1) Which of the following gives the normal direction of signal transmission in a neuron?
A. from the axon to the cell body to the dendrites
B. from the dendrites to the cell body to the axon
C. from the cell body to the axon and dendrites
D. from the dendrites to the axon to the cell body
2) Novocain is a local anesthetic used by many dentists. Novocain most likely inhibits the action
potential of a neuron by:
A. stimulating calcium voltage gated channels at the synapse.
B. increasing chloride ion efflux during an action potential.
C. uncoiling Schwann celIs wrapped around an axon.
D. blocking sodium voltage gated channels.
3) A cell membrane is normally slightly passively permeable to potassium ions. If a neuronal
membrane
Were to become suddenly impermeable to potassium ions but retain an active Na+/K+-ATPase,
the neurons resting potential would:
A. becomes more positive because potassium ion concentration would increase inside the
neuron.
B. become more positive because potassium ion concentration would increase outside the
neumn.
C. become more negati-.:e because potassium ion concentration would increase inside the
neuron.
D. become more negative because potassium ion concentration ~could increase outside the
neuron.
4) If an acetyl cholinesterase inhibitor were administered into a cholinergic synapse, what
would happen to the activity of the postsynaptic neuron?
A. It would decrease, because acetylcholine would be degraded more rapidly than normal.
B. It would decrease, because acetyl cholinesterase would bind to postsynaptic membrane
receptors Less strongly. '
C. It would increase, because acetylcholine would be produced more rapidly than normal.
D. It would increase, because acetylcholine would be degraded more slowly than normal.
5) White matter in the brain and spinal cord appears white because:
A. it contains large amounts of myelinated axons.
B. it does not contain any myelinated axons.
C. it is composed primarily of cell bodies.
D. it contains a high concentration of white blood cells to protect the central nervous system
from infection.
6) The jumping of an action potential from one node of Ranvier to the next is known as:
A. Brownian motion
B. saltatory conduction
C. a threshold stimulus
D. an all-Of-nothing response
7) What is the ratio of sodium ions to potassium ions transferred by the Na+/K+ pump out of
and into the cell?
A. 2 sodium ions in; 3 potassium ions out
B. 3 sodium ions in; 2 potassium ions out
C. 3 sodium ions out; 2 potassium ions in
D. 2 sodium ions in; 3 potassium ions in
8) Which of the following is found in vertebrates but NOT in invertebrates?
A. a dorsal. hollow nerve chord
B. mylenation to increase the speed of nervous impulse transmission along the axon
C. axons through which the nervous impulse is conducted
D. Na+/K+-pump
9) If an acetylcholine antagonist were administered generally into a person. All of the following
would be affected EXCEPT:
A. the neuroeffector synapse in the sympathetic nervous system.
B. the neuroeffector synapse in the parasympathetic nervous system
C. the neuromuscular junction in the somatic nervous system.
D. the ganglionic synapse in the sympathetic nervous system.
10) A neuron at rest has a charge difference across its cell membrane, with the interior of the
cell negative relative to the exterior. This difference in charge across the plasma membrane is
referred to as ________ potential
A) action
B) resting
C) graded
D) refractory
E) depolarization
11) Each of the following statements correctly describes an action potential EXCEPT which one?
A) Once triggered, an action potential always looks exactly the same in form and voltage.
B) An action potential continues to propagate itself into the next region of an axon.
C) Action potentials are propagated by the sodium-potassium pump.
D) Action potentials include a depolarization phase followed by a repolarization phase.
E) Action potentials temporarily reverse the polarization of the axon membrane.
12) Synaptic transmission depends upon:a-Direct transmission of impulses from the presynaptic neuron to the postsynaptic neuron
b- Diffusion of neurotransmitters from synaptic knobs into the soma and dendrites of
postsynaptic neurons
c- Presence of voltage-gated Ca ++ channels in membrane of synaptic knobs
d- Presence of voltage-gated Ca ++ channels in the subsynaptic membrane
13) Synaptic knobs :a- synthesize different types of neurotransmitters
b- Release neurotransmitters by diffusion across their membranes
c- Have ligand-gated Ca ++
d- are located at the terminal end of dendrites
14) Postsynaptic receptors include all the following types, except :a- G-protein coupled receptors
b- ligand-gated cation channels
c- G-protein regulated K + channels
d- voltage-gated Cl- channels
15) Connexons of gap junctions in electric synapses :-
a- are Ligand-gated
b- are voltage-gated
c- allow transmission of potential changes in both directions between the preand post- synaptic
neurons
d- close whenever the presynaptic neuron becomes hyperpolarized
16) Chemical synapses in the nervous system :a- allow diffusion of chemical substances form the presynaptic neuron into the
postsynaptic neuron
b- allow transmission of potential changes in one direction only; from the presynaptic to the
postsynaptic neurons
c- have potential-gated ionic channels
d- are more numerous in the peripheral nervous system than the central nervous system
17) Receptor potential initiated by an adequate stimulus :a- develops always at it full magnitudes
b- Undergoes temporal summation only
c- Undergoes spatial summation only
d- Could initiate an action potential
18) When stimulated by effective steady stimuli, sensory receptors :a- continuously discharge impulses
b- stop discharging after a short time
c- produce an initial high rate of impulse discharge followed by decline of this rate
d- differ in their response ; some types discharge continuously, while other types do not
respond at all
19) Slowly adapting receptors differ from rapidly adapting receptors in:-
a- stopping to discharge after a relatively longer period of constant stimulation
b- detecting the dynamic properties of stimuli
c- detecting velocity of stimuli
d- generating receptor potentials as long as stimulus is applied.
20) Parietal lobe neglect :a- is characterized by inability to use skeletal muscles on the opposite side of the body
b- is characterized by inability to use skeletal muscles on the same side of the body
c- results from damage of primary sensory cortex.
d- causes loss of sensations on the same side of the body