Shared Flashcard Set

Details

Endocrine physiology
SOM2014 endocrine physiology
104
Medical
Professional
03/12/2011

Additional Medical Flashcards

 


 

Cards

Term
what part of the brain controls appetite and food intake?
Definition
Hypothalamus
Term
what hormone is produced by white adipose tissue?
Definition
leptin (decrease food intake)
Term
What 4 peptide signaling molecules are produced by adipose tissue?
Definition
TNF-a and resistin (bad)
Adiponectin (good)
Plasminogen activator inhibitor-1 (bad)
Peroxisome proliferator-activated receptor (good)
Term
what gene produces leptin?
Definition
Ob gene

lack of Ob gene causes obesity and diabettes
Term
what is the affect of Leptin on NPY and a-MSH secretion?
Definition
Inhibits NPY
Increaess a-MSH
Term
what is the function of NPY?
Definition
stimulates food intake
Term
what is the function of a-MSH?
Definition
inhibits food intake
Term
what are the metabolic affects of leptin?
Definition
Increase lipolysis

Decrease TG storage

Increase sympathetic nervous system
Term
what hormone stimulates leptin secretion?
Definition
Insulin
Term
what neurons are affected by leptin?
Definition
Inhibits NPY/AgRP (decrease NPY)

Activates POMC/CART neruon (increase a-MSH)
Term
What hormones inhibit appetitie?
Definition
Leptin
Insulin
a-MSH
CART
Serotonin
CRH
Term
how does puperty affect leptin concentration?
Definition
leptin increased during puberty
Term
during pregnancy, what is the major source of leptin?
Definition
The placenta
Term
Relative leptin resistance causes what?
Definition
Obesity in humans
Term
what are some causes of hypoglycemia?
Definition
Eating pure carbohydrate meal
excercise
diabetic patients skipping meal
Insulinoma
Term
what are some consequences of no insulin?
Definition
Hyperglycemia
Acidosis
Volume depletion
Catecholamine increase
Term
what are the affects of insulin resistance in type II DM?
Definition
Increased circulating VLDL and TG
Increased CHOLESTEROL
Increased FFA
Increased catabolism of HDL
Term
where is testosterone produced?
Definition
Leydig cells
Term
what do pancreatic a-cells produce?
Definition
glucagon
Term
what do pancreatic b-cells produce
Definition
insulin, amylin
Term
what do pancreatic f-cells produce
Definition
pancreatic polypeptide
Term
what decreases insulin secretion?
Definition
Fasting
Somatostatin
Leptin
a-adrenergic activity
exercise
Term
what causes a greater insulin responce: insulin given orally or intravenously?
Definition
Orally

GLP-1 and GIP petentiate glucose stimulated insulin secretion
Term
insulin circulates bound to what carrier protein?
Definition
No carrier protein

Binds to membrane receptors => conformational change => internalization of membrane receptor (tyrosine kinase)
Term
what glucose transporter is glucose dependant?
Definition
GLUT-4 (muscle and adipose)
Term
what are the target tissues of insulin?
Definition
Liver, muscle and adipose
Term
what is the affect of insulin on muscle?
Definition
Increase glucose transport into cell (GLUT-4)
increase glucose storage (glycogen formation)
Increase amino acid uptake (increased protein synthesis)
Term
what is the affect of insulin on adipose?
Definition
Increase fat storage
Decrease lipolysis
Term
what is the affect of insulin on the liver?
Definition
increase glucose uptake
increase glycogen production
increased cholesterol and TG
Term
what are the overall effects of insuline on plasma substrates?
Definition
Decreases...
glucose
free fatty acids
amino acids
ketoacids
Term
what inhibits glucagon secretion?
Definition
Increased glucose
Somatostatin
Insulin
Term
what is the relationship between glucagon output and glucose concentration?
Definition
inversely proporional
Term
where is the major site of glucagon action?
Definition
liver
Term
what are the overall effects of glucagon on substrate flow in plasma?
Definition
Increases
Glucose
Ketoacids
Free fatty acids
Decreases
Amino acids
Term
what hormone favors glycolysis?
Definition
Insulin
(causes dephosphorylation of kinase, formation of pyruvate)
Term
what hormone favors gluconeogenesis?
Definition
Glucagon
(phosphorylates kinase, forms glucose)
Term
what inhibits somatostatin?
Definition
Insulin
a-adrenergic activity
Neurotransmitters
Term
glucagon stimulates secretion of what hormones?
Definition
Insulin
SST
Term
what is the dominant effect of postprandial period?
Definition
Insulin secretion increases

