Nervous System Flashcards
1
Q
_____is an extensive, intricate network of neural structures that activates, coordinates, and controls all functions of the body
A
The nervous system
2
Q
The nervous system is an extensive, intricate network of neural structures that activates, coordinates, and controls all functions of the body, including:
A
• Muscle contraction
• Joint movements
• Stimulates glands to secrete
• Regulates the systems of the body (vascular system, digestive system, etc.)
• Allows sensation to be perceived
3
Q
What are the two main divisions of the nervous system?
A
• Central nervous system: Brain and spinal cord
• Peripheral nervous system: All of the nervous tissue outside of the brain and spinal cord
4
Q
The functional cellular component of the nervous system
A
Neuron
5
Q
Neurons are composed of what three parts?
A
• Neural cell body
• Two types of cytoplasmic processes: Axon and Dendrite
6
Q
___provides metabolic support for the entire neuron
A
Neural body
7
Q
___transmits electrical impulses away from the cell body to other neurons or target tissues
A
Axon
8
Q
____acts as the primary receiver of signals from other neurons
A
Dendrite
9
Q
Long, thin, singular cable-like process
A
Axon
10
Q
The axon is encased in
A
its own membrane and can also be additionally covered by a myelin sheath
11
Q
What is a Myelin sheath?
A
• A fatty, insulating layer that wraps around the axons of nerve cells
• Acts like a protective coating
• Allows electrical impulses to travel quickly and efficiently along the nerve fiber
12
Q
Threadlike process surrounding the cell body
A
Dendrite
13
Q
Dendrites usually contains multiple_____
A
branches
14
Q
Functions to receive impulses and conduct those impulses towards the cell body
A
Dendrites
15
Q
Bundles or tracts of nerve fibers within the nerve
A
Fascicles
16
Q
Bundle of neural processes outside the central nervous system and in the peripheral nervous system
A
Nerves
17
Q
Nerves allow information to be
A
carried to and from the brain
18
Q
Junction between two neurons that allows a signal to pass between them
A
Synapse
19
Q
Two main types of synapses:
A
• Chemical
• Electrical
20
Q
In order to function, tissues, structures and organs require ____
A
Innervation
21
Q
Innervation
A
a supply of nerves to the body part
22
Q
An accumulation of neuron cell bodies located in the peripheral nervous system
A
Ganglion
23
Q
An appendage to a peripheral nerve where neuronal cell bodies are found outside the
CNS
A
ganglion
24
Q
Ganglion are associated with ____nerves
A
all sensory and autonomic
25
Preganglionic fibers
the autonomic neuronal fibers that enter a ganglion
26
Postganglionic fibers
the autonomic neuronal fibers that leave the ganglion after synapsing with preganglionic fibers
27
Two types of nerves:
• Afferent nerves
• Efferent nerves
28
Afferent nerves
• Sensory nerves
• Carries information away from the periphery of the body, to the brain or spinal cord
• Touch, taste, pain, proprioception
29
Efferent nerves
• Motor nerves
• Carries information away from the brain or spinal cord, to the periphery of the body
• Activates muscles
• One motor neuron with its branching processes) may control hundreds of muscle fibers
30
The body is________, with positively and negatively charged ions floating around
electrically neutral
31
Some areas of the body have more positive ions, while other areas have more negative ions. Our body has barriers to keep the positive and negative ions separate until we are ready to use them
This barrier is the_____
neural membrane
32
Fluid outside the neural membrane has a___ charge
positive
33
Fluid inside the membrane has a____ charge
negative
34
The difference between the + and - charge is called
resting potential
35
Nerves work by____
depolarizing at the cell membrane to transmit impulses
36
Nerves work by depolarizing at the cell membrane to transmit impulses. This nerve impulse is called_____
action potential
37
Action potential spreads to____
adjacent areas, which sends the impulses
38
To send impulses across synapses, we need____
neurotransmitters (chemical agents)
39
Example of neurotransmitters
norepinephrine, acetylcholine, dopamine
40
The CNS has what two main divisions?
• Brain
• Spinal cord
41
The CNS is surrounded by
bone (skull or vertebrae), and a layering of membranes
42
The CNS is surrounded by bone (skull or vertebrae), and a layering of membranes. What is the purpose of this?
to protect the CNS
43
The membranes of the CNS are called
Meninges
44
What are the three layers of meninges?
