chapter 14: cranial nerves Flashcards
1
Q
what are the main parts of the brain and what do they consist of
A
- Brainstem ◦ Medulla oblongata, pons, and
midbrain - Diencephalon ◦ Thalamus, hypothalamus,
epithalamus - Cerebrum
- Cerebellum
2
Q
what are is the brain protected by and how does they spinal meninges differ from the cranial meninges
A
- Cranial bones
- Cranial meninges
- dura, arachnoid, and pia maters.
▪ Unlike the spinal dura mater, the cranial
dura mater has 2 layers – periosteal layer
(external) and meningeal layer (internal)
▪ Two layers are fused together except
where they separate to enclose venous
sinuses (drain blood and CSF)
▪ No epidural space around brain
3
Q
what are the 3 dura mater extentions
A
◦ Falx cerebri – separates the cerebrum
hemispheres. It attaches to the crista
galli of the ethmoid bone
◦ Falx cerebelli – separates the
cerebellum hemispheres
◦ Tentorium cerebelli – separates the
cerebrum from cerebellum
4
Q
why are oxygen and glucose so important for the brain
A
20% of oxygen & glucose in blood gets used by brain
Good supply of O2
and glucose is vital to brain function
◦ no glucose stores in brain
◦ low level of O2 or glucose in blood leads to confusion,
dizziness, unconsciousness
◦ 1–2-minute interruption leads to impaired function
◦ > 4 minutes = permanent damage
brief slowing can cause disorientation or lack of consciousness
5
Q
which ways does blood in the brain flow. what makes blood flow increase
A
lood flow to brain:
◦ Internal carotid and vertebral arteries
Blood flow away from brain to heart:
◦ Dural venous sinuses drain into internal
jugular veins
When activity of neurons and neuroglia
increases in a region of the brain → flow to
that area also increases
6
Q
what does the blood brain barrier do and what are the 3 things that form the blood brain barrier
A
Protects brain cells from harmful substances
by preventing substances from blood entering
brain tissue
Three things form the BBB:
1. Tight junctions seal endothelial cells of
brain capillaries
2. A thick basement membrane surrounds
endothelial cells
3. Astrocytes press up against capillaries –
secrete substances that selectively
allow/inhibit substances to pass from
blood to neurons
7
Q
what substances can and can not cross the blood brain barrier
A
Lipid-soluble substances cross easily (i.e. oxygen,
carbon dioxide, alcohol, nicotine, caffeine, and
most anesthetic agents)
Water-soluble substances may be transported
(i.e. glucose)
Other substances are transported across very
slowly (i.e. most ions)
Big molecules (antibiotic drugs, proteins) do not
enter at all
8
Q
what is cerebrospinal fluid and what is it’s function in the brain
A
Clear liquid containing glucose & O2
and other chemicals essential to neurons
and neuroglia
Functions
◦ mechanical protection
◦ softens contact/impact with skull, and makes brain float (reducing weight)
◦ chemical protection
◦ regulation of pH and other ions concentration
◦ circulation
◦ Clearance of waste products into the bloodstream
9
Q
where is CSF contained in the brain
A
2 lateral ventricles (one of each cerebral hemisphere)
interventricular forman, third ventricle alond midline between right and left halves of thalamus
cerebral aqueduct and fourth ventricle between brainstem and cerebellum
10
Q
what is the choroid plexus
A
a network of capillaries in walls of ventricles covered by ependymal cells
ependymal cells make the CFS by filtration of blood plasma
Ependymal cells are joined by
tight junctions, so substances
from blood MUST go through
cells before they enter the
brain ventricles
11
Q
describe circulation of CFS
A
- flows from lateral ventricles to 3rd ventricle via interventricular foramina
- next through cerebral aqueduct to 4th ventricle (through midbrain)
- then into subarachnoid space through median and 2 lateral apertures in 4th ventrcile
- into the central canal of the spinal cord and subarachnoid space of the cord and brain (purple arrows)
12
Q
hydrocephalus
A
when CSF production exceeds reabsorption
◦ accumulation of fluid in brain (swelling)
◦ in newborn or fetus, fontanels allow expansion of skull
◦ implantation of shunt can redirect CFS to veins
◦ in adults, skull can’t expand so swelling can lead to rapid death
13
Q
Cerebral spinal fluid is produced in which
structure(s)?
a) Choroid plexuses
b) Cerebral aqueduct
c) Arachnoid villi
d) Median aperture
e) All the above
A
a) choroid plexus
14
Q
Which of the following statements is true about the
blood-brain barrier and blood-CSF barrier?
