Ex Phys DG CHAP 5

What regulates the concentration of a hormone in blood

Rate of hormone release into blood - rate of hormone removal from blood

downregulation

decrease in receptors in response to high amounts of hormone to reduce overstimulation

upregulation

increase in receptor density in response to a low amount of hormones

Factors that influence magnitude of hormone effect

concentration of hormone, number of receptors, and affinity of the receptor to the hormone

Why are most hormones released?

To increase energy availability during exercise

Two major homeostatic systems involved in the regulation of physiological functions

nervous system and endocrine system

Hormone actions mediated by intracellular receptors

Lipid-soluble hormones + non-charged hormones enter the cell and bind to receptors in the cytosol/nucleus for protein synthesis and transcription

hormone actions mediated by membrane receptors

catecholamines cannot cross cell membrane, therefore they bind to a receptor on the cell membrane to exert their effects on the cell. binding to either G protein coupled receptors or catalytic receptors

Hormones released from the anterior pituitary gland during exercise

Thyroid stimulating hormone and growth hormone

Hormones rleased from the posterior pituitary gland during exerixse

Anti-diuretic hormone (ADH)

effect of ADH

less peeing

effect of growth hormone

increased gluconeogenesis

gluconeogenesis

Using non-carbohydrates to make new glucose

glycolysis

Breaks down stored glycogen to release glucose

glycogenesis

stores glucose as glycogen

effect of thyroid hormones t3+t4

increases metabolic rate, effects many tissues

adrenal medulla hormones

Norepinephrine, epinephrine

adrenal cortex hormones

aldosterone, cortisol

effects of cortisol

mobile tissue amino acids, mobile free fatty acids, stimulate gluconeogenesis, blocks entry of glucose into tissue

effect of insulin released in pancreas

decreased effects of endurance and resisntance exercise on blood levels, increased uptake of glucose into tissues

effect of glucagon released in pancreas

increased effects of endurance and resistant exercise on blood levels, released during exercisee to promote BG and lipolysis

effect of skeletal muscle hormone IL-6

 promotes fat metabolism and glucose uptake into cells, chronically high blood levels promote inflammation whereas acute increases exert anti-inflammatory effects 

impact of white adipose tissue hormones

storage site, appetite suppressor, promotes inflammation, increases insulin sensitivity

Hormone control of fuels used during exercise

regulate of primary fuel source (Carbs and fats) metabolism

two primary sources of carbohydrate available to skeletal muscles

muscle glycogen and blood glucose

what is glycogenolysis related to

related to exercise intensity, higher intensity results in more rapid oxygen depletion

plasma epinephrine is a powerful stimulator of what

glycogenolysis, high intensity exercise/hot environment increases concentration of it

why is insulin an exception of a hormone

while most hormones are for releasing energy, insulin says to store energy, less glycogen and less lipid breakdown

how is plasma glucose maintained during exercise

• Mobilization of ffa from adipose tissue

• Mobilization of glucose from liver glycogen store

• Gluconeogenesis from amino acids , lactic acid ,and glycerol

• Blocking the entry of glucose into cells, forces use of ffa as fuel 

what hormones control glucose homeostasis during exercise and do they overlap

Cortisol, GH, epi and norepi, insulin, and glucagon, yes they ovelap

two sources of fat for prolonged execise

muscle triglycerides and FFA transported into the blood

lipolysis defintion

breakdown of triglycerides into ffas and glycerol, occurs in fat cells and muscle fibers because of lipase enzymes

fat storage locations

white adipose tissue and skeletal muscle fibers (in the form of triglyercides)

what does hormone sensistive lipase do

responds to changes in hormones to increase rates of lipolysis

two primary hormones involved in maintaining hydration status

aldosterone and ADH

during exercise aldosterone goes which way and blood plasma goes which way

aldosterone up and plasma down

what is most important to be elevated during exercise for muscle growth

lactate and decorin

when does hypetrophy occur

when protein synthesis exceeds protein breakdown

is baseline or spikes of test/gh more important for hypertrophy

baseline levels

decorins significance for muscle growth

promotes growth by decreased muscle protein breakdown and blocking myostatin which inhibits protein synthesis