• Dura mater: Also surrounds and supports the venous channels; Carry blood from the brain to the heart - these channels are the dural sinuses
• Arachnoid mater
• Pia mater
45
Also surrounds and supports the venous channels; Carry blood from the brain to the heart - these channels are the dural sinuses
Dura mater
46
Four major divisions of the brain:
• Cerebrum
• Cerebellum
• Brain stem
• Diencephalon
47
• Largest division of the brain
Cerebrum
48
The cerebrum consists of how many hemispheres?
Consists of two cerebral hemispheres
49
Function of the cerebrum
• Produces muscle coordination
• Maintains normal muscle tone and posture
• Coordinates balance
50
Second largest division of the brain
Cerebellum
51
Function of cerebellum
• Coordinates sensory data and motor functions
• Governs aspects of intelligence and reasoning, learning, and memory
52
What are the divisions of the brain stem?
Divisions include medulla, pons, and midbrain
53
Function of the medulla
Regulates heartbeat, breathing, vasoconstriction (blood pressure)
Houses reflex centers for vomiting, coughing, sneezing, swallowing, and hiccuping
Houses the cell bodies of the motor neurons for the tongue
54
The pons houses
the cell bodies for cranial nerves V and VII
55
The midbrain houses
relay stations for hearing, vision, and motor pathways
56
What is the function of the midbrain?
Regulates pain and mood
57
The Diencephalon primarily includes the
thalamus and hypothalamus
58
The thalamus is the
central relay point for incoming nerve impulses
59
The hypothalamus regulates____
homeostasis
60
What is homeostasis?
state of balance among all the body systems needed for the body to survive and function correctly
61
Runs along the dorsal side of the body; links the brain to the rest of the body
Spinal cord
62
The spinal cord is encased in
a series of bony vertebrae that comprise the vertebral column
63
Spinal column consists of what two components of brain substance?
• Gray matter - consists of unmelinized cell bodies and dendrites
• White matter - made up of bundles of myelinated axons
64
The spinal cord is responsible for______. It is also involved in___
carrying messages to and from the brain; reflexes that do not immediately involve the brain (responses that are automatic responses to stimuli
65
____is composed of all the nerves and nerve pathways in the body
PNS
66
PNS is composed of all the nerves and nerve pathways in the body, including:
• Pathways among the CNS
• Receptors
• Muscles
• Glands
67
PNS is further divided into what two systems?
• Sensory Nervous System or Afferent nervous system
• Motor Nervous System or Efferent nervous system
68
The Motor Nervous System of the PNS is subdivided into
somatic and autonomic nervous systems
69
The sensory Nervous System of the PNS processes input from the
environment
70
What input from the environment does the sensory nervous system of the PNS process?
• Sight
• Smell
• Taste
• Touch
• Hearing
71
Sensory nerves transmit information to the central nervous system (CNS) through the
peripheral nerves
72
This nervous system controls unconscious processes in the body
Autonomic nervous system
73
What are some unconscious processes that the autonomic nervous system controls?
• Breathing
• Digestion
• Heart rate
74
Contains sensory neurons that monitor the internal environment and make changes to maintain homeostasis
Autonomic nervous system
75
• The autonomic nervous system has both ____
motor pathways and sensory neurons
76
The autonomic system has what two divisions?
the sympathetic and parasympathetic nervous systems
77
Responsible for the "fight or flight" response, which is activated when the body is under stress or in danger
Sympathetic nervous system
78
Responsible for "rest and digest" mode, which is activated when the body is relaxed and not in danger
Parasympathetic nervous system
79
The cranial nerves are part of the ____nervous system.
Peripheral
80
There are ___paired cranial nerves
12
81
The 12 paired cranial nerves are all connected to the brain at its
base
82
The cranial nerves pass through the skull by way of___
fissures or foramina
83
The cranial nerves serve to innervate
structures in the head or neck
84
the tenth cranial or vagus nerve also descends into the
thorax chest) and abdomen where it innervates internal organs
85
Cranial nerves are either______
afferent or efferent (some are both)
86
Cranial nerves are numbered according to their
location in the brain (Anterior to posterior)
87
The cranial nerves are numbered by
Roman numerals (I to XII)
88
What is cranial nerve I?
Olfactory nerve
89
The olfactory nerve is an___ nerve
afferent
90
This cranial nerve transmits smell
Cranial nerve I or olfactory nerve
91
"Olfaction"
smell
92
The olfactory nerve enters the skull through
perforations in the cribriform plate of the ethmoid bone
93
The olfactory nerve terminates at the
olfactory bulb
94
What is cranial nerve II?
