A&p Ch 7 Nervous System

Front 1

Carry information towards the CNS.

Back 1

afferent axons

Front 2

Carry commands to effectors.

Back 2

efferent axons

Front 3

Also called association neurons, these are the most numerous
neurons that have their processes entirely within the CNS and are involved in processing information for an appropriate response.

Back 3

interneurons

Front 4

consists of the skeletal muscles and body surface

Back 4

somatic region

Front 5

consists of the soft internal organs of the digestive system, lungs, heart, and blood vessels, etc.

Back 5

visceral region

Front 6

A class of the somatic sensory system that includes touch,
temperature, and pain that project from the body surface, as
well as muscle, tendon, and joint receptors that give information about the position and movement of the body in
space.

Back 6

general somatic senses

Front 7

sight, hearing, taste, and smell.

Back 7

special senses

Front 8

Because it is responsible for movements that are under conscious control.

Back 8

voluntary nervous system

Front 9

That part of the peripheral nervous system that supplies
motor innervation to the viscera.

Back 9

autonomic nervous system

Front 10

Which are capable of generating electrical signals used for communication within the nervous system

Back 10

neurons

Front 11

The supporting cells of the nervous system.

Back 11

glia

Front 12

A class of glial cells in the CNS that control the composition and volume of the fluid microenvironment that surrounds central neurons.

Back 12

astrocytes

Front 13

A class of glial cells in the CNS that is responsible for laying down the myelin sheaths that surround the axons of some central neurons.

Back 13

oligodendrocytes

Front 14

A class of glial cells in the CNS.

Back 14

ependymal cells

Front 15

fine, highly branched projections that resemble the branches of a tree also the region of the cell that receives information from the environment or other neurons

Back 15

dendrites

Front 16

A single tubular axon that sprouts from the cell body at a bump. Also called an initial segment.

Back 16

axon hillock

Front 17

Surround the dome axons of some central neurons.

Back 17

myelin sheaths

Front 18

The electrical signals used for long-distance communication
in the nervous system.

Back 18

action potentials

Front 19

Branches formed at the end of axons, ending in axon
terminals.

Back 19

telodendria

Front 20

Structures that allow neurons to communicate with each
other and with effectors.

Back 20

axon terminal

Front 21

In the resting cell, the plasma membrane is mainly permeable to K+, and the inside-to-outside concentration gradient tends to drive K+ toward the outside of the cell, giving the membrane a slight excess of positive charge on
the outside surface of the membrane and a corresponding
slight excess of negative charge on the inside.

Back 21

resting potential

Front 22

Any change in the direction of a less-negative potential.

Back 22

depolarization

Front 23

Any change in the direction of an even more inside-negative potential.

Back 23

hyperpolarization

Front 24

When an action potential occurs, the membrane potential changes rapidly from its resting inside-negative value to an inside-positive value (peaking typically in the range of +20 to +50 mV) and just as quickly returns to the resting value.

Back 24

spike

Front 25

Stimulation of the dendrites results in a local depolarization that decreases in intensity as it travels through the dendrites to the cell body.

Back 25

decremental threshold

Front 26

The period during which the neuron is functionally unable to generate a second spike, occurring early in the period of repolarization and afterhyperpolarization.

Back 26

absolute refractory period

Front 27

A period after the absolute refractory period during which a second action potential can be initiated, but the stimulus must be more intense.

Back 27

relative refractory period

Front 28

An Na+ channel state in which the pore is blocked by an internal activation gate that senses the transmembrane potential and can be opened by depolarization, switching the channel to the open state.

Back 28

closed state

Front 29

Senses the transmembrane potential and can be opened by depolarization.

Back 29

activation gate

Front 30

When the inactivation gate remains closed, the channel cannot be reopened by depolarization.

Back 30

inactivated state

Front 31

A rapid rise in the membrane potential.

Back 31

upstroke

Front 32

In the PNS, the glial cells responsible for myelinating CNS
neurons.

Back 32

Schwann cells

Front 33

Sites in a myelinated axon in which the sheath is interrupted at regular intervals, leaving the axonal membrane bare.

Back 33

nodes of Ranvier

Front 34

Encloses each axon.

Back 34

endoneurium

Front 35

A wrapping that separates fascicles from one another.

Back 35

perineurium

Front 36

The points of close contact between axon terminals and the target cells.

Back 36

synapses

Front 37

The process of sending information across synapses.

Back 37

synaptic transmission

Front 38

The most common form of synapse in which the axon terminal releases a specific neurotransmitter chemical that acts on the plasma membrane of the target cell, either to excite or to inhibit electrical activity in the recipient cell.

Back 38

chemical synapse

Front 39

A small, membrane-bound vesicles that stores neurotransmitter chemicals in the axon terminal.

Back 39

synaptic vesicles

Front 40

In a synaptic transmission, the recipient cell.

Back 40

postsynaptic

Front 41

A narrow space that separates the presynaptic cell and the postsynaptic cell.

Back 41

synaptic cleft

Front 42

Caused by the binding of transmitter to its receptor initiates a
permeability change in the postsynaptic cell.

