Nervous Tissue Practice

________ open or close in response to binding specific molecules.

Chemically / ligand gated channels

________ line the brain ventricles and spinal canal.

Ependymal cells

________ monitor the position of skeletal muscles and joints.

Proprioceptors

Which of the following statements about the action potential is false?

The rapid depolarization phase is caused by the entry of potassium ions.

The period during which an excitable membrane cannot respond to further stimulation is the ________ period.

absolute refractory

The part of the peripheral nervous system that carries sensory information to the CNS is designated

afferent

The ________ nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity.

autonomic

Functions of astrocytes include all of the following except

conducting action potentials.

Opening of sodium channels in the axon membrane causes

depolarization

Graded potentials

may be either a depolarization or a hyperpolarization

Which of the following is not a function of the neuroglia?

memory

The myelin sheath that covers many CNS axons is formed by

oligodendrocytes

Which of the following is not a recognized structural classification for neurons?

pseudopolar

The ________ nervous system controls the skeletal muscles.

somatic

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated

spatial summation.

A neuron that receives neurotransmitter from another neuron is called

the postsynaptic neuron.

Regions of the CNS with an abundance of myelinated axons constitute the ________ matter.

white

At the normal resting membrane potential of a typical neuron, its sodium-potassium exchange pump transports

3 intracellular sodium ions for 1 extracellular potassium ion.

The efferent division of the peripheral nervous system innervates ________ cells.

All of the answers are correct.

________ provide information about the external environment.

Exteroceptors

________ channels open or close in response to physical distortion of the membrane surface.

Mechanically gated

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?

The axon would be unable to generate action potentials.

Regions of the CNS where neuron cell bodies dominate constitute the ________ matter.

gray

If the permeability of a resting axon to sodium ion increases,

inward movement of sodium will increase and the membrane will depolarize.

Small, wandering cells that engulf cell debris and pathogens in the CNS are called

microglia

The tiny gaps between adjacent Schwann cells are called

nodes of Ranvier.

The site of intercellular communication between a neuron and another cell is the

synapse

When a second EPSP (excitatory postsynaptic potential) arrives at a single synapse before the effects of the first have disappeared, what occurs?

temporal summation