Muscle

Question 1

Three types of muscle

Answer 1

skeletal, smooth, and cardiac

Question 2

Skeletal Muscle

Answer 2

Striated Voluntary (somatic nervous system) Many nuclei per cell

Question 3

Slow Twitch

Answer 3

AKA Red Fibers High myoglobin content Primarily derive energy aerobically Contain many mitochondria

Question 4

Fast twitch

Answer 4

AKA white fibers Less myoglobin (rely on glycolysis and fermentation to make ATP)

Question 5

Smooth Muscle

Answer 5

Involuntary action (autonomic nervous system) Single nucleus in cell Capable of tonus Myogenic activity

Question 6

Myogenic activity

Answer 6

Can contract without nervous system input`

Question 7

tonus

Answer 7

a constant state of low-level contraction -may be seen in blood vessels

Question 8

Cardiac muscle

Answer 8

Mainly uninucleated Involuntary (automatic nervous system) Striated Myogenic activity Depolarization: SA node–>AV node –>bundle of His–>Purkinje fibers

Question 9

Sarcomere

Answer 9

Thick (myosin) and thin (actin) filaments Z-lines: end of the alphabet and the end of the sarcomere M-line: middle of the myosin filament I-band: I is a thin letter (thin filaments only) H-zone: H is a thick letter (thick filaments only) A-band: All of the thick filament (whether or not its overlapping) During contraction, all smaller except A band

Question 10

Titin

Answer 10

a protein that acts as a spring and anchors the actin and myosin filaments together, preventing excessive stretching of the muscle

Question 11

Myocyte

Answer 11

AKA muscle fiber Contains many myofibrils arranged in parallel. Many myocytes in parallel form a muscle

Question 12

Sarcolemma

Answer 12

Cell membrane of a myocyte. Capable of propagating an action potential and can distribute to all sarcomeres using a system of transverse tubules.

Question 13

Motor unit

Answer 13

The nerve terminal (end of neuron) and the group of myocytes it controls

Question 14

Muscle contraction

Answer 14

Binding of ATP is required for releasing the myosin head from the actin filament.

Question 15

Tropomyosin and Troponin

Answer 15

Proteins associated with actin microfilament. When action potential reaches sarcoplasmic reticulum, Ca is released–>binds to troponin–> conformational change in tropomyosin–>exposes myosin binding sites on actin

Question 16

Twitch

Answer 16

the response of a single muscle fiber to a brief stimulus. Latent period (time between reaching threshold and onset of contraction), contraction period, and relaxation period.

Question 17

tetanus

Answer 17

When contractions become so frequent that the muscle is unable to relax. Leads to fatigue.

Question 18

Creatine Phosphate

Answer 18

created by transferring a phosphate from ATP to Creatine during times of rest: C + ATP –> ADP + CP This can be reversed during muscle use to quickly generate ATP: ADP + CP –> ATP + C

Question 19

oxyhemoglobin dissociation curve shift

Answer 19

Right shift occurs: increased CO2, H+ (lower pH), and temp