Endocrine Disorders 2 Flashcards
What feedback mechanism controls hypothalamic and pituitary hormone secretion
Negative
What hormones work on the thyroid gland
TRH - Thyroid releasing hormone (from hypothalamus)
TSH - thyroid stimulating hormone (from pituitary)
What hormones work on the Adrenal Cortex
CRH - corticotrophin releasing hormone (from hypothalamus)
ACTH - Adrenocorticotrophic hormone (from pituitary)
What hormones does the adrenal cortex release
Glucocorticoids
What hormones work on the Gonads
GnRH - Gonadotrophin releasing hormone (from hypothalamus)
FSH - Follicle stimulating hormone and LH - luteinising hormone (From pituitary)
What are the mechanisms by which endocrine disorders manifest themselves
– Overproduction of hormones
– Underproduction of hormones
– Normal function but structural defect for e.g. compression due to enlargement
What are the causes/aetiology of endocrine disorders
– Primary dysfunction of gland
– Secondary dysfunction of gland ( over or understimulation by other gland or exogeneous hormones)
– Receptor dysfunction
Where is the thyroid gland located
Just below the cricoid cartilage of the pharynx come bop bop
What hormones does the thyroid hormone release
Thyroxine hormones T4, T3
What are the target organs of the thyroid gland
Brain Bone Heart Gut Skin Metabolism
Where are the adrenal glands found
Both are found on top of the kidneys
What part of the adrenal glands produce which hormones
- Cortex - Androgens
- Medulla - Cortisol, Aldosterone, Adrenaline
What adrenal disorders cause overproduction
- Cushing’s Syndrome
- Phaeochromocytoma
What adrenal disorders cause underproduction
Addison’s disease
What kind of disorder is addison’s disease and what can it be associated with
Autoimmune
Can be associated with TB and sarcoidosis
What can cause secondary addisons disease
Pituitary not producing enough ACTH
Exogenous Steroids
What are the physiological actions of cortisol
– Anti-inflammatory and immunosuppressive actions
– Stress response
– Metabolism
■ Gluconeogenesis
What can happen if we produce excess steroid hormones/cortisol
– Stimulates hepatic gluconeogenesis and glycogenlysis- elevated blood glucose
– Stimulates proteolysis- muscle wasting
– Sodium retention , potassium loss- limb/facial swelling
– Stimulates lipolysis-Dyslipidaemia
– hypertension
What are the clinical features of Addison’s disease
- Hypotension
- Hypoglycaemia
- Weight loss
- Lethargy
- Anorexia
- Abdominal pain
- Skin and oral pigmentation (Increase MSH and ACTH)
How can exogenous steroids cause secondary adrenal insufficiency
- Mainly for patients on long term systemic steroids
- Can cause suppression of HPA axis upon discontinuation
- Should taper down the dose
What is an Addisonian crisis
– New presentation
– Precipitated by infection
– Non-compliance with medication
– Poor absorption of steroids (diarrhoea)
– Life-threatening if untreated (medical emergency)
Why must oral infections be managed aggressively in patients with adrenal insufficiency
To prevent an acute adrenal insufficiency - addison ian crisis
What is the steroid cover for major procedures
– IM Hydrocortisone 100mg QDS, 1 hr prior to treatment on day of surgery and until oral intake satisfactory
– Once oral intake satisfactory, double oral dose for 3-5 days
– Consult endocrine specialist for individualised plan
What is the steroid cover for minor procedures
Take double oral steroid dose at same time (24 hour should be sufficient)
What are some steroid precautions that you should be aware of
– Steroid card, bracelet
– Emergency intramuscular Hydrocortisone pack
– Sick day rules
Where are the parathyroid glands
They’re like 4 nodules on the back side of the thyroid
What do the parathyroid hormones release and what effect does this hormone have
Parathyroid hormone - regulates the calcium levels in the blood
What can Primary hyperparathyroidism be caused by
– Parathyroid adenoma
– Parathyroid hyperplasia including genetic familial HP, MEN
– Parathyroid carcinoma