|
|
| (4 intermediate revisions not shown) |
| Line 2: |
Line 2: |
| | | | |
| | | | |
| - | ==Exercise physiology==
| + | 1jnF0F Very good post. |
| - | | + | |
| - | ===Objectives===
| + | |
| - | *The student will be able to describe the 3 metabolic systems that supply energy during exercise and relate exercise conditions with nutrient fuel use.
| + | |
| - | *The student will understand how oxygen consumption varies with exercise intensity.
| + | |
| - | *The student will be able to describe the 2 stages of oxygen recovery.
| + | |
| - | *The student will be able to describe respiratory changes during exercise.
| + | |
| - | *The student will be able to describe chemical and neural mechanisms stimulating ventilation during exercise.
| + | |
| - | *The student will be able to describe the dynamic relationship between changes in stroke volume and heart rate during exercise.
| + | |
| - | *The student will be able to describe the redistribution of blood flow to muscles and other organs during exercise.
| + | |
| - | *The student will understand the unique regulation of temperature during exercise.
| + | |
| - | *The student will understand the effect of training on cardiovascular, respiratory and metabolic function.
| + | |
| - | | + | |
| - | ===Metabolic aspects of exercise===
| + | |
| - | *Exercise requires lots of ATP for all the work the muscle is doing.
| + | |
| - | *ATP can be generated in three ways: the phosphagen system, the glycogen-lactic acid system, or the aerobic system.
| + | |
| - | **The phosphagen system uses creatine kinase to move the phosphate group off of creatine to ADP, generating ATP.
| + | |
| - | ***The phosphagen system (and the resident ATP) covers the energy for the 0-60 seconds of vigorous exercise.
| + | |
| - | **The glycogen-lactic acid system runs glycogen through glycolysis to generate lactic acid.
| + | |
| - | ***The glycogen-lactic acid system covers the energy for the 1-4 minutes of vigorous activity.
| + | |
| - | **The aerobic system uses the electron transport chain to generate ATP from glucose, fatty acids, and amino acids.
| + | |
| - | ***Aerobic oxidation of muscle glycogen, plasma glucose, and liver glycogen cover the energy for minutes 4-200 (and then tapers off).
| + | |
| - | ***Aerobic oxidation of plasma FFA (free fatty acids) and adipose tissue TAGs (triacylglycerides) cover the energy for minutes 45 and beyond.
| + | |
| - | | + | |
| - | ===Energy conversion in skeletal muscle===
| + | |
| - | *Recall that glycolysis takes glucose to two pyruvate molecules, generating 6 ATP and 2 NADH.
| + | |
| - | *Recall that bursts of heavy activity utilize the phosphagen system and the glycogen-lactic acid systems for production of ATP.
| + | |
| - | | + | |
| - | ===Energy suply to muscle during exercise===
| + | |
| - | *During exercise, epinephrine is elevated which signals to the liver, skeletal muscle, and adipose tissue.
| + | |
| - | | + | |
| - | | + | |
| - | *Epinephrine at the liver:
| + | |
| - | **Epinephrine causes the liver to increase glycogenolysis and gluconeogenesis.
| + | |
| - | **Epi--like glucagon--binds to a receptor that elevates cAMP levels and thus triggers activation of appropriate enzymes.
| + | |
| - | **Note that gluconeogenesis can use lactic acid as a precursor to be converted into glucose.
| + | |
| - | | + | |
| - | | + | |
| - | *Epinephrine at the muscle:
| + | |
| - | **Epinephrine at the skeletal muscle signals for the use of glycolysis (the anaerobic burning of glucose).
| + | |
| - | **Epinephrine binds to a cAMP elevating receptor on skeletal muscle which leads to activation of appropriate enzymes for converting glucose into ATP and aerobic intermiediates (think NADH and pyruvate).
| + | |
| - | **Glucose converted to pyruvate too quickly to be used in the (limited capacity citric acid cycle--oxphos) can be converted to lactic acid and secreted into the blood to be used in gluconeogenesis at the liver.
| + | |
| - | ***Recall that this loop (glucose -> pyruvate (to get the ATP and NADH) -> lactic acid -> liver -> glucose -> muscle -> pyruvate...) is called the '''cori cycle'''.
| + | |
| - | | + | |
| - | | + | |
| - | *Epinephrine at the adipose tissue:
| + | |
| - | **Epinephrine at the adipose tissue causes TAG breakdown into FFAs for secretion into the blood.
| + | |
| - | **Epinephrine binds to a receptor that activates the '''hormone-sensitive lipase'''.
| + | |
| - | | + | |
| - | | + | |
| - | ===Oxygen consumption during exercise===
| + | |
| - | *The basal rate of oxygen consumption is about 0.25 L / minute.
| + | |
| - | *Light exercise can elevate oxygen consumption 3-fold to about 1 liter.
| + | |
| - | *Heavy exercise can elevate oxygen consumption 8-10 fold to nearly 3.5 liters.
| + | |
| - | | + | |
| - | ===V<sub>O<sub>2</sub></sub>: Maxiumum O<sub>2</sub> consumption===
| + | |
| - | | + | |
| - | *stopped here on 04/11/11.
| + | |
| - | *started here on 04/12/11.
| + | |
| - | | + | |
| - | | + | |
| - | ===Objectives===
| + | |
| - | *The student will be able to describe the 3 metabolic systems that supply energy during exercise and relate exercise conditions with nutrient fuel use.
| + | |
| - | *The student will understand how oxygen consumption varies with exercise intensity.
| + | |
| - | *The student will be able to describe the 2 stages of oxygen recovery.
| + | |
| - | *The student will be able to describe respiratory changes during exercise.
| + | |
| - | *The student will be able to describe chemical and neural mechanisms stimulating ventilation during exercise.
| + | |
| - | *The student will be able to describe the dynamic relationship between changes in stroke volume and heart rate during exercise.
| + | |
| - | *The student will be able to describe the redistribution of blood flow to muscles and other organs during exercise.
| + | |
| - | *The student will understand the unique regulation of temperature during exercise.
| + | |
| - | *The student will understand the effect of training on cardiovascular, respiratory and metabolic function.
| + | |
| - | | + | |
| - | | + | |
| - | *stopped here on 04/12/11.
| + | |
