A & P Unit III B, CH 8

a) -70 mV

What is the value for the resting membrane potential for most neurons? a) -70 mV b) +30 mV c) -90 mV

a) microglia

Small phagocytic glial cells, which are derived from white blood cells, are called: a) microglia b) astrocytes c) ependymal cells d) Schwann cells e) oligodendrocytes

C) Opening of Na+ channels

"The depolarization phase of an action potential results from which of the following? A) Opening of K+ channels B) Closing of Na+ channels C) Opening of Na+ channels D) Closing of K+ channels"

E) Ependymal cells"

"Which neuralgia cells produce CSF in some regions of the brain? A) Microglia B) Schwann Cells C) Astrocyte D) Oligodendrocytes E) Ependymal cells"

c) Na+ and Cl-

The concentrations of which two ions are highest outside the cell? a) Na+ and A- (negatively charged proteins) b) K+ and A- (negatively charged proteins) c) Na+ and Cl- d) K+ and Cl-

c) the opening of K+ channels

The repolarization phase of an action potential results from __________. a) the opening of Na+ channels b) the closing of Na+ channels c) the opening of K+ channels d) the closing of K+ channels

E) Afferent

The______division of the nervous system brings sensory information to the central nervous system: A) efferent B) spinal c) Motor D descending E) Afferent

d) depolarization

A shift of positively charged ions into the cell is called__________? a) repolarization b) polarized c) hyperpolarization d) depolarization

c) microglia d) Nissl bodies

Clusters of rough endoplasmic reticulum and free ribosomes are known as: a) neurofilaments b) synapses c) microglia d) Nissl bodies e) neurofibrils

Label the structural class of neurons

Label the structural class of neurons

c) potassium

When a neuron is at rest, which ion passes through its membrane most easily? a) sulfate b) sodium c) potassium d) chloride e) proteins

d) sensory neuron

A neuron that sends messages to the CNS, and is composed of one or more dendrites and a single axon, is functionally classified as an: a) efferent neuron b) multineuron c) interneuron d) sensory neuron

B) dendrite

A) cell body B) dendrite C) synapse D) axon

d) Nissl bodies

Clusters of rough endoplasmic reticulum and free ribosomes are known as: a) neurofilaments b) synapses c) microglia d) Nissl bodies e) neurofibrils

c) slow closing of K+ channels

Hyperpolarization results from ___________? a) fast closing K+ channels b) slow closing Na+ channels c) slow closing of K+ channels

Identify parts of the neuron

Identify parts of the neuron

d) 3,1,2,4

Identify the correct sequence of steps in the generation of an action potential: 1. Activation of sodium channels and rapid depolarization 2. Inactivation of sodium channels and activation of potassium channels 3. depolarization to threshold 4. closing of potassium channels a) 4,3,2,1 b) 3,1,4,2 c) 1,3,2,4 d) 3,1,2,4 e)1,3,4,2

b) presynaptic neuron

In a synapse, neurotransmitters are stored in vesicles located in the _______. a) synaptic cleft b) presynaptic neuron c) neuroglia cell d) postsynaptic neuron

c) from the axon hillock down the axon away from the cell body

Action potentials move in which directions? a) from the axon hillock toward the cell body b) in both directions from the axon hillock, toward the cell body and down the axon c) from the axon hillock down the axon away from the cell body

b) collaterals

Branches that sometimes occur along the length of an axon are called: a) action potentials b) collaterals c) hillocks d) synaptic knobs e) synapse

d) tracts

Bundles of CNS axons that share a common origin, destination, and function are called _______. a) centers b) the cortex c) nuclei d) tracts e) ganglia

b) bipolar

Neurons that have one axon and one dendrite with the soma between them are called: a) unipolar b) bipolar c) tripolar d) polypolar e) multipolar

d) Schwann cells

Oligodendrocytes are to CNS as ______ are to PNS. a) microglia b) astrocytes c) satellite cells d) Schwann cells

c) -70 mV

The resting potential of a neuron is _____: a) +10mV b) 0 mV c) -70 mV d) -10 mV e) +70 mV

a) capable of cell division

Unlike neurons, neuroglia are: ________ a) capable of cell division b) very large cells c) not very numerous d) only found in CNS

d) calcium

Which ion is needed to trigger the release of acetylcholine, via exocytosis, into the synaptic cleft? a) sodium b) potassium c) zinc d) calcium

b) acetylcholinesterase

Which of the following is NOT a neurotransmitter? a) dopamine b) acetylcholinesterase c) GABA d) serotonin

a) a large, myelinated axon

The velocity of the action potential is fastest in which of the following axons? a) a large, myelinated axon b) a large, unmyelinated axon c) a small, unmyelinated axon

E) autonomic

The_______nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity: A) central B) collateral c) somatic D) ganglionic E) autonomic

c) maintain the resting membrane potential

What is the function of the Na+ -K+ pump? a) establish the resting membrane potential b) to decrease the resting membrane potential c) maintain the resting membrane potential d) to make sure there are more positively charged particles inside the cell than outside the cell

D) peripheral

All of the nervous tissue outside of the central nervous system comprises the_____nervous system: A sympathetic B) somatic C) autonomic D) peripheral E) central

b) Ca2+ channels

An action potential releases neurotransmitter from a neuron by opening which of the following channels? a) Cl- channels b) Ca2+ channels c) Na+ channels d) K+ channels

c) K+; Na+

The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _______. a) Na+; Cl- b) Na+; K+ c) K+; Na+ d) K+; Cl-

d) oligodendrocytes

The myelin sheaths that surround the axons of some of the neurons in the CNS are formed by: a) ependymal cells b) microglia c) astrocytes d) oligodendrocytes e) Schwann cells

b) Ependymal cells line the central canal and ventricle of the brain and produce cerebrospinal fluid (CSF).

