Question 1

Which statement best describes the Neuron Doctrine as proposed by Santiago Ramón y Cajal?

Accepted Answer

Neurons are discrete units that communicate via specialized connections, with information flowing in one direction: input → integration → output.

Question 2

Which of the following is a function of astrocytes in the central nervous system?

Accepted Answer

Regulating the extracellular environment and supporting neurons metabolically.

Question 3

A patient with multiple sclerosis (MS) is experiencing muscle weakness. Which cellular process is most directly affected in MS?

Accepted Answer

Formation of myelin sheaths by oligodendrocytes in the central nervous system.

Question 4

Which equation predicts the equilibrium potential for a single ion across a membrane?

Accepted Answer

The Nernst equation: $E_{ion} = \frac{61}{z} \log \frac{[ion]_{out}}{[ion]_{in}}$

Question 5

Which of the following best explains why the resting membrane potential of a neuron is closest to the Nernst potential for potassium ($K^+$)?

Accepted Answer

The membrane permeability to $K^+$ is much higher than to $Na^+$ at rest.

Question 6

Which type of glial cell is responsible for forming myelin sheaths in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 7

A neuron receives multiple excitatory and inhibitory inputs. Which region integrates these signals to determine if an action potential will be generated?

Accepted Answer

Axon hillock

Question 8

Which of the following best describes graded potentials?

Accepted Answer

They are variable in strength and used for short-distance communication.

Question 9

Which of the following is TRUE regarding action potentials?

Accepted Answer

They are brief, large depolarizations that follow the all-or-none principle.

Question 10

Which of the following scenarios would most likely result in permanent paralysis?

Accepted Answer

Death of the cell body of a motor neuron.

Question 11

Which equation is used to calculate the membrane potential considering multiple ions and their permeabilities?

Accepted Answer

Goldman-Hodgkin-Katz (GHK) equation: $V_m = 61 \log \frac{P_K [K^+]_{out} + P_{Na} [Na^+]_{out} + P_{Cl} [Cl^-]_{in}}{P_K [K^+]_{in} + P_{Na} [Na^+]_{in} + P_{Cl} [Cl^-]_{out}}$

Question 12

Which of the following is a plausible consequence of damage to the axon hillock?

Accepted Answer

Impaired integration of synaptic inputs, leading to failure in action potential initiation.

Question 13

Which of the following best explains why glial cells are a main source of brain cancer?

Accepted Answer

Glial cells retain the capacity to divide mitotically throughout life.

Question 14

Which of the following is TRUE about neuronal regeneration in the nervous system?

Accepted Answer

If the cell body dies, the neuron cannot regenerate.

Question 15

Which of the following best describes the role of voltage-gated ion channels in neurons?

Accepted Answer

They control membrane permeability and are selective for specific ions based on pore structure and amino acid composition.

Question 16

A patient suffers a traumatic injury that severs the axon of a sensory neuron in the peripheral nervous system. What is the most likely outcome?

Accepted Answer

Loss of sensation from the innervated area, with possible regeneration of the axon.

Question 17

Which of the following is a key difference between graded potentials and action potentials?

Accepted Answer

Graded potentials can summate, while action potentials cannot.

Question 18

Which of the following best describes the process of anterograde axonal transport?

Accepted Answer

Movement of organelles and materials from the cell body to the axon terminal.

Question 19

Which of the following would most likely increase the speed of action potential conduction along an axon?

Accepted Answer

Increasing the diameter of the axon and adding myelin sheaths.

Neurons: Cellular and Network Properties – Study Notes

Study Guide - Practice Questions

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