The meninges consist of
the brain and spinal cord.
the membranes that delineate all of the major brain parts.
the pia mater, arachnoid mater, and dura mater.
nerve tracts that run up and down the spinal cord.
The ____________ is the thin meninx attached to the surface of the brain, containing many nerves and blood vessels.
The fourth ventricle is in the
midline of the brain, beneath the corpus callosum.
right cerebral hemisphere.
left cerebral hemisphere.
When the flexor muscles of one arm contract in a withdrawal reflex, the extensor muscles of the other arm contract. This phenomenon is called
crossed extensor reflex.
flexor extensor reflex.
crossed flexor reflex.
The spinothalamic tract conducts impulses
up the spinal cord to the thalamus.
down the spinal cord from the thalamus.
that stimulate skeletal muscles.
The spinal cord has
a cervical and lumbar enlargement.
a core of gray matter surrounded by white matter.
all of the above.
The part of the brain that coordinates voluntary muscular movements is the
The cytoplasmic extensions that, together with the cell body, provide the main receptive surfaces for neurons are
chromatophilic substance (Nissl bodies).
Masses of myelinated nerve fibers appear
Most of the neurons in the brain and spinal cord are
Which of the following cells is only found in the PNS?
Dendrites on unipolar neurons are parts of
An action potential is triggered if
EPSPs overpower IPSPs.
IPSPs overpower EPSPs.
chloride channels open.
the membrane hyperpolarizes.
The types of neurons that are organized into neuronal pools are
Diverging axons amplify an impulse by
contacting many neurons.
returning the impulse to the neuron of origin.
splitting into multiple axons.
The brain and spinal cord comprise the central nervous system.
What is the correct sequence of events along an axon that follows a membrane reaching threshold potential?
1. The membrane depolarizes.
2. Sodium channels open and sodium ions diffuse inward.
3. The membrane repolarizes.
4. Potassium channels open and potassium ions diffuse outward.
4, 1, 3, 2
3, 2, 4, 1
2, 1, 4, 3
1, 2, 4, 3