A & P Physiology of muscle contraction

Question 1

The function of acetylcholine esterase is to

Answer 1

stops the process of muscle contraction

Question 2

True or false. The chemical bonds in glucose provides the supply of energy contained in a creatine phosphate molecules

Answer 2

False

Question 3

Contraction causes:

Answer 3

Only the sarcomere to shorten

Question 4

Define synape

Answer 4

The place where a nerve cell meets either another nerve cell or effector organ

Question 5

Effector organ

Answer 5

The organ the nerve controls

Question 6

Neuromuscular junction

Answer 6

A special type of synapse where the axon of a nerve muscle meets a muscle cell

Question 7

Which of the following produces the least amount of energy for muscle contraction:

Answer 7

Creatine phosphate

Question 8

True or false. A fast twitch muscle would be expected to have a fast rate at which glucose is converted into ATP

Answer 8

False

Question 9

The function of ACh (acetylcholine) is to:

Answer 9

Cause an action potential occurs in the muscle cell

Question 10

Rigor mortis happens?

Answer 10

Because ATP is needs to myosin and actin to released since ATP is not present in a dead body, myosin and actin cannot release until the myofilament decay.

Question 11

Describe the transmission of a nerve impulse across the neuromuscular junction.

Answer 11

1. Motor neuron receives signal to stimulate movement
2. Synaptic vesicles move to end of neuron and release Ach
3. Ach attaches to receptors
4. Generic cation channels open, stimulating contraction
5. Enzyme breaks down Ach, stopping contractions

Question 12

Aerobic cellular respiration

Answer 12

Glucose reacts with oxygen forming ATP

Question 13

Muscle tone

Answer 13

Relaxed muscles are in a state of slight contraction

Question 14

Synaptic cleft

Answer 14

The small space between effector organ and axon of the nerve cell

Question 15

Glycolysis/ Anaerobic respiration

Answer 15

Glucose is converted into pyruvic acid which supplies energy to cells.

Question 16

What is the role of tropomyosin in muscle contraction?

Answer 16

To prevent myosin from continuing to slide up the actin filament

Question 17

What is the role of acetylcholine in calcium release?

Answer 17

Stimulates cellular contraction by opening voltage-gated ion channels

Question 18

Muscle component from largest to smallest

Answer 18

muscle, fascicle, muscle fibers, myofibrils, sarcomeres, & myofilaments

Question 19

Location of Sarcomere

Answer 19

In between the z line

Question 20

What is an aponeurosis?

Answer 20

A thin flat tendon-like sheet that anchors a muscle or connects it to the part that muscle moves

Question 21

Sliding Filament theory

Answer 21

Step 1:The sarcoplasmic reticulum stimulated to release calcium ions
Step 2: Calcium is released from the sarcoplasmic reticulum
Step 3: Calcium ions bind to troponin
which causes troponin to destabilize tropomyosin which exposes the myosin bind on actin
Step 4: Myosin becomes phosphorylated which means myosin can do work also known as high energy conformation of myosin
Step 5: Myosin binds to actin know as crossbridge attachment
Step 6: Powerstroke which is ADP and P are released from myosin head which makes myosin lose their energy and turn back to original state
Step 7: Crossbridge detachment is new molecule of ATP binds and myosin and actin unbinds and muscle relaxes

Question 22

Fast Glycolytic Fibers

Answer 22

• largest in diameter and contain the most myofibrils which can generate the most powerful contractions.
• low myoglobin content, relatively few blood capillaries, and few mitochondria.
• appear white in color because have very few myoglobin.
• large amounts of glycogen and generate ATP mainly by glycolysis.
• large size and their ability to hydrolyze ATP rapidly, FG fibers contract strongly and quickly.
• The fast‐twitch fibers are adapted for intense anaerobic movements of short duration, such as weight lifting or throwing a ball.
• they fatigue quickly.
• Strength training programs that engage a person in activities requiring great strength for short times increase the size, strength, and glycogen content of fast glycolytic fibers.

Question 23

Fast oxidative fibers

Answer 23

intermediate in diameter.

• large amounts of myoglobin and many blood capillaries, pinkish red appearance.
• generate considerable ATP by aerobic cellular respiration.
• which gives them a moderately high resistance to fatigue.
• intracellular glycogen level is high, so they also generate ATP by anaerobic glycolysis.
• are “fast” because the ATPase in their myosin heads hydrolyzes ATP three to five times faster than the myosin ATPase in SO fibers.
• twitches of FOG fibers reach peak tension more quickly than those of SO fibers but are briefer in duration—less than 100 msec.
• contribute to activities such as walking and sprinting.

Question 24

Slow oxidative fibers

Answer 24

smallest in diameter.

• least powerful.
• dark red- large amounts of myoglobin and many blood capillaries. many large mitochondria.
• generate ATP mainly by aerobic cellular respiration.
• “slow” because the ATPase in the myosin heads hydrolyzes ATP relatively slowly and the contraction cycle proceeds at a slower pace than in “fast” fibers.
• slow speed of contraction.
• Their twitch contractions last from 100 to 200 sec, and they take longer to reach peak tension.
• resistant to fatigue and are capable of prolonged, contractions for many hours.
• adapted for maintaining posture and for aerobic, endurance‐type activities such as running a marathon.

Question 25

Which muscle twitch fatigue faster

Answer 25

Fast twitch

Question 26

Which muscle twitch uses doesn’t use a lot if energy

Answer 26

Slow twitch