E: Pituiatry labs Flash Cards

Play Memory | Create Card File | Append to Card File
Title: E: Pituiatry labs
Description: Kathryn's lecture/syllabus pt 1
Number of Cards: 17
Save Count: 0
Author: DRS
Created: 2010-02-17
Tags: endocrine medicine pathophysiology test1
Private No

Save Count represents the number of people who have saved this card set to their flashcard list. Consider this an endorsement!

    • Question
    • Answer
    • Side 3
    • What are some things can can cause variations in hormonal patterns?
    • cicadian, seasonal, episodic pulses of release (stressors, meals, exercise, menstrual cycle, varies with age), positional changes
    • Is protein-bound hormone biologically active? What does "total" give you?

      What types of proteins can bind hormones?
    • no. Just the free is active.

      Total = protein bound + free

      albumin, prealbumin (transthyretin), and specific carrier proteins (cortisol binding globulin, thyroid binding globulin, IGF b/ protein)
    • List the anterior pituitary hormones. Then, list the cells responsible, the releasing hormones, the inhibiting factors (if any), the target gland, and the function.
    • - ACTH: Corticotropes; Corticotropin RH (CRH), AVP; <N/A>; adrenal; stimulation of corticoS and adrenal Androgens.
      - GH: Somatotropes; GHRH; Somatotropin rel. inhib. fc. (SRIF); Perip. tiss & liver; direct and indirect (IGF-1) growth stim.
      - PRL; lacto; TRH; PIF; Mammary, stim of lactation
      - TSH; Thyro; TRH; SRIF, PIF; Thyroid; stim of thyroid hormone release
      - LH; Gonado; GnRH; <N/A>; Ovary/testis; stim of E and T
      - FSH; gonado; GnRH; <N/A>; "..."
    • What is another name for GnRH?

      SRIF?

      What is the main PIF?
    • LHRH

      somatostatin or GHIH (GHIF)

      DA is the main one.
    • What non-hypothalamic peptide has recently been found to play a role in GH regulation by directly inducing secretion of both GHRH and GH?
    • Ghrelin
    • What sets the baseline for GH? What controls the spikes?
      - additional secretory control?
    • inhibitory (SRIF)
      GH-RH does the pulsatile activity
      - ghrelin
    • What initiates the synth of IGF-1 by the liver?
      - what effects does IGF-1 have on tissues?
    • GH.
      - bunch of insulin like effects, as well as promoting the growth of cartilage.
    • Is GH release pulsatile? Episodic?

      Under what conditions should we strive to measure GH lvls in pts?
    • both

      fasting, at rest for 30min, but NOT asleep.
    • On GH stimulation test, 70% of normal people will show what? The other 30%?
      - what does this mean re: dx of GH def?
      - what types of stimulations are used for a "GH stim" test?
    • increase in GH of 7-10 ng/mL or 3 times over baseline
      - won't show a "normal" increase
      - sometimes two abnormal stim tests are thus required before a dx of GH def. is made.
      - 20-30 min of exercise; arginine; Glucagon; L-DOPA; Clonidine
    • Is a low IGF-1 specific for GH def?
    • no, you have to rule out poor nutrition, renal dz, hypothyroidism, psychological dz, etc.
    • What is a test that is done for GH excess?

      What is seen in this test for pts with GH excess?
    • oral glucose challenge
      - then measure serial GH lvls.
      - you'd expect a suppression

      Pts either (1) don't show suppression or (2) show a paradoxical increase in GH lvls (~20% of pts)
    • Regulation of PRL is stimulatory or inhibitory? What is the main factor? What are the factors for the opposite function?
    • primarily inhibitory
      Main PIF = DA

      TRF, Vasoactive intestinal peptide, Estrogen.
    • What is the most common hypothalamic-pituitary disorder investigated?
      - most common etiology for lvls >150ng/mL?

      Does the converse have any clinical importance?
    • hyperprolactinemia
      - PRL > 150 usually means a PRL secreting tumor.
      - no, PRL deficiency has no recognized clinical importance.
    • When Anterior Pituitary fx is lost due to destruction or compression, what is the order of hormone actv loss? What might happen to PRL lvls?
    • GH --> LH/FSH --> TSH --> ACTH

      they might be high because their reg is primarily inhibitory.
    • What three conditions lead to polyuria?
    • HDI (CDI), NDI, psychogenic polydipsia
    • Walk through the assessment of a pt that presents with polyuria.

      When do you look for non-ADH-related causes?

      Next step if we decided it *is* related to ADH?
    • - 24hr urine collection
      - urine glucose
      - Serum osmolality, serum Na, and fasting glucose

      + if osm > 295 or serum Na >145, look for non-DI causes.

      Water deprivation test --<duration>--> once urine osmol's are constant, admin AVP! One of 3 things will happen:
      - Normal/psychogenic etiology: only 3-5% drop in BW during water dep test; serum osmol & Na WNL; urine osm no change.
      - HDI: ^serum Na or osm; AVP --> u osm ^^ ... NDI: " "; but w/ no change in u osm on AVP
      - partial HDI/NDI: u osm > 300.... *measure ADH lvls on earlier samples to see if appropiate to Na and osm
    • Pt's lab values:
      - low serum Na, osm, urea N, uric acid
      - urine osm (>300) > serum osm
      - high ADH
      - low renin actv (--> low aldosterone)

      Dx?
    • SIADH: autonomous, sustained production of ADH in the absence of known stimuli
      - this is presuming you can rule out cardiac, hepatic, renal, thyroid, adrenal, and drug related causes.