Sections 9.5-9.10

What is a synapse?

• A. A type of neurotransmitter

• B. A junction between two communicating neurons

• C. A part of the neuron that sends impulses

• D. A muscle fiber

What is the small gap between the neurons called?

• A. Synaptic knob

• B. Presynaptic neuron

• C. Synaptic cleft

• D. Neurotransmitter

Which neuron sends the impulse in a synapse?

• A. Postsynaptic neuron

• B. Synaptic cleft

• C. Synaptic knob

• D. Presynaptic neuron

Which neuron receives the impulse in a synapse?

• A. Synaptic cleft

• B. Presynaptic neuron

• C. Postsynaptic neuron

• D. Synaptic knob

How is communication across a synapse accomplished?

• A. By electrical signals only

• B. By a physical connection between neurons

• C. By a chemical called a neurotransmitter

• D. By direct contact between neurons

What happens to neurotransmitters after they are released in response to a nerve impulse?

• A. They are destroyed immediately

• B. They bind to receptors on the membrane of the postsynaptic neuron

• C. They return to the presynaptic neuron

• D. They diffuse into the bloodstream

Why is polarization important for neurons?

• It helps in the digestion of food.

• It allows for the conduction of nerve impulses.

• It prevents the neuron from firing.

• It maintains the neuron in a constant state.

What happens during an action potential?

• The neuron loses its polarization permanently.

• The neuron's membrane potential becomes more positive inside than outside.

• There is a specific change in membrane polarization, followed by a return to the resting state.

• The neuron's membrane becomes completely permeable to all ions.

How is the distribution of ions inside and outside of cells described?

• Equal distribution

• Unequal distribution

• Random distribution

• Static distribution

Which type of ions has a greater concentration outside the cells than inside?

• Potassium ions

• Calcium ions

• Sodium ions

• Chloride ions