nervous

Question 1

The strength of local potentials will vary depending on

Answer 1

how much neurotransmitter is released into the synaptic cleft
how long the neurotransmitter remains bound to receptors in the postsynaptic membrane
how many ligand-gated channels are opened
how long the ligand-gated channels remain open

Question 2

The plasma membrane of a neuron can function as an electrical insulator because __________________.

Answer 2

ions cannot cross directly thru the phospholipid bilayer

Question 3

When the voltage of a plasma membrane shifts from +30mV towards 0 mV, we say the cell is

Answer 3

repolarizing

Question 4

Membrane potential is functionally important because

Answer 4

it is a form of stored energy that can be used to do work

Question 5

Which of the following would be structures or processes associated with the axon of a neuron? Select the five that are correct.

Answer 5

Ion flow/current
Anterograde transport of neurotransmitters
Diffusion of K+ out of the cell
Microtubules
Mitochondria

Question 6

Immediately after an action potential has peaked and membrane potential has begun to fall, which gates are open?

Answer 6

K+ channel gates

Question 7

Which one of the following could NOT occur as a result of TEMPORAL summation?

Answer 7

both excitatory and inhibitory graded potentials

Question 8

The best general description of the purpose of intercellular signaling is to ____________________.

Answer 8

modify the activity of the receiving cell

Question 9

Which of the following events are linked by ion flow? Choose all that apply.

Answer 9

action potential at the trigger zone and action potential in the adjacent segment of the axon
action potentials at consecutive nodes of Ranvier
synaptic knobs and the membrane of a postsynaptic neuron
action potential at the trigger zone and action potential in the adjacent segment of the axon
action potentials at consecutive nodes of Ranvier
graded potential and action potential

Question 10

Put the following events of synaptic transmission in order, beginning with an action potential arriving at the synaptic knob of a presynaptic neuron from its propagating zone. Your last step should be something happening in the postsynaptic cell.

Answer 10

1.synaptic knob depolarizes
2.voltage-gated ca2+channels open
3.ca2+ ions enter the synaptic knob
4.Synaptic vesicles move to and fuse with the plasma membrane of the presynaptic neuron
5.Neurotransmitter enters the synaptic cleft and diffuses to the postsynaptic cell
6.Neurotransmitter binds to receptors on the postsynaptic cell
7.Channels open changing the permeability of the postsynaptic cell membrane
8.Membrane potential changes in the postsynaptic cell

Question 11

Which one of the following does not occur during an action potential?

Answer 11

Opening of Na+ ligand-gated channels

Question 12

Which of the follow is not a feature of graded potentials?

Answer 12

They exhibit refractory periods in which the membrane cannot be stimulated

Question 13

If a neuron is receiving simultaneous stimuli from several presynaptic neurons, each of which triggers the opening of sodium channels, the neuron is undergoing ___________ summation and the result could be ____________ at the trigger zone.

Answer 13

spatial; depolarization

Question 14

A segment of the axon enters its absolute refractory period when _______________, and leaves its absolute refractory period when ______________.

Answer 14

the voltage-gated Na+ channels open; the voltage-gated Na+ channel activation gates close

Question 15

If a neuron is receiving simultaneous stimuli from several presynaptic neurons, some of which trigger the opening of sodium channels and some of which trigger the opening of chloride channels, the neuron is undergoing ___________ summation and the result could be ____________ at the trigger zone.

Answer 15

spatial; depolarization or hyperpolarization

Question 16

Intracellular receptors can be activated by

Answer 16

any type of signaling molecule as long as it can pass through the phospholipid bilayer

Question 17

Ligand-gated channels are typically found on _________________. Select the three answers that apply.

Answer 17

Dendrites of neurons
Cell bodies of neurons
Receiving zone of neuron

Question 18

The ability of a specific tissue or organ to respond to the presence of a ligand is dependent on:

Answer 18

the presence of the appropriate receptors on or in the cells of the target tissue or organ

Question 19

Differences in signal strength are produced during action potential propagation by

Answer 19

varying the frequency of action potential propagation

Question 20

The functional significance of the absolute refractory period is that

Answer 20

it prevents action potential propagation from reversing direction

Question 21

When a neuron is at rest _______________. Select the three that apply.