• Dietary carbohydrates and lipids are
transferred to storage depots in liver,
adipose tissue, and muscle
• Amino acids are converted to
proteins in various tissues
• Extrahepatic tissues use dietary
glucose and fat to meet their needs
instead of glucose derived from
hepatic glycogen or fatty acids
mobilized from adipose tissue
• Hepatic glycogen increases
• Fatty acids mobilization is inhibited
Term
what hormones increases with fasting?
Definition
Glucagon, catecholamines, and GH
Term
at 3 days of fasting what happens?
Definition
FFA mobilization increases
Ketogenesis becomes significant
Term
what happens with 24 hr fasting?
Definition
Glucose metabolism in muscle/adipose inhibited
FFA mobilization accelerated
Muscle proteins break down providing amino acids for gluconeogenesis
Term
what tissues take up glucose independant of insulin?
Definition
Brain
Blood cells
Term
what cells produce growth hormone?
Definition
acidophilic cells of anterior pituitary
Term
when is the most growth hormone?
Definition
During deep sleep (pulsatile fashion)
Term
what are the anabolic affects of GH?
Definition
increase AA uptake, protein, and RNA/DNA sysnthesis

decrease amino acid/protein degradation
Term
what are the ketogenic affects of GH
Definition
increase lipolysis
increase fatty acid oxidation => ketones
Term
what are the diabetogenic effects of GH?
Definition
increase plasma glucose
increase insulin secretion
Term
what effect does GH have on bones?
Definition
increase total bone mass and mineral content
widens epiphyseal plates
extending lenght of long bones
Term
which IGF (somatotropin) is GH dependant?
Definition
IGF-I (synthesized in the liver)
Term
IGF-I can cross react with what other hormones receptor?
Definition
Insulin (can cause hypoglycemia)
Term
what stimulates GH secretion?
Definition
sleep, stress, fasting, protein meal
Term
what hormone stimulates GH release?
Definition
GHRH from hypothalamus
Term
what inhibits GH secretion?
Definition
glucose increase
FFA increase
Somatostatin
IGF
Aging
Obesity
Cortisol
exogenous growth hormone
Term
effect of protein intake on GH substrate flow?
Definition
increase GH, IGF, Insulin

Increase Protein synthesis, growth

No change on calorie storage
Term
effect of carbohydrate intake on GH substrate flow?
Definition
Decrease GH
No change of IGF
Increase insulin

No change on protein synthesis, growth

Increase caloric storage
Term
effect of fasting on GH substrate flow?
Definition
Increase GH
Decrease IGF
Decrease Insulin

Decrease protein synthesis and growth

Increase calorie mobilization
Term
what causes acromegaly?
Definition
excess GH secretion after puberty

increased periosteal bone growth, increased organ size, glucose intolerance
Term
posterior pituitary orginates from what tissue?
Definition
Neural tissue
Term
where are hypothalamic hormones secreted to before being absorbed?
Definition
Median eminance
Term
what are the effects of a hypophysectomy (removal of pituitary)
Definition
atrophy of thyroid and adrenals
retardation of metabolic process
Lack of strengh
Cachexia (general ill health and malnut.)
Atrophy of gonads and accessory reproductive structures
Term
what is the precursor hormone for ACTH and MSH in ant. pituitary?
Definition
POMC
Term
what are the actions of prolactin?
What inhibits its secretion?
Definition
Stimulates milk production, breast development, inhbits GnRH (prolactinoma decreased sexual function)

inhibited by dopamine (PIF)
Term
What hormone is released from suproptic nuclei?
Definition
ADH
(binds neurophysin II)
Term
What hormone is released from suproptic nuclei?
Definition
ADH
Term
What hormone is released from paraventricular nuclei?
Definition
oxytocin
(binds neurophysin I)
Term
what are the actions of oxytocin?
Definition
induce labor contraction
reduces postpartum bleeding
stimulates milk let down
Term
what are the affects of SIADH?
Definition
increased ADH
water retention
hyponatremia
Term
explain central diabetes insipitus
Definition
Cause: failure of ADH secretion

