Bios 3500 Exam 3

Front 1

True or False. Black widow spider toxin prevents the release of ACh at the NMJ.

Back 1

False

Front 2

True or False. Skeletal muscles that have a fine degree of control have small motor units.

Back 2

True

Front 3

True or False. MD is a hereditary disease where actin and myosin filaments are replaces with fibrous tissue, resulting in the loss of cross bridge activity.

Back 3

True

Front 4

True or False. Veins carry blood toward the heart.

Back 4

True

Front 5

True or False. Muscle spindles in skeletal muscle respond to changes in muscle tension.

Back 5

False

Front 6

True or False. The velocity of shortening decreases as skeletal muscle contraction load increases.

Back 6

True

Front 7

True or False. Increasing the number of recruited motor units in skeletal muscle increases its force and strength of contraction.

Back 7

True

Front 8

True of False. Cardiac muscle contains T-tubules that physically connect to foot proteins in the SR. During isometric contraction of the hiceps

Back 8

False

Front 9

Accirdinf to the sliding-filament mechanism of skeletal muscle contraction, the thin filaments..

Back 9

Slide inward toward the center of the A band

Front 10

Which of the following muscles would be inner area by the largest number of small motor units: arm muscle, back muscle, fingertip muscle, calf muscle, or chest muscle?

Back 10

Fingertip

Front 11

During tetanus...

Back 11

The muscle fiber is stimulated at a high frequency to produce maximal contraction.

Front 12

The smallest functional unit of a skeletal muscle is...

Back 12

Sarcomere

Front 13

The source of ATP for skeletal muscle is..

Back 13

Creatine phosphate stores

Front 14

What would occur is ACh was not removed from nicotinic receptors at the NMJ?

Back 14

The muscle would continue to contract until fatigued.

Front 15

The striated appearance of skeletal muscle is due to...

Back 15

Regularly ordered arrangement of thick and thin filaments into the I and A bands.

Front 16

All calcium needed for skeletal muscle comes from...

Back 16

The SR

Front 17

The T-tubules in skeletal muscle...

Back 17

Provide means of rapidly transmitting action potentials from the surface of the muscle into the central portions of the muscle fiber.

Front 18

Which vessel contains the highest amount of oxygenated blood in the body?

Back 18

Pulmonary vein

Front 19

Intrafusal muscle fibers...

Back 19

Are innervated by gamma motor neurons

Front 20

Optimal length of a skeletal muscle occurs...

Back 20

When there is optimal overlap between actin and myosin fibers to generate the greatest tension.

Front 21

Troponin...

Back 21

Consists of 3 subunits that bind to Ca2+, tropomyosin, and actin

Front 22

When a muscle atrophies..

Back 22

It decreases in mass and actin and myosin is lost

Front 23

The relaxation of skeletal muscle occurs when...

Back 23

There is no longer a depolarization of the T-tubule

Front 24

Foot proteins in skeletal muscle...

Back 24

Release Ca2+ into the cytoplasm after depolarization of the dihydropyridine receptors

Front 25

Describe the mechanism of parasympathetic innervation to the single-unit smooth muscle in the digestive system.

Back 25

Activates the muscarinic receptors in the intestinal smooth muscle to increase motility and secretions.

Front 26

Describe the body’s lever systems.

Back 26

Muscles must exert greater forces than the load they lift.

Front 27

Single unit smooth muscle and cardiac muscle are_________ and contain_________ so that they can perform _________.

Back 27

Myogenic, gap junctions, functional syncytium.

Front 28

What fiber type can be changed to fast-glycolytic fibers by following a weight lifting routine?

Back 28

Fast-oxidative

Front 29

Which fibers have the largest diameter?

Back 29

Fast glycolytic

Front 30

Which fibers have slower myosin ATPase enzyme activity?

Back 30

Slow-oxidative

Front 31

Which fiber is the most powerful?

Back 31

Fast glycolytic

Front 32

Which fiber type most readily fatigues?

Back 32

Fast glycolytic

Front 33

Which fiber type is found predominantly in muscles adapted for sprinting?

Back 33

Fast oxidative

Front 34

Which fiber type is predominantly found in muscles designed for long duration use?

Back 34

Slow oxidative