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, and information flows in one direction: input → integration → output.

Question 2

Which glial cell type is responsible for forming myelin sheaths in the central nervous system (CNS)?

Accepted Answer

Oligodendrocytes

Question 3

A patient with multiple sclerosis (MS) experiences muscle weakness and loss of coordination. Which cellular process is most directly affected in MS?

Accepted Answer

Autoimmune attack on myelin sheaths in the CNS

Question 4

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

Accepted Answer

Nernst equation: $$E_{ion} = \frac{61}{z} \log \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

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 permeability to $$K^+ is $$much higher than to $$Na^+$$, due to a large number of $$K^+$$ leak channels.

Question 6

Which of the following is a correct application of the Goldman-Hodgkin-Katz (GHK) equation for membrane potential?

Accepted Answer

It calculates membrane potential based on the permeability and concentration gradients of multiple ions.

Question 7

A neuron receives a stimulus that causes a graded potential. Which of the following best describes a graded potential?

Accepted Answer

It is a variable-strength signal used for short-distance communication.

Question 8

Which of the following is true about action potentials in neurons?

Accepted Answer

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

Question 9

A patient suffers a traumatic injury that severs a motor neuron in the peripheral nervous system (PNS). What is the most likely outcome?

Accepted Answer

The cell body and attached segment may survive, but the target muscle will experience permanent paralysis.

Question 10

Which of the following best describes the role of astrocytes in the central nervous system?

Accepted Answer

They have multiple subtypes and perform several roles, including supporting neurons and maintaining the blood-brain barrier.

Question 11

Which of the following is a key difference between Schwann cells and oligodendrocytes?

Accepted Answer

Schwann cells myelinate a single segment of one axon in the PNS, while oligodendrocytes can myelinate multiple axons in the CNS.

Question 12

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 13

Which of the following scenarios best illustrates the principle of dynamic polarization in neurons?

Accepted Answer

A signal is received by dendrites, integrated in the cell body, and transmitted down the axon to the synaptic terminal.

Question 14

Which of the following is true regarding ion channel selectivity?

Accepted Answer

The diameter of the pore and the charge of amino acids lining the channel determine which ions can pass.

Question 15

Which type of axonal transport moves organelles and vesicles from the cell body to the axon terminal at rates up to 400 mm/day?

Accepted Answer

Anterograde transport

Question 16

Which of the following best describes the function of microglia in the CNS?

Accepted Answer

They act as specialized immune cells, removing debris and responding to injury.

Question 17

Which of the following is a correct statement about adult neurogenesis?

Accepted Answer

New neurons can be produced throughout life in specific brain regions such as the olfactory bulb and dentate gyrus.

Question 18

Which of the following best explains the effect of axon diameter and myelination on the speed of action potential conduction?

Accepted Answer

Larger axons and myelinated fibers conduct action potentials faster due to reduced resistance and ion leak.

Question 19

Which of the following is a real-world example illustrating the association between brain regions and personality?

Accepted Answer

Phineas Gage's injury to the frontal lobes resulted in dramatic changes to his personality and behavior.

Neurons: Cellular and Network Properties – Study Notes

Study Guide - Practice Questions