Back 42

postsynaptic potential
(PSP)

Front 43

Postsynaptic potentials that increase the likelihood that the
postsynaptic cell will initiate an action potential at the axon
hillock.

Back 43

excitatory postsynaptic potential
(EPSP)

Front 44

Postsynaptic potentials that tend to decrease the likelihood that the postsynaptic cell will initiate an action potential at the axon hillock.

Back 44

hyperpolarizing inhibitory postsynaptic potential
(IPSP)

Front 45

Several action potentials that arrive one after the other at the same synapse.

Back 45

temporal summation

Front 46

Multiple synapses located on the same postsynaptic cell.

Back 46

spatial summation

Front 47

An enzyme that packages for reuse or breaks down any given molecule of recovered norepinephrine.

Back 47

monoamine oxidase

Front 48

Continual use of a particular pathway may result in depletion of the stores of transmitter, decreasing the efficacy of the synapses.

Back 48

synaptic fatigue

Front 49

One type of neurotransmitter receptor that is also an ion
channel. Binding of the transmitter to the ionotropic receptor
opens the channel, resulting directly in a permeability
change.

Back 49

ionotropic receptors

Front 50

A receptor that is coupled to intracellular second messengers
by way of G proteins and may be coupled to different second
messenger systems in different cell types.

Back 50

metabotropic receptor

Front 51

Rapid, automatic motor responses to stimuli

Back 51

Reflexes

Front 52

The organization of neurons and effectors, which is the simplest way of organizing the nervous system to achieve an appropriate response.

Back 52

reflex arc

Front 53

A reflex arc consists, at a minimum, of the following elements

Back 53

A sensory receptor
An integrating center
A motor neuron
An effector

Front 54

The only type of human reflex that is monosynaptic

Back 54

stretch reflex

Front 55

The reflex arc includes one or more interneurons. The withdrawal reflex is a commonly experienced polysynaptic spinal reflex that results in a generalized flexion of an
appendage in response to an aversive stimulus.

Back 55

polysynaptic withdrawal reflex

Front 56

Originates in early development and is formed from a dorsal infolding of ectoderm, the outermost of the three embryonic cell layers.

Back 56

neural tube

Front 57

The prosencephalon (forebrain), mesencephalon (midbrain),
and rhombencephalon (hindbrain) make up ?

Back 57

primary brain vesicles

Front 58

In the forebrain, the cerebral cortex and basal nuclei.

Back 58

telencephalon

Front 59

A division of the prosencephalon vesicle, containing the
thalamus and hypothalamus regions.

Back 59

diencephalon

Front 60

The cerebellum and pons portion of brain stem.

Back 60

metencephalon

Front 61

The medulla oblongata portion of brain stem.

Back 61

myelencephalon

Front 62

The central matter of the spinal cord and much of the cortex.

Back 62

gray matter

Front 63

Forming the outer layer of the spinal cord; also the location of the cerebral basal nuclei.

Back 63

white matter

Front 64

The bulk of gray matter in the brain.

Back 64

cortex

Front 65

he paired, C-shaped ventricles within the cerebral hemispheres.

Back 65

lateral ventricles T

Front 66

Located in the center of the diencephalon.

Back 66

third ventricle

Front 67

The hindbrain, connected to the third ventricle by the cerebral aqueduct.

Back 67

fourth ventricle

Front 68

Connects the third and fourth ventricle, running through the midbrain, dividing it into a dorsal tectum and paired ventral cerebral peduncles.

Back 68

cerebral aqueduct

Front 69

The three membranes of connective tissue that surround the whole CNS. The outermost membrane is the tough dura mater. Just deep to the dura mater is the arachnoid mater, and inside that the pia mater.

Back 69

meninges

Front 70

A membrane attached to the roofs of the four ventricles that secretes CSF.

Back 70

choroid plexus

Front 71

Fingerlike projections of the arachnoid that act as valves projecting through the dura into the dural blood sinuses.

Back 71

arachnoid villi

Front 72

Separates the cerebral hemispheres from the cerebellum.

Back 72

transverse fissure

Front 73

Separates the cerebrum into right and left hemispheres.

Back 73

longitudinal fissure

Front 74

Shallow grooves created by folding of the cortex as it grows.

Back 74

sulci (sulcus)

Front 75

Ridges that are created by folding of the cortex as it grows.

Back 75

gyri (gyrus)

Front 76

The primary motor areas of the cortex.

Back 76

precentral gyrus

Front 77

The primary somatosensory areas of the cortex.

Back 77

postcentral gyrus

Front 78

Located in the temporal lobe.

Back 78

primary auditory area

Front 79

Fiber tracts that connect corresponding parts of the right and
left halves of the CNS.

Back 79

commissures

Front 80

Smaller and less important fiber tracts that connect corresponding parts of the right and left halves of the CNS.

Back 80

anterior commissure

Front 81

Both sensory and motor pathways cross from one side of the CNS to the other before they enter or leave the brain.

Back 81

decussate

Front 82

The map-like organization of the brain.

