Endocrine

Question 1

what is the endocrine system?

Answer 1

• system of the glands and organs
• make hormones
• release them into the blood
• to other tissues and organs

Question 2

how does the hypothalamus and pituitary gland work?

Answer 2

• afferent fibres to the hypothalamus
• hypo sends signals to the pituitary
• pituitary produce hormones to go into circulation
• hormone stimulates another gland to produce an active hormone

both can affect the action of the pancreas

Question 3

what glands can the pituitary gland act on?

Answer 3

thyroid
adrenal
testes and ovaries

Question 4

what is the feedback loop? how does it work in the thyroid for example

Answer 4

it either amplifies or reduces the systems behaviour

hypothalamus tells pituitary to produce hormone
- pituitary releases the hormones
- the presence tells the hypothalamus not to stimulate the pituitary anymore

Question 5

Thyroid
- where is it
- pathway from the hypothalamus
- what conditions can affect it?

Answer 5

lower anterior neck

• TTRH released from hypothalamus and acts on pituitary (thyrotropin releasing hormone)
• TSH is produced by pituitary (thyroid stimulating hormone)
• act on thyroid gland
• produces - T4 and T3
• act on peripheral tissues - function -»_space;> metabolic activity

conditions
- goitre - thyroid swelling, moves when you swallow
- iodine deficiency - ‘Derbyshire Neck’ - have hypothyroidism

Question 6

describe hypothyroidism
-aetiology including iatrogenic.
- describe congenital hypothyroidism
- symptoms
- treatment

Answer 6

• low T3 and T4 produced by the thyroid

aetiology
- iodine deficiency
- drugs
- auto-immunity - destroys thyroid

iatrogenic - thyroidectomy or radio-iodine treatment (for thyroid cancer)

congenital hypothyroidism
- in childhood
- leads to development delay and short stature

symptoms
- weight gain
- loss of energy and appetite
- low heart rate, low BP
- intolerable to the cold
- thoughts slow down, depression
- hair and nail changes

tx: thyroid replacement therapy - taking hormone meds

Question 7

describe hyperthyroidism
- signs/symptoms
- aetiology
- treatment

Answer 7

symptoms
- weight loss
- tachycardic
- atrial fibrillation
- heart murmur
- palpitations
- heat intolerance
- tremor

psychological symptoms - anxiety, mania/psychosis

aetiology
- auto-immune
- thyroid tumour
- graves disease - autoimmune, body produces antibodies that stimulate the thyroid to produce T3 and T4

treatment
- thyroidectomy - partial/complete removal of the thyroid
- radio-iodine - thyroid takes up the iodine, the radioactivity damages the gland

Question 8

how do you test for hyper/hypothyroidism

Answer 8

clinical examination - heart rate, weight loss
blood tests - TSH, T3, T4

imaging - ultrasound, CT, MRI

Question 9

adrenal glands
- where are they
- the pathway from the hypothalamus
- what hormones do they produce
- what type of feedback loop is it?

Answer 9

situated just above the kidneys

1. hypothalamus releases corticotrophin releasing hormone (CRH)
2. pituitary releases adrenocorticotrophic hormone (ATCH)
3. acts on the adrenal cortex to release cortisol

hormes:
- glucocorticoids - cortisol - function = glucose metabolism
- mineralocorticoids - aldosterone - function = salt and water balance
- adrenaline, noradrenaline - function = HR, BP
- androgens - function = masculinisation

= negative feedback loop

Question 10

what condition do you get when there is excess cortisol produced by the adrenal cortex?
- symptoms
- aetiology

Answer 10

Cushing’s Syndrome

syndromes
- central obesity - apple on a stick
- diabetes
- peripheral wasting and weakness
- facial hair
- thin hair and skin
- acne
- moon face
- buffalo hump

aetiology
- iatrogenic-steroid prescription
- Cushing’s Disease
- other tumours secreting ACTH - lung cancers etc

Question 11

whats the difference between Cushing’s Syndrome and Cushing’s Disease?

