Lecture 2

Which type of neuron is described as tree-like in appearance and is located in the brain and spinal cord? A. Unipolar neuron B. Bipolar neuron C. Pseudounipolar neuron D. Multipolar neuron

D. Multipolar neuron

What structural feature characterizes a bipolar neuron? A. It has multiple dendritic trees branching directly off the axon hillock. B. It has the cell body positioned in the center of the neuron structure. C. It lacks an axon and communicates solely through dendrites. D. It possesses cell bodies located exclusively in the peripheral ganglia.

B. It has the cell body positioned in the center of the neuron structure.

Approximately what percentage of the cells in the brain are glial cells? A. 10% B. 50% C. 90% D. 25%

C. 90%

Which cell types comprise the glial cells of the central nervous system? (Select all that apply) A. Astrocytes B. Oligodendrocytes C. Microglia D. Ependymal cells

A. Astrocytes; B. Oligodendrocytes; C. Microglia; D. Ependymal cells

What are the key functional roles of astrocytes? (Select all that apply) A. Structural support B. Neurotransmitter uptake C. Potassium (K+) uptake D. Myelination of peripheral nerves

A. Structural support; B. Neurotransmitter uptake; C. Potassium (K+) uptake

What is the primary function of oligodendrocytes? A. Immune defense and phagocytosis in the CNS B. Form myelin sheaths in the CNS C. Secretion of cerebrospinal fluid D. Structural support and neurotransmitter uptake

B. Form myelin sheaths in the CNS

What is the primary function of microglia in the central nervous system? A. Structural support B. Myelin formation C. Immune cells D. CSF circulation

C. Immune cells

Which glial cells are responsible for forming myelin sheaths around peripheral nerves? A. Oligodendrocytes B. Schwann cells C. Astrocytes D. Ependymal cells

B. Schwann cells

Where are voltage-gated channels (Na+ and K+) specifically located to contribute to the action potential? A. Cell body (Soma) B. Dendrites only C. Exclusively on the axon D. Synaptic cleft

C. Exclusively on the axon

At rest, what physiological state is a neuron in? A. Depolarization B. Polarization C. Hyperpolarization D. Absolute refractory state

B. Polarization

During neuronal membrane permeability changes, which ions flow INTO the cell, and which ion flows OUT of the cell? (Select all that apply) A. Na+ flows inside B. Cl- and Ca2+ flow inside C. K+ flows outside D. Na+ and Ca2+ flow outside

A. Na+ flows inside; B. Cl- and Ca2+ flow inside; C. K+ flows outside

How do potassium (K+) and sodium (Na+) movement affect the membrane potential? (Select all that apply) A. K+ leaking out makes the membrane more negative B. Na+ entering the cell makes the membrane more positive C. K+ entering the cell makes the membrane more negative D. Na+ leaking out makes the membrane more positive

A. K+ leaking out makes the membrane more negative; B. Na+ entering the cell makes the membrane more positive

Which step of neuronal transmission does Botulinum toxin directly affect? A. Myelination speed along peripheral nerves B. Synthesis of voltage-gated Na+ channels C. Release of neurotransmitters D. Reuptake of potassium (K+) by astrocytes

C. Release of neurotransmitters

What general functional effect do presynaptic receptors usually have? A. Inhibitory B. Excitatory C. Depolarizing D. Neutral

A. Inhibitory

What general functional effects can postsynaptic receptors exhibit? (Select all that apply) A. Excitatory B. Inhibitory C. Exclusively myelinating D. Uniquely mechanical

A. Excitatory; B. Inhibitory

Where are graded potentials initiated in a neuron? A. Axon hillock B. Synapses C. Nodes of Ranvier D. Axon terminal

B. Synapses