Term
What makes an endocrine gland an endocrine gland? |
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Definition
endocrine glands are ductless glands that secrete hormones |
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Term
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Definition
chemical messengers that can regulate biological processes |
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Term
what types of biological processes can hormones regulate? |
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Definition
metabolism, water balance, reproduction, growth and development |
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Term
where are hormones metabolized? |
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Definition
hormones can be metabolized in any tissue that has a receptor for the hormone |
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Term
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Definition
a tissue that has a receptor for the hormone |
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Term
what is hormone degradation? |
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Definition
hormone degradation occurs when the liver removes hormones from the blood and deactivates them |
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Term
what is metabolic clearance of a hormone |
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Definition
pulling the hormone out of the blood, either for uptake or for degradation |
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Term
what 2 factors collectively define metabolic clearance rate |
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Definition
hormone uptake at the target tissue + hormone degradation in the liver |
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Term
is metabolic clearance rate the same for all hormones |
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Definition
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Term
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Definition
a receptor that can't respond to the hormone for 1 of 2 reasons |
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Term
what are the 2 causes of a down receptor |
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Definition
the receptor could be saturated (in use by hormones) OR it could be inside the cell nucleus and not available for hormones to bind |
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Term
do hormones each have an individual purpose? |
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Definition
no. individual hormones can have a number of different jobs |
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Term
what determines a hormone's role? |
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Definition
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Term
what is an acute exercise session? |
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Definition
a single exercise session |
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Term
what is chronic exercise? |
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Definition
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Term
How does training change hormone levels at baseline? |
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Definition
If a person becomes trained, most hormones at rest will tend to be a little bit lower than before training. |
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Term
How does training change hormone levels at submaximal exercise |
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Definition
all submaximal exercise responses of hormones are lower in a trained person than in untrained people |
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Term
How does training change the hormone response to maximal exercise? |
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Definition
A maximal exercise response of hormones can be greater in a trained person because the person can handle the increase in hormones. |
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Term
what is an exception to the "lower baseline hormone levels in a trained person" rule? |
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Definition
if you do lots of resistance training, you might find that your resting testosterone levels are slightly higher. This is different from what we usually see with hormones |
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Term
how do hormones change to an acute bout of exercise? |
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Definition
hormones can increase, decrease, or remain the same with an acute bout of exercise. |
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Term
what determines the amount that a hormone responds to an acute bout of exercise? |
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Definition
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Term
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Definition
intensity, frequency, duration of exercise |
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Term
why do hormones respond to exercise? |
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Definition
hormones have a physiological role to help the body meet demands of exercise |
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Term
what are the necessary actions of hormones that help the body meet the demands of exercise? |
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Definition
Hormones: 1. Increase energy expenditure by mobilizing substrates and turning on energy pathways, 2. Increase cardiovascular adjustments, 3. Alter hydration status for thermoregulation, 4. Increase stress reactivity and the immune system |
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Term
How is the response of hormones with exercise a feed forward mechanism? |
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Definition
The changes made by hormones can further increase hormonal responses |
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Term
Give an example of a feed forward response of a hormone |
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Definition
increasing energy production can increase heat which can cause fluid loss which can cause further endocrine response |
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Term
In what ways is hormone concentration in the blood increased? |
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Definition
increased hormone production, increased hormone secretion, decreased metabolic clearance of hormone, increased hemoconcentration |
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Term
in what ways is hormone concentration in the blood decreased? |
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Definition
Decreased hormone production, decreased hormone secretion, increased metabolic clearance of hormone, increased hemodilution |
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Term
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Definition
the amount of solid in a liquid |
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Term
what is hemoconcentration? |
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Definition
loss of blood fluid (loss of plasma volume) |
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Term
how does hormone concentration change with hemoconcentration? |
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Definition
blood fluid is lost, so the amount of hormone per unit of blood is increased |
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Term
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Definition
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Term
how does hormone concentration change with hemodilution? |
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Definition
if we have increased plasma volume, the concentration of hormone will decrease |
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Term
with what does fluid shift in and out of the blood? |
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Definition
