muscle test

Most preganglionic fibers in the sympathetic nervous system synapse with __________. no neurons somatic neurons parasympathetic neurons 10-20 postganglionic neurons effectors directly

10-20 postganglionic neurons

During muscle contraction, a single myosin head consumes ATP at a rate of about __________ ATP per second. 1 3 5 7 9

5

Which of the following individuals would have more mitochondria in her skeletal muscle? A 50-year-old sedentary computer programmer A 22-year-old soccer player A long-term hospice patient A model on a reduced-calorie diet A newborn

A 22 year old soccer player

The bond between the active site on actin and the myosin head is broken when an __________. ATP molecule binds to the myosin head ATP molecule binds to the actin molecule ATP molecule breaks down on the myosin head ATP molecule breaks down on the actin molecule ADP molecule and a phosphate molecule bind to the myosin head

ATP molecule binds to the myosin head

Parasympathetic

-associated with reduced energy expenditure decreases the frequency of impulses initiated by the sinoatrial node of the heart stimulates the smooth muscles of the digestive tract. Rest and digest

Sympathetic

Active during physical stress increases the amount of air entering the alveoli of the lungs maintains blood pressure releases norepinephrine to the heart results in decreased urine production Fight or flight

An action potential causes calcium ions to diffuse from the ________ into the ________. sarcoplasmic reticulum; sarcolemma sarcoplasmic reticulum; sarcoplasm sarcoplasm; sarcoplasmic reticulum sarcoplasm; sarcolemma sarcolemma; sarcoplasm

Sarcoplasm reticulum; sarcoplasm

Which structure do the calcium ions bind to when muscle contraction is initiated? The actin myofilament The troponin molecule The tropomyosin molecule The sarcoplasmic reticulum The sarcolemma

The troponin molecule

Which fibers are primarily responsible for producing lactic acid? Type I slow oxidative fibers Type IIA intermediate glycolytic fibers Type IIB fast glycolytic fibers Type I slow-twitch fibers Red fibers

Type IIB Fast glycolytic fibers

he neurotransmitter(s) associated with autonomic ganglia is(are) __________. norepinephrine (NE) acetylcholine (ACh) and norepinephrine (NE) acetylcholine (ACh) dopamine dopamine and norepinephrine (NE)

acetylcholine (ACh)

Cross-bridges form between the __________ and the __________. troponin; tropomyosin calcium; sodium sarcolemma ; sarcoplasmic reticulum T tubules; sarcolemma actin filaments; myosin heads

actin filaments; myosin heads

Where is dystrophin, the protein that is defective in muscular dystrophy, normally found? Between the outermost myofilaments and the sarcolemma of a muscle fiber As a transmembrane protein of the sarcolemma In the Z discs of skeletal and cardiac muscle In the dense bodies of smooth muscle Bridging the gap between the sarcolemma and synaptic knob

between the outermost myofilaments and the sarcolemma of a muscle fiber

Muscle contractions are initiated by the binding of __________ to __________. potassium ions; troponin potassium ions; tropomyosin calcium ions; troponin calcium ions; tropomyosin calcium ions; troponin and tropomyosin

calcium ions; troponin

The transfer of phosphate from CP to ADP is catalyzed by __________. myokinase creatinine cAMP creatine kinase ATP

creatine kinase

The digestive tract has a nervous system of its own called the _________ nervous system. enteric parasympathetic sympathetic peripheral central

enteric

The effect of autonomic fibers on target cells is _________. The effect of somatic fibers on target cells is __________. always excitatory; always excitatory excitatory or inhibitory; always excitatory excitatory or inhibitory; excitatory or inhibitory always inhibitory; excitatory or inhibitory always inhibitory; always excitatory

excitatory or inhibitory; always excitatory.

