A. moves tropomyosin to allow myosin to bind to actin
B. provides energy for myosin to bind to actin
C. opens calcium channels so calcium can bind to myosin
D. allow myosin to release actin and cock bacle
Type of muscle fibers is least resistant to fatigue (fatigues the easiest?)
A. slow oxidative
B. fast oxidative
C. slow glycolytic
D. fast glycolyti
When an acethylcholinesterase (AchE) antagonist is in the synapse
A. there will be more breakdown of acetylcholine
B. more acetylcholine will be released
C. there will be less diffusion of acetylcholine
D. there will be less response in the postsynaptic
cell
E. there will be more acetylcholine in the synape
Rigor mortis occurs in a dead person because
A. ATP, which is necessary for the removal of Ca2+ from the sarcomere is not being formed
B. ATP, which is necessary for the formation of cross bridges, is not being formed
C. ATP, which is necessary for the formation of cross bridges, continues to be formed for several hours after death
D. deterioration of muscle proteins prevents
detachment of cross bridges
E. none of the above
Which of the following statements regarding the shortening of a skeletal muscle fiber is not true? When a skeletal muscle fiber
shortens,
A. the sarcomeres shorten
B. the distance between Z line decreases
C. the actin and myosin myofilaments shorten
D. the actin and myosin myofilaments slide past each other
E. the length of the a bands remains the same
Which neurotransmitter is implicated in Parkinson’s disease?
A. epinephrine
B. dopamine
C. serotonin
D. acetylcholine
E. histamine
The tension in a skeletal muscle can be increased by
A. temporal summation of a muscle fiber
B. motor unit summation
C. increasing the number of fibers in the muscle through exercies
D. A and B
E. A, B and C
An inhibitory postsynaptic potential (IPSP)
A. is produced by an increased membrane permeability to both Na+ and K+
B. is produced by an increased membrane permeability to K+
C. is a small depolarization in a postsynaptic cell
D. can be summed with other IPSP’s to trigger an action potential in the postsynaptic cell
E. A and D are true
What will happen to the concentration of a
neurotransmitter in a synaptic cleft when the frequency of action potentials increases in the presynaptic neuron?
A. it increases
B. it decreases
C. it remains constant
D. it has no effect
In EPSPs from the different synapse occur at the same time and cause a larger depolarization than either one alone could cause. This is an example of
A. a resting membrane potential
B. inhibition
C. temporal summation in neurons
D. spatial summation in neurons
Which of the following is a parasympathetic nervous system function?
A. increase smooth muscle contraction in the
digestive tract
B. cause vasodilation in vessels supplying skeletal
muscles
C. cause the release of epinephrine from the adrenal medulla
D. cause dilation of the bronchioles
E. all of the above
Thebinding of a neurotransmitter synaptic to its receptor at an inhibitor synapse
can lend to theofchannels
A. closing ; potassium
B. closing : chloride
C. opening : sodium
D. opening : potassium
E. opening : calcium
Predict the response of the smooth muscle of the uterus to sympathetic nervous system stimulation
A. excitation and contraction
B. inhibition and contraction
C. excitation and relaxation
D. inhibition and relaxation
E. none of the above
Exocytose is of a neurotransmitter into the synaptic cleft is triggered by an influx of Ca2+
(to the presynaptic cell) in response to the arrival of an action potential into the axon terminal
A. K+
B. Na+
C. Ca2+
D. ATP
E. Cl-
When a skeletal muscle has been working for an extended period of time (more than 15m, but less than 40), the primary source of ATP is
A. creative phosphate
B. fermentation
C. metabolism of blood glucose
D. breakdown of myosin
E. none of the above
The transverse (T)tubules in a skeletal muscle
fiber,
provide a neurons of transmitting an actionpotential in the muscle sarcolemma to the central portion of the muscle fibers
The neurotransmitter used in communication between a sympathetic motor neuron and a cardiac muscle cell is
A. norepinephrine
Which of the following is a biogenic amine that is not classified as a catecholamine
serotonin
place the following steps of crossbridge formation in the correct order.
