clinical biochemistry II final exam review

primary endocrine diseases

affect target organs, ex: thyroid, adrenal glands

secondary endocrine disorders

affect the gland that regulates the target organ, usually the pituitary gland

tertiary endocrine disorders

arise from the hypothalamus

corticotropin releasing hormone (CRH)

increases ACTH and other hormones

thyrotropin releasing hormone (TRH)

increases thyroid stimulating hormone (TSH)

gonadotropin releasing hormone (GnRH)

increases follicle stimulating hormone (FSH) and luteinizing hormone (LH)

Prolactin inhibiting factor (PIF)

decreases prolactin (PRL)

prolactin releasing factor (PRF)

increases prolactin (PRL)

growth hormone releasing hormone (GHRH)

increases growth hormone

melanocyte inhibiting factor (MIF)

decreases melanocyte stimulating hormone (MSH)

antidiuretic hormone (ADH)

increases reabsorption of water and vasoconstriction of smooth muscle

oxytocin

stimulates uterine contraction

stimulates milk let down

diabetes insipidus

caused by a decrease of ADH from a pituitary tumor

SIADH

caused by an increase of ADH from a pituitary tumor

panhypopituitarism

caused by a decrease of all pituitary hormones

lactotrophic adenoma

caused by an increase of prolactin from an adenoma

somatotropic adenoma

caused by an increase of GH from an adenoma

adrenocorticotropic adenoma

caused by an increase of ACTH from an adenoma

medulla site

chromaffin cells

medulla hormone type

catecholamines

medulla hormones

dopamine

epinephrine

norepinephrine

action of dopamine, epinephrine, and norepinephrine

short term stress

precursor of dopamine, epinephrine, and norepinephrine

tyrosine

cortex sites

zona glomerulosa (outer)

zona fasciculata (middle)

zona reticularis (inner)

zona glomerulus hormone type

mineralocorticoids

zona fasciculata hormone type

glucocorticoids

zona reticularis hormone type

androgens

mineralocorticoid hormone

aldosterone

glucocorticoid hormone

cortisol

androgen hormone

testosterone

cortex hormone action

long term stress

cortex hormones precursor

cholesterol

dopamine final metabolite

HVA

epinephrine and norepinephrine final metabolite

VMA

pheochromocytoma

caused by an increase of epinephrine and norepinephrine from a chromaffin cell tumor

hypertension, tachycardia, sweating, headaches

neuroblastoma

caused by sporadic increases of epinephrine and norepinephrine from neuron precursor cell tumor (usually in adrenal gland in children)

action of cortisol

increases glucose levels by gluconeogenesis and glycogenolysis

diurnal secretion (peaks in the morning and trough at night)

aldosterone action

regulation of sodium and potassium by reabsorption of those ions in kidneys

renin-angiotensin pathway

1. renin: secreted by kidneys in response to low blood pressure, low sodium conc, converts to angiotensinogen

2. angiotensin I: converted into angiotensin II by ACE

3. angiotensin II: a potent vasoconstrictor that increases blood pressure by narrowing blood vessels, also stimulates the release of aldosterone from the adrenal glands which promotes sodium and potassium excretion

porter-silber method

tests for 17-hydroxycorticosteroids in urine to determine levels of cortisol

zimmerman method

tests for 17-ketogenic steroids in urine to determine levels of cortisol

ACTH stimulation test

synthetic ACTH is given to patient very 30 min

used when cortisol is low to determine if absence of ACTH of an adrenal insufficiency

if increased the lack of ACTH is due to pituitary problem (secondary disorder)

if unchanged low cortisol is due to a primary disorder

dexamethasone suppression test

patient is given dexamethasone then the cortisol level is drawn the next day in the morning

dexamethasone is an analog of cortisol that suppresses the secretion on ACTH

if levels are normal ACTH is suppressed and cortisol drops

if levels are increased the adrenal gland is suspected

congenital adrenal hyperplasia

caused by a decrease of enzymes to synthesize adrenal hormones

ACTH is increased and cortisol is decreased

hyperplasia of adrenal cortex

cushing’s (hypercortisolism)

caused by adenoma, nodules or carcinoma

ACTH is decreased and cortisol is increased

glucose intolerance, increased sodium, loss of diurnal variation

moon face, hyperplasia

Addison’s

chronic adrenal insufficiency caused by an autoimmune response

ACTH is increased and cortisol is decreased

weakness, fatigue, hyperpigmentation

Conn’s (hyperaldosteronism)

caused by an adrenal adenoma

aldosterone is increased

hypertension, polyuria, polydipsia

structural unit of the thyroid gland

follicle

lumen

each follicle of a single circle of cell surrounds this

filled with colloid

hypothyroidism

intolerance to cold

anorexia

hair loss

hyperthyroidism (Graves disease)

bulging eyes

intolerance to heat

enlarged thyroid

LCSH (LH) in males

stimulates interstitial cells (cells of leydig) in the testes to produce androgens, especially testosterone

FSH in males

along with testosterone, stimulates spermatogenic cells in seminiferous tubules to produce sperm

testosterone

stimulates development of a man’s primary and secondary sex characteristics and affects their sexual behavior. Along with FSH, stimulates spermatogenic cells to undergo spermatogenesis, feeds back to hypothalamus and pituitary where it inhibits GnRH secretion and LH

inhibin

maturing sperm causes sertoli cells in seminiferous tubules to secrete this, which leeds back to pituitary inhibiting its production of FSH

FSH in females

stimulates ovaries to develop mature follicles, follicles produce increasingly high levels of estrogen

LH in females

stimulates the release of the ovum by the follicle. follicle then converted into a corpus luteum that secretes progesterone

estrogen

stimulates repair of endometrium of uterus, negative feedback inhibits hypothalamus production of GnRH

progesterone

stimulates thickening of and maintains endometrium, negative feedback effect inhibits hypothalamus production of LH

prolactin

stimulates milk production after childbirth

androgens in females

stimulates sexual drive

hCG

stimulates production of progesterone

female reproductive cycle

1. follicular phase: hypothalamus signals the pituitary gland to release FSH which stimulates the growth of ovarian follicles, as those develop they produce estrogen

2. ovulation: a surge of LH triggers the release of a mature egg from the dominant follicle in the ovary

3. luteal phase: the ruptured follicle transforms into the corpus luteum which secretes progesterone

estradiol

screening for ovarian function

estriol

active hormone

major estrogen in urine of PG women

fetoplacental distress indicator

pregnanediol and pregnanetriol

fertility evulations

an increase of androgens in prepubescent males causes…

male precocious puberty

an increase of androgens in prepubescent females causes…

female virilization

an increase of androgens in adult females causes…

hirsutism

a decrease of androgens in inborn males causes…

Klinefelter’s

a decrease of androgens in adult males causes…

impotence feminization

an increase of estrogen in prepubescent females causes…

females precocious puberty

an increase of estrogen in adult males causes…

testicular atrophy and breast enlargement

an increase of estrogen in adult females causes…

infertility irregular menses and PCOS

an increase in estrogen in older females causes…

postmenopausal bleeding

a decrease in estrogen in inborn females causes…

turners

a decrease of estrogen in prepubescent females causes…

female delayed puberty

a decrease in estrogen in adult females causes…

amenorrhea

effect of parathyroid hormone

increases bone resorption

increases Ca reabsorption

decreases PO4 reabsorption

increases 1,25(OH)2 vitamin D

effects of 1,25(OH)2 vitamin D

increases CaBP synthesis

increases Ca absorption

increases PO4 absorption

bright yellow urine can be caused by

multivitamins

riboflavin

yellow-orange/ green/brown urine can be caused by

bilirubin

urobilin

biliverdin

Pyridium

red urine can be caused by

hemoglobin

red blood cells

porphyrins

myoglobin

certain drugs

beets

red-brown urine can be caused by

hemoglobin

red blood cells

myoglobin

methemoglobin

green/blue-green urine can be caused by

methylene blue

some urine antiseptics

biliverdin

milky white urine can be caused by

fat

bacteria

white blood cells

brown/black urine can be caused by

homogentisic acid

melanin

certain drugs

principle of pH urine reagent strip

double buffer system

clinical significance of the pH urine reagent strip

acid base balance

UTI

renal calculi

principle of protein urine reagent strip

protein error of indication

clinical significance of protein urine reagent strips

renal disease

UTIs

strenuous exercise

orthostatic proteinuria

principle of glucose urine reagent strips

glucose oxidase

clinical significance of glucose urine reagent strips

diabetes mellitus

principle of ketone urine reagent strips

sodium nitroprusside reaction

clinical significance of ketone urine reagent strips

diabetes mellitus

starvation

principle of blood urine reagent strips

peroxidase activity of hemoglobin and myoglobin

clinical significance of blood urine reagent strips

glomerular disease

trauma

hemolytic anemias

strenuous exercise

principle of bilirubin urine reagent strips

diazo reaction

clinical significance of bilirubin urine reagent strips

liver disease

biliary obstruction

principle of urobilinogen urine reagent strips

Ehrlich’s reaction