All preganglionic fibers of the ANS pass through the sympathetic chain of ganglia, synapsing at least once there. True False

false

he sliding filament theory of muscle contraction has emerged from research only in the last 10 to 15 years. True False

false

Which of the following is not an example of an autonomic receptor? Muscarinic Nicotinic Cholinergic Adrenergic Ganglionic

ganglionic

Antagonistic effects of the two divisions of the autonomic nervous system are exemplified in the control of __________. blood clotting blood flow to the skeletal muscles sweating hair erection gastrointestinal motility

gastrointestinal motility

Which of the following is not a feature of the sympathetic division of the ANS? It originates in the thoracolumbar region of the spinal cord. It has long postganglionic fibers. It has long preganglionic fibers. Its ganglia are adjacent to the spinal column. It has an extensive neural divergence and a relative widespread effect.

its a long preganglionic fibers

During muscle contractions, cross-bridges form between the _________ and the __________. myosin heads; tropomyosin filaments myosin heads; actin filaments myosin heads; ATP molecules actin heads; troponin filaments actin heads; tropomyosin filaments

myosin heads; actin filaments

Which of the following happens as actin and myosin filaments slide past each other during muscle contraction? Actin filaments shorten, while myosin filaments do not. Myosin filaments shorten, while actin filaments do not. Either actin or myosin filaments shorten, but not both at the same time. Both actin and myosin filaments shorten. Neither actin nor myosin filaments shorten.

neither actin nor myosin filaments shorten.

Sympathetic fibers do not release __________. acetylcholine nitric oxide (NO) substance P neuropeptide Y norepinephrine

nitric oxide (no)

Which of the following is more effective in producing bronchodilation? Acetylcholine Nicotine Muscarine Norepinephrine Thyroxine

norepinephrine

The autonomic nervous system controls all of the following except the __________. adrenal gland smooth muscle in the walls of the aorta cardiac muscle in the right atrium skeletal muscle in the rectus abdominis parotid salivary gland

skeletal muscle in the rectus abdominis

To stimulate muscle contraction, acetylcholine is released from the ___________ into the synaptic cleft. synaptic vesicles junctional folds sarcoplasmic reticulum sarcolemma terminal cisterna

synaptic vesicles

Which of the following best describes the role of Ca2+ in muscle contraction? It binds to tropomyosin, moving troponin, so that myosin heads can bind to actin. It binds to tropomyosin, moving troponin, so that actin heads can bind to myosin. It binds to troponin, moving tropomyosin, so that myosin heads can bind to actin. It binds to troponin, moving tropomyosin, so that actin heads can bind to myosin. It binds to actin, moving myosin, so that troponin can bind to tropomyosin.

t binds to troponin, moving tropomyosin, so that myosin heads can bind to actin.

An action potential enters the depths of a muscle fiber by way of __________. diffusion the T tubules the calcium ion channels the sarcoplasmic reticulum the actin myofilament

the T tubes

Why does one continue to breathe heavy after rigorous physical activity has stopped? The diaphragm is waiting for its acetylcholine to run out. The body requires more oxygen to restore levels of ATP and creatine phosphate. The lungs can't stop breathing until the heart rate slows down. Myosin heads need more oxygen to fully detach from actin. The kidneys require oxygen to dispose of excess lactic acid.

the body requires more oxygen to restore levels of ATP and creatine phosphate.

Which of the following is predominately made up of myosin? G actin F actin The thin filament The thick filament The elastic filament

the thick filament

Which of the following statements about the "heads" of the myosin molecules is true? They form permanent links with actin filaments. They can attach to different sites on the actin filament. They straighten the myosin filaments. They allow the myosin filaments to wrap around each other. None of these are true statements.

they can attach to different sites on the actin filament.

The __________ is described as two strands of actin molecules wrapped together. thick filament thin filament elastic filament troponin-tropomyosin complex terminal cistern

thin filament

The protein that acts as a calcium receptor in skeletal muscle is __________. F actin tropomyosin troponin titin dystrophin

troponin

During contraction of a muscle, calcium ions bind to the __________. actin myofilament troponin molecule tropomyosin molecule sarcoplasmic reticulum sarcolemma

troponin molecule

An isometric contraction does not change muscle length. True False

true

The sequence of cross-bridge formation and myofilament movement will be repeated as long as calcium ions and ATP are present. True False

true

The motor pathway of the autonomic nervous system usually involves __________ neurons. no one two three four

two

Most fibers of the parasympathetic nervous system travel in the __________. vagus trigeminal splanchnic facial sciatic

vagus

When body temperature increases, thermoreceptors are stimulated and send nerve signals to the CNS. The CNS sends motor signals to sweat glands, which attempt to reduce body temperature. This is an example of a __________ reflex. stretch tendon organ withdrawal visceral somatic

visceral

Which of the following is the site of ATP binding and hydrolysis? Troponin Tropomyosin Actin Myosin Troponin and tropomyosin

Myosin

Which of the following is not a filamentous protein? Actin Myosin Troponin Tropomyosin

Troponin