a) Both involve astrocytes
b) Both involve tight junctions
c) Both involve ependymal cells
d) A and B
e) B and C
A
b) both invlove tight junctions
15
Q
what is the brainstem and what are the 3 sections
A
The brainstem is the part of the brain between the diencephalon and the spinal
cord
3 sections:
◦ Medulla oblongata
◦ Pons
◦ Midbrain
16
Q
describe the medulla oblongata of the brain stem
A
A continuation of spinal cord containing:
◦ Ascending sensory tracts
◦ Descending motor tracts
◦ Nuclei
◦ Integrating centers
◦ Send information in and out of cerebellum
17
Q
describe the white matter of the medulla
A
composed of ascending sensory tracts and motor descending tracts
the anterior portion of the medulla bulges out; theses are called the pyramids and are composed of motor tracts
about 90% of pyramidal tracts on left cross to right, and vice versa; called decussation (meaning crossing)
18
Q
what does the decussation of pyramids cause
A
due to the decussation of pyramids, the left side of the brain controls the right side of the body and vice versa
19
Q
The term “decussation” means?
a) To split in half
b) Control of movement
c) A form of sensory input
d) Crossing of axons
e) Leaping of axons
A
d) crossing of axons
20
Q
A common site of decussation for motor tracts is
a) In the pyramids of the medulla
b) In the anterior area of the medulla
c) In the pons
d) In the midbrain
e) a and b
A
e
21
Q
describe the grey matter of the medulla
A
the medulla contains many nuclei that act as integration centers or relay centers
22
Q
what are inferior olivary nucleus and where are the found
A
lateral to each pyramid is an oval-shaped swelling called an olive
◦ Contains inferior olivary nucleus
◦ Receives input from cerebral
cortex, midbrain and spinal cord
◦ Sends input to cerebellum
→Controls proprioceptive signals
→Gives precision to movements
23
Q
what do the nuclei of the medulla do and what do the other nuclei of the medulla do?
A
Control many vital body functions
◦ Cardiovascular center
-Controls force and rate of heartbeat, diameter of blood vessels
◦ Respiratory center
◦ Sets basic rhythm of breathing
◦ Reflex centers for coughing, sneezing, swallowing, vomiting, hiccupping
Other nuclei of the medulla:
Gracile and cuneate nuclei: Associated with somatic sensations (touch, pressure,
vibration, conscious proprioception)
Gustatory (taste), cochlear (hearing), and vestibular (equilibrium) nuclei
Nuclei for cranial nerves (VIII-XII)
24
Q
describe the pons
A
Located superior to the medulla
Consists of both nuclei and tracts
The pons (“bridge”) connects the parts of brain with each
other via tracts
◦ Connects right and left sides of cerebellum
◦ Relays nerve impulses related to voluntary skeletal
movements from the cerebral cortex to the cerebellum
(both sensory and motor tracts)
25
what do the nuclei of the pons do
Nuclei in the Pons control aspects of breathing, sleep, swallowing, bladder
control, hearing and equilibrium, as well as taste and facial expressions.
The Pons contains nuclei for cranial nerves V-VIII
26
describe the midbrain
Extends from pons to diencephalon
Contains cerebral aqueduct, which connects 3rd ventricle above to 4th ventricle
below
Contains sensory tracts, motor tracts and nuclei (visual and auditory info)
27
describe the white matter of the midbrain
The anterior midbrain contains the cerebral peduncles. These contain tracts
of motor neurons leading to different parts of the CNS from the cerebrum;
they also contain sensory tracts leading up from medulla to thalamus
28
grey matter of the midbrain: what does the superior colliculi do?
In the posterior midbrain, the superior
colliculi (nuclei) deal with visual reflexes
* tracking
* direct movement of head, neck and eyes
in response to visual stimuli
29
gray matter of the midbrain: what does the inferior colliculi do?
the inferior colliculi (nuclei)deal with auditory reflexes
* direct movement of head, neck and eyes in response
to sudden/loud auditory stimuli (startle reflex)
30
the gray matter of the midbrain: what does the substantial nigra do?
The substantia nigra is the site
of Dopamine production
* helps control subconscious
muscle activity
* involved in rewards and
addiction
also the one that has issues when people have parkinsons
31
Grey matter of midbrain: what does the red nuclei do?
axons from the cortex and the
cerebellum synapse in the Red
nuclei to assess and coordinate
upper limb movements and
overall muscle tone
32
where are the nuclei for cranial nerves III and IV found
in the midbrain
33
Parkinson disease results from
a) a decrease in the size of the midbrain
b) a decrease in neurons from the substantia nigra
c) a decrease in the release of serotonin
d) a decrease in neurons from the pyramids
e) b and c
b)
34
b
35
Excessive hiccupping could indicate
dysfunction in which part of the brain?
a) Midbrain
b) Medulla oblongatta
c) Pons
d) RAS
e) Mesencephalon
c) pons
36
Where are the cerebral peduncles found?
a) Midbrain
b) Medulla oblongatta
c) Pons
d) RAS
e) Cerebrum
a) midbrain
37
what is the reticular formation and what does it do
The Reticular formation is a series of scattered nuclei located in the brain stem. They are
involved in:
* maintaining posture and muscle tone
* relaying pain and analgesic information
* sleep, alertness and consciousness (via the Reticular activating system - RAS)
* differentiate between meaningless stimuli (e.g., background noise) and meaningful ones
38
Which part of the brain has failed this student?
