2 Endocrine Workshop Flashcards
What is the purpose of cortisol
Maintains BP - water and salt homeostasis
What are the three main hormones secreted by the thyroid and their actions
T3 - main hormone
T4 - pro-hormone
Calcitonin - reduced blood calcium for bone turnover - opposing effect to parathyroid hormone
t 3 or t 4 is more powerful?
T 3
More t 3 or 4 is produced
80% t 4 - converted peripherally to t3 in the liver etc.
How is thyroid hormone regulated
Hypothalamus releases trh
Pituitary releases TSH
Thyroid releases thyroid hormones
What is trh
Tyroppid releasing hormone
How does iodine in affect thyroid funciton
Thyroid hormone is synthesised from circulating iodine. Excessive or insufficient causes dysfunction
What are 2 main physiological functions of thyroid hormone
Growth and development
Metabolism
Name three drugs that can induce thyroid diseases
Lithium
Amioderone
Cholestyramine p
How does amioderone affect thyroid function
Hypo caused by blocking conversion of T4 to T3
Hyper due to iodine content of the drug
How does lithium affect thyroid function
Hypo – inhibits iodine uptake and thyroid hormone release
Hyper – unknown mechanism
How does cholestyramine affect thyroid funciton?
Affects absorbtion of levothyroxine
Signs of hypothyroidism
Fatigue Cold sensitivity Dry skin and hair Depression Impaired concentration and memory Muscle pain and weakness Horse voice Pernicious anaemia (megloblstic b12 deficient)
Treatment for hypo thyroidism
T four is treatment of choice.
Exclude hyhpopituitaryism
Signs of hyperthyroidism
Insomnia Tremor Irritability Weight loss Decreased appetite AF Diarrhoea
Treatment for hyperthyroidism
Antithyroid drugs - propylthiouracil, thiamazol, carbimazole
Symptoms of Cushings
Weight gain Thinning skin, brides easily Purple stretch marks Moon face, buffalo hump Decreased interest in sex Oestoperosis
Treatments for Cushings
Eradicate tumours
Reduce steroid dose
Metyropone/ketoconazole
Symptoms of addisons diseases
Fatigue Lethargy Muscle weakness Low mood Loss of appetite Frequent urination Thirst Hyperpigmentation Craving salty food
Treating Addisons diseases
Glucocorticoid replacement : hydrocortisone
Mineralocorticoid replacement: fludrocortisone
Signs of over and under replacement in addisons
Over - hypertension, glucose intolerance, thin skin, hyperglycaemia, electrolyte abnormalities
Under - fatigue, postural hypotension, weight loss, salt craving.
Goals of hypothyroidism treatment
symptom relief
Normal TSH levels - not too low as osteroperosis risk
When to monitor TSH levels?
Change slowly so 4-6 weeks after initiating therapy and then annually.
Laxative guidelines
exercise, fibre, fluids
1: bulk forming
2: osmotic if hard, stimulant if soft
Opioid- osmotic or docusate
