Question 1

Which of the following best describes the primary difference between the nervous system and the endocrine system in maintaining homeostasis?

Accepted Answer

The nervous system works faster but its effects are short-lived, while the endocrine system works slower but its effects are longer-lasting.

Question 2

Which division of the nervous system is responsible for transmitting sensory information from receptors to the central nervous system?

Accepted Answer

Afferent division of the peripheral nervous system

Question 3

A patient presents with muscle cramps and a positive Trousseau's sign. Which electrolyte imbalance is most likely responsible, and what is the physiological explanation?

Accepted Answer

Hypocalcemia; decreased calcium lowers the threshold for action potential generation, leading to increased neuromuscular excitability.

Question 4

Which neuroglial cell type is responsible for forming the myelin sheath in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 5

What is the primary function of the sodium-potassium pump ($$Na^+/K^+$$ ATPase) in establishing the resting membrane potential?

Accepted Answer

It actively transports $$3 Na^+$$ out of the cell and $$2 K^+$$ into the cell, maintaining ionic gradients.

Question 6

During the depolarization phase of an action potential, which ion moves and in which direction?

Accepted Answer

$$Na^+$$ moves into the cell

Question 7

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

Accepted Answer

Action potentials in myelinated axons jump from one node of Ranvier to the next, a process called saltatory conduction.

Question 8

Which of the following is TRUE regarding graded potentials?

Accepted Answer

Their amplitude is proportional to the strength of the stimulus.

Question 9

A neuron receives simultaneous excitatory and inhibitory inputs. Which postsynaptic potential would result if the inhibitory input dominates?

Accepted Answer

Inhibitory postsynaptic potential (IPSP)

Question 10

Which of the following best describes the 'absolute refractory period' of an action potential?

Accepted Answer

A period when no stimulus, regardless of strength, can generate another action potential.

Question 11

Which of the following is a correct sequence for the organization of the nervous system in response to a stimulus?

Accepted Answer

Receptor → Sensory NS → CNS → Motor NS → Effector

Question 12

Which of the following is NOT a function of astrocytes in the CNS?

Accepted Answer

Producing cerebrospinal fluid

Question 13

Which of the following best describes the role of oligodendrocytes?

Accepted Answer

They form myelin sheaths around axons in the CNS.

Question 14

Which of the following statements about the propagation of action potentials is correct?

Accepted Answer

Action potentials propagate by depolarizing adjacent regions of the membrane, but cannot be generated in regions in the absolute refractory period.

Question 15

Which of the following is a correct description of a ganglion?

Accepted Answer

A collection of neuron cell bodies outside the CNS

Question 16

Which process is responsible for the removal of acetylcholine from the synaptic cleft?

Accepted Answer

Enzymatic breakdown by acetylcholinesterase

Question 17

Which of the following equations best represents the Nernst equation for calculating the equilibrium potential of an ion?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

Question 18

Which of the following would most likely result from a loss of myelination in the CNS, as seen in multiple sclerosis?

Accepted Answer

Decreased speed and reliability of action potential propagation

Question 19

Which of the following is TRUE regarding the 'all-or-none' principle of action potentials?

Accepted Answer

Once threshold is reached, an action potential is always produced with the same amplitude.

Question 20

Which of the following best describes the effect of increased extracellular $$Ca^{2+}$$ concentration on neuronal excitability?

Accepted Answer

Neurons become less excitable and are hyperpolarized.

Integration of the Nervous System: Structure, Function, and Physiology

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