exercise, probably other stuff too |
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Term
what has to happen for there to be a steady state of hormone level with exercise? |
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Definition
Either the amount of metabolic clearance = the amount of secretion OR hemoconcentration = hemodilution |
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Term
with a steady state of hormone during exercise, is the hormone truly not changing? |
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Definition
It might look like exercise has no effect on the hormone, but there are actually factors to increase and decrease the hormone that occur in the same amount |
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Term
what are modifiers of hormonal response to exercise? |
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Definition
gender, age, nutritional status, hydration status, affective state, hypobaric conditions, hyperbaric conditions |
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Term
What will my hormonal response be if I start an exercise bout and am low in carbohydrates, dehydrated, and feeling blue? |
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Definition
My hormonal response would be much greater than if those things were in a proper status prior to starting the exercise |
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Term
what factors and conditions influence hormonal response to exercise? |
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Definition
competitive vs training stress; time of day; time of year; mode of exercise; recovery response; bioavailability of the hormone |
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Term
what is the recovery response? |
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Definition
some hormones respond rapidly after an exercise session, quickly returning to normal; some hormones take a long time to increase after exercise and then slowly return to normal; some hormones decrease after an exercise session |
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Term
what affects the bioavailability of the hormone? |
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Definition
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Term
what is the hormone half-life of ACTH |
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Definition
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Term
what is the half-life of antidiuretic hormone? |
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Definition
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Term
what is the half life of aldosterone |
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Definition
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Term
what is the half life of the catecholamines |
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Definition
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Term
what is the half life of cortisol? |
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Definition
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Term
what is the half life of glucagon? |
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Definition
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Term
what is the half life of growth hormone? |
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Definition
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Term
what is the half life of insulin? |
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Definition
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Term
what is the half life of testosterone? |
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Definition
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Term
what is the half life of TSH? |
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Definition
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Term
what is the half life of triiodothyronine? |
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Definition
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Term
what does "bioavailability" include? |
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Definition
amount of free hormone, number of functional receptors, affinity level of receptors for the hormone, post-receptor amplification mechanisms |
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Term
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Definition
a hormone not currently bound to a receptor site |
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Term
how does chronic exercise affect basal resting hormone levels (for the most part)? |
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Definition
chronic exercise reduces basal resting hormone levels |
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Term
how does chronic exercise affect hormone response to maximal exercise? |
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Definition
maximal exercise in a trained person will provoke larger hormone responses than before the training |
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Term
why does submaximal exercise not provoke an increased hormone in a trained person? |
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Definition
exercise becomes less of a physical stress to the body in a trained person |
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Term
In what ways is exercise less of a physical stress to a trained person? |
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Definition
Training improves homeostasis so that exercise no longer messes things up on the inside of cells; target tissue doesn't need as much hormone to get the desired effect because it has improved sensitivity |
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Term
How quickly after exercise does insulin begin to return to its pre-training response values? |
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Definition
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Term
what happens to hormones with continued inactivity after training? |
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Definition
they return to their pre-training values |
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Term
what are the 2 catecholamine hormones |
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Definition
norepinephrine, epinephrine |
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Term
what are the specific ways in which norepinephrine and epinephrine affect metabolism? |
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Definition
1. increase breakdown of glycogen into glucose in liver and muscle; 2. increase breakdown of triglycerides into free fatty acids and glycerol; 3. decrease entry of glucose into some cells and tissues because of a preferential treatment of the oxidation of free fatty acids |
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Term
During an incremental, progressive exercise test resulting in maximal effort, how will plasma norepinephrine and epinephrine change? |
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Definition
as oxygen consumption increases, plasma norepinephrine and epinephrine increase exponentially with the increase in norepinephrine beginning before the increase in epinephrine |
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Term
is there typically more norepinephrine or epinephrine in circulation? |
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Definition
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Term
During a submaximal, steady state exercise at a fixed intensity, what is the catecholamine response? |
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Definition
The catecholamine response increases dramatically at first and then increases slowly throughout the duration of exercise. |
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Term
At a higher magnitude of steady state exercise, how will the catecholamine response change compared to a lower magnitude of steady state exercise? |
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Definition
at a higher magnitude of steady state exercise, the magnitude of increase of catecholamines will be higher |
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Term
what determines whether a tissue will respond to catecholamines? |
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Definition
The tissue must have a receptor for the catecholamine |
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Term
what determines the magnitude of the effect of catecholamines on a tissue |
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Definition
the number of receptors, the level of receptor saturation |
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Term
what are the 2 receptors to which norepinephrine binds? |
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Definition
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Term
what are the receptors to which epinephrine binds at LOW doses? |
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Definition
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Term
what are the receptors to which epinephrine binds at HIGH doses? |
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Definition
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Term
what catecholamine responds to alpha 1? |
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Definition
norepinephrine. Epinephrine at high doses. |
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Term
Why does it take high doses of alpha 1 receptors to take E? |
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Definition
alpha 1 receptors have a greater affinity for NE. They will switch to having an affinity for E when there is a lot of E. |
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Term
What are the effects of a catecholamine binding to an alpha 1 receptor? |
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Definition
vasoconstriction in the GI and vascular systems |
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Term
Why does vasoconstriction from alpha 1 receptors occur more strongly in the GI system than in the vascular system? |
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Definition
there are more alpha 1 receptors in the GI system than in the vascular system |
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Term
what catecholamine responds to beta 1 receptors? |
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Definition
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Term
what does it meant hat N and slightly E binds to Beta 1 receptors? |
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Definition
beta 1 receptors like to respond to norepinephrine, but they will take epinephrine if there is no other option |
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Term
what do beta 1 receptors do? |
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Definition
cause myocardial acceleration and myocardial contractility (heart beats more powerfully) |
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Term
what hormone binds to beta 2 receptors? |
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Definition
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Term
why do beta 2 receptors only receive E at low dosage? |
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Definition
beta 2 receptors become overwhelmed with too much epinephrine |
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Term
what is the result of catecholamines responding to beta 2 receptors? |
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Definition
vasodilation in arterioles (heart, muscle) |
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Term
what is the effect of training on basal levels of catecholamines? |
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Definition
slightly lower. Possibly no change since you don't typically have a lot of catecholamines floating around at rest |
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Term
what is the submaximal exercise response of catecholamines in a trained person compared to an untrained person? |
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Definition
slightly lower catecholamines in the trained person. Right after submaximal exercise, a trained individual will have decreased catecholamines. |
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Term
what is the maximal exercise response of catecholamines in a trained person compared to an untrained person? |
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Definition
could be increased since you have the ability to enhance production and secretion. The levels of catecholamines in the trained person are less up until the point where you reach maximal exercise |
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Term
why does an untrained person have an increase in catecholamines with exercise? |
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Definition
stress reactivity causes over response of sympathetic nervous system |
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Term
what is the primary hormone responsible for the uptake and storage of glucose and free fatty acids? |
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Definition
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Term
what creates changes in insulin? |
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Definition
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Term
what happens with insulin if blood glucose increases? |
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Definition
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Term
how does the concentration of insulin change during exercise? |
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Definition
the concentration of insulin decreases during exercise as intensity increases |
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Term
compare the effects of insulin and glucagon in one word |
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Definition
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Term
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Definition
increased glucose in the blood |
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Term
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Definition
causes glucose to move out of the blood and into the tissue of muscle, adipose, and liver |
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Term
what stimulates glucagon? |
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Definition
decreased glucose in the blood |
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Term
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Definition
glucagon breaks down adipose into triglycerides to elevate blood FFA and glycerol AND causes amino acids and glycogen to break down into blood glucose |
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Term
what are the 2 transport proteins on skeletal muscle cells? |
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Definition
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|
Term
what do glut 1 transporters do? |
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Definition
constantly pull glucose into the skeletal muscle |
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Term
do glut 1 transport proteins require insulin to work? |
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Definition
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Term
are there many glut 1 transporters in skeletal muscle? |
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Definition
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Term
what does muscle tissue need to be able to exercise? |
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Definition
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Term
how is insulin helpful to skeletal muscle? |
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Definition
helps it to pick up glucose from the blood |
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Term
where are glut 4 transport proteins found? |
