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42 Cards in this Set
- Front
- Back
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Important regulation during exercise |
-Controls substrate metabolism -Regulates fluid, electrolyte balance (role in blood pressure)
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hormone |
any chemical that controls and regulates the activity of certain cells or organs |
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Binding proteins |
-provides reservoir or pool of hormone-control levels -extends the half life of hormones
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Free hormones |
-Fast acting -role in acute metabolic response (catecholamines)
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Hormone secretion |
-High level of downstream change decrease secretion -Low level of downstream change increase secretion |
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Hormone activity |
Down regulation- decrease number of receptors during high plasma concentration= desensitization
Up regulation- increase number of receptors during high plasma concentration= sensitization |
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Classifying hormones |
peptide, amino acids or steroids |
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Steroids |
-Derived from cholesterol -Lipid soluble, diffuse through membranes -Direct gene activation-nucleus -Enzymes for cellular processes -structural proteins-protein synthesis -regulatory proteins |
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nonsteroid hormones |
-not lip soluble, cannot cross membranes -Receptors on cell membrane -signal second messengers -Activation of cellular enzymes -Change in membrane permeability -Promote protein synthesis -Change cellular metabolism -stimulate cell secretions |
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two types of nonsteroid hormones |
-Protein/peptide hormones -most nonsteroid hormones -From pancreas, hypothalamus, pituitary -Amino acid-derived hormones -Thyroid hormones -Adrenal medulla hormones |
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The focal point of hormonal control of metabolism is blood glucose regulation |
-If glucose levels increase they must be brought down (insulin, exercise) -If blood glucose decrease -mobilize liver glucose production -Mobilize fatty acid release from adipose tissue -block glucose entry into tissue -Synthesize new glucose from amino acid breakdown, lactate and glycerol
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remember the goal of metabolism regulation |
glucose homeostasis |
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hormones of metabolism |
insulin glucagon catecholamines (E and NE) Growth hormones Cortisol Thyroid hormone |
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insulin |
-released in response to hyperglycemia and promotes glucose uptake by most tissue: including muscle and liver -Glycogen synthesis -Glucose use -Inhibits fat ozidation -Protein synthesis -Fat synthesis |
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Insulin release |
-Release from beta cells of pancreas -Elevated glucose is the key sensor for beta cells
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Insulin Action |
Insulin activates GLUT4 glucose transporter |
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Insulin regulation |
Hyperglycemia=increase Parasympathetic (Ach)= increase Sympathetic (NE)= decrease |
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Glucagon |
-Release from pancreas and stimulate gylycogenolysis, gluconeogensis, and ketogenesis -Acts on liver cardiac and skeletal muscle |
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Glucagon action |
-increases glucose availability from liver -increases fat oxidation -increases protein breakdown in muscle (gluconeogensis) |
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Glucagon release and regulation |
-released from alpha cells of pancreatic islet
Signal -decrease glucose -rising amino acids is key reulator -catechoamine activation (E/NE)
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Catecholamines |
-Epinephrine and norepinephrine -release from chromaffin cells of adrenal medulla and SNS
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Catecholamine release and regulation |
metabolic signals -mainly through sympathetic activation during exercise -hypoglycemia -sympathetic nervous system acts on the adrenal medulla causing E/NE release
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Growth hormones |
-released from the anterior pituitary -increases gluconeogenesis in liver -blocks glucose entry to adipose cell to favor fat mobilization Signals -Drop in blood glucose -stress -exercise
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Cortisol |
-assists in maintaining blood glucose levels -amino acid release from muscle -hepatic gluconeogenesis -FFA release -Control of cortisol secretion
Signal -falling blood glucose -prolonged exercise -stress |
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Thyroid hormone |
-Thyroxine (T4)-greater amounts released-most is bound to binding proteins in blood -Trioodothyronine (T3)- active form of the hormone - T4 is converted to T3 in tissue and regulates metabolism
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Thyroid hormone actions and regulation |
Action -increase oxygen consumption -Glycogenolysis -lipolysis Metabolic signals -increase CHO intake (metabolic rate) -cold stress -any condition that increases body energy requirments
