Question 1

Which of the following best describes the role of the cell body (soma) in a neuron?

Accepted Answer

It acts as the control center, integrating incoming signals and housing the nucleus and organelles.

Question 2

Which glial cell type is responsible for forming myelin in the peripheral nervous system (PNS)?

Accepted Answer

Schwann cells

Question 3

A sudden increase in Na$$^+$$ permeability in a neuron would favor movement of Na$$^+$$ ions in which direction, and why?

Accepted Answer

Into the cell, down both the concentration and electrical gradients

Question 4

Which equation is used to predict the membrane potential when multiple ions are involved?

Accepted Answer

The Goldman-Hodgkin-Katz (GHK) equation: $$V_m = \frac{RT}{F} \ln \frac{P_{K^+}[K^+]_{out} + P_{Na^+}[Na^+]_{out} + P_{Cl^-}[Cl^-]_{in}}{P_{K^+}[K^+]_{in} + P_{Na^+}[Na^+]_{in} + P_{Cl^-}[Cl^-]_{out}}$$

Question 5

Which of the following is NOT a function of astrocytes in the central nervous system?

Accepted Answer

Phagocytosing pathogens and debris

Question 6

What is the primary function of dendrites in a neuron?

Accepted Answer

To receive incoming signals from other neurons

Question 7

Which of the following best explains why action potentials are considered 'all-or-none' phenomena?

Accepted Answer

They only occur if the membrane potential reaches threshold, and their magnitude does not vary with stimulus strength.

Question 8

During the rising phase of an action potential, which ion channels open and what is the direction of ion movement?

Accepted Answer

Voltage-gated Na$$^+$$ channels open, allowing Na$$^+ to $$enter the cell.

Question 9

Which membrane transporter maintains sodium and potassium concentration gradients across a neuron's cell membrane?

Accepted Answer

Na$$^+/K$^+$$ ATPase pump

Question 10

Which of the following would most likely result in hyperpolarization of a neuron?

Accepted Answer

Opening of chemically-gated K$$^+$$ channels

Question 11

Which statement best describes the effect of myelination on axonal conduction?

Accepted Answer

It increases the speed of conduction by enabling saltatory conduction between nodes of Ranvier.

Question 12

Which of the following is a correct description of the absolute refractory period?

Accepted Answer

A period when no action potential can be generated, regardless of stimulus strength.

Question 13

Which of the following is a property of chemical synapses but NOT electrical synapses?

Accepted Answer

Transmission via neurotransmitter release into the synaptic cleft

Question 14

Which of the following best describes spatial summation in postsynaptic neurons?

Accepted Answer

Multiple graded potentials arriving at different locations simultaneously

Question 15

Which of the following is a major difference between ionotropic and metabotropic (GPCR) receptors?

Accepted Answer

Ionotropic receptors directly open ion channels, while GPCRs activate second messenger pathways.

Question 16

Which of the following would most likely increase neuronal excitability?

Accepted Answer

Hyperkalemia (elevated extracellular K$$^+)$$

Question 17

Which of the following best describes the process of neurotransmitter release at a chemical synapse?

Accepted Answer

Neurotransmitters are released by exocytosis triggered by Ca$$^{2+}$$ influx.

Question 18

Which of the following is a correct statement about the Nernst equation?

Accepted Answer

It predicts the equilibrium potential for a single ion based on its concentration gradient.

Question 19

Which of the following is a plausible consequence of a mutation that prevents the inactivation of voltage-gated Na$$^+$$ channels?

Accepted Answer

The neuron would remain depolarized and unable to fire subsequent action potentials.

Study Notes: Organization and Function of the Nervous System

Guida di studio - Domande di pratica

Study guide - Flashcard