ENDO-Pituitary Flashcards by JHope .

What occurs in the hypothalamus-pituitary axis?

Negative Feedback-reverses of current reaction, NOT Down,
Hypothalmus release TRH hormone 
anterior pituitary hormone TSH, LH, FSH
peripheral endocrine gland
 targets

How well did you know this?

Not at all

Perfectly

What is Primary endocrine disorder?

Defect at producing gland

Ex. Thyroid gland

How well did you know this?

Not at all

Perfectly

What is a Secondary endocrine disorder?

Producing gland normal, defect in stimulation

Usually next step up-Pitutary

How well did you know this?

Not at all

Perfectly

What is a tertiary endocrine disorder?

Defect of hypothalamic dysfunction (two glands removed from target organ)

How well did you know this?

Not at all

Perfectly

List the hormones in the anterior pituitary?

FLAT PiG
FSH- sperm and egg producing
LH- luetenzing (ovulation)
ACTH- adrenocorticotripic hormone
Prolacin
GH-growth hormone

How well did you know this?

Not at all

Perfectly

What provides linear growth of bones?

GH
AKA- Somatotropin, 
produces somatotropes cells w/in the anterior pituitary
necessary for growth and maintenance, 
 linear bone growth in children

How well did you know this?

Not at all

Perfectly

What are the effects of growth hormone on the liver?

Wide spread, no truly organ
Fat cells and LIVER =”peripheral gland”
Effects through secondary hormones called somatomedins,
Liver- releases insulin-like growth factors produced by liver

How well did you know this?

Not at all

Perfectly

What tissues are affected by growth hormone

effects on carbohydrates, lipids and protein metabolism

How well did you know this?

Not at all

Perfectly

Describe the effects of growth hormone on adipose tissue

Reduces body fat mass by 1] Increases Lipolysis (HSL) 2] Reduce glucose uptake, 3] Reduce lipogenesis, 4] Reduces re-esterification of FFA

How well did you know this?

Not at all

Perfectly

Describe the MOA of GH on adipocytes

GH acts on B3 adrenergic receptors -> Gs proteins -> Adenylate cyclase -> cAMP -> HSL -> triglycerides -> glycerol + FFA

How well did you know this?

Not at all

Perfectly

Describe the effects of growth hormone on skeletal muscle

Increase Beta-oxidation by 1] Reduces glucose uptake and 2] Increases LPL activity

How well did you know this?

Not at all

Perfectly

Describe the effects of growth hormone on liver

Increase production and uptake of IDL, LDL, HDL by 1] Increasing VLDL secretion, 2] HL activity, 3] Reduces PARalpha expression

How well did you know this?

Not at all

Perfectly

Describe the metabolic effects of GH

1] Inhibition of glucose utilization, by increased insulin resistance, 2] Promotion of fatty acid metabolism for fuel

How well did you know this?

Not at all

Perfectly

Describe the half-life of GH

Short half-life – unbound in plasma

How well did you know this?

Not at all

Perfectly

Describe what controls the release of Growth hormone

1] GHRH – releasing hormone, 2] Somatostatin – inhibitory, 3] Ghrelin newly identified, unknown action

How well did you know this?

Not at all

Perfectly

What is the primary causes the short statue in children?

growth hormone deficiency, but many factors affect GH, so broad testing must be done to determine cause of short stature/growth delay

How well did you know this?

Not at all

Perfectly

What causes Growth Hormone Deficiency

1] Idiopathic – lack of GHRH from hypothalamus for undefined reason, 2] Primary causes include pituitary tumors and pituitary agenesis, Consider panhypopituitarism

How well did you know this?

Not at all

Perfectly

How is growth hormone deficiency determined?

Chart growth conscientiously, Look for deviations across growth lines vs consistent trajectory

How well did you know this?

Not at all

Perfectly

Describe congential growth hormone deficiency

usually children of normal size at birth expressing delayed growth over first 1-2 years

How well did you know this?

Not at all

Perfectly

What are the associated features of growth hormone deficiency

intelligence normal, short, obese, immature fascies, delayed skeletal growth and sexual maturation, hypoglycemia and seizures in neonate

How well did you know this?