Optic nerve
95
The cranial nerve II an efferent or afferent nerve?
Afferent
96
The optic nerve or cranial nerve II enters skull through
optic canal of the sphenoid bone
97
In the skull, both right and left optic nerves join at the___
optic chasm
98
Fibers of the optic nerve___ before continuing into the brain
cross
99
What is cranial nerve III?
Oculomotor Nerve
100
The Oculomotor Nerve is an efferent or afferent nerve?
Efferent nerve
101
The oculomotor nerve is responsible for
eye movement and pupillary constriction
102
The oculomotor nerve or cranial nerve III is located in the
lateral wall of the cavernous sinus
103
The oculomotor nerve or cranial nerve III exits the skull through the
superior orbital fissure of the sphenoid bone
104
What is Cranial Nerve IV?
Trochlear Nerve
105
What type of nerve is the trochlear nerve?
Efferent nerve
106
The trochlear nerve is responsible for
eye movement and proprioception
107
What is Proprioception?
the body's ability to sense movement, action, and location
108
The trochlear nerve is located
in the lateral wall of the cavernous sinus
109
The trochlear nerve exits the skull through the
superior orbital fissure of the sphenoid bone
110
What is cranial nerve V?
Trigeminal nerve
111
Is the trigeminal nerve an afferent or efferent nerve?
Both
112
Efferent fibers of the trigeminal nerve controls
the muscles of mastication and some cranial muscles
113
The Afferent fibers of the trigeminal nerve innervates
the teeth, tongue, oral cavity, and skin of
the face and head
114
Largest cranial nerve
Cranial nerve V or trigeminal nerve
115
The trigeminal nerve has what two roots?
Sensory and motor roots
116
The sensory root of the trigeminal nerve has what three divisions?
• Ophthalmic nerve (first division)
• Maxillary nerve (second division)
• Mandibular nerve (third division)
117
The Ophthalmic nerve (first division, V1) of the trigeminal nerve passes through the
superior orbital fissure
118
The Ophthalmic nerve (first division, V1) of the trigeminal nerve carries sensory fibers to:
• the eyeball, conjunctiva, lacrimal glands
• skin of the forehead, eyelid, and nose, and part of the nasal mucosa
119
The Maxillary nerve second division, V2) of the trigeminal nerve Passes through the
foramen rotundum
120
The Maxillary nerve second division, V2) of the trigeminal nerve carries sensory fibers to:
the middle third of the face
121
The Mandibular nerve (third division, V3) of the trigeminal nerve passes through the
foramen ovale
122
The motor root of trigeminal nerve travels with____
Mandibular nerve (third division, V3) of the sensory root of the trigeminal nerve
123
The Mandibular nerve (third division, V3) of the trigeminal nerve Provides sensory information from the
lower face, including the jaw, tongue, mouth floor, and cutaneous tissues between the lower lip and base of the mandible
124
The motor root of the trigeminal nerve supplies motor innervation to the
muscles of mastication and other muscles in the floor of the mouth
125
What is cranial nerve VI?
Abducens Nerve
126
The abducens nerve is a afferent or efferent nerve?
Efferent nerve
127
The abducens nerve or cranial nerve VI is responsible for
Eye movement
128
The abducens nerve or cranial nerve VI controls one muscle of the eye called the
Lateral rectus muscle
129
The abducens nerve or cranial nerve VI exits the skull through the
superior orbital fissure of the sphenoid bone
130
What is cranial nerve VII?
Facial nerve
131
Is the facial nerve an efferent or afferent nerve?
Both
132
The Efferent fibers of the facial nerve or cranial nerve VII controls the
muscles of facial expression and posterior supra hyoid muscles
133
The efferent portion of the facial nerve or cranial nerve VII also provides parasympathetic innervation to the
lacrimal gland, submandibular salivary gland, and sublingual salivary gland
134
The afferent portion of the facial nerve or cranial nerve VII serves
a tiny patch of skin behind the ear, and taste sensation with the taste buds of certain lingual papillae from the anterior two-thirds of the tongue
135
The facial nerve efferent fibers of the cranial nerve VII leaves the cranial cavity by passing through the _____and exits the skull through the____
internal acoustic meatus; stylomastoid foramen
136
The facial nerve Branches into what three segments?
