Endocrine Flashcards
(212 cards)
what is the relationship between hypothalamus, pituitary and adrenal gland
hypothalamus releases releasing hormones to pituitary in brain
pituitary releases secreting hormones to adrenal
adrenal gland feeds back to hypothalamus
what things can go wrong with glands (3)
overproduction
underproduction
benign/malignancy
where do we find adrenal glands
1 on the superior aspect of each kidney
what is the shape and structure of an adrenal gland
triangular/pyramidal in shape
Composed of cortex and medulla.
Cortex (outer part) composed of three layers; zona glomeruloa (produces aldosternone), zona fasciculata (produce cortisol), zona reticularis (produce androgenic steroids).
Medulla (inner part of gland) produces stress hormones (adrenaline and noradrenaline).
what is the cortex of the adrenal gland split into and what do they produce
Cortex (outer part) composed of three layers; zona glomeruloa (produces aldosternone), zona fasciculata (produce cortisol), zona reticularis (produce androgenic steroids).
what does the medulla of the adrenal gland produce
produces stress hormones (adrenaline and noradrenaline).
how can we detect adrenal problems
24 hour cortisol urine test
Serum ACTH levels
Diurnal pattern of serum cortisol levels
Dexamathasone suppression test
what are the 3 main pathway causes of adrenal problems
Secondary: disease of pituitary or hypothalamus
Primary: adrenal disease: Developmental, haemorrhagic necrosis, autoimmunity, destruction by TB or tumour
Iatrogenic: Suppression due to steroid therapy
if the adrenal gland is yellow and cheese like in the middle, what is the likely cause
tuberculosis
what does Waterhouse-Friderichsen syndrome affect and how does it resent
causes haemorrhage of the adrenal gland cortex
adrenal glands turn black with blood clot
what are some effects of adrenal insufficiency
Skin pigmentation
Hypotension
Muscle weakness
Hypoglycaemia
Hyponatraemia
Hyperkalaemia
Renal dysfunction
what are some causes of adrenal overactivity
Cushing’s syndrome - adrenal tumours, iatrogenic
Cushing’s disease – pituitary microadenomas
Conn’s syndrome - excessive aldosterone
compare cushing’s syndrome and cushings disease
Cushing’s syndrome - adrenal tumours, iatrogenic
Cushing’s disease – pituitary microadenomas
what does Cushing’s syndrome cause
Obesity
Hypertension
Osteoporosis
Hyperglycaemia
Myopathy
Skin atrophy
Polycythaemia
Susceptibility to infection
what is Paroxysmal hypertension and what is this a key sign of
rapid increase in blood pressure that slightly decreases over time
sign of Phaeochromocytoma
what is Phaeochromocytoma and what is its key symptom
Tumour adrenal medulla forming a catecholamine producing tumour
Paroxysmal hypertension
how do we decide the behaviour of pheochromocytoma
PASS: pheochromocytoma of adrenal gland scoring system.
Could be malignant or benign. Metastasis is indicator of malignancy.
what is the pathway of thyroid gland secretions
hypothalamus secretes thyroid releasing hormone TRH
pituitary released thyroid stimulating hormone TSH
thyroid releases T3 and T4 - inhibit hypothalamus and pituitary
how might we diagnose thyroid problems
Serum T3, T4, TSH, calcitonin
Ultrasound
Radioactive iodine uptake studies
FNA cytology - fine needle aspiration
Core biopsy
why is cytology good for thyroid diagnosis and why might it be disadvantageous
Safe- Reduces need to excise benign lesions
Thy 1-5 categories
Can establish diagnosis of some types carcinoma: papillary, medullary, anaplastic
Can’t distinguish between benign and malignant follicular lesions
which type of thyroid cancer can cytology not differentiate between malignant and benign
follicular
what might cause hypothyroidism
Iodine deficiency
Developmental
Autoimmune
Radiotherapy, radioiodine therapy
Drugs
what might cause hyperthyroidism
Autoimmune
Toxic adenomas
masses
what is goitre
swollen thyroid gland = large swollen neck