Physiology Exam 3

Front 1

The most abundant neurotransmitter in the peripheral nervous system is acetylcholine.

Back 1

True

Front 2

Which of the following endocrine glands is innervated by sympathetic preganglionic neurons (ie. which endocrine gland is a direct extension of the sympathetic system)?

Back 2

adrenal medulla

Front 3

A skeletal muscle is composed of a number of ________, each composed of many muscle fibers bundled by connective tissue.

Back 3

fascicles

Front 4

The preganglionic neurons of the sympathetic nervous system emerge from the ________ of the spinal cord.

Back 4

thoracic and lumbar regions

Front 5

Physiological stressors will cause parasympathetic nervous system activity to increase.

Back 5

False

Front 6

The preganglionic neurons of the parasympathetic nervous system emerge from the ________ of the central nervous system.

Back 6

brainstem and sacral region of the spinal cord

Front 7

What is the protein component of the thin filament that binds to calcium thereby initiating skeletal muscle contraction?

Back 7

troponin

Front 8

The region of the striated muscle's banding patterns that contains ONLY the connections linking of thick filaments is the ________.

Back 8

M Line

Front 9

At rest, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?

Back 9

Both systems are active but the parasympathetic predominates.

Front 10

The shortening of a skeletal muscle fiber during contraction involves ________.

Back 10

the sarcomeres shortening

Front 11

11. Thick filaments have many protrusions along their middle (head of the myosin filaments) but none at their ends.

Back 11

False

Front 12

Parasympathetic postganglionic neurons release the neurotransmitter ________;

Back 12

acetylcholine

Front 13

Sympathetic postganglionic neurons release the neurotransmitter ________.

Back 13

norepinephrine

Front 14

Parasympathetic neurons from which cranial nerve innervate most of the viscera in the thoracic and abdominal cavities (ie. which parasympathetic nerve innervates almost every organ)?

Back 14

X

Front 15

Which area of the sarcomere is light NOT able to pass through (ie. the dark band)?

Back 15

A Band

Front 16

A ________, the fundamental repeating unit of the myofibril that gives skeletal muscle its striated appearance, is bordered by ________.

Back 16

sarcomere: Z lines

Front 17

The repeated, oscillating interaction between actin and myosin that results in the generation of force by a skeletal muscle cell is called ________.

Back 17

crossbridge cycle

Front 18

The myosin head is converted into the high-energy state by ________.

Back 18

the hydrolysis of ATP

Front 19

Contraction of smooth muscle cells is driven by binding of calcium to calmodulin.

Back 19

True

Front 20

What is the protein component of the thin filament that binds to calcium thereby initiating skeletal muscle contraction?

Back 20

Troponin

Front 21

In order for crossbridge cycling to occur, the actin-myosin complex must be broken by the ________.

Back 21

binding of ATP to myosin

Front 22

The sequence of events that links the action potential to changes in skeletal muscle force development is called ________.

Back 22

excitation-contraction coupling

Front 23

The binding of calcium complex located on the actin molecule will directly result in ________.

Back 23

the movement of tropomyosin, thereby exposing the myosin binding site on the actin molecule

Front 24

Normalized for any variability in skeletal muscle length, the speed of contraction of a skeletal muscle fiber is dependent upon ________.

Back 24

the rate of myosin ATPase activity

Front 25

Which of the following is a property of isometric skeletal muscle contraction?

Back 25

load is greater than force generated by muscle

Front 26

What causes some muscle to appear red?

Back 26

presence of myoglobin

Front 27

The longest phase of a twitch is the ________ phase.

Back 27

relaxation

Front 28

The release of an inorganic phosphate from the myosin molecule directly results in the ________.

Back 28

power stroke

Front 29

The interaction between actin and myosin in smooth muscle requires ________.

Back 29

that the calcium-calmodulin complex activates myosin light-chain kinase, which phosphorylates myosin light chain thereby allowing myosin to bind with actin

Front 30

During the crossbridge cycle, ATP binding to myosin causes ________.

Back 30

the myosin head to detach from actin

Front 31

Which of the following adaptations does NOT occur due to an increase in activity?

Back 31

Type 2a fibers can become Type 1 fibers