Not at all

Perfectly

Describe the cause of acquired defiency later in life

usually tumor related

How well did you know this?

Not at all

Perfectly

What if growth is reduced by growth hormone levels are normal

Consider IGF deficiency

How well did you know this?

Not at all

Perfectly

Why is growth hormone important in adults

GH still important for maintenance

Describe causes of adult GH deficiency

May be carry-over from childhood or new onset – related to tumor or treatment

What are the associated risk factors with adult GH deficiency

Cardiac risk, central obesity, atherosclerosis, metabolic syndrome

How is adult GH deficiency diagnosed

Test with stimulation studies

Describe what results in excess GH

Excessive bone growth caused by IGF stimulation

Describe what occurs if the excess GH is before closure of epiphyses

gigantism

Describe what occurs if the excess GH is after closure of epiphyses

circumferential bone growth (widened, rather than longer) and acromegaly

What usually causes gigantism and acromegaly

1] somatotrope adenoma, 2] Some caused by hypothalamic and other tumors

What are the metabolic changes due to excess GH

increased FA metabolism, increased ketone production, decreased glucose uptake, gluconeogenesis by liver, increased insulin from pancreas (insulin resistance syndrome, ultimately DM)

Describe the associated adenoma causing GH excess

HA, visual field defects, CN III, IV, VI palsies, secondary deficiency of other pituitary hormones

Describe the associated symptoms in GH excess

Excessive sweating, oily skin, wt gain, weakness, fatigue, menstrual changes, decreased libido, HTN, apnea

What are the associated risk due to GH excess

Increased risk of colonic polyps and colorectal cancer

Describe the treatment of GH excess

surgery, reversal of GH/IGF effects

Describe the function of Prolactin

stimulates milk production by the female breast during pregnancy. Drop of estrogen at birth triggers let down.

Why don't post-partum women ovulate

Due feedback that suppresses FSH & LH after childbirth that drops estrogen at birth triggers let down.

What hormone causes milk gland growth?

progesterone

What hormone causes milk production?

prolactin

What is the most common type of pituitary tumor

Prolactinoma

Describe the incidence rate of Prolactinoma

1] F>M, 2] May be familial as part of MEN-1 syndrome, 3] Most are microadenomas which rarely grow

What is MEN syndrome?

Multiple endocrine neoplasia syndrome, endocrine tumors that are usually associated with each other

What is the result of hyperprolatinemia

Hypogonadotropic hypogonadism - term used to define low sex hormone production by the gonads as a result of low production of FSH/LH from the pituitary (gonadotropic hormones)

Describe Hypogonadotropic hypogonadism in Women

Oligomenorrhea or amenorrhea, galactorrhea common, increased risk of osteoporosis

Describe Hypogonadotropic hypogonadism in Men

ED, diminished libido, gynecomastia classic but not 100%, never with galactorrhea.

What are the hallmarks for prolactinoma

a man or woman comes in with breast sx

What should you do with hyperprolactinemia

1] Rule out secondary causes, 2] MRI

If the MRI show microadenomas with regular menses what is the next step

No treatment

If the MRI show microadenomas with infertility what is the next step

Bromocriptine (pariodel)

If the MRI show microadenomas with Amenorrhea what is the next step

Dopamine agonist or estrogen progesterone

If the MRI show macroadenoma intrasellar with infertility what is the next step

Bromocriptine (pariodel)

If the MRI show macroadenoma intrasellar with Amenorrhea what is the next step

Dopamine agonist

If the MRI show macroadenoma suprasellar with infertility what is the next step

Bromocriptine (pariodel), surgery or both

If the MRI show macroadenoma suprasellar with Amenorrhea what is the next step

Dopamine agonist, surgery or both

What the most common cause Hyperprolactinemia

Pregnancy

What are the other causes of Hyperprolactinemia

1] Hypothyroidism, 2] Renal failure, 3] Cirrhosis, 4] SLE, 5] Drugs: psychotropic agents, cimetidine, TCAs, OCP

What are the treatments for Hyperprolactinemia

1] stop offending agents, 2] dopamine agonists first line, 3] surgery for large or unresponsive tumors, 4] radiation tends to cause global loss of pituitary function and should be used cautiously