ch 11

Neurons can be classified structurally by the number of processes extending from their cell bodies. Which of the following is the most common neuron type in humans?

• bipolar

• pseudounipolar

• multipolar

• unipolar

The sensory, or afferent, division of the peripheral nervous system transmits information from the __________ to the CNS.

• sweat glands

• skin

• heart

• kidney

Relative to extracellular fluid, the interior of a neuron has a negative charge because __________.

• potassium diffuses out of the cell

• sodium is actively pumped into the cell

• potassium is actively pumped into the cell

• potassium is actively pumped out of the cell

The Nissl bodies in the neuron cell body are otherwise known as which cellular organelle(s)?

• microtubules

• nucleus

• mitochondria

• rough endoplasmic reticulum

Which of the following statements best describes the resting membrane state in the neuron?

• only voltage gated Na channels are open

• all of voltage gated Na and K channels are closed

• only voltage gated K channels are open

• only voltage gated K channels are closed

Which cells line the central cavities of the brain and spinal cord and provide a fairly permeable barrier between the CSF and nervous tissue?

• ependymal cells

• oligondendrocytes

• schwann cells

• astrocytes

Which of the following characteristics is NOT associated with a myelinated nerve fiber?

• formation by oligondendrocytes in CNS

• presence of nodes of ranvier

• slow conduction of nerve impulses

• formation by shwann cells in PNS

Which of the following events occurs at an electrical synapse?

• nuerotransmitters bind to postsynaptic receptors

• neurotransmitter is released by exocytosis

• calcium channels open in presynaptic region

• ions flow directly form one neuron to next

Which of the following electrical events occurs when a certain threshold is reached?

• IPSP

• action potential

• EPSP

• resting membrane potential

Which of the following factors is associated with increased conduction velocity in an axon?

• small diameter

• absense of myelin sheaths

• presence of collaterals

• large diameter