of the pituitary gland; pituitary tumour, usually benign leads to excess secretion of ACTH

Question 29

What is the consequence of cushings disease ?

Answer 29

increased cortisol production

Question 30

What is cushings syndrome?

Answer 30

usually an issue in adrenal gland signs and symptoms associated with excess cortisol increased cortisol decreased ACTH (due to negative feedback effect)

Question 31

What are the potential causes of cushings syndrome?

Answer 31

* adenoma * adenocarcinoma * hyperplasia of the adrenal gland can also be caused by therapeutic steroid use e.g. prednisolone

Question 32

Outline the presentation of Cushings (disease/syndrome)

Answer 32

* moon face * central obesity; peripheral wasting * flushing * buffalo hump * stretch marks * menstrual irregularity (uterus cannot maintain its weight) * hypertension (cortisol acts on MRs) * diabetes- blood glucose levels * osteoporosis- stops synthesis of bone * acne * depression * decreased libido * hisrsuitism | MR- mineralcorticoid receptors

Question 33

What are the risk factors for cushings (disease/syndrome)

Answer 33

* pituitary oedema * exogenous steroid use * Female * adrenal adenoma * lung cancers- produce hormones that mimic cortisol

Question 34

What is the management of cushings disease?

Answer 34

* surgical resection of offending tumour * post surgical hormone replacement (hydrocortisone)

Question 35

Synthetic cortisol is...

Answer 35

hydrocortisone

Question 36

What is the management of cushings syndrome?

Answer 36

rationalise the use of steroids decrease steroids in reducing regime

Question 37

What is addisons disease?

Answer 37

autoimmune disease that wipes out the adernal cortex autoantibodies in the adrenal cortex

Question 38

What is the consequence of addisons disease?

Answer 38

reduced or absent release of cortisol and aldosterone hypotension hypoglycaemia

Question 39

What is the cause of hyperpigmentation in addisons disease?

Answer 39

* lack of negative feedback * leads to release of a hormone called pro-opiomelanocortin (has similar effects to ACTH and MSH) * results in hyperpigmentation | MSH- melanocyte stimulating hormone

Question 40

What is the presentation of addisons disease?

Answer 40

* fatigue * anorexia * weight loss * hyperpigmenation of mucosa and sun exposed areas - includes mouth * nausea * postural hypotension * vomiting

Question 41

What are the first line therapies of addisons disease?

Answer 41

* oral glucocorticoud and mineral corticoid replacement for life

Question 42

What is the hormone replacement therapy for aldosterone?

Answer 42

fludrocortisone acetate

Question 43

During periods of stress, trauma, infection and pregnancy; how should you adjust your hormone replacement therapy in addisons disease

Answer 43

glucocorticoid replacement should be increased

Question 44

What is the cause of acute adrenal insufficiency?

Answer 44

usually due to suddenly stopping exogenous steroids adrenal hypotrophy as they are no longer used to producing steroids

Question 45

What are the symptoms of acute adrenal insufficiency?

Answer 45

Hypotension (aldosterone) vomiting hyperkalaemia (lack of aldosterone) hyponatraemia (lack of aldosterone) hypoglycaemia (lack of cortisol) seizures confusion

Question 46

What is the management of an acute adrenal insufficiency?

Answer 46

ABCD resuscitation IV hydrocortisone IV fluids

Question 47

What are the dental considerations for addisons and cushings syndrome?

Answer 47

poor wound healing mucosal hyperpigmentation in addisons consider steroid replacement if on long term steroids quality of bone implants

Question 48

What is a pheochromocytoma?

Answer 48

tumour of the adrenal medulla can be isolated or with MEN2 syndrome | MEN- multiple endocrine neoplasia

Question 49

What is the consequence of a pheochromocytoma?

Answer 49

secretion of large amounts of catecholamines- adrenaline and noradrenaline

Question 50

What is the clinical presentation of a pheochromocytoma?

Answer 50

hypertension sweating headaches tachycardia tremours anxiety headaches sweating palpitations