PBSI 235 Exam 1

Which of the following is found in all cells, not just neurons?

• Nucleus

• Axon

• Synapse

• Myelin

Tags

NGSS.MS-LS1-1

NGSS.MS-LS1-2

Which structure receives input from other neurons?

• Soma

• Dendrite

• Axon terminal

• Myelin

The axon hillock is best described as:

• The site of ribosome production
  

• The integration zone that decides whether to fire an action potential

• The site of neurotransmitter release

• 1. The location of the nucleus

Which part of a neuron is most directly specialized for sending signals long distances?

• Dendrites

• Soma

• Axon

• Synapse

Myelin increases conduction speed by:

• Increasing the number of ion channels

• Preventing ion leak along the membrane

• Making axons thinner

• 1. Shortening the axon

At rest, the inside of the neuron is negative relative to the outside. This is due mostly to:

• High extracellular Na⁺ and Cl⁻

• High intracellular Na⁺

• High extracellular K⁺

• 6. Equal ion distribution

Depolarization occurs when:

• K⁺ leaves the cell

• Na⁺ enters the cell

• Cl⁻ enters the cell

• 6. Ca²⁺ leaves the cell

Which factor helps maintain the resting potential?

• Voltage-gated Ca²⁺ channels

• Sodium-potassium pump

• Synaptic vesicles

• 6. Diffusion of neurotransmitters

Tags

NGSS.HS-LS1-3

If the resting potential shifts from –70 mV to –60 mV, this is called:

• Hyperpolarization

• Depolarization

• Refractory

• 6.  Synaptic delay

Tags

NGSS.HS-PS2-5

Which event occurs at the threshold of an action potential?

• K⁺ channels open first
  

• 11. Chloride enters the cell

• Sodium-potassium pump reverses

• 11. Voltage-gated Na⁺ channels open rapidly