Endocrine Flashcards
2 hormones secreted by the posterior pituitary
ADH, oxytocin
6 hormones secreted by anterior pituitary
TSH – thyroid stimulating hormone FSH – follicle stimulating hormone LH - luteinizing hormone GH – growth hormone ACTH – adrenocorticotrophic hormone Prolactin
ADH
Anti-diuretic Hormone
Acts on Principle Cells of distal renal tubules and collecting ducts to increase H20 re-absorption
Osmoreceptors
In hypothalamus; are very sensitive to blood osmolarity. Stimulations of these receptors results in the posterior pituitary release of ADH
Baroreceptors
in the left atrium, aortic arch, and carotid artery sense hypovolemia / hypervolemia signaling the hypothalamus to decrease/increase secretion of ADH
Diabetes Insipidus
is a condition characterized by excessive thirst and excretion of large amounts of severely diluted urine
- Neural
- Nephrogenic
SIADH
Syndrome of Innappropriate ADH secretion
- Oat cell carcinoma
- decreased Na+ = total body Na+ is normal; too much total body free water
Oxytocin
- Uterine contraction, helps in baby delivery
- “Let down of milk” (milk moves from production areas to traveling down the ductal system)
- Milk ejection
Acromegaly
Too much GH but growth plates CLOSED
Gigantism
Too much GH and growth plates OPEN
Growth Hormone
- Increase in linear growth (before bone growth plates close)
- Increase protein synthesis, increased lean body mass
- Promotes utilization of fats for energy source
- Diabetogenic – increases insulin resistance
Prolactin
- Lactogenesis
- Inhibits ovulation (inhibits GnrH)
- Breast development at puberty and pregnancy
Galactorrhea
Milk production unassociated with pregnancy.
- trauma to pituitary
- no dopamine production to inhibit release
- give Bromocriptine (dopamine agonist)
TSH
- Stimulted by release of TRH in hypothalamus
- Regulates secretion of T3 and T4
- T3 is the “steady” state hormone
T4
- Thyroxine
- Tissues turn T4 in to T3
T3 Physiologic Effects
- Increased thermogenesis, sweating
- Increase rate/depth respiration (increased 02 consumption/ C02 production)
- Increase cardiac output, arrhythmias
- Increased pulse pressure (positive inotropic effects)
- Increased utilization of nutrients, increased food intake, weight loss
T3 Actions
- Growth/bone formation and maturation
- Maturation of CNS
- BMR (Na+, K+, O2, Heat)
- Metabolism (glucose absorption, glyconeogenesis, lipolysis, protein synthesis)
- Cardiac Output
Grave’s Disease
- antibodies bind to TSH receptors in thyroid and turn it “ON”
- the gland starts to produce more T3/T4
- TSH levels are decreased because of negative feedback exerted by high plasma levels of T3 / T4
Hypothyroidism
• Cold intolerance
• Weight gain
• Slowness in movement, speech, and thought
• Lethargy
• Myxedema – puffiness of skin, non-pitting edema, pleural, cardiac effusions
Thyroid Hormones = low, TSH/TRH= high
Myxedema
puffiness of skin, non-pitting edema, pleural, cardiac effusions caused by HYPOTHYROIDISM
Cretinism
is a condition of severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones
Catecholamines
Epi
Norepi
Dopamine
Hormones of the adrenal medula
catecholamines: epi, norepi, dopamine
Hormones and layers of the adrenal cortex
Zona Reticularis = Androgens
Zona Fasciculata = Glucocorticoids
Zona Glomerulosa = Mineralcorticoids
CRH
cortico-trophin releasing hormone; released from hypothalamus and heads to pituitary; stimulates secretion of ACTH
ACTH
adrenocorticotrophic hormone; released from pituitary and tells adrenal cortex to release cortisol; includes
Glucocorticoids
Cortisol
• Stimulates gluconeogenesis; HIGH blood sugar
• Antiinflammatory – inhibits inflammatory response
• Suppresses immune response –(T cells); organ transplant patients will get steroids to fight immune system attack
• Maintains vascular response to catecholamines; need steroids so that your body can respond to sympathetic nervous system
• Inhibits bone formation
Aldosterone
- Increases Na+ resorption resulting in ECF volume expansion, hypertension
- Increases renal K+ secretion - hypokalemia
- Increases renal H+ secretion – metabolic alkalosis
MSH
melanocyte stimulating hormone; part of ACTH family; released from pituitary; high MSH can lead to hyperpigmentation
Addison’s Disease
adrenal insufficiency:
Hypoglycemia, anorexia, weakness, hyperpigmentation (high ACTH levels, high MSH)
Cushing’s Disease
Excess glucocorticoids (too much cortisol)
GnRH
gonadotropin releasing hormone; releases FSH and LH from pituitary
FSH
folllicle stimulating hormone
• Stimulates development of follicles in the ovary
• Stimulates spermatogenesis
LH
luteinizing hormone
• Stimulates development of corpus luteum in the ovaries
• Stimulates testosterone secretions of testes
Estrogen and Progesterone
feedback hormones that stimulate release of FSH and LH
Conn Syndrome
HyperAldosterone
- hypertension
- hypokalemia
- metabolic alkalosis
Insulin
Hormone of Abundance
- secreted when serum GLUCOSE is HIGH
- Increasing glucose transport into cells
- Promotes K+ uptake into cells
- Promoting formation of glycogen (chain of glucose) in liver and muscle
- Decreases blood lipid levels and stores fats
Type I Diabetes Mellitus
not making adequate insulin, “early onset”
- cells can’t uptake insulin
- cells break down fat for energy (ketones)
- hyperglycemic, ketoacidosis, polyuria, polydipsia,
Type II Diabetes Mellitus
making adequate insulin but cells don’t respond, “insulin resistence.”
- don’t get ketoacidotic
- hyperglycemic
- Treat with weight loss and Metformin (improves tissues use of insulin)
GLP/ GIP 1
promote insulin secretion
ALPHA Cells
produce glucagon
BETA Cells
produce insulin
Glucagon
Hormone of Starvation
- secreted when serum GLUCOSE is LOW
- increases blood glucose; works opposite of insulin
Somatostatin
Released by hypothalamus:
- inhibits growth hormone
- modulates response of glucose/glucagon to food ingestion
Physical signs of hypocalcemia
- Hyperreflexia
- Muscle cramping
- Spontaneous twitching
- Tingling and numbness
- Chvostek sign: twitching of facial muscle caused by tapping on facial nerve
- Trosseau sign: carpopedal spasm with inflation of BP cuff
Physical signs of hypercalcemia
- Polyuria
- Polydipsia
- Hyporeflexia
- Constipation
- Lethargy, coma, death
PTH
Parathyroid Hormone:
- secretion stimulated with low serum Ca++
- Kidney = Ca++ reabsorption, phosphate excretion
- Bone = resorption of calcium (break down bone)
- Intestine = Ca++ absorption
Hyperparathyroidism
too much PTH; hypercalcemia; osteoperosis
Hypoparathyroid
too little PTH; hypocalcemia
Vitamin D
Cholecalciferol
- bone growth and remodeling
- calcium and phosphate resorption
Vitamin D deficiency
Rickets in kids
Osteoperosis in adults
