Q: Which equation correctly represents the action of the sodium-potassium pump in neurons?

$$3 \mathrm{Na}^+_{\text{in}} + 2 \mathrm{K}^+_{\text{out}} + \text{ATP} \rightarrow 3 \mathrm{Na}^+_{\text{out}} + 2 \mathrm{K}^+_{\text{in}} + \text{ADP} + \text{P}_i$$

Question 1

Which of the following best describes the main function of the nervous system?

Accepted Answer

To control perception, direct voluntary movement, and regulate homeostasis with the endocrine system

Question 2

A patient suffers a spinal cord injury at the level of the first lumbar vertebra. Which division of the nervous system is most directly affected?

Accepted Answer

Central nervous system (CNS)

Question 3

Which of the following is TRUE regarding the somatic motor division of the nervous system?

Accepted Answer

It transmits signals to skeletal muscle under voluntary control

Question 4

Which neuroglial cell is responsible for forming the blood-brain barrier?

Accepted Answer

Astrocyte

Question 5

A neuron with one axon and one dendrite, found in the retina of the eye, is classified as:

Accepted Answer

Bipolar

Question 6

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelin insulates the axon, allowing action potentials to 'jump' between nodes of Ranvier (saltatory conduction)

Question 7

Which of the following is NOT a function of astrocytes?

Accepted Answer

Form myelin sheaths in the CNS

Question 8

A local anesthetic like lidocaine blocks voltage-gated sodium channels. What is the physiological effect of this on neurons?

Accepted Answer

It prevents depolarization, so action potentials cannot be generated

Question 9

Which equation correctly represents the action of the sodium-potassium pump in neurons?

Accepted Answer

$$3 \mathrm{Na}^+_{	ext{in}} + 2 \mathrm{K}^+_{	ext{out}} + 	ext{ATP} ightarrow 3 \mathrm{Na}^+_{	ext{out}} + 2 \mathrm{K}^+_{	ext{in}} + 	ext{ADP} + 	ext{P}_i$$

Question 10

During the repolarization phase of an action potential, which event occurs?

Accepted Answer

Voltage-gated potassium channels open and potassium exits the cell

Question 11

Which of the following best describes the 'all-or-none' principle of action potentials?

Accepted Answer

If threshold is reached, an action potential will occur completely; if not, it will not occur at all

Question 12

A patient with multiple sclerosis (MS) experiences muscle weakness and numbness. Which of the following best explains the underlying cause?

Accepted Answer

Loss of myelin sheaths in the CNS, slowing action potential propagation

Question 13

Which of the following is the correct sequence of events at a chemical synapse?

Accepted Answer

Action potential arrives at axon terminus, neurotransmitter is released, neurotransmitter binds to receptors, local potential occurs in postsynaptic cell

Question 14

Which type of ion channel opens in response to a neurotransmitter binding to its receptor on the postsynaptic membrane?

Accepted Answer

Ligand-gated sodium channel

Question 15

Which of the following is NOT a method for terminating synaptic transmission?

Accepted Answer

Receptor fatigue

Question 16

A neuron is at rest with a membrane potential of $$-70\ \mathrm{mV}. If a $$ligand-gated sodium channel opens, what will happen to the membrane potential?

Accepted Answer

It will become less negative (depolarization)

Question 17

Which of the following best explains why action potentials only travel in one direction along an axon?

Accepted Answer

The refractory period prevents reactivation of voltage-gated sodium channels in the previous segment

Question 18

Which of the following is a characteristic of Type A nerve fibers?

Accepted Answer

Large diameter, myelinated, fast conduction

Question 19

Which of the following is TRUE about the role of calcium ions ($$\mathrm{Ca}^{2+}) at $$the synaptic terminus?

Accepted Answer

Calcium influx triggers neurotransmitter release from synaptic vesicles

Introduction to the Nervous System and Nervous Tissue: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards