CORRECT QUESTIONS AND ANSWERS
What is isometric contraction? - ANSWER-Muscle produces internal tension while an
external resistance causes it to stay the same length or become longer.
What is isotonic contraction? - ANSWER-Muscle changes in length but the tension
stays the same.
What is concentric muscle contractions? - ANSWER-Muscle shortens while tension
stays the same.
What is eccentric muscle contractions? - ANSWER-Muscle lengthens as it maintains
tension.
All muscle contraction depends on what? - ANSWER-ATP.
ATP depends on the availability of what two things? - ANSWER-1. Oxygen
2. Glucose and fatty acids
What two ways does ATP get synthesized? - ANSWER-1. Anaerobic fermentation
2. Aerobic respiration
Describe anaerobic fermentation. - ANSWER-Enable cells to produce ATP in the
absence of oxygen.
Yields little ATP and toxic lactic acid which plays a major role in fatigue.
Describe aerobic respiration. - ANSWER-Produces far more ATP.
Less toxic products.
Requires continual supply of oxygen.
Explain how ATP is supplied during short intense exercise. - ANSWER-Oxygen is
supplied through myoglobin for limited aerobic respiration.
How is ATP demand met? - ANSWER-ATP demand is met by borrowing phosphate
groups from other molecules and transferring them to ADP.
What two enzymes control the transfer of phosphate groups? - ANSWER-1. Myokinase
2. Creatine kinase
, What is myokinase? - ANSWER-Transfers a phosphate group from one ADP to another
converting it latter to ATP.
What is creatine kinase? - ANSWER-Obtains phosphate from a phosphate-storage
molecule creatine phosphate.
What does the phosphagen system provide for? - ANSWER-Nearly all energy used for
short burst of intense activity.
As the phosphagen system is exhausted what happens? - ANSWER-Muscles shift to
anaerobic fermentation.
In the absence of oxygen, glycolysis can generate a net gain of _______ ATP for every
glucose molecule consumed. - ANSWER-2
Where do muscles obtain glucose from? - ANSWER-Blood and their own stored
glycogen.
Aerobic respiration produces ______ ATP molecules per glucose. - ANSWER-36.
What are the 6 causes of muscle fatigue? - ANSWER-1. ATP synthesis declines as
glycogen is consumed.
2. ATP shortage slows down Na(+) and K(+) pumps.
3. Lactic acid lowers pH of sarcoplasm.
4. Accumulation of extracellular K(+)
5. Motor nerve fibers use up their ACh
6. Less signal output to skeletal muscles
What is endurance determined by? - ANSWER-Large part by one's maximum oxygen
uptake.
What is the maximum oxygen uptake? - ANSWER-The point at which the rate of oxygen
consumption reaches a plateau and does not increase with an added workload.
What composes the muscular system? - ANSWER-Skeletal muscles only
What is the study of the muscular system called? - ANSWER-Myology
What are the 4 functions of muscles? - ANSWER-1. Movement
2. Stability
3. Control of body openings and passages
4. Heat production