Human Anatomy and Physiology I- Chapter 12 Quiz

select all that are true of excitatory postsynaptic potentials:

- chemically gated cation channels open and let sodium in and potassium out - postsynaptic neuron depolarizes

select all that apply to myelinated axons:

- myelinated axons have faster nerve impulse conduction than unmyelinated axons. - in myelinated axons, the nerve impulses "jump" from node to node and do not have to travel the entire length of the axon membrane. - myelinated axons use less energy than unmyelinated axons.

place the following labels in the proper position on the curve where each of the indicated items would occur:

A - potential across the membrane becomes less negative B - threshold - at threshold, voltage-gated Na+ channels open quickly - --55 mV C - voltage0gated potassium channels open D - hyperpolarization E - resting membrane potential - --70 mV

the fundamental physiological properties that enable nerve cells to communicate with other cells are. . .

all of the choices are correct [- the ability to respond to environmental changes - the ability to produce electrical signals that are quickly conducted to other cells at distant locations - the ability to secrete a chemical that will stimulate the next cell when an electrical signal reached the end of an axon]

what is the correct order for the events of neurotransmitter release from the synaptic terminal? a. extracellular Ca+ enters terminal and binds to sensor protein in the cytoplasm b. exocytosis of neurotransmitter into synaptic cleft c. action potential reached axon terminal d. Ca+ protein complex stimulate fusion of the docked synaptic vesicle with the plasma membrane e. voltage-gated Ca+ channels open

c-e-a-d-b

acetylcholinesterase. . .

catalyzes hydrolysis of ACh to remove it from the synaptic cleft.

when a neurotransmitter binds a protein channel, it opens and lets sodium diffuse down its concentration gradient. this is an example of. . .

chemically gated sodium channels.

a message traveling from one presynaptic neuron to multiple postsynaptic neurons is an example of a ___ circuit.

diverging

neurons that carry signals from the CNS to skeletal muscle for contraction would be classified as ___ neurons.

efferent

classify the given items with the appropriate category:

excitatory neurotransmitter actions - binds to a chemically gated sodium channel - sodium moves down concentration gradient into the neuron - the inside of the neuron becomes more positive inhibitory neurotransmitter actions - binds to a chemically gated potassium channel - binds to a chemically gated chloride channel - potassium moves down its concentration gradient out of the neuron - chloride moves down its concentration gradient into the neuron

place the following labels in the proper position to designate the appropriate glial cells:

oligodendrocytes - form the myelin sheath in the CNS ependymal cells - function in the production and circulation of cerebrospinal fluid microglia - cells of the lymphatic system - macrophages of the CNS astrocytes - most abundant CNS glial cells - involved with neurogenesis, scar formation, and blood-brain barrier maintenance neurolemmocytes - form the myelin sheath in the PNS satellite cells - PNS cells that surround and insulate the somas

place the neurons into the proper classification group:

structural classification - multipolar neuron - bipolar neuron - unipolar neuron functional classification - sensory neuron - motor neuron - interneuron neuron - afferent neuron - efferent neuron - association neuron

the negative value of the resting membrane potential means that. . .

there are more negatively charge particles on the inside of the membrane than on the outside.