CHAPTER 11

Ca2+ diffuses into the cell and causes synaptic vesicles to undergo exocytosis, releasing neurotransmitter molecules.

2

Neurotransmitter molecules diffuse from the presynaptic terminal across the synaptic cleft.

3

Neurotransmitter molecules bind their receptor sites, causing ligand-gated Na+; channels to open. Na+; diffuses into the cell or out of the cell, causing a change in membrane potential.

4

Identify the two primary branches of the peripheral nervous system.

ALL ARE CORRECT

EPSP

depolarization and membrane becomes

The membrane potential becoming more positive in value is called _________whereas, _________refers to the membrane potential becoming more negative than the resting membrane potential.

depolarization; hyperpolarization

Schwann

form myelin

oligodendrocytes

form myelin in CNS

ependymal

function in the production

Identify the statement that best differentiates gray matter and white matter.

gray matter: cell bodies and dendrites white matter:myelinated axons

microgila

macrophages

Along myelinated axons of the peripheral nervous system, ion currents must cross the plasma membrane of the neuron

nodes of ranvier

higher concentration inside cells

potassium ions negatively charged

Identify the correct sequence of structures involved in the passage of information across a chemical synapse.

presynaptic, cleft, membrane

Action potentials arriving at the presynaptic terminal cause voltage-gated Ca2⁺ channels to open.

1

astrocytes

BBB

IPSP

a membrane potential hyperpolarization The membrane

The nervous system

all of these are correct

When threshold is reached, depolarization of the same magnitude occurs for all action potentials. If threshold is not reached, an action potential does not begin at all. This describes

all or none

higher concentration outside cell

chloride and sodium ions

The equilibrium centers of the brain receive information from inner ear structures as well as the retina of the eyes. This arrangement is an example of a ______ circuit.

converging

Homeostatic regulation of receptor levels often forms the basis of addiction. In Ralph's case the increased release of dopamine caused a progressive

decrease in dopamine receptor numbers in dopaminergic postsynaptic membranes.

Compounds classified as ______ alter synaptic transmission by changing neurotransmitter receptor numbers or affecting the breakdown and/or removal of neurotransmitter.

nueromodulators

The neurons that conduct information towards the CNS are

sensory neurons

The concentration of _________ions is much greater outside the cell as compared to inside the cell, whereas the concentration of _________ ions is much greater inside the cell as compared to outside the cell.

sodium; potassium

The _________ nervous system communicates with the skeletal muscles and the _________ nervous system communicates with the smooth and cardiac muscle as well as glands.

somatic; autonomic

satelitle

support cells