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Definition
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Term
are glut 4 or glut 1 transport proteins more common? |
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Definition
glut 4 transport proteins are more common |
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Term
what is usually necessary for glut 4 transport proteins to work? |
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Definition
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Term
does glut 4 ALWAYS require insulin to tell it what to do? |
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Definition
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Term
when does glut 4 not need insulin to tell it to pull glucose in? |
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Definition
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Term
what makes fat cells pull glucose in out of the blood? |
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Definition
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Term
are adipose cells insulin dependent or independent |
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Definition
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Term
how does the battle over glucose between adipocytes and muscle cells change during exercise and why? |
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Definition
When Glut 4 transport proteins become insulin independent, the muscle cells are more able to pick up more glucose without insulin. The adipocytes continue to require insulin, but there is less insulin during exercise so the adipocytes are not pulling as much glucose out of the blood. There is more glucose in the blood available for muscle, and the muscle is better at getting the glucose out of the blood. |
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Term
what 2 things increase the number of glut 4 transporters in the membrane |
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Definition
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Term
what 2 things activate glut 4 transporters at rest |
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Definition
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Term
how are glut 4 transport proteins able to become insulin independent during exercise? |
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Definition
intracellular signaling mechanisms help to up regulate glut 4 transport proteins |
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Term
what are the changes in insulin in response to a submaximal exercise session (steady state)? |
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Definition
insulin decreases initially and then plateaus |
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Term
how do trained and untrained people compare in insulin response to steady state, submaximal exercise bout? |
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Definition
trained and untrained both have reduced insulin, but an untrained person has a slightly greater loss of insulin |
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Term
how does training change your basal insulin levels? |
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Definition
if you have low insulin levels at rest already, training won't make a big difference. But if you have high insulin levels (prediabetic), your basal insulin levels will decrease with training. |
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Term
why does insulin decrease during exercise? |
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Definition
we stop producing insulin during exercise because our glut 4 transporters are working now AND catecholamines decrease production of insulin. We will use up the insulin that is there, but no more will be produced to replace it. |
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Term
why does a trained person have less of a decrease in insulin? |
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Definition
training creates a smaller catecholamine response. Catecholamines stop insulin production. With fewer catecholamines, there will be less of a decrease in insulin. |
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Term
what are the differences in insulin levels in a trained vs untrained person during a maximal exercise bout? |
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Definition
a maximal exercise bout will create a GREATER decrease in insulin in a trained person than in an untrained person. |
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Term
why does a maximal exercise bout create a greater decrease in insulin in a trained person than in an untrained person. |
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Definition
The trained person at maximal exercise can push harder than an untrained person, resulting in a greater catecholamine response and therefore a greater insulin suppression. |
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Term
What is Type II diabetes? |
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Definition
tissues not responding to insulin = receptors are either not there or not functional. |
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Term
how to decrease insulin in type 2 diabetes? |
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Definition
diet, exercise, medications |
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Term
what is insulin sensitivity? |
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Definition
the ability to move glucose into tissues with less insulin |
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Term
how can you improve insulin sensitivity |
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Definition
training: after 14 weeks of physical training, the tissue is much more sensitive to insulin, meaning it takes very little insulin to move glucose in. |
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Term
what is insulin resistance? |
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Definition
a condition in which cells fail to respond to the normal actions of hormones. |
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Term
do we want high or low insulin sensitivity? |
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Definition
we want high insulin sensitivity |
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Term
do we want high or low insulin resistance |
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Definition
we want low insulin resistance |
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Term
how does the amount of glucagon change during exercise as you move from low to moderate to high intensity? |
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Definition
glucagon increases with exercise as you increase in intensity |
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Term
how does glucagon change over the course of a submaximal, steady state exercise? |
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Definition
glucagon will increase and will eventually plateau |
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|
Term
does a trained or untrained person need less glucagon during exercise? |
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Definition
a trained person needs less glucagon during exercise |
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|
Term
why does a trained person need less glucagon during exercise than an untrained person? |
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Definition
The amount of fats you're metabolizing as an energy source influences the amount of glucagon you need to break down glycogen in the liver to make glucose. A trained person is better at breaking down fats into an energy result. As a result, a trained person needs less glucagon during exercise to tell the liver to break down glycogen into glucose. |
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|
Term
what is the change in basal levels of glucagon with exercise training? |
