chap 12 questions

Which cavity contains a component of the central nervous system?

Cranial cavity

What structure predominates in the white matter of the brain?

Myelinated axons

Which part of a neuron transmits an electrical signal to a target cell?

Axon

What term describes a bundle of axons in the peripheral nervous system?

Nerve

Which functional division of the nervous system is responsible for physiological changes during exercise?

Autonomic nervous system

What type of glial cell provides myelin for axons in a tract?

Oligodendrocyte

Which part of a neuron contains the nucleus?

Soma

What substance is least able to cross the blood-brain barrier?

White blood cells

What type of glial cell is the resident macrophage behind the blood-brain barrier?

Microglia

What two types of macromolecules are the main components of myelin?

Lipids and proteins

If a thermoreceptor is sensitive to temperature, what would a chemoreceptor be sensitive to?

Molecules

Where does the greatest level of integration take place when testing the temperature of the shower?

Cerebral cortex

How long does all the signaling through the sensory pathway and central nervous system take?

Fraction of a second

What is the target of an upper motor neuron?

Lower motor neuron

What ion enters a neuron causing depolarization of the cell membrane?

Sodium

Voltage-gated Na+ channels open upon reaching what state?

Threshold

What does a ligand-gated channel require to open?

Binding of a neurotransmitter

What does a mechanically gated channel respond to?

Physical stimulus

Which voltage is most likely measured during the relative refractory period?

-80 mV

Which option is likely to propagate an action potential fastest?

A thick, myelinated axon

How much of a change is needed for the summation of postsynaptic potentials to generate an action potential?

+10 mV

What type of graded potential occurs when a negative ion enters the cell?

Hyperpolarizing

What neurotransmitter is released at the neuromuscular junction?

Acetylcholine

What type of receptor requires an effector protein to initiate a signal?

Metabotropic receptor

Which neurotransmitter is associated with inhibition exclusively?

GABA