ENDOCRINE Flashcards
What is the arrangement of the endocrine system
- hypothalamus (recieves signals from nerves/ peripheries)
- piturity gland: secrete hormones to specific glands- thyroid, adrenal, overaries/ testes/ pancreas
How does the endocrine system work?
feedback loops
What is the role of the thyroid
regulate metabolic activity: secrete T4 &Calcitonin
How does the thyroid hormone work?
stimulated by PTH
1. T4-> T3
Hypothalamus (pth)
thyroid (t4->t3)
What is a goitre
thyroid gland is not getting enough iodoine
hypothalamus hormone produces TRH which cause thyroid to grown (goitre)
What is hypothyroidism and the causes of it?
Hypothyroidism: low T3/ T4
causes: idodine deficiency, drugs (carbazepine), goitre
- autoimmune destruction of thyroid (HASHIMOTOS)
- thyroidectomy
Signs and symptoms of hypothyroidism
- slow heart rate
- low bp
- low energy
- weight gain
- loss of appetite
- cold tolerance
- hair and nail changes
-depression
What is congential hypothyroidism and how does it present
t3 and t4 required for growth and development
- results in a short stature and developmental delay
What is meant by hyperthyroidism
increased t3 & t4
what are the signs and symptoms of hyperthyroidism
- tachycardia
- anxious
-loss of weight - heat intolerance
-temor - mania
- heart murmer
- diarrohea
-bulging of eyes
What are the causes of hyperthyroidism
Autoimmune stimulation: Graves disease
- thyroid tumour
Management
suppress activity: remove gland, radio-iodine
What is hashimotos
autoimmune disorder attacking thyorid gland- less t3&t4 produced
what is graves disease
Auto immune disease causing increase in t3/t4
What is the role of adrenal + give examples
produces hormones:
glucorticoids - manage sugar and energy: glucose metabolsim
mineralocorticoids: aldosterone salt & water - heart rate, blood sugar
corticosteroids: andrenaline
andogren: masculitinity
Give the pathway for adrenal cortex stimulation
hypothalamus: CRH
Pituitary gland: ACTH
Adrenal gland: cortisol
How does synthetic corticosteroids affect feedback loop
act same way as corticosteroids:
stops hypothalamus producing CRH
- Less ACTH
- Less cortiosl
What is cushing syndrome
excess cortisol production from adrenal cortex
What are the signs and symptoms of cushing syndrome
- diabetes, moon face, buffalo hump, acne, thin hair, facial hair, thin skin, peripheral wasting and weakness
What are the causes of Cushing syndrome
- iatrogenic damage
- iatrogenic damage- steroid prescription
- cushing disease
- other tumours secreting ACTH
What is cushing disease
piturity adenoma secreting ACTH
What is adrenal insufficency
Low cortisol levels
What are the signs and symptoms of adrenal insufficiency
Non-specific:
Malaise, weight loss, nause, vomiting, abdominal pain, fatigue, depression, muscle pain, joint pain
What are the causes of adrenal insufficency
- primary adrenal insufficiency: ADDISIONS DISEASE
- Secondary adrenal insuffiency: atrophy of adrenal glands due to exogenous steorids. Therefore, hypothalamus stimulates adrenal gland less:
- adrenal gland unable to respond to illness etc
What does adrenal insufficency affect?
affects mineralocorticoids, glucocorticoids, (salt water balance), catecholamines ( maintain blood pressure)→ more profound effects
Pt who has addisions what do they take
take daily endogenous steroids
Who is at risk of secondary adrenal insufficency
- Long term oral steroids (>5mg prednisolone/da for 4 weeks)
- High dose short courses (40>mg prednisolone for 7 days repeated/ also taking long term lower doses)
- Inhaled steroids (>1000mcg/day) usual dose is 800mcg/day
How do you manage a pt at risk of secondary adrenal insufficency
- don’t stop taking steroids
- assess risk (addisions higher than steroid tx)
- assess steroid cover
- educate pt and ensure enough steroids
- maintain fluids
- prescribe steroids/ extra if needed
What are the signs of adrenal crisis
Postural hypotension, malaise, fatigue, vomiting
What is the role of PTH
control calcium homeostasis & bone metabolism
Where is PTH secreted from
parathyroid hormone
Describe how PTH works
LOW BLOOD CALCIUM LEVEL:
- Detected by parathyroid gland→ PTH is produced
- PTH mainly affects bone (osteoclasts to dissolve bone, release calcium into blood)
- Small effects on kidney (stimulates vitamin D3 is calcitriol stimulates absorption of calcium from the gut)
Increasing levels of calcium
What is hypoparathyroidism
Parathyroidism glands working less: lower blood calcium- less pTH
What are the causes of hypoparathyroidism
- autoimmune
- thyroidectomy
- hypocalcemia
what are the causes of hyperparathyroidism
overreactive parathyorid gland: mobile and absorb more calcium
primary:
- pTH secreting tumour
- tumour of parathyroid gland
- other cancers
secondary causes:
- renal failure
vitamin deficiency- cannot asborb calcium
What is the consequence of hyperparathyroidism
Hypercalcaemia
Stones, bones (osteoporosis/ pathological fractures), abdominal groans (constipation, obstruction of gut), psychic moans
