ANA 171 Neurons

In this high power image of a nerve, which structure, indicated by the arrow, facilitates saltatory conduction along myelinated axons?

• Nissl substance

• Node of Ranvier

• Axon

• Myelin sheath

The site of communication between two neurons is called the:

What is the function of Schwann cells?

• Transmitting impulses

• Producing cerebrospinal fluid

• Forming myelin sheath

• Filtering toxins from blood

Which of the following best describes the resting membrane potential of a neuron?

• The inside is positively charged compared to the outside

• The inside is negatively charged compared to the outside

• The charge inside and outside is equal

• The inside of the cell is always depolarized

In the image, the arrow labeled 'S' is pointing to a structure within the neuron. What is its function?

• Synthesizing proteins for neuronal function

• Transmitting action potentials along the axon

• Storing neurotransmitters for synaptic release

• Providing electrical insulation

_________________ are chemicals that transmit signals across synapses

If a person’s myelin sheath deteriorates due to a disease like multiple sclerosis, which of the following would occur?

• Conduction would slow down, leading to weaker muscle responses

• Action potentials would travel faster due to lack of insulation

• The neuron would stop producing neurotransmitters

• The synaptic cleft would widen

During a dental procedure, a local anesthetic is applied to block sodium (Na⁺) channels in the sensory neurons of the oral cavity. What effect does this have on the nerve?

• Action potentials can no longer be generated, numbing the area.

• The neuron fires faster, reducing the sensation of pain

• The neuron releases more neurotransmitters, heightening pain sensation.

• The neuron becomes hypersensitive to stimuli.

Which ion is primarily responsible for the depolarization of a neuron during an action potential?

• Calcium (Ca²⁺)

• Chloride (Cl⁻)

• Potassium (K⁺)

• Sodium (Na⁺)

A patient with temporomandibular joint (TMJ) disorder might experience chronic pain. Which part of the neuron is involved in transmitting this pain signal?

• Axon terminals

• Myelin sheath

• Dendrites and synaptic cleft

• Soma