Nervous system messages facts (4)
- travel at high speeds - defined pathways - activate a limited number of target cells. - rapid response, short duration
Endocrine messages facts (4)
- travel more slowly - bloodstream - act on specific target cells throughout the body - slow response, longer duration
ADH and oxytocin
created in the hypothalamus and travel down axons to the post. pit where they are stored and released
Oxytocin is stimulated by....
Suckling (release of milk by the breast) Vaginal distention, cervical dilation in labor
2 actions of oxytocin?
Milk ejection from breasts (facilitates nursing of infants) Stimulates uterine contraction in labor
ADH is stimulated by.....
Increased plasma osmolality (most sens) Hypovolemia, hypotension Other nonosmotic stimuli (SIADH)
What are the 2 actions of ADH?
Conserves water (causes water retention by kidney) Raises blood pressure (constricts arterioles)
Normal plasma Osm range?
3 actions of growth hormone?
1. increases muscle mass 2. promotes bone growth 3. Opposes the action of insulin and raises BG (diabetogenic/insulin resistance
what are the 4 insulin opposing hormones?
1. GH 2. glucagon 3. Epi 4. cortisol
Growth hormone is stimulated by?
- Low blood glucose - Fasting, starvation - Hormones of puberty - Exercise - Stress
Growth hormone is inhibited by?
- Hyperglycemia - Obesity - Somatostatin and somatomedins - Senescence
Thyroid hormones circulate mostly bound to....
Thyroxine-binding globulin (TBG)*** T4-binding prealbumin (transthyretin) Albumin
Which fraction of thyroid is the active portion?
THE FREE FRACTIONS OF CIRCULATING T4 AND T3
Alterations of binding protein levels affect.....
TOTAL T4 and T3, but NOT FREE T4 and T3
growth actions of TSH?
increases growth and bone maturation
CNA actions of TSH?
maturatin of CNS
Cardiovascular actions of TSH?
increase cardiac output
Metabolism actions of TSH? (5)
1. increase glucose absoprtion 2. increase glycogenolysis 3. increase gluconeogenesis 4. increase lipolysis 5. increase protein synthesis and degredation
BMR actions of TSH? (4)
1. increase Na/K ATPase 2. increase O2 consumption 3. increase heat production 4. increase BMR
Prolactin is stimulated by..... (4)
1. Pregnancy (estrogen) 2. Breast feeding 3. Thyrotropin-releasing hormone (TRH) 4. Dopamine antagonists
Prolactin is inhibited by
1. Dopamine (PIF) 2. Dopamine agonists(bromocriptine, cabergoline) 3. Somatostatin 4. Prolactin
What are the 3 actions of prolactin?
1. puberty-- breast development 2. pregnancy-- mammary gland growth and developement 3. Lacation-- milk production and secretion; inhibits ovulation
ACTH and mineralcorticoid secretion?
exerts a MINOR tonic stimulatory effect (aldosterone release)
G/c effects on catabolic and diabetogenic effects...
- increase Proteolysis (catabolic), gluconeogenesis, and lipolysis
G/c effects on anti-inflammatory and immunosuppresive
- inhibit meadiators of inflammation (leukotrienes, interlukins, histamine) - inhibit mediators of immune system
g/c effects on adipose tissue
- cuase redistribution to the truncal area, moon face, buffalo hump
g/c effects on BP
- enhance vascular responsiveness to catecholamines to help maintain a normal BP
g/c effects on bone
- inhibit bone formation (decrease syn of bone matrix, osteoblast, Ca abs)
g/c effects on blood
- stimulation of neutrophil release
g/c effects on renal-electrolytes
- increased GFR due to afferent arteriole dilation - mild mineralcorticoid effect (Na retention, edema, low K, metabolic alkalosis
g/c effects on gastric secretions
increased HCl and pepsin
g/c effects on brain function
- decreased REM sleep - increased wake time - may cause euphoria, irritbaility, mania, depression
High K relationship with Aldo?
-will increase Aldo secretion - Increase renal K secretion and excretion - causes a decrease in plasma K level
Low K relationship with aldo?
- will decrease aldo secretion - decrease renal K secretion and excretion - causes an increase in plasma K level
8 effects of adrenal androgens in males
- Increased muscle mass - Growth spurt and epiphyseal plate closure - Growth of penis and seminal vesicles - Male hair pattern - Deepening of voice - Spermatogenesis - Libido - in utero, differntiates male genital tract
2 effects of adrenal androgens in females
- Stimulate growth of pubic and axillary hair - Libido
The medulla is responsible for which 2? and percents?
Epi (80) and Norepi (20)
What portion of Ca is the bio active?
ionized/ free Ca
What are the actions of PTH in the bone?
- bone resoprtion (major) - Bone formation (transient)
What are the actions of PTH in Kidney?
- decreased calcium excretion - increased phos secretion - increased calcitrol
What are the actions of PTH in the GI tract?
-increased abs. of Ca and phos
what is the net effect of PTH
-increase serum Ca - decrease phos
PTh secretion is stimulated by....
- Low serum calcium - High serum phosphorus
PTH is inhibited by....
- High serum calcium - 1,25(OH)2D (calcitriol
What are the actions of Vit D in the GI tract?
- increase Ca and phos abs
What are the actions of Vit D in bone?
- works with PTH to increase bone resorption - promotes osteoid mineralization in growing children
What are the effects of Vit D in the kidney?
- decrease Ca and Phos excretion
What are the effects of Vit D in the parathyroid?
- decrease PTH production
What is the net effect of Vit D?
increase Ca and Phos
Insulin is stimulated by?
- Hyperglycemia - Glucagon - Potassium - Incretins (GLP-1; GIP)
Insulin is inhibited by?
- Hypoglycemia - Fasting - Exercise - Somatostatin
Glucagon secretion is increased by....
fasting and by low blood glucose
Glucagon secretion is inhibited by....
- insulin - somatostatin - elevated fatty acid and ketoacid concentrations
_____ are Peptides secreted by small intestine in response to food
2 examples of incretins?
GLP-1 (glucagon-like peptide 1) GIP (glucose-dependent insulinotropic peptide)
4 things that incretins do?
Increase insulin secretion Decrease glucagon secretion Delay gastric emptying (slows rise of blood glucose) Decrease food intake causing weight loss
actions of aldosterone at the distal tubule?
1. retention of Na 2. excretion of K 3. excretion of H
What are 3 locations that release somatostatin and its roles?
1. pancreas-- after meals (inhibits insulin AND glucagon) 2. hypothalamus-- (inhibits release of growth hormone) 3. intestine-- (inhibits GI hormones and intestinal mobility)