Practice exam Flashcards
- Which of the following correctly describes the effect of morphine on synaptic transmission?
a. Morphine inhibits substance P re-uptake
b. Morphine induces substance P release
c. Morphine reduces membrane permeability to potassium
d. Morphine promotes closing of voltage-gated calcium channels at the presynaptic terminal
d. Morphine promotes closing of voltage-gated calcium channels at the presynaptic terminal
- A molecule that stimulates neurokinin 1 receptor (NK1-receptor) would produce which of the following effects?
a. Heighten the perception of touch
b. Stimulate a painful sensation
c. Inhibit perception of pain
d. Reduce two-point discrimination threshold
stimulates a painful sensation
- The area of the somatic sensory cortex devoted to each part of the body is _______.
a. Proportional to the surface area of the part
b. Related to the distance of the part from the brain
c. Proportional to the number of specialized sensory receptors in the part
d. Apparently unrelated to any known aspect of the part
e. Inversely proportional to the surface area of the part
c. Proportional to the number of specialized sensory receptors in the part
- While recording the responses of a mechanoreceptor to stimulation of the skin, an investigator observes an increase in the number of action potentials generated during one second intervals. This increase usually signifies ________.
a. Increased intensity of a stimulus
b. Cessation of a stimulus
c. Adaptation of the receptor
d. A stimulus of constant strength
e. An increase in the action potential conduction velocity
a. Increased intensity of a stimulus
- An excitatory postsynaptic potential (EPSP) does which of the following?
a. Depolarizes a neuron, decreasing the likelihood of an action potential
b. Hyperpolarizes a neuron, decreasing the likelihood of an action potential
c. Depolarizes a neuron, increasing the likelihood of an action potential
d. Hyperpolarizes a neuron, increasing the likelihood of action potential
c. Depolarizes a neuron, increasing the likelihood of an action potential
- Increasing the length of refractory period would have what effect on action potentials?
a. Decrease the amplitude of action potentials
b. Decrease the frequency of action potentials
c. Increase the amplitude of action potentials
d. Increase the frequency of action potentials
b. Decrease the frequency of action potentials
- Which of the following involved in the peripheral transmission both in sympathetic and parasympathetic nervous system?
a. Nicotinic receptors
b. Muscarinic receptors
c. Norepinephrine
d. Sympathetic ganglia
e. Epinephrine
b. Muscarinic receptors
- Which of the following is achieved by acetylcholine release from the sympathetic nerve terminals and stimulation of muscarinic receptors?
a. Penile erection
b. Stimulation of sweat glands
c. High epinephrine secretion by the adrenal medulla
d. Constipation
e. Increased heart rate - Acetylcholine released from
b. Stimulation of sweat glands
- Acetylcholine released from preganglionic autonomic fibers stimulates which type of receptors on postganglionic neurons?
a. Metabotropic cholinergic receptors
b. Nm cholinergic receptors
c. Ionotropic cholinergic receptors
d. Muscarinic and nicotinic cholinergic receptors
e. M3 cholinergic receptors
d. Muscarinic and nicotinic cholinergic receptors
- Which of the following ligands can activate both ionotropic and metabotropic receptors?
a. GABA
b. Nicotine
c. Muscarine
d. Norepinephrine
e. Epinephrine
a. GABA
- Administration of the drug which blocks ryanodine receptors (RYR1) channel will result in which of the following?
a. Muscle relaxation
b. Prolonged muscle contraction
c. Failure of muscle to relax
d. Increased concentration of calcium in the sarcoplasm
e. Decreased stimulation of nicotinic cholinergic receptors on the muscle membrane
a. Muscle relaxation
- The patient is exposed to the toxin which blocks voltage-gated Ca2+ channels at the neuromuscular junction. Which of the following is the most likely explanation for muscle paralysis in this patient?
a. Failure of action potential conduction in the motor nerve terminal
b. Failure of acetylcholine synthesis in the motor nerve terminal
c. Failure of acetylcholine release from the motor nerve terminal
d. Accelerated breakdown of acetylcholine in the synaptic cleft
e. Inhibition of acetylcholinesterase
c. Failure of acetylcholine release from the motor nerve terminal
- Which of the following occurs during skeletal muscle contraction?