• Facial nerve (Main trunk)
• Chorda tympani
• Greater petrosal nerve
137
What is Cranial Nerve VIlI?
Vestibulocochlear Nerve
138
The Vestibulocochlear Nerve or cranial nerve VIII is an afferent or efferent nerve?
Afferent
139
The vestibulocochlear nerve conveys signals from the
inner ear to the brain
140
The vestibulocochlear nerve functions in ___
Hearing and balance
141
Where is the Inner ear located?
in the temporal bone
142
Cranial nerve VIII or the vestibulocochlear nerve enters the cranial cavity through the
internal acoustic meatus
143
What is Cranial Nerve IX?
Glossopharyngeal Nerve
144
Is the glossopharyngeal nerve an afferent or efferent nerve?
Both
145
The efferent portion of cranial nerve IX or the glossopharyngeal nerve controls the
pharyngeal muscle and the stylopharyngeus muscle
146
The efferent portion of cranial nerve IX or the glossopharyngeal nerve controls the pharyngeal muscle and the stylopharyngeus muscle. It also provides parasympathetic innervation to the______
parotid salivary gland
147
The Afferent portion of the glossopharyngeal nerve innervates the____ and allows for____
oropharynx; taste and general sensation from the base of the tongue
148
_____is the afferent limb of the gag reflex
CN IX
149
Responsible for carrying sensory information about blood pressure to the brain along with the vagus nerve (X)
Afferent portion of the glossopharyngeal nerve or cranial nerve IX
150
Cranial nerve IX or the glossopharyngeal nerve passes through the skull at the
jugular foramen
151
CN IX has several branches, including:
• Tympanic branch
• Stylopharyngeal branch
• Tonsillar branch
• Lingual branch
• Carotid branch
• Pharyngeal branch
152
The Tympanic branch of CN IX supplies the
middle ear
153
The Tympanic branch of CN IX leaves the skull through the
foramen ovale of the sphenoid bone as the lesser petrosal nerve
154
Stylopharyngeal branch of the CN IX control the
stylopharyngeus muscle, which aids in swallowing and speaking
155
Tonsillar branch of the CN IX forms the
tonsillar plexus, which innervates the palatine tonsils
156
The Lingual branch of CN IX provides
general and taste sensation to the posterior third of the tongue
157
The Lingual branch of CN IX provides
general and taste sensation to the posterior third of the tongue
158
The Carotid branch of the CN IX innervates the
carotid artery
159
The Pharyngeal branch of CN IX combines with the vagus nerve (X) to form the
pharyngeal plexus, which innervates the mucosa of the oropharynx
160
What is cranial nerve X?
The vagus nerve
161
Is the vagus nerve or cranial nerve X an Efferent or afferent nerve?
Both
162
The large efferent component of the vagus nerve or cranial nerve X controls the
Muscles of the soft palate, pharynx, and larynx
163
The large efferent component of the vagus nerve or the cranial nerve X controls the muscles of the soft palate, pharynx, and larynx. It also provides parasympathetic innervation to
many organs in the thorax and abdomen (including the thymus gland, heart, and stomach)
164
The Afferent portion of the vagus nerve innervates
a small amount of skin around the ear, and provides taste sensation for the epiglottis
165
The three cranial nerves that carry taste information are
VII (facial), IX (glossopharyngeal), and X (vagus)
166
• Responsible for carrying sensory information about blood pressure to the brain along with the glossopharyngeal nerve (X)
Vagus nerve or cranial nerve X
167
Cranial nerve X or the vagus nerve passes through the skull at the
jugular foramen
168
What is cranial nerve XI?
The accessory nerve
169
Is the cranial nerve XI an efferent or afferent nerve?
Efferent nerve
170
Innervates the trapezius and sternocleidomastoid muscles
Cranial nerve XI
171
The accessory nerve or cranial nerve XI assists the vagus nerve (X) in
innervating the muscles of the soft palate and pharynx
172
The accessory nerve or cranial nerve XI assists the vagus nerve (X) exits the skull through the____
jugular foramen
173
What is Cranial Nerve XII?
Hypoglossal Nerve
174
is Cranial Nerve XII or the hypoglossal nerve an afferent or efferent nerve?
• Efferent nerve
175
The Cranial Nerve XII or the hypoglossal nerve innervates the
intrinsic and extrinsic muscles of the tongue
176
The Cranial Nerve XII or the hypoglossal nerve exits the skull through the
hypoglossal canal in the occipital bone