Back 82

somatotopy

Front 83

A map of the cortex representing the body surface

Back 83

homunculus

Front 84

In the cerebral cortex, responsible for forming a unified picture of the sensory world, associating key elements of it with the resources of past experience, and formulating
complex behaviors.

Back 84

association areas

Front 85

Lies rostral to the motor areas of the precentral gyrus, and is
important for activities that involve reasoning, complex learning abilities, long-term planning, and judgment and is also involved in mood, emotions, and social behavior.

Back 85

prefrontal cortex

Front 86

Large parts of the temporal, parietal, and occipital lobes that
appear to be critical for integrating multiple modes of sensory information into a comprehensive understanding of a situation.

Back 86

general association area

Front 87

A critical area located in only one hemisphere.

Back 87

cortical dominance

Front 88

Now called basal nuclei, these are islands of neuronal cell bodies in the cerebral white matter.

Back 88

basal ganglia

Front 89

Islands of neuronal cell bodies in the cerebral white matter that are involved in the control of movement.

Back 89

caudate nucleus

Front 90

The principal diencephalic structures are the _____ , _______ and _______.

Back 90

thalamus, hypothalamus, and epithalamus

Front 91

Relay information from the somatosensory, visual, auditory,
olfactory, and gustatory sensory systems to the primary processing areas in the cortex.

Back 91

thalamocortical fiber tracts

Front 92

An extremely important element of the endocrine system, projects inferiorly from the hypothalamus

Back 92

pituitary gland,

Front 93

Forms the supralateral walls of the third ventricle

Back 93

The thalamus

Front 94

Forms the inferolateral walls of the third ventricle.

Back 94

The hypothalamus (“beneath the thalamus”)

Front 95

The most dorsal part of the diencephalon, forming the roof of the third ventricle

Back 95

The epithalamus

Front 96

From rostral to caudal, the three brain stem regions are the _______,_______ and _________.

Back 96

midbrain, pons, and medulla oblongata

Front 97

Contains olfactory fibers; no efferents

Back 97

Olfactory Nerve I

Front 98

Contains retinal afferents; no efferents

Back 98

Optic Nerve II

Front 99

Contains efferents that innervate four of the six extrinsic eye muscles and parasympathetic fibers that innervate the iris of the eye

Back 99

Oculomotor Nerve III

Front 100

Innervates the superior oblique muscle of the eye

Back 100

Trochlear Nerve IV

Front 101

Contains afferents from the face and innervates masticatory (chewing) muscles

Back 101

Trigeminal Nerve V

Front 102

Innervates the muscle that abducts the eye

Back 102

Abducens Nerve VI

Front 103

Innervates facial muscles; provides parasympathetic innervation to tear and salivary glands; carries gustatory afferents from the anterior tongue

Back 103

Facial Nerve VII

Front 104

Carries afferents from the cochlea (auditory system) and vestibular system (balance and equilibrium)

Back 104

Vestibulocochlear (auditory) Nerve VIII

Front 105

Mixed nerve that serves part of the tongue and throat; carries gustatory afferents from posterior tongue and afferents from the carotid body and carotid sinus that convey information about blood pressure and blood oxygenation; innervates parotid salivary gland

Back 105

Glossopharyngeal Nerve IX

Front 106

The only cranial nerve to extend beyond the head/neck; innervates larynx and contains afferents and parasympathetic efferents from/to thoracic and abdominal viscera

Back 106

Vagus Nerve X

Front 107

Formed by fusion of a cranial and a spinal nerve root; cranial part innervates larynx, pharynx, and soft palate; spinal part innervates trapezius and sternocleidomastoidal muscles of neck and shoulder

Back 107

Accessory Nerve XI

Front 108

Mainly innervates the muscles of the tongue

Back 108

Hypoglossal Nerve XII

Front 109

Coordinates and smooth body movements, particularly rapid
ones.

Back 109

cerebellum

Front 110

Embedded within the cerebellum’s core of white matter.

Back 110

deep cerebellar nuclei

Front 111

The reflex arc does not include brain neurons and is typically limited to one or a few adjacent spinal segments.

Back 111

spinal reflexes

Front 112

Each spinal segment has a pair that project from the posterolateral surface on each side.

Back 112

dorsal roots

Front 113

Each spinal segment has a pair that project from the anterolateral surface.

Back 113

ventral roots

Front 114

Contains the cell bodies of somatic sensory afferents.

Back 114

dorsal root ganglion

Front 115

The major nerves of the spine; there are thirty-one pairs of spinal nerves.

Back 115

spinal nerve

Front 116

A spinal nerve branch.

Back 116

dorsal ramus

Front 117

A spinal nerve branch.

Back 117

ventral ramus

Front 118

In all, there are ______ pairs of spinal nerves

Back 118

thirty-one
eight cervical
twelve thoracic
five lumbar
five sacral
one coccygeal

Front 119

The first neuron of the autonomic pathways; its cell body is
in the CNS, and its axon projecting to a peripheral autonomic ganglion.

Back 119

preganglionic neuron

Front 120

The second neuron of the autonomic pathways; In the
peripheral ganglion, the neuron on which the preganglionic cell’s axon synapses and then projects to an effector in a visceral organ.

Back 120

postganglionic neuron