endocrine vs paracrine vs autocrine
- endo: acts on any tissue in body
- para: acts on a tissue in local area
- auto: acts on tissue that provided secretion
hormone receptor complexes determined by
3 of them
- # of hormones avail
- # of receptor avail
- bindgin affinity btwn hormone and receptor
factors determining concentration in plasma
4 of them
- rate of secretion
- rate of metab, inactivation or exretion of hormone
- quantity of transport protein
- changes in plasma volume
what are binding proteins
extends half life of hormones
what are steroid hormones
- move freely across lipid membrane of cells
- need to be bound to move around cell
what are amino acid and peptide hormones
- need receptor to cross membrane
- bind to surface receptors and signal 2nd messengers
what does target cell activation depend on?
3 of them
- hormone concen in blood
- senstivity of receptor for hormone
- # of target cell receptors
up vs down regulation
up: form more receptors
down: caused by long term exposure to hormone
- cell becomes desensitized
fast vs slow acting hormones
fast: work quickly during ex to maintain glucose concentration
slow: allow other hormones to exert full effect
- involved in reg of CHO, fat, protein metab
originating gland of GH
what happens to GH during exercise
anterior pituitary
-increases w/ ex
stims/inhibitors of GH
stim: exercise, sleep, stress, decrease glucose
inhib: insulin like growth factor
GH’s actions
- stim protein synthesis
- increase glucagon
- increase fat metab
originating gland of thyroid hormone
what happens to it during exercise
- pituitary gland
- increases
actions of thyroid hormone
increased O2 consumption
metabolism of hormones secretd by thyroid gland
stimulators of thyroid hormone
- cold
- increased energy required
originating gland of ACTH
what happens to it during exercise
- pituitary
- doesnt get effected by exercise until 25% of VO2 max
stimulators of ACTH
-none
secreted in AM
actions of ACTH
- regs hormones secreted by adrenal medulla
- facilitate protein breakdown
- increase FFA utilization
- increase gluconeogenesis
origainting gland of ADH
what happens to it during exercise
- posterior pituitary
- increase during exercise b/c of sweating
stimulators/inhibitors of ADH
stim: decrease BP/fluid loss
inhib: fluid overloads
actions of ADH
- increase H20 reabsorb
- conservation of fluids
originating gland of E/NE (catecholamines)
what happens to them during exercise
- adrenal medulla
- increase with exercise
- E @ 75% VO2 max
- NE @ 50% VO2 max
stimulators of catecholamines
- decreased BP and glucose
- too much stress
actions of catecholamines
increase in:
- glucogenolysis
- FFA utilize
- HR and SV
- peripheral resistance