Answer 21

the Na+/K+ pump returns leaked Na+ and K+ back across the membrane to maintain the RMP
K+ leaks out of the cell along a favorable concentration gradient
Na+ leaks into the cell along a favorable electrochemical gradient

Question 22

G proteins

Answer 22

relay ligand stimuli to secondary messengers

Question 23

An excitatory postsynaptic potential that is subthreshold strength when it reaches the axon hillock will cause

Answer 23

no action potential to be produced

Question 24

Nervous system

Answer 24

Central nervous (CNS)-the bodys master control unit
peripheral nervous (PNS)-the bodys link to the outside world

Question 25

central nervous system (CNS)

Answer 25

Spinal cord brain stem brain

Question 26

peripheral nervous system (PNS)

Answer 26

the autonomic nervous system the somatic nervous system

Question 27

function of CNS

Answer 27

process incoming sensory info make decisions initiate commands to effectors higher functions reflexes

Question 28

neural tissue

Answer 28

brain and spinal cord Components:neuroglia and neurons organization white and gray matter

Question 29

Gray matter

Answer 29

brain cortex SC horns nuclei (brain) sites where synapse occur between the synaptic knobs and dendrites/cell body integration center

Question 30

white matter

Answer 30

tracts and columns (spinal cord) bundles of mostly myelinated axons transmission lines carrying signals between gray matter areas

Question 31

functions of PNS

Answer 31

sensory (afferent) somatic (aware of) visceral (not aware of) motor (efferent) Autonomic nervous system (ANS) visceral motor Smooth muscles parasympathetic (resting & digest) sympathetic (fight or flight) somatic motor activity (voluntary) skeletal muscles

Question 32

PNS structure

Answer 32

consist of axons (nerve fibers) Organized and isolated by layers oof fibrous CT (EPi,, peri and endoneurim most nerves are mixed (sensory and motor fibers)

Question 33

PNS receptors

Answer 33

types: thermo baro mechano photo tactile chemo noci Location: extero intero proprio

Question 34

nerves

Answer 34

made up of Schwann cells (cells myelinate) bundles of axons

Question 35

bundles of axons

Answer 35

spinal 31 pairs mixed cranial 12 pairs sensory & mixed

Question 36

spinal and cranial nerves

Answer 36

make up peripheral nerves

Question 37

spinal cords and nerves

Answer 37

link between brain sensory receptors and effectors integration center for some reflexes minimal information processing

Question 38

somatic reflexes

Answer 38

visceral sensory receptors autonomic motor smooth/cardiac muscle glands adipose tissue maintain homeostasis

Question 39

gray matter

Answer 39

organized into horns which are made uo of nuclei and gray commissures (points of cross-over between the left and right side)

Question 40

white matter

Answer 40

is organized into columns which are made up of tracts of axons

Question 41

dorsal roots

Answer 41

carry incoming (sensory) neuronal axons and anterior roots carry outgoing (motor) neuronal axons

Question 42

dorsal and anterior roots

Answer 42

unite to form spinal nerves that emerge between adjacent vertebrae

Question 43

dorsal root ganglia

Answer 43

contain cell bodies of sensory (unipolar) neurons

Question 44

dermatomes

Answer 44

are areas of the skin that are served by specific spinal nerves

Question 45

a ganglion is a

Answer 45

cluster of neuron cell bodies in the PNS

Question 46

how many spinal nerves are there

Answer 46

8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

Question 47

plexuses

Answer 47

only ventral rami form plexuses

Question 48

the cervical plexus gives origin to the __ nerve(s)

Answer 48

phrenic

Question 49

the autonomic division of the nervous system directs

Answer 49

processes that maintain homeostasis

Question 50

A ganglion is a swelling along a nerve containing cell bodies of peripheral neurons. (T/F)

Answer 50

true

Question 51

gray matter contains

Answer 51

neurosomas, dendrites, and proximal parts of axons of neurons

Question 52

what sensory function involves neurons in the posterior root ganglia

Answer 52

touch

Question 53

Neuron cell bodies of sensory neurons are located in the ___, whereas neuron cell bodies of lower motor neurons are located in the ___

Answer 53

posterior root ganglion; anterior horn of the spinal cord

Question 54

The ___ surrounds individual nerve fibers (axons) within a nerve and keeps them isolated from one another.

Answer 54

endoneurium

Question 55

The largest and longest nerve of the body is found in the:

Answer 55

sacral plexus

Question 56

there are __ pairs of spinal nerves

Answer 56

31

Question 57

Each portion of the spinal cord served by a spinal nerve is called a segment of the cord.(T/F)

Answer 57

true

Question 58

Lateral horns of gray matter are found

Answer 58

in the thoracic and superior lumbar region of the spinal cord where preganglionic neurons of the sympathetic division emerge.

Question 59

Tracts in the CNS correspond to ____________ in the PN

Answer 59

nerves

Question 60

From superficial to deep, the meninges occur in this order:

Answer 60

dura mater arachnoid mater pia mater

Question 61

least likely to cause a spinal cord injury

Answer 61

a fracture of vertebra L4

Question 62

You go to the movies after a long day and you begin to nod off as soon as the movie starts. Your head starts to lower a little but this reflex causes your head to rise. This is called the

Answer 62

stretch (myotonic) reflex

Question 63

A major nerve of the lumbar plexus is the:

Answer 63

femoral

Question 64

___ carry motor commands from the brain along the spinal cord.

Answer 64

descending tracts

Question 65

medulla oblongata

Answer 65

Provides a site for crossing over of incoming signals from one side of the body to the other side of the cerebrum. Regulate respiration

Question 66

cerebellum

Answer 66

Monitor motor activity and make adjustments to ensure coordinated motor activity occurs.