Answer 11

Cushing’s Syndrome
- excess cortisol

Cushing’s Disease
- a pituitary adenoma secretes ACTH

Question 12

what 2 conditions can you get when there is insufficient adrenal hormones?

Answer 12

Addisons disease
Addisonian Crisis

Question 13

Addison’s Disease
- definition
- aetiology
- epidemiology
- symptoms
- treatment

Answer 13

autoimmune destruction of adrenal gland

• epidemiology = rare

symptoms
- malaise
- weight loss
- nausea, vomming
- fatigue
- depression
- muscle pain
- joint pain

treatment:
- take steroids daily

Question 14

Addisonian Crisis
- definition
- aetiology
- pathophysiology
- symptoms
- those at risk

Answer 14

acute adrenal insufficiency - life-threatening

aetiology = Secondary Adrenal Atrophy
- patient has exogenous steroids (manmade)
- mimics cortisol
- negative feedback, < CRH, <ACTH secretion = atrophic adrenal gland and produce less cortisol
- adrenal becomes unable to respond
- body won’t be able to respond well to stress

non-specific symptoms
- malaise
- weight loss
- nausea, vomming
- fatigue, depression
- muscle and joint pain

those at risk:
- long term oral steroids - >5mg Prednisolone/day for 4 weeks
- OR high dose short courses >40mg prednisolone for 7 days
- OR inhaled steroids >1000mcg/day - usual = 800mcg/day
- think about combined dosage of inhaled, oral, cream, injections or nasal

Question 15

if a patient had Addison’s disease or taken steroids above a certain level, what would they carry around with them?

Answer 15

a steroid emergency card

• tells px what to do if they feel unwell
• how to manage their sick days
• tells healthcare prof what to do

Question 16

how do you manage Addison’s in the dental setting?

Answer 16

1. do not stop the steroids
   - will make the px unwell
2. assess the risk
   - Addison’s - high risk
   - steroid treatment - low risk
3. does the px need steroid cover?
   Addisons
   - exam or radiographs - no
   - restorations, hygiene - additional dose 1hr before
   - extractions - double dose pre-op + 24hrs after
   surgery - 100mg hydrocortisone prep, double dose 24hrs after

Exogenous Steroids
- exam or radiographs - no
- restorations, hygiene - no
- extractions - double dose pre-op
- surgery - 100mg hydrocortisone prep, double dose 24hrs after

4. post-op
   - patient education - dry socket, infection, post-op pain
   - maintain fluids
   - don’t stop steroids
   - adrenal crisis warning signs - hypotension, malaise, fatigue, vomiting - take additional steroids - steroid rescue pack and see doctor

Question 17

what systems do a drop in calcium affect?

Answer 17

cardiovascular system
central nervous sytem
GIT

Question 18

what major hormone influences bone?

Answer 18

parathyroid hormone

Question 19

parathyroid hormone
- produced by?
- whats there a risk of with a thyroidectomy?
- link with the hypothalamus and pituitary
- how does it affect the bone and kidneys?

Answer 19

produced by parathyroid glands

• risk of taking the parathyroid gland out with a thyroidectomy
• doesn’t have anything to do with the hypothalamus or the pituitary
• effect on bone - stimulates osteoclasts - releases calcium into the blood
• effect on kidney - stimulate metabolism of vitamin D3 into calcitriol - stimulates absorption of calcium from the gut - increase calcium in the blood

Question 20

hypoparathyroidism
- aetiology
- what does it lead to?

Answer 20

• autoimmunity
• thyroidectomy

leads to hypocalcaemia

Question 21

hyperparathyroidism
- aetiology
- what does it lead to?

Answer 21

primary causes
- PTH secreting tumour
- other cancers

secondary causes
- hypocalcaemia - negative feedback
- vitamin d deficiency - negative feedback
- renal failures

Question 22

give 4 presentations of hypercalcaemia

Answer 22

kidney stones
weak bones
abdominal groans
psychic moans