Endorine Flashcards
what is the difference between water/fat soluble hormones?
water - unbound, bind to cell surface receptor, short halfe-life, fast clearance eg protein
fat - protein bound to transport, diffuse into cell, long half-life, slow clearance eg steroid, thyroid
what is endocrine vs paracrine vs auto crine hormones?
Endocrine – blood-borne, acting at distant sites
Paracrine – acting on adjacent cells
Autocrine – feedback on same cell that secreted hormone
what are the classes of hormones?
peptides
amines
Iodothyronines
Cholesterol derivatives and steroids
how is hormone secretion controlled?
basal secretion - continuous or pulsatile
superadded rhythms - eg day night ACTH
Release inhibiting factors – dopamine inhibiting prolactin
releasing factors
what determines the action of hormones?
Hormone metabolism – increased metabolism to reduce function
Hormone receptor induction – induction of LH receptors by FSH in follicle
Hormone receptor down regulation – hormone secreted in large quantities cause down regulation of its target receptors
Synergism – combined effects of two hormones amplified (glucagon with epinephrine)
Antagonism - one hormone opposes other hormone (glucagon antagonizes insulin)
how are peptide hormones stored?
granules
what is the definition of anorexia?
lack of appetite
what are the BMI ranges classified as?
<18.5 underweight
18.5 - 24.9 normal
25.0 - 29.9 overweight
30.0 - 39.9 obese
>40 morbidly obese
what are some risks of obesity?
Type II diabetes
Hypertension
Coronary artery disease
Stroke
Osteoarthritis
Obstructive sleep apnoea
Carcinoma
what part of the body regulates appetite?
hypothalamus
what gut peptides affect appetite?
CCK
Ghrelin
PYY
what is leptin responsible for?
switching off appetite
what are the blood levels of leptin after eating?
increased
what central controllers increase appetite?
NeuroPeptideY
MCH - Melanin-Concentrating Hormone
AgRP - Agouti-related peptide
Orexin
endocannabinoid
what central controllers decrease appetite?
alpha-MSH
CART - cocaine and amphetamine regulated transcript
GLP-1
seretonin
what does peptide YY do?
inhibits gastric motility - reducing appetite
how does CCK affect appetite?
delays gastric emptying
gall bladder contraction
insulin release
- satiety via VAGUS nerve
what does Ghrelin stimulate?
Growth hormone release
appetite - orexigenic
how do leptin and insulin work in appetite?
- Stimulate- POMC/CART neurons increase CART and alpha-MSH levels
- Inhibit NPY/AgRP neurons, so decrease NPY and AgRPNet effect : increase Satiety and decrease Appetite
how does ghrelin work?
stimulates NPY/AgRP, increase NPY and AgRP secretion
↑ Appetite
what cells secrete peptide YY?
neuroendocrine cells in ileum, pancreas and colon
in response to food
what are the effects of incretin?
- blunting glucagon
- beta-cell stimulation of insulin production
- improved satiety
- decreased gstric motility
where does glucose come from in the fasting state?
glycogen breakdown and gluconeogenesis from liver
little bit from kidney
in the fasting state what are the insulin levels?
low