Chapter 30

______ relay messages from the brain and spinal cord to muscles and glands. a. Motor neurons b. Sensory neurons c. Interneurons d.Neuroglia

When a neuron is at rest, _____. a. it is at threshold potential b. gated sodium channels are open c. the sodium-potassium pump is operating d. both a and c

Action potentials occur when _____. a. a neuron receives adequate stimulation b. more and more sodium gates open c. sodium-potassium pumps kick into action d. both a and b

Neurotransmitters are released by _____. a. axon endings b. the cell body c. dendrites d. the myelin sheath

The most abundant cells in the brain are _____. a. Schwann cells b. microglia c. astrocytes d. neurons

Skeletal muscles are controlled by _____. a. sympathetic signals b. parasympathetic signals c. somatic nerves d. both a and b

When you sit quietly on the couch and read, output from the _____ system prevails. a. sympathetic b. parasympathetic c. Both prevail. d. Neither prevails.

Skeletal muscles contract in response to _____. a. ACh b. dopamine c. serotonin d. all of the above

The cerebrum is part of the ______. a. forebrain b. midbrain c. hindbrain d. brain stem