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Definition
no change at the basal level |
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|
Term
why is there no change at the basal level of glucagon at rest? |
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Definition
there isn't normally a lot of glucagon in the blood at rest |
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|
Term
what is the change in glucagon in a trained person with submaximal exercise? |
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Definition
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|
Term
what is the maximal exercise response of glucagon in a trained person? |
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Definition
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|
Term
how does a single exercise bout affect the sympathetic nervous system? |
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Definition
exercise activates the sympathetic nervous system |
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|
Term
how does the sympathetic nervous system affect catecholamines? |
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Definition
the SNS increases catecholamines |
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|
Term
how does E, NE affect the liver? |
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Definition
E, NE cause the pancreas to decrease insulin and increase glucagon production |
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|
Term
why is it helpful that E, NE decrease insulin during exercise? |
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Definition
when you decrease insulin, there will be greater breakdown of triglycerides into FFA. |
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|
Term
why is it helpful that glucagon is increased during exercise? |
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Definition
increased glucagon (and increased catecholamines) promote breakdown of glycogen into glucose. This increases blood glucose and FFA for energy. |
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Term
what are the 4 controls of the breakdown of muscle glycogen for utilization |
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Definition
1. E and NE to activate cyclic AMP; 2. Calcium to implement glycogen phosphorylase; 3. glucagon; 4. glycogenolysis |
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|
Term
at what exercise intensity does the greatest depletion of glycogen occur |
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Definition
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|
Term
why do you have less glycogen depletion at exercise intensity levels lower than 75% VO2 max? |
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Definition
at lower intensities you have greater fact contribution |
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|
Term
why do you have less glycogen depletion at exercise intensities greater than 75%? |
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Definition
you can't maintain higher intensities for a long enough period of time. |
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|
Term
do you have higher or lower plasma epinephrine concentration at high levels of exercise intensity? |
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Definition
more epinephrine with higher intensity exercise |
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|
Term
What are the mechanisms to maintain blood glucose during exercise? |
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Definition
1. mobilization of glucose from glycogen in the liver; 2. mobilization of FFA from adipose tissue to spare blood glucose; 3. gluconeogenesis from amino acids, lactic acid, and glycerol; 4. hormonal blocking to prevent glucose from leaving the blood and to force some tissues to use FFA during exercise to spare blood glucose |
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|
Term
at what point does gluconeogenesis from amino acids, lactic acid, and glycerol occur MOST? |
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Definition
during recovery from exercise |
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|
Term
what organ produces insulin and glucagon |
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Definition
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|
Term
why is there so much NE in our blood? |
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Definition
sympathetic spillover. There are many nerve fibers that release lots of NE. |
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Term
what are the 2 glands where epinephrine is made |
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Definition
2 adrenal medullary glands |
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|
Term
what are the primary destinations for NE? |
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Definition
liver, pancreas, skeletal muscle |
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|
Term
what happens to all the extra NE that the liver, pancreas, and skeletal muscle can't use? |
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Definition
the NE will diffuse into nearby capillary beds as spillover |
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|
Term
NE is an indicator of what? |
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Definition
sympathetic nervous system |
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|
Term
E is an indicator of what? |
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Definition
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|
Term
when does E bind to alpha 1 receptors |
|
Definition
extremely intense exercise |
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|
Term
what do alpha 1 receptors cause? |
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Definition
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|
Term
what happens at extremely high exercise when alpha 1 receptors are activated by E? |
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Definition
vasoconstriction: decreased blood => decreased oxygen to muscle => decreased waste removal => feels bad => most people won't push that hard |
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|
Term
why are there no alpha 1 receptors in the heart and brain? |
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Definition
we don't want to be able to shut down blood flow to the heart and brain |
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|
Term
why do E and NE have overlapping and redundant actions? |
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Definition
NE and E create processes that have to occur or we will die. So we ant to have a back-up to be certain that the processes will occur to keep us alive |
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|
Term
what hormone overlaps with insulin? |
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Definition
insulin like growth factors |
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|
Term
why is it bad for a person with a glucose of 300 to exercise? |
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Definition
With this much glucose in the blood, the muscle cell will take in all the glucose from the blood rapidly. Glycolysis likes to do glucose metabolism. If glucose is showing up in the cell during exercise, the cell will ignore the glycogen stores in the muscle. The transporters will turn on and run fast because there is a high concentration of glucose in the blood. The rapid pulling in of glucose from the blood can lead to rapid hypoglycemia |
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|
Term
What is the ADA recommendation for exercise for people with uncontrolled diabetes? |
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Definition
low intensity and intermittent: walk for 5 minutes, rest for 5 minutes. Make certain that the person feels good and is not rapidly exhausting glucose in their blood. |
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