a. A band length remains constant
b. I band length remains constant
c. Z lines move further apart
d. I band increases in size
a. A band length remains constant
- True of False? Muscle relaxation requires ATP.
a. True
b. False
true
- A skeletal muscle fiber develops its maximal force if it is at the _______ in the beginning of contraction.
a. Shortest length
b. Intermediate length
c. Maximum length
b. Intermediate length
- As ATP binds to myosin head at the beginning of a muscle contraction cycle __________.
a. Myosin head binds to actin
b. Myosin head tightens its bond with actin
c. Myosin head detaches from actin
d. ATP does not bind to myosin head
c. Myosin head detaches from actin
- In the sliding filament mechanism crossbridges are _________.
a. Actin heads bound to myosin filaments
b. Thin filaments bound to each other
c. Two myosin molecules forming a dimer
d. Myosin heads that bind active sites on a thin filament
d. Myosin heads that bind active sites on a thin filament
- Which of the following drugs can be used to dilate the pupil?
a. Muscarine
b. Nicotine
c. Acetylcholinesterase inhibitor
d. Muscarinic cholinergic antagonist
d. Muscarinic cholinergic antagonist
- Which of the following is typically caused by activation of the sympathetic nervous system?
a. Anhidrosis (lack of swelling)
b. Bradycardia (decreased heart rate)
c. Ciliary muscle contraction
d. Mydriasis
e. Bronchoconstriction
d. Mydriasis
- Which has its cell body in a ganglion?
a. Preganglionic neuron
b. Postganglionic neuron
c. Somatic motor neuron
d. Preganglionic neuron and postganglionic neuron
b. Postganglionic neuron
- The patient experiences mydriasis and constipation upon administration of an experimental drug as a part of clinical trial. Based on the information that you have the drug blocks which of the following receptors?
a. Muscarinic cholinergic receptors
b. Alpha adrenergic receptors
c. Beta adrenergic receptors
d. Muscle type of nicotinic cholinergic receptors
a. Muscarinic cholinergic receptors
- All of the following are actions of muscarinic receptors except…
a. Increase GI motility
b. Increase GI secretions
c. Increased bronchoconstriction
d. Increase skeletal muscle contraction
d. Increase skeletal muscle contraction
- Activation of which type of cholinergic receptor will result in faster cell response to acetylcholine?
a. M1 muscarinic cholinergic receptor
b. Nicotinic cholinergic receptor
c. M2 muscarinic cholinergic receptor
d. M3 muscarinic cholinergic receptor
e. M5 muscarinic cholinergic receptor
b. Nicotinic cholinergic receptor
- Direct activation of which of the following receptors will result in the opening of an ion channel?
a. Alpha-1 adrenergic receptor
b. Nicotinic cholinergic receptor
c. Alpha-2 adrenergic receptor
d. Beta-1 adrenergic receptor
e. Muscarinic cholinergic receptor
b. Nicotinic cholinergic receptor
- Which of the following is directly responsible for the rising phase of neuronal action potential?
a. Increased membrane permeability to potassium
b. Opening of voltage-gated sodium channels
c. Membrane hyperpolarization
d. Generation of receptor potential
e. Decreased membrane permeability to sodium
b. Opening of voltage-gated sodium channels
- During a brain surgery, through which the patient remained conscious, a part of the dorsal column-medial lemniscus (DCML) pathway was exposed and stimulated. Which of the following sensations will the patient most likely experience?
a. A feeling that his fingers are warming up
b. A feeling as if something was touching his index finger
c. Mild pain but he is unable to explain exactly where it hurts
d. Strong pain in his arm
b. A feeling as if something was touching his index finger
- Which property correctly describes receptor (generator) potential?
a. Increases in amplitude as more intense stimulus is applied
b. Always leads to an action potential
c. Is an all-or-none phenomenon
d. Does not require opening or closing of ion channels
a. Increases in amplitude as more intense stimulus is applied