The Nervous System

Which statement accurately describes the functional specialization of the human brain's hemispheres?

• The right hemisphere primarily controls speech and language processing.

• The left hemisphere is generally responsible for processing visual information from the left field of view.

• The left hemisphere typically controls speech and is involved in processing visual information from the right field of view.

• Both hemispheres equally share responsibility for all cognitive functions, including speech and vision.

What is the primary function of the corpus callosum in the human brain?

• It regulates involuntary bodily functions like breathing and heart rate.

• It connects the two cerebral hemispheres, allowing them to communicate and share information.

• It is responsible for processing sensory input from the body.

• It controls motor coordination and balance.

What is the role of ion channels during the depolarization phase of an action potential in a neuron?

• They actively pump sodium ions out of the cell.

• They open to allow sodium ions to rush into the cell.

• They facilitate the movement of potassium ions out of the cell.

• They maintain the resting membrane potential by balancing ion concentrations.

Which part of a neuron is primarily responsible for receiving signals from other neurons?

• Axon

• Myelin sheath

• Dendrite

• Nucleus

What is the primary function of the myelin sheath in a neuron?

• To generate neurotransmitters

• To insulate the axon and speed up signal transmission

• To connect the neuron to other cells

• To provide structural support to the cell body

At a neuron's resting potential, how are sodium and potassium ions typically distributed across the cell membrane?

• Higher concentration of sodium inside, higher concentration of potassium outside

• Higher concentration of both sodium and potassium inside

• Higher concentration of sodium outside, higher concentration of potassium inside

• Equal concentrations of both ions inside and outside

What event primarily causes the rising phase (depolarization) of an action potential?

• Potassium ions flowing out of the cell

• Sodium ions flowing into the cell

• Chloride ions flowing into the cell

• Proteins being actively pumped out of the cell

During the falling phase (repolarization) of an action potential, which ion movement is primarily responsible for restoring the negative charge inside the neuron?

• Sodium ions moving out of the cell

• Potassium ions moving into the cell

• Potassium ions moving out of the cell

• Calcium ions moving into the cell

During the rising phase of an action potential, which ion channels open, causing the membrane potential to become more positive?

• Potassium channels, allowing potassium to exit the cell.

• Sodium channels, allowing sodium to enter the cell.

• Calcium channels, allowing calcium to enter the cell.

• Chloride channels, allowing chloride to enter the cell.

How does the nervous system distinguish between a light touch and a strong painful stimulus?

• Stronger stimuli produce action potentials with a higher amplitude.

• Stronger stimuli produce action potentials with a longer duration.

• Stronger stimuli cause a higher frequency of action potentials.

• Stronger stimuli activate different types of neurons that send unique signals.