Nervous System and Synapses Quiz

What is the function of dendrites in a neuron?

• Conduct electrical impulses away from the cell body

• Allow the electrical signal to jump between nodes of Ranvier

• Create the myelin sheath around axons

• Receive incoming signals and electrical impulses

Which part of the nervous system regulates involuntary bodily functions such as heart rate and digestion?

• Spinal nerves

• Cranial nerves

• Central Nervous System

• Autonomic Nervous system

What is the function of Schwann cells in the peripheral nervous system?

• Allow the electrical signal to jump between nodes of Ranvier

• Create the myelin sheath around axons

• Conduct electrical impulses away from the cell body

• Receive incoming signals and electrical impulses

What is the resting membrane potential of a neurone?

• -40 mV

• +40 mV

• -70 mV

• 0 mV

What is the function of the sodium-potassium pumps in the cell surface membranes of neurons?

• Receive incoming signals and electrical impulses

• Conduct electrical impulses away from the cell body

• Allow sodium and potassium ions to move across the membrane by facilitated diffusion

• Create a concentration gradient for both sodium ions and potassium ions

What is the result of the neurone membrane being less permeable to sodium ions than potassium ions?

• No difference in the distribution of positive ions inside and outside the neurone

• More positive ions on the inside of the neurone than on the outside

• Equal distribution of positive ions inside and outside the neurone

• More positive ions on the outside of the neurone than on the inside

What is the potential difference at the point of depolarization during an action potential?

• 0 mV

• -70 mV

• -40 mV

• +40 mV

What is the principle that states an impulse is only transmitted if the initial stimulus is sufficient to increase the membrane potential above a threshold potential?

• Threshold principle

• Saltatory conduction principle

• All-or-nothing principle

• Depolarization principle

What is the function of saltatory conduction in myelinated nerve fibers?

• Allows the nerve impulse to travel much slower compared to unmyelinated axons

• Slows down the transmission of nerve impulses along the axon

• Conserves energy as the impulse only requires depolarization at the nodes

• Reduces the efficiency and speed of signaling in the nervous system

What occurs at the synapse when the calcium channels open up and the calcium ions move down the concentration gradient?

• The neurotransmitter attaches to specific receptors on the post synaptic membrane

• The neurotransmitter is released into the synaptic cleft

• The synaptic vesicles containing the neurotransmitter pass through the synaptic cleft

• The arrival of one impulse at the synaptic knob increases the permeability of the presynaptic membrane