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Resting metabolism |
Insulin and glucagon are the major regulator sf resting metabolism Eat=increased insulin Fasted or amino acid ingestion=increased glucagon |
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Resting metabolism (hormones) |
-Greater PNS control-reduced catecholamine levels (E and NE) -Growth hormone- follows circadian rhythms as normal -Cortisol- may be variable based on stress levels -Thyroid hormone- consistent variable regulation based on energy needs
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Moderate intensity exercise |
Blood Glucose maintenance during exercise -GH increase -lipolysis from adipose tissue -Amino acid breakdown -Decrease glucose uptake by muscle -Increase of NE/E -Glycogenolysis in skeletal muscle -Lipolysis in adipose tissue -Decrease insulin -Increase in glucagon -increase in thyroid hormone -mobilization of fuels -Increase metabolic rate -Decline in cortisol
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high intensity exercise |
Blood glucose maintenance during exercise Utilization of fuel sources -GH large increase (stress) -lipolysis from adipose tissue -Large increase of NE/E -Glycogenolysis in skeletal muscle -Lipolysis in adipose tissue -decrease insulin -increase in glucagon -increase in cortisol (stress) -FFA mobilization -maintain blood glucose -Increase in thyroid hormone -mobilization of fuels -increase metabolic rate
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Prolonged exercise |
Blood glucose maintenance during exercise Utilization of fuel sources GH large increase (stress and hypglycemia) -lipolysis from adipose tissue -Amino acid breakdown -reduced muscle uptake of glucose large increase of NE/E -Glycogenolysis in skeletal muscle -lipolysis in adipose tissue -decrease insulin -increase in glucagon Increase in cortisol (stress and hypoglycemia) -FFA mobilization -Maintain blood glucose -Amino acid breakdown Increase in thyroid hormone -mobilization of fuels -increase metabolic rate
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Prolonged exercise chart |
Prolonged exercise v Drop in plasma glucose v Insulin < Hormones release > Glucagon decrease v GH Mobilization of amino acids, E/NE reduced glucose uptake, FFA Cortisol v Blood glucose maintenance during exercise
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What happens when we start to sweat during exercise? |
We must preserve cardiac output and blood pressure
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Hormonal regulation of fluid and electrolytes during exercise |
During exercise, plasma volume decreases, causing -increase osmolality -decrease plasma water content via sweat= increase heart strain, decrease blood pressure Hormones correct fluid imbalance -posterior pituitary gland (ADH) -adrenal cortex (aldosterone) -kidneys |
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Osmolality |
Osmolality- measure of concentration of dissolved particles (proteins, ions etc. ) in body fluid compartments
Osmolaity and osmosis -if compartments osmolality increase, water drawn in -if compartments osmolality decrease, water drawn out |
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Sodium depletion |
Sodium depletion will cause water to move to higher concentration causing damage to cells |
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Posterior pituitary |
Posterior pituitary -secretes ADH, oxytocin Only ADH involved with exercise -Increase water reabsorption at kidneys -less water in urine, antidiuresis - also called vasopressin Stimuli for ADH release -decrease plasma volume= hemoconcentration= increase osmolality -increase osmolality stimulates osmoreceptor in hypothalamus -activated when plasma levels reach 290 -ADH released, increasing water retention by kidneys -minimizes water loss, sever dehydration SEE GRAPH
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Adrenal cortex |
Adrenal cortex -secretes mineralocorticoids -major mineralocorticoid: aldosterone Aldosterone effects -increase NA++ retention by kidneys -increase water retention via osmosis -increase K+ excretion Stimuli for aldosterone release -decrease plasma NA+ -decrease blood volume, blood pressure -increase sympathetic activation -decrease plasma K+ |
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Osmolality |
Aldosterone-where Na+ moves, water follows -NA+ rentention= increase osmolality -increase osmolality= increase water rentention osmotic water movement minimizes loss of plasma volume, maintains blood pressure |
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The kidneys and renin |
stimulus for renin release decrease blood volume decrease blood pressure sympathetic nervous system impulses renin-angiotensin-aldosterone mechanism -renin- converts angiotensinogen to angiotensin I -ACE- converts angiotensin I to angiotensin II -Angiotensin II stimulates aldosterone release |
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Atrial natriuretic peptide (ANP) |
-release from atria -causes NA+ excretion -increase natriuresis
Activated by increase stretch or plasma volume |
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Kidneys |
Kidneys -target tissue for ADH, aldosterone -Secrete renin -secrete EPO EPO -low blood Os in kidneys=EPO release -stimulates red blood cell production -critical for adaption to training, altitude
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