Endocrine

- Pituitary gland- anterior & posterior- anterior (adenohypophysis), posterior (neurohypophysis)- Anterior produce hormone and secrete into systemic circ.

It secretes follicular stimulating & luteinising (gonadotropin), growth (somatotropins), prolactin, thyroid stimulating (tyrotropin), adrenocorticotropic (corticotropin)

- Posterior din produce. It release. Hypothalamus produce oxytocin and vassopressin that secreted from nerve axon into capillary bed, store in cells and released by posterior pit gland into circ.

- Vasopressin (antidiuretic hormone) act on V2 R of distal tubules to reabsorp water, thus incr total body water & decr urine vol

{if def of antidiuretic hormone, the v2 fail to reabsorp water thus caue polyuria subsequently polydipsia}- Oxytocin cause contraction of uterine muscle (labour) & initiate mechanism of breastfeeding

-hypopituitarism => low trophic hormone (hormone from pituitary gland) > low target hormone > subphysiological stimulate of pituitary hormone (however it is suboptimal, inappropriate or absent) > low target hormone & normal or low trophic hormone

Hypopituitarism• Reduced secretion of ant pituitary hormone, follow the seq growth hormone>

gonadotrophins (follicular-stimulating, luteinising hormone)> prolactin> thyroid hormone> adrenocorticotrophic hormone, antidiuretic hormone GGPTAA

Causes(according etiology)********-tumour (pituitary tumour, craniopharyngioma)-trauma-iatrogenic – irridation, surgery-infection –encephalitis-infarction – seehan’s syndrome(according anatomy)-hypothalamus: Kallman’s syndrome, tumour, infection, infarction, inflammation-pituitary stalk: mass lesion (craniopharyngioma), meningioma, trauma, surgery, carotid artery aneurysm- pituitary: infiltration (haemochromatosis, metastases, amyloid), tumour, irridiation, inflammation, autoimmune, ischaemia (Sheehan’s syndromw, pituitary apoplexy)

Signs & symptoms1. GROWTH HORMONESx: -Hypoglycaemia (dizzy, hunger, weakness, trembling, numbness)-dry wrinkly skin-reduced balance strength exercise ability wellbeing-osteoporosisSigns: -short stature-central obesity2. GONADOTROPHINSx: -Impotence/ reduced libido-Irregular menses-Infertility/ dyspareunia/ erectile dysfx-Osteoporosis Signs-Hypogonadism- sparse axillary, pubic and facial hair-Hypogonadism- Small breast, clitoris( female), small penis & testes (male)-High- pitched voice-Thin skin

3. ADRENOCORTICOTROPHIC HORMONESxNon specific-nausea, fatigueHypoglycaemiaSignsPallor (skin, areola)4. THYROID HORMONESx-Cold intolerance-Fatigue-ConstipationSigns-bradycardia-hypothermia-slow relaxation of knee jerk

5. PROLACTINSxFailure of lactation

6. ANTIDIURETIC HORMONESxPolyuria, polydipsia

Ix1. Basal test-follicular stimulating, luteinising hormone, testosterone, estradiol-insulin-liked growth factor-prolactin-thyroid function test-thyroid stimulating hormone, free t4-cortisol-U&E (Na+ decr)-Hb (normochromic normocytic)

2. Dynamic test-short Synacthen test-insulin tolerance test -arginine + growth hormone releasing test- Glucagon stimulation test (alternative for insulin tolerance test if failed)

Thyroid gland enlargement

• Hyperthyroidism– Graves disease– Multinodular goiter– Malignancy

• Hypothyroidm– Iodine deficiency (esp in endemic area)– Hashimoto’s thyroiditis

• Others– Familial goiter

Hypothyroidism

• Causes– Destruction– Drugs– Enzyme deficiency - dyshormonogenesis– Autoimmune T– H

• History taking– Causes, symptoms, diagnosed (onser sx, test done,

medication, complication), family history, other associated autoimmune disease

– Cold intolerance, lethargy, weight gain– 手 cold intolerance, dry scaly skin, Carpal tunnel

syndrome – numbness, pain, tingling (myxoedematous infiltration causing compression on the median nerve), Muscle weakness

– 头 Alopecia, coarse brittle hair, lethargy, impaired memory and cognition

– 脸 Facial changes: loss of lateral 1/3 of eyebrow, periorbital puffiness, hoarseness of voice

– GI- constipation, decr apetite, weight gain– Sexual – menorrhagia

• PE (refer pg 55)• Q & A• Neurological manifestation and why

– Carpal tunnel synd (infiltration of myoedematous causing compression of median n)– Myopathy (segmental demyelination in peripheral nerve> decr nerve conduction velocity>

polyneuropathy> weakness)– Slow relaxation of ankle knee jerk– Pseudodementia (impair hippocampal neurogenesis, maturation and differentiation in

development of brain> memory and cognition impairment)– Cerebellar syndrome (antithyroid Ab mediated immune response> cerebellar

degeneration)– Myoedema coma (ultimate hypothyroidism state before death may preceded by

surgery(thyroidectomy/radioiodine/pit surgery), infection, MI, stroke, trauma)• Cvs manifestation and why• Causes of aneamia• Autoimmune disease associated

– DM– Pernicious anaemia– Rheumatoid arthritis– Myasthenia gravis– Hypoparathyroidism– Addison’s disease