CH 9 Q &A

The sites where the motor nerve impulse is transmitted from the nerve endings to the skeletal muscle cell membranes are the

neuromuscular junctions

The ions that enter the skeletal muscle during action potential generation are

sodium ions

Describe the structure of a sarcomere and indicate the relationship of the sacromere to myofilaments.

A sarcomere is a segment of a myofibril containing thick and thin filaments. Sarcomere is the contractile unit, composed of myofilaments.

Which provides ATP fastest?

A) a coupled reaction of creatine phosphate with ADP

Which does (do) not require that oxygen be available?

A) a coupled reaction of creatine phosphate with ADP) & C) Aneaerobic glycolysis

During muscle contraction, ATP is provided by

A) a coupled reaction of creatine phosphate with ADP, B) aerobic desperation of glucose, and C) anaerobic glycolysis

Characteristics of isometric contractions include all but

Shortening

Explain the sliding filament theory of contraction

States that during contraction the thin filaments slide past the thick ones so that actin and myosin filaments overlap to a greater degree. In a relaxed muscle fiber the thick and thin filaments overlap only at the ends of the A band.

The neurotransmitter released by somatic motor neurons is

acetylcholine

Explain how a slight but smooth contraction differs from a vigorous contraction of the same muscle; use the concepts of multiple motor unit summation

...

Thick and thin myofilaments have different compositions.

...

What is the importance of acetylcholinesterase in muscle contraction?

...

Which has carbon dioxide and water products?

B) aerobic desperation of glucose

Which is most important in endurance sports?

B) aerobic desperation of glucose

Which provides the highest yield of ATP per glucose molecule?

B) aerobic desperation of glucose

Which results in the formation of lactic acid?

C) anaerobic glycolysis

The connective tissue covering that encloses the sarcolemma of an individual muscle fiber is called

Endomysium

Name and describe the 4 special functional abilities of muscle that are the basis for muscle response

Excitability; ability to receive and respond to a stimulus on the inside or outside of the body. Contractility; ability to shorten forcibly when adequelty stimulated. Extensibility; ability to be stretched or extended. Elasticity; ability to recoil and resume its resting length after being stretched.

Distinguish between direct and indirect muscle attachments and tendon and an aponeurosis

In direct or (FLESHY) attachment the epimysium of the muscle is fused to the periosteum of a bone or perichondrium of cartilage. In indirect attachments the muscles connective tissue wrappings extend beyond the muscle as either a rope like tendon or as a sheet like aponeurosis. A tendon is rope like and aponeurosis sheet like.

Contractions elicited by a single brief stimulus is called

a twitch

A fascicle is a

bundle of muscle fibers enclosed by a connective tissue sheath

A smooth, sustained contraction resulting from very rapid stimulation of the muscle, in which no evidence of relaxation is seen is called

fused tetanus

Myoglobin has a special function in muscle tissue, it

holds a reserve supply of oxygen in the muscle

Aerobic exercise results in all of the following except

increased size and strength of existing muscle cells

Contains ATPases

thick

Contains myosin

thick

Does not lie in the I band

thick

Attaches to the z disc

thin

Contains troponin

thin

contains actin

thin fillament

The function of T tubules in muscle contraction is to

transmit the action potential deep into the muscle cells