MOD 5 Flashcards
What can pituitary growth do to vision?
pit tumor can compress optic chaism giving headaches and diplopia etc
Which pituitary (ant or post) makes its own hormones?
anterior! post just releases them
What does somatostatin inhibit
GH and TSH!
What does TRH stimulate?
TSH and PRL!
What gets converted to T3?
Free (unbound) T4!
What does LH do? FSH?
GnRH (pulsatile) in hypothal causes LH and FSH from ant pit. LH goes to Leydig cells in testes to make testosterone, and FSH goes to Sertoli cells in testes to make Inhibin B (and mature sperm)
In females, LH and FSH go to ovary and stimulate estriol and inhibin
What stim PRL?
TRH!
What does PRL inhib?
GnRH and thus FSH/LH (for inhibiting ovulation)
What drugs stim PRL secretion?
estrogens such as OCPs, and DA antags such as antipsychotics
What does PRL stim secretion of?
DA! DA inhibits PRL
What hormone does GH stim?
IGF-1 from liver! and SS!
What inhibits GH?
Somatostatin and IGF-1 (igf also inhib GHRH)
What does IGF-1 stim in hypothal?
SS! (igf stim SS which inhib GH)
What is the glucose tolerance test?
used to find cause of excess GH
give glucose which should inhib GH, if GH still high then there may be pit adenoma
post pit is made of?
SON (ADH) and
PVN (oxytocin, lactation and uterine contraction)
ADH receptors
V2- on basolateral memb of distal
V1 on SM regulates bp
most impt determinant of ADH release
plasma osmolality!
DI
central
nephrogenic
and tests
DI = DILUTE urine (cant conc urine)
- central: not making enough ADH
- nephrogenic- making adh but kidneys resistant to it
- dipsogenic DI is excess water drinking
- test with water deprivation test: if urine still dilute, is DI. if give desmopressin (DDAVP) and still dilute, its nephrogenic
Insulin tolerance test
-giving insulin to stim hypoglycemia
should cause increase in ACTH, cortisol and GH (these are diabetogenics)
Cushings disease vs syndrome
Acquired disorder of the pituitary
- Cushings Disease: pit ADENOMA making too much ACTH
- SYNDROME is just excess cortisol from adrenal glands making too much
Hyperprolactinemia vs Real Prolactinemia
Hyper- elev PRL due to drugs hypothy etc
Real- elev PRL due to pit adenoma!
what can elev PRL cause?
infertility, amenorrhea from neg feedback to pit (suppr LH and FSH), galactorrhea in women, irreg menstru, breast atrophy; in men may cause impotence, visual field abnormalities if large and affecting optic chiasm
Tx for elev PRL
bromocriptine or carbegoline (DA agonist) or surg
Dont eval PRL levels during….
preg! bc always high
Null Cell tumor
endocrinologically inactive tumor, only alpha chains (eg same in TSH HL and GH) are made, may show positive immunostaining
GH excess causes
gigantism in kids, acromegaly in adults (incl bone enlargement, sep of teeth, HTN and impaired glucose tolerance bc diabetogenic)
tx for GH excess
surg, rad, somatostatin analog to suppress GH, or GH-R antag, DA agon (last resort)
GH deficiency
reduced strength, incr fat, decr muscle, intolerance to cold, incr waist hip ratio, thin dry skin, low labile mood
SIADH
too much ADH results in fluid retention so LESS SALT (HYPONATREMIA) in blood (euvol but less salt ratio)
Para-pituitary tumors
Craniopharyngeoma compresses optic chiasm causing bitemporal hemianopsia (CONFUSED with pit adenoma bc similar sx), pit stalk can be severed during surg
Hypopituitarism
laceration of stalk, trauma, radia, infarct, iniltrations of sarcoid/langerhans histio/hemochromatosis (must rule out esp in hypognadism), infxn (TB, abcess, syphilis), Sheehan’s
Sheehan’s syndrome?
post-partum pit necrosis, can’t lactate
Why does DM incr sus to infxn?
bc of hyperglycemia!
How does hyperglycemia make DM pts more prone to infxn?
-GLYCOSYLATION of proteins is ABNORMAL
-PHAGOCYTE dysfxn (so macros dont work properly/migrate)
-PERFUSION to tissues is reduced (too much ROS and not enough NO, so vasoconstr), and endoth/SM dysfxn causing vessel damage
-NEUROPATHY of lower extremities increases infxn
(NOT due to immunodef!)
Infxns that are more likely in DM?
Pneumonia UTI TB react Candida Lower extremity ulcers w osteomyelitis Malignant otitis externa Zygomycosis Fournier's gangrene Emphysematous cholecystitis
What tx do we give pts with foot ulcers with or without underlying osteomylelitis?
With means > 6 wk of IV abx, possible surg, if no osteo then 2-6 wk oral abx
Charcot’s foot
ligaments and bones in foot displaced leading to swelling (worsens bc pain unnoticed by pt), assoc with osteomyelitis
What is osteomyletiits in foot ulcer and how do you dx?
ulcer all the way down to bone
dx with imaging etc
drainage is sign of DM foot infxn, along with inflam markers such as ESR and CRP (more advanced form is ulcer-assoc osteomyelitis, chronic)
What abx coverage do you give for minor vs major diabetic foot infxn?
Minor- gram + coverage
Major- ALSO gram - and anaerobes
staph and strep are common causes
what happens if no tx for DM foot ulcer infxn?
amputation
What strep org may lead to foot infxn?
strep AGALACTAE
gram + org that grows in chains, B-hemolytic
What is Fournier’s gangrene
orgs
tx
necrotizing infxn of genetalia and and perineum
- gram + incl MRSA gram - and ana
- tx with METRO and clindamycin
Murcormycoses/Zygomycoses
- causes rhinocerebral infxn (eg caused by Rhizopus bread mold)
- Ketoacidosis reduces affinity for transferrin freeing up iron which fungal cells use
- CNS issues, invasion of blood vessels
- Black escar on nares/mouth
- dx: biopsy, histo: nonseptate RIGHT ANGLE BRANCHINGHYPHAE
- tx antifungal or surge etc
Emphysemetous cholecystitis
orgs
compl
infxn of GB with gas forming orgs (eg CLOSTRIDIUM), leads to GAS GANGRENE/perforation
Malignant otitis externa
org
sx
tx
ext ear infxn extending to soft tissue bone and possibly CNS
- caused by PSEUDOMONAS aeruginosa
- pain at night then causes bells palsy and osteomyelitis of TMJ
- tx with ciprofloxacin (but res so can use cefs or piper/tazo or carbs), or surg if later
What should we vax for in DM
Influenza, pneumococcus, varicella
Foot care!
Things like GANGRENE, FUNGAL infxns, OTITIS, OSTEOMYELITIS, etc are caused by?
DM!
as well as foot ulcers