What do ependymal cells do? a) Ependymal cells serve as electrical insulation and increases the speed of impulses. b) Ependymal cells line the central canal and ventricle of the brain and produce cerebrospinal fluid (CSF). c) Ependymal cells are phagocytic cells derived from white blood cells. d) Ependymal cells secretes chemicals vital to the maintenance of the blood-brain barrier (BBB).

a) saltatory carries impulses at a faster rate than continuos propagation

What is the difference between saltatory and continuous propagation of nerve impulses? a) saltatory carries impulses at a faster rate than continuos propagation b) saltatory occurs in unmyelinated fibers, whereas continuous occurs in myelinated fibers c) saltatory and continuous carry the impulses at the same rate d) continuous carries impulses at a faster rate than salutary propagation

c) opening of Na+ channels

The depolarization phase of an action potential results from which of the following? a) opening of K+ channels b) closing of Na+ channels c) opening of Na+ channels d) closing of K+ channels

c) release of a neurotransmitter from the axon terminal

The arrival of an action potential at the end of an axon results in the _______ a) mechanical stimulation of the effector cell b) the release of ions from the axon terminal c) release of a neurotransmitter from the axon terminal d) generation of a new action potential

C) central nervous system

The brain and spinal cord comprised the: A) efferent nervous system D) afferent nervous system C) central nervous system D) autonomic nervous system E) peripheral nervous system

b) sodium channels are inactive

Why can't an action potential be generated during the absolute refractory period? a) calcium channels b) sodium channels are inactive c) sodium channels are active, but potassium channels are inactive

A) Saltatory carries impulses at a faster rate than continuous propagation

"What is the difference between saltatory and continuous propagation of nerve impulses? A) Saltatory carries impulses at a faster rate than continuous propagation B) Saltatory occurs in unmyelinated fibers, whereas continuous occurs in myelinated fibers C) Saltatory and continuous carry the impulses at the same rate D) Continuous carries impulses at a faster rate than saltatory propagation"

a) is faster than conduction on an unmyelnated axon.

Saltatory conduction: a) is faster than conduction on an unmyelnated axon. b) occurs only if the myelin sheath is continuous c) occurs at the synapse d) is slower than conduction on an unmyelinated axon. e) occurs only if nodes of Ranvier are lacking.

a) all stimuli great enough to bring the membrane to threshold will produce identical action potentials

The all-or-none principle states that: a) all stimuli great enough to bring the membrane to threshold will produce identical action potentials b) only sensory stimuli can activate action potentials c) all stimuli will produce identical action potentials d) only motor stimuli can activate action potentials

E) Sending signals to muscles

Which of the following is a function of the efferent division of the nervous system? A) Providing sensation of the internal and external environments B) Regulating or controlling peripheral structures and systems C) Integrating sensory information D) coordinating voluntary and involuntary activities E) Sending signals to muscles

c) 4,1,3,2

Which of the following is the correct order of events that occur at a cholinergic synapse? 1. Extracellular calcium enters the axon terminal, triggering the exocytosis of acetylcholine. 2. Acetylcholine is removed by acetylcholinesterase 3. Acetylcholine binds to receptors and depolarizes the postsynaptic membrane 4. Axon terminals depolarize a) 1,4,3,2 b) 2,3,1,4 c) 4,1,3,2 d) 3,4,1,2 e) 4,1,2,3

d) all arte matched correctly

Which of the following pairs are mismatched: a) dendrites: receive messages b) axons, send messages c) cell body: nucleus d) all arte matched correctly

C) somatic nervous system

Which of the following provides control over skeletal muscle? A) parasympathetic nervous system D) efferent division C) somatic nervous system D) autonomic nervous system

b) Na+ is pumped out of the cell andK+ is pumped into the cell

Which statement accurately describes the action of the Na+ -K+ pump? a) Both Na+ and K+ are pumped into the cell b) Na+ is pumped out of the cell andK+ is pumped into the cell c) Both Na+ and K+ are pumped out of the cell d) K+ is pumped out of the cell and Na+ is pumped into the cell

a) An influx of sodium ions from the current action potential depolarizes the adjacent area

How is an action potential propagated along an axon? a) An influx of sodium ions from the current action potential depolarizes the adjacent area b) An efflux of potassium from the current action potential depolarizes the adjacent area c) Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon

c) depolarize

If the binding of the neurotransmitter to its receptor results in the opening of Na+ channels, it will cause the membrane of the postsynaptic neuron to _______. a) remain at its resting membrane potential b) hyperpolarize c) depolarize

b) depolarization

Opening of voltage-gated sodium channels in the membrane of a neuron results in : a) increased negative change inside the membrane. b) depolarization c) myelination d) repolarization e) hyperpolarization

a) acetylcholine

The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken doen by an enzyme before being returned? a) acetylcholine b) glutamate

D) afferent division

The part of the peripheral nervous system that brings information to the central nervous system is the: A) efferent division B) Motor division C) autonomic division D) afferent division E) somatic division

d) 100 mV

What is the magnitude (amplitude) of an action potential? a) 30 mV b) 15 mV c) 70 mV d) 100 mV

c) nodes

Which structure is labeled "B"? a) oligodendrocyte b) Schwann cell c) nodes d) internodes