Lab Exam III Ch. 12 study (multiple choice)
_______ Form the myelin sheath in the CNS
Olidendrocytes
_______ Anchor neurons and blood vessels, maintain extracellular environment around neurons, assists in the formation of the blood-brain barrier
Astrocytes
_______ are Ciliated cells in the CNS that form and circulate cerebospinal fluid
Ependymal cells
Where are synaptic vesicles located? a. Axon terminals b. Dendrites c. Cell body d. Both a and b are correct e. All of the above
a. Axon terminals
Neurotransmitters that bind the postsynaptic membrane generally generate a/am a. local potential b. action potential c. resting membrane potential d. pacemaker potential
a. local potential
What triggers exosytosis of synaptic vesicles? a. arrival of a local potential and the cell body b. Hyperpolarization of the postsynaptic membrane c. Neurotransmitters binding to the postsynaptic membrane d. The influx of calcium ions into the axon terminal
d. The influx of calcium ions into the axon terminal
Put in correct order: ___ Voltage-gated sodium ion channels close, and voltage-gated potassium ion channels open ___ Potassium ions continue to exit the cell, causing hyperpolarization ___ Voltage-gated sodium ion channels open, and the axon depolarizes ___ Potassium ions exit the cell, causing repolarization
1. Voltage-gated sodium ion channels open, and the axon depolarizes 2. Voltage-gated sodium ion channels close, and voltage-gated potassium ion channels open 3. Potassium ions exit the cell, causing repolarization 4. Potassium ions continue to exit the cell, causing hyperpolarization
_______ are Phagocytic cells of the CNS
Microglial cells
What is the function of the myelin sheath?
Protection and insulates the axon and speeds up the conduction of impulse action potential
_______ Surround the cell bodies of neurons in the PNS
Satellite cells
_______ create the myelin sheath in the PNS
Shwann cells
Which part of the neuron is capable of generating an action potential? a. Dendrite b. Axon c. Myelin sheath d. Cell body
b. Axon