Diagnosis: low ADH, Desmopressin inejection increases urine osmalality by >50%
Term
explain nephrogenic diabetes inspitus
Definition
kidneys are resistant to effects of ADH

Diagnosis: low ADH, desmopressin injection increases urine osmalaltiy by <50%
Term
PTH effect on kideys?
Definition
increased Ca2+ reabsorption
Term
what are used as markers of osteoblast activity?
Definition
alkaline phosphatase and osteocalcin
Term
osteoclasts are inhibited by what hormone?
Definition
calcitonin
Term
where is PTH produced?
Definition
Cheif cells of the parathyroid
Term
Where is calcintonin produced?
Definition
Parafollicular cells of thyroid
Term
how does OPG inhibit bone resorption?
Definition
binding to RankL
Term
what are the effects of loss of estrogen on bone?
Definition
loss of OPG leads to increased bone resoprtion (same effect as cortisol)
Term
what hormones have a steriod (nuclear) receptor?
Definition
"PET CAT"
progesterone
estrogen
testosterone

cortisol
aldosterone
T3/T4
Term
What hormones have a tyrosine kinase receptor?
Definition
Growth hormone and Insulin
Term
where is Vit D activated?
Definition
kidney
Term
what leads to activation of Vit D?
Definition
low Ca, Low P, incrased PTH
Term
how does Vit D control PTH?
Definition
negative feedback loop (also increased Ca inhibits PTH)
Term
what are the overal affects of PTH?
Definition
increase plasma Ca
Decreased plasma P
increase urinary cAMP
Term
what kind of receptors doe osteoblats have?
Definition
PTH receptor
Term
what are the major sites of PTH action?
Definition
Bone and kidney (indirect effect on intestine)
Term
what are some symptoms of hyperparathyroidism?
Definition
"Stones, Bones and Groans"

Kidney stones
osteoporosis
GI disturbances
muscle weakness
increased urinary Ca, P, and cAMP
Term
what are some symptoms of hypoparathyroidism?
Definition
tetany
decreased serum Ca, increased serum Pi
Term
where is the major target for calcitonin?
Definition
Osteoclasts to inhibit bone resorption
"calciTONin TONes down Ca"
Term
what is the overall effect of Vit D?
Definition
increase serum Ca and Pi
Term
what stimulates calcitonin release?
Definition
Increased serum Ca
Term
What are the effects of chronic renal failure on bone?
Definition
decreased Vit D and increased Pi (bc its not excreted)
causes decreased serum Ca
stimulates PTH
Inreases bone reabsorption
Term
what hormones are produced in the thyroid?
Definition
T3/T4 and calcitonin (parafollicular cells)
Term
what is the wolff-chaikoff effect?
Definition
low I intake stiumlates the iodide trap and synthesis of T3/T4

High I intake inhibits iodide trap
Term
where is T4 converted to T3?
Definition
pituitary
Term
What is the effect of estrogen on T4 levels?
Definition
Increases hepatic TBG synthesis leading to decreased free T4
Term
what enzyme converts T4 to T3?
Definition
5-deiodinase in pituitary
Term
what affect does thryoid hormone have on puplse pressure?
Definition
increase stroke volume + decreased peripheral resistance leads to Increased pulse pressure
Term
what hormone is the best indicator of hormone status?
Definition
TSH
Term
what cell types require insulin to move glucose into cell?
Definition
Adipose and muscle
Term
what cell types don't require insulin to move glucose into cells?
Definition
BRICK L

Brain
RBC
Intestine
Cornea
Kidney
Liver
Term
what enzyme converts testosterone to estradiol?
Definition
Aromatase p450
Term
what hormones are low in 21-hydroxylase deficiency?
Definition
Aldosterone and cortisol
(increased sex hormones)
Term
what hormones are low in 17a-hydroxylase deficiency?
Definition
Sex hormones and cortisol
(increase aldosterone)
Term
what hormones are low in 11b-hydroxylase deficiency?
Definition
cortisol, aldosterone and sex steriods
Supporting users have an ad free experience!