1. AP reaches T-tubule
3. Ca2+ is released from the SR
5. Ca2+ binds to tropopin
2. tropomysion move to reveal active sites
4. crossbridge forms
Which of the following statements about
acetylcholine is correct :
A. acetylcholine binds to cholinergic receptor
B. acetylcholine binds to nicotinic and muscarinic receptors
An EPSP in a membrane
is often to direct result of the opening of chemical gated Na+ channels in the membrane
“motor unit” refers to
a single motor neuron plus all of the skeletal muscle fibers it innervates
a marathon runner’s legs would likely contain extremely well-trainedfibers?
Slow oxidative
A myofibril is
B. composed of action and myosin
C. composed of proteins
The way in which the nervous system can detect the intensity of a stimulus is
The frequency of action potentials
During a skeletal muscle fiber twitch, Ca2+
is pumped back into the sarcoplasmic reticulum primarily during the
Relaxation
which of the following drugs does not at opiod
receptor?
LSD
Which of the following neurotransmitter is
lipid-soluble and is contained in chocolate?
anadamide
The respond of a single skeletal muscle cell to a single action potential is termed
A twitch
Calcium is released from the sarcoplasmic reticulum and the travels to the sarcomere viaand it is taken back up into the SR via
diffusion; primary active transport
The nervous system usesCa2+ to initiate neurotransmitters exocytosis, and skeletal muscle usesCa2+ to initiate sarcomere contraction
extracellular, intracellular
Place the following actions of synaptic transmission in the correct order
2. Voltage gated Na2+ channels open an axon of presynaptic cell
1. Voltage gated Ca2+ channels open on synaptic terminal of presynaptic cell
4. Chemical-gated channels open an postsynaptic cell
3. Neurotransmitter released
Which the following neurotransmitter binds to
adrenergic receptors?
A. adrenaline
B. epinephrine
C. norepinephrine
A postsynaptic neuron has three presynaptic inputs from neurons X, Y and Z, when X and Y are stimulated simultaneously and repeatedly the postsynaptic neuron reaches threshold and undergoes and action potential, when X and Z are stimulated simultaneously, however, there is no change in the membrane potential of the postsynaptic neuron. What can you tell
about presynaptic neurons Y and Z?
Y is probably excitatory and Z is probably
inhibitory
is all amino acid neurotransmitter
at excitatory synapse whereasis an amino acid neurotransmitter at inhibitory synapse
aspartate; glycine
The neurotransmitter released form postganglionic neuron in the parasympathetic nervous system is
acetylcholine
Endorphins and endophalins bind to which of the following receptors
opiod
The release of a phosphate form the myosin molecule directly results in which of the following?
power stroke
Put the following sources of energy for skeletal
muscle contraction in the order in which they would be utilized
ATP bound to myosin thick filament
creatine phosphate
stored glycogen
blood glucose
fatty acid metabolism
The binding of calcium to troponin will directly cause which of the following?
The movement of tropomyosin, exposing the actin action sites
Aerobic, or low- intensity, muscle training
eventually result in
B. more capillaries
D. more myoglobin
What is the effect of parasympathetic postganglionic, acetylcholine?
Not enough information to determine
The paraganglionic synapse in the sympathetic
nervous system are
excitatory and cholinergic
Which molecule is not physically associated with or part of the thin filament?
ATP
In a resting state,cover the actin active site
tropomyosin
Multi-unit smooth muscle has gab junction and all cells act as a single functional unit: False
FALSE
Muscles used for delicate, finely controlled movements have smaller, more numerous motor unit than more coarsely controlled muscles
TRUE
The afferent division of the peripheral nervous system consists of the somatic nervous system and the autonomic nervous system
FALSE
The difference in color between white muscle fibers and red muscle fibers is accounted for by the greater abundance of glycogen in white
muscle fibers
FALSE
A neurotransmitter that opens chemical-gated sodium channels on the postsynaptic cell could cause an IPSP n the postsynaptic cell
FALSE
During isotonic contraction of a skeletal-muscle fiber, tension increase but the fiber length stays the same
FALSE
The site of calcium ion storage in muscle cells is the transverse tubule
FALSE
During skeletal muscle contraction, the I band and H zone shorten but the A band stays the same
TRUE
The neurotransmitter used primarily form reward and reinforcement in the CNS is GABA
FALSE
If a somatic motor neuron is damaged permanently the muscle cell it stimulates can still contract normally
