path 1/2- hypothalamus/pit

adenohypophysis

anterior lobe of the pituitary gland

neurohypophysis

posterior lobe of the pituitary gland

blood supply to the anterior lobe of the pituitary is mostly

venous --> portal system

blood supply to the posterior lobe of the pituitary is mostly

arterial

which lobe of the pituitary is more vulnerable to hypoperfusion

anterior

somatotrophs release

GH

lactotrophs secrete

prolactin

thyrotrophs release

TSH

corticotrophs release

ACTH

gonadotrophs release

FSH and LH

lactotrophs are stimulated by

TRH

lactotrophs are inhibited by

dopamine

2 functions of oxytocin

uterine contraction

milk ejection

Functional pituitary adenoma

hormonal excess

assocaited clinical s/s

Nonfunctional pituitary adenoma

non-hormone producing

no clinical s/s

invasive adenomas

not encapsulated

infiltrating neighboring tissues (cavernous and sphenoid sinuses)

describe what bitemporal hemianopsia looks like

what is seen in microscopy for pituitary adenoma

monomorphic polygonal cells arranged in sheets/cords

prolactinomas have a tendency to

calcify

atypical adenomas

brisk mitotic activity

Ki-67 +

P53 +

peak incidence for pituitary adenomas

35-60

most common hyper functioning pituitary tumor

prolactinoma

s/s of prolactinoma in women

amenorrhea

galactorrhea

infertility

s/s of prolatinoma in men

dec libido

impotence

galactorrhea (rare)

physiologic causes of hyperprolactinemia

pregnancy

breastfeeding

stress

drugs than can cause hyperprolactinemia

birth control

haloperidol

alpha methyl dopa

reserpine

____thyroidism can lead to hyperprolactinemia

hypo

bc of inc TRH

2nd MCC of pituitary adenoma

GH adenoma

functions of GH

IGF-1 synthesis in liver

gluconeogenesis + aa uptake in muscle

functions of IGF-1

stimulates growth of bone (linear and lateral), cartilage, soft tissue

IGF-1

insulin-like growth factor 1

acromegaly can cause what other disease

diabetes mellitus

MSK findings for acromegaly

weakness

carpal tunnel

lumbar canal stenosis

lab findings for acromegaly

inc GH

inc IGF-1

definitive test for acromegaly

oral glucose tolerance test

pos = failure of GH to dec after ingesting glucose

microscopic findings for acromegaly

densely granulated acidophilic monomorphic cells (strong + for GH)

sparkly granulated chromophobic pleomorphic cells (weak + for GH)

treatment for acromegaly

surgery

somatostatin analog

GH R antagonist

Cushing syndrome

too much cortisol

Cushing disease

too much cortisol due to ACTH secreting pituitary adenoma

Nelson's syndrome

pituitary adenoma discovered years after BL adrenalectomy for chushings syndrome

due to loss of inhibitory effect of cortisol of a preexisting corticotroph adenoma

S/S of nelson syndrome

hyperpigmentation

is there high cortisol w/ nelson syndrome

no (adrenals removed)

most important sign of pituitary carcinoma

craniospinal or systemic metastasis

are pituitary carcinoma or metastatic tumors more common

metastatic tumors

MCC of SIADH

Small cell carcinoma of the lung

hypofunction of the AP happens when ___% or more of the parenchyma is lost

75

Causes of hypopituitarism

tumors/lesions

brain trauma

subarachnoid hemorrhage

ablation of pituitary (surgery/radiation)

pituitary apoplexy

Sheehan

pathogenesis of Sheehan syndrome

AP enlarges in pregnancy w/o inc in blood supply --> relative anoxia

further blood less due to obstetric bleeding/shock = infarction of AP

s/s of sheehan syndrome

empty sella syndrome causes

hypopituitarism

empty sella syndrome

congenital sella defect

herniation of arachnoid & CSF into the sella compresses & destroys pituitary gland

pituitary gland is "absent" on imaging

hypothalamic lesion in children that causes hypopituitarism

craniopharyngioma

MCC of hypopituitarism in children

Craniopharyngioma

craniopharyngioma is derived from

Rathke's pouch

age for craniopharyngioma

bimodal

5-15

60-70

s/s of craniopharyngioma

headache

endocrine def

mass effect

central DI

what craniopharyngioma variant is MC in kids

adamantinomatous

what craniopharyngioma variant is MC in adults

papillary

appearance of craniopharyngioma

cystic, "motor-oil" fluid filled

areas of calcification

histo of craniopharyngioma

cholesterol crystals

keratinizing squamous cells

calcifications

s/s of dec gonadotropins in men

low libido

impotence

testes shrink

s/s of dec gonadotropins in women

low libido

dyspareunia (painful sex)

breast atrophy

s/s of GH def in infants

hypoglycemia

TSH deficiency

secondary hypothyroidism

dec T4 and TSH

ACTH def

secondary adrenal insufficiency

hypoglycemia

prolactin def

failure of lactation in post-partum pts

MSH def

pallor due to loss of stimulatory effects of MSH on melanocytes

ADH and oxytocin are synthesized in the

neurons of the supraoptic and paraventricular nuclei in hypothalamus

causes of central DI

transection of pituitary stalk

hypothalamic disease

posterior pituitary disease

what part of the nephron is affected in nephrogenic DI

collecting tubules

causes of nephrogenic DI

hypokalemic nephropathy

drugs

nephrocalcinosis

drugs that can cause nephrogenic DI

Lithium, demeclocycline

what can be done to differentiate DI from other causes

fluid deprivation test

urine concentrated in normals, not in DI

what can be done to differentiate pituitary from renal causes of DI

desmopressin stimulation or administration of ADH

CDI --> inc urine concentration

NDI --> no urine conc

principle secretory product of pineal gland

melatonin

pineal gland tumor commonly take the form of

germinomas