Question 67

primary motor area

Answer 67

Innervate motor neurons that, in turn, innervate skeletal muscles

Question 68

visual association area

Answer 68

Enable recognition of visual images that have been seen before.

Question 69

primary somatosensory cortex

Answer 69

Receipt of a perceptible signal from a sensory receptor in the skin

Question 70

Hypothalamus

Answer 70

Regulate appetite

Question 71

substantia nigra

Answer 71

Regulate the activity of the basal nuclei

Question 72

association tract

Answer 72

Provide a communication pathway between the premotor cortex and the primary motor area

Question 73

commissural tract

Answer 73

Provide a communication pathway between the left and right cerebral hemispheres

Question 74

thalamus

Answer 74

Filter sensory information before it reaches the cerebral hemisphere

Question 75

reticular formation

Answer 75

Maintain a state of consciousness

Question 76

broca's area

Answer 76

Enable one to form words to speak

Question 77

limbic system

Answer 77

Establish emotional states

Question 78

prefrontal cortex

Answer 78

Allow one to think rationally and predict consequences of actions

Question 79

choroid process

Answer 79

Produce cerebrospinal fluid

Question 80

The reticular formation is a web of ___ scattered throughout the ____.

Answer 80

gray matter, brainstem

Question 81

damage to the____ would affect motor control

Answer 81

basal nuclei substantia nigra cerebellum motor association area

Question 82

in order for a motor command originating on the right side of the cerebral cortex to innervate a muscle on the left side of the body, the signal must cross over to the left side of the CNS in the

Answer 82

medulla oblongata or the spinal cord

Question 83

Damage to the ____________ would affect a person's ability to predict the consequences of their actions.

Answer 83

prefrontal cortex

Question 84

Commissural fibers connect the cerebral hemispheres. The largest collection of these fibers is the ___________.

Answer 84

corpus callosum

Question 85

Most gray matter of the cerebrum is located in

Answer 85

the cortex

Question 86

Planning, motivation, and social judgment are functions of the prefrontal cortex, located in the

Answer 86

frontal lobe of the cerebrum

Question 87

Motor commands that pass from the cerebral cortex to lower brain regions travel along __________,

Answer 87

projection tracts

Question 88

Respiratory centers are found in

Answer 88

the medulla oblongata and the pons.

Question 89

In order for a motor command originating on the right side of the cerebral cortex to innervate a muscle on the left side of the body, the signal must cross over to the left side of the CNS in the

Answer 89

medulla oblongata or the spinal cord

Question 90

We can localize sensations that originate in different areas of the body because

Answer 90

sensory neurons from specific body regions project to specific cortical regions.

Question 91

A reduction in sensitivity in the presence of a constant stimulus is referred to as

Answer 91

adaptation

Question 92

For the last few weeks, you have had an odd sensation on your upper thigh. When you touch the naked skin, it feels very strange, like you are touching your skin through layers of cloth. The surrounding area feels normal. Your doctor thinks that this may be related to spinal nerve damage related to a herniated disc. The doctor calls this change in sensation

Answer 92

paresthesia

Question 93

Stimulation of a neuron that terminates in the superior region of the left postcentral gyrus would produce

Answer 93

a sensation in the right leg

Question 94

The ________ nervous system carries impulses to skeletal muscles.

Answer 94

somatic

Question 95

Descending (motor) pathways always involve at least ________ motor neuron(s

Answer 95

two

Question 96

Damage to the pyramidal cells of the cerebral cortex would directly affect

Answer 96

voluntary motor activity

Question 97

The link between peripheral receptor and cortical neuron is called a(n)

Answer 97

labeled line

Question 98

Based on the motor homunculus, which of the following body regions has the fewest number of motor units involved?

Answer 98

back trunk

Question 99

The sensory receptors, sensory neurons and sensory pathways make up the ________ division of the nervous system.

Answer 99

afferent

Question 100

Mechanoreceptors that respond to changes in blood pressure are called

Answer 100

baroreceptors

Question 101

Which areas of the brain monitor and adjust activities of the motor pathways?

Answer 101

basal nuclei and cerebellum

Question 102

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.

Answer 102

lower motor

Question 103

Which is an example of a slow-adapting receptor?

Answer 103

pain

Question 104

The cerebellum adjusts motor activity in response to all of the following except

Answer 104

touch sensations

Question 105

Action potentials from receptors involved in general sensations are interpreted in the

Answer 105

primary sensory cortex

Question 106

Thalamic neurons that project to the primary sensory cortex are ________.

Answer 106

third-order neurons

Question 107

Your brain is not constantly bombarded with signals telling it that you are wearing socks. This is because the touch receptors around your ankle are

Answer 107

phasic and fast-adapting receptors

Question 108

The muscle fiber or gland cell that responds to the efferent impulses is known as the ____________________.

Answer 108

effector