Pituitary and Hypothalamus Flashcards
Hypthalamus hormones
Releasing homrones
GnRH CRH TRH PRH GHRH ADH Oxytocin
The paradigm
Hypothalamus releasing to pituitary…pituitary stimulating to end organ…end organ systemic that feedback on hyphtalamus and piutity
Thyroid hormones
TrH—–TSH—-Free T4
Cortisol horomones
CRH—-ACTH—-Cort
Pituitary adenomas includingmass effects
Most common anterior
Benign
Visual impairments
Increased ICP
Enlargement of sella turcica
Hypopituitaritarism
Compression of anterior lobe…needs to be compressed over 75% to have clinical effect
Pituitary stalk syndrome
Impedes transit of dopamine from hypothalamus to anterior lobe
Disinhibition of lactotrophs
Prolactinoma (symptoms and signs) and tx
Premenopause - amenorrhea, galactorrhea, infertility
post - may not be apparent
Bromocriptine or transspendoidal resection
Somatotroph adenoma
Excissive GH
Acromegaly (post puberal) - fused epiphyses prevent bone overgrwoth Pituitary gigantism (prepubertal) - non fused enable bone overgrowth
Both acromegaly and pituitary gigantism associated with
Soft tissue overgrwoth Organomegaly DM, HTN, CHF Arthropathy, myopathy Hypogonadism
Acromegaly
Postpubertal onset
Bones of face, hand and feed
Apositional growth (non-longitudinal)
Pituitary giagntism
Prepubertal
Bones include longitudinal growht
Corticotroph adenoma clinical manifestations
Obesity (back) Osteoporosis Skin fragility DM HTN
Cushing’s syndrome vs. dz
Dz - from corticotroph pituitary adenoma
Syndrome - anything else
Syndrome could be from steroid tx, broncial carcinoid tumor, or other tumr
Most corticotroph adenomes are
microadenomas
IPSS
Inferior pterosal-sinus sampling used to determine the side of the tumor in Cushing’s dz
Sample ACTH
Blood supply of pituitary
Anterior only portal system…means suspect to thrombosis
Shock (hypotension)
DIC
Sickle cell
Increased ICP
Pituitary apoplexy
Happens when anerior lobe is dying
Sheehan syndrome
Postpartum pituitary necrosiss
Hypertrophy of anterior lobe during preganancy secondary to lactotroph hyperplasia
Exacerbates susceptibility of anterior lobe
Typically a delayed onset
Empty sella syndrome
Risk - chonric intracranial hypertension
May be in obese multiparous women
DI
Central diabetes insipidis
Not enough ADH
Lesion of median eminence or posterior lobe…below median eminence can cause transient
Polyuria, nocturia, polydipsia
Tx with ADH
SIADH causes
Nervous system disorders
Neoplasms
Pulm dz
Drugs
SIADH clinical and tx
Dilutional hyponatremia
Tx with fluid restirction
Overcorrection of hyponatremia is SIADH
CPM or EPM
Osmotic demyelination
