Flashcards
Pituitary disease
Cards in this deck (26)
- 1Where is the hypothalamus and what does it do? See Met2 notes PBL6The hypothalamus is located below the Thalamus and above the Pituitary gland. It is part of the limbic system and links the nervous system to the endocrine system by secreting releasing hormones which stimulate the pituitary gland Its the size of an almond.
- 2Describe the pituitary glandLies outside dura in sella turcica below optic chiasm - accessible via sphenoid bones.
Anterior secretes 6 hormones: ACTH, GH, LH, FSH, TSH, Prolactin
Posterior secretes Oxytocin and ADH, supplied by inferior hypophyseal artery and drains into hypophyseal veins directly into systemic circulation - 3For each hormone describe disease of excess or deficiencyGH - Acromgaly and GH deficiency
Prolactin - Hypogonadism and Failed lactation
FSH/LH - Rare and Hypogonadism
ACTH - Cushings and Adrenal insufficency (Addisons)
TSH - Hyper and hypothyroidism
ADH - SIADH and diabetes insipidus - 4Pituitary adenomas cause which clinical symptomsHypersecretion of hormones leading to: Prolactinoma (amenorrhea or abscece of menstruation/glactorrhea - milky discharge from nipple), Acromegaly, Cushing's, Thyrotoxicosis (secondary)
Mass effect also causes: headaches, vision loss, pituitary hyposecretion, pituitary apoplexy (hypopituitarism due to low 02 at childbirth due to bleeding) - 5What sizes are pituitary micro and macro adenomamicro is <1cm
macro is >1cm - 6Prolactinoma: signs, symptoms, tests and treatmentsSymptoms: amenorhea/glactorrhea, erectile dysfunction
Signs: glactorrhoea, hypohonadism, bitemporal hemianopa
Tests: prolactin, LH/FSH, MRI
Mx: Dopamine agonists as dopamine inhibits prolactin release (bromocriptine/cabergoline) - 7Causes of high prolactinProlactinoma
Antacids
Anti-psychotics
Anit-emetics
LActation/pregnancy
Stalk compression
Dopamine antagonist
Stress
Seizures - 8GH excess conditionsGigantism due to GH excess is before puberty where growth plates are still open
Acromegaly due to GH excess after puberty as growth plates have now closed - 9Describe Acromegaly signs, symptoms, tests, treatmentsAcromegaly usually due to tumour
Symptoms: headaches, sweating, increased ring size, arthralgia, carpal tunnel, atherosclerosis, diabetes
Signs: Big hands, coarse face, big supraorbital ridge, wide spaced teeth,
Tests: Serum IGF-1 main test followed by Oral glucose tolerance test to confirm - normally raised glucose stops GH but in acromegaly GH does not stop.
Mx: Excision, Ocreotide (Somatostatinanalogue) Pegvisomont (GH antagonist). - 10What is the function of ACTHACTH stimulates release of cortisol and so its release is early morning as is cortisol
- 11What is the function of cortisolCortisol is produced by the adrenal glands in response to stress and hypoglycaemia. Cortisol raises blood sugar by simulating gluconeogenesis, lipolysis and inhibiting glucose uptake
- 12What is Cushing'sCushing's syndrome is due to excess ACTH usually due to a pituitary adenoma. It is ACTH dependent. It affects 30-50yr olds.
Cushings can be ectopic - due to small cell lung cancer
ACTH independent Cushing's - adrenal issue - adenomas, steroids - 13Cushing's signs and symptomsMETABOLIC ALKALOSIS
Moon face
Central obesity
OSTEOPOROSIS
Diabetes
Excess hair growth
Amenorrhoea
Mood change
Buffalo hump
BRUISES
Skin weakness
MUSCLE WEAKNESS - 14Cushing's screeningCortisol levels
24hr urinary free cortisol
1st line: Overnght Dexamethasone Suppression test: it suppresses ACTH so lowers cortisol but not in Cushing's. Give at night and assess in morning
2nd line: if 1st line abnormal. 48hr Dexamethasone test
Plasma ACTH - if undetectable then likely adrenal tumour
Insulin stress test induces hypoglycaemia so should cause cortisol release - 15Cushing' s treatmentTransphenoidal surgery
Adrenolytics - Ketoconazole and Metyrapone - 16Hypopituitarism - the worksLoss of ACTH, GH, LH/FSH, TSH, Prolactin
Due to adenoma, irradiation, infarction (Sheehans)
Symptoms: loss of libido, amenorhoea, impotence, depression, hypothyroidism, weakness
Signs: pallor, hypothyroid, no pubic hair, visual defects, hypotension
Tests: insulin stress test; Low T4; MRI;
Mx: Hydorcortisone first, testosterone, HRT - 17What is pituitary ApoplexyPituitary Apoplexy is an abrupt acute haemorrhagic infarction of a pituitary adenoma
Presents with headache, visual impairment, Low GCS
Mx: surgery and glucocorticoid replacement due to adreneal insufficiency (cortisol) - 18What hormones does the adrenal gland produce See Met2 notes3 zones of cortex producing steroids
Zona Glomerulosa: Mineralocorticoids (Aldosterone)
Zona Fasciculata: Glucocorticoids (cortisol)
Zona Reticularis: Androgens (testosterone)
Renal medulla produces catecholamines adrenaline and noradrenaline - 19Revise RAASKidneys detect low volume and release Renin
Renin converts angiotensin from liver to angiotensin 1
ACE from lings converts angiotensin 1 to 2
Angiotensin 2 lead to Aldosterone secretion and re-uptake of salt increasing blood volume
Angiotensin 2 leads to vasoconstriction increasing pressure; also ADH secretion leading to H20 reabsorption - 20Cushing's is due to excess ACTH. What results from ACTH deficiency?Addison's or adrenal insufficiency
- 21Describe Addison's Signs symptomsDue to hypoadrenalism, lack of ACTH
Chronic: Weight loss, anorexia, fatigue, increased pigmentation (see slides), dizzy on standing, nausea and vomiting
Postural hypotension, vitiligo
In Addisonian crisis there is dizzyness on standing, nausea and vomiting, abdo pain, collapse, hypoglycaemic symptoms, severe hypotension, hypoglycaemia, shock - death - 22What do blood tests show in AddisonsLAw salt (normal 135-145) and high potassium (normal (3.6-5.2)
METABOLIC ACIDOSIS
Low glucose//cortisol - do 9am cortisol test
Do ACTH stimulation test (short synathen test)
Give synthetic ACTH and check cortisol - if suboptima then hypoadrenalism
Adrenal antibodies in Addisons - 23Addison's managementIf Addisonian crisis its an emergency; Give 0.9% saline with IV hydrocortisone.
Longer term oral hydrocortisone
Educate patient, carry steroid pack and wear steroid bracelet to show. Can double dose when ill. Also take before exercise - 24What are the causes of Addison's/adrenal insuffuciencyPrimary adrenocortical insufficiency = destroyed adrenal cortex - usually autoimmune, a be TB, also metastases
Secondary adrenal insufficiency = iatrogenic - long term steroid therapy suppresses pituitary-adreno axis - 25What are the sick day rulesSteroid card
Medico-alert bracelet
Never miss a dose
Double dose if febrile
IM injection
Admission for parenteral steroids if vomit, diarrhoea, severe illness - 26Describe primary hyperaldosteronismPrimary hyperaldosteronism is too much aldosterone from the adrenal glomerulosa due to either adenoma (Conn's) or hyperplasia
Hypertension
Hypernatraemia
Hypokalaemia
Muscle weakness
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- MET3B Flashcards on Pituitary disease, created by Gaffer Ji on 21/06/2020.
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