a) Midbrain
b) Medulla oblongatta
c) Pons
d) RAS
e) Mesencephalon
d) RAS
39
what does te cerebellum do
~10% of weight of
the brain, but 50%
of the neurons
* Evaluate how well movements initiated by motor
areas in the cerebrum are being carried out
* Adjusts postural muscles to maintain balance
* Programs and fine tunes both voluntary and
involuntary movements
* Stores memories of learned movements
40
what are the different parts of the cerebellum
Cerebellar hemispheres (left and right) each consist of
anterior and posterior lobes separated by fissures
Flocculonodular lobe
Cerebellar peduncles (superior, middle, inferior)
41
what does the superior part of the cerebellum do?
involved in regulating subconscious aspects of skeletal muscle movements
42
what does the cerebellar peduncles do in the cerebellum?
attach the cerebellum to the brain stem, they contain tracts that link the cerebellum to other parts of the brain
43
what does the flocculodonular lobe do in the cerebellum
involved in balance/ equilibrium
44
what can happen when the cerebellum is damaged? what can cause it?
Damage to the cerebellum can cause ataxia = loss of ability to coordinate
movements
No sense of proprioception
Uncoordinated speech muscles and abnormal walking (like a drunk person –
alcohol affects cerebellar functions)
Can also be result of side effect of certain diseases or medication
45
Which statement about the cerebellum is true?
a) The cerebellar peduncles attach it to the cerebrum
b) The cerebellar lobes are also called tentorium cerebelli
c) Its main function is to ‘fine tune’ motor function
d) Its main function is to initiate motor function
c
46
where is the diencephalon found in the brain?
- Between the top of the brain stem
and the bottom of the cerebrum
- Wraps around the third ventricle
47
describe the diencephalon/thalamus
Think structure
* the thalamus forms ~80% of the diencephalon
* it is mainly a mass of gray matter – nuclei with interspersed tracts
* two egg-shaped halves, connected by the intermediate mass,
surrounding 3rd ventricle
48
what sensory functions does the thalamus have?
The thalamus mainly acts as a relay station for sensory and motor functions:
Sensory functions:
◦ sensory info from spinal cord and brain stem goes through thalamus to
cerebral cortex
◦ pain, temperature, pressure, hearing…
◦ the thalamus acts as a filter, passing on to the cerebral cortex only a small
portion of the sensory information it receives
◦ each region of the thalamus contains nuclei that connect to specific regions of
the cerebral cortex
49
what are the motor functions of the thalamus
Motor functions:
◦ sends information from cerebellum & basal nuclei to primary motor areas of
cerebral cortex
◦ acts as relay station between parts of cerebrum
Also involved in consciousness, learning, memory, emotions, cognition (thinking
and knowing)
50
what are the function of thalamuc nuclei
Functions: emotions, alertness, memory, learning,
awareness, cognition, integration of sensory info, motor
planning, somatic sensations, vision, and auditory relay
decides if info is important to relay out or not
51
describe the hypothalamus
* the hypothalamus is located between the thalamus and the pituitary gland
* it contains about 12 nuclei –divided into four major groups
* It plays a big role in
maintaining homeostasis
52
what does the mammillary region of the hypothalamus do? and where is it found
* the mammillary region is in
the posterior part of the
hypothalamus, anterior to the
midbrain
* it is associated with olfaction,
and feeding reflexes
(swallowing, licking)
53
describe location and function of the tuberal region of the hypothalamus
* the tuberal region is just anterior
to the mammillary region
* It contains the hormonal center,
and is involved in the control of
the anterior pituitary gland
54
supraoptic region of the hypothalamus. location and function
* the supraoptic region is just anterior to the tuberal region
* Axons from these nuclei synthesize and transport antidiuretic hormone (ADH) and
oxytocin (OT) along the
hypothalamo-hypophyseal tract
to the posterior pituitary lobe
55
preoptic region of the hypothalamus location and function
the preoptic region is in the
anterior region of the
hypothalamus
* Involved in regulating
certain autonomic activities
such as body temperature
56
what are some other functions of the hypothalamus
▪Controls and integrates activities of the ANS which regulates smooth & cardiac
muscle (heart rate, GI tract, bladder) and glands
▪Regulates emotions/behavior such as rage, aggression, pain, pleasure & sexual
arousal
▪Regulates hunger and thirst
▪Helps regulate circadian rhythm (daily patterns of sleep)
57
Which of the following is NOT a function of the
hypothalamus?
a) It controls the activity of the anterior pituitary gland via different
hormones
b) It is associated with olfaction and feeding reflexes
c) Is controls hunger, thirst and feeding reflexes
d) It acts as a relay station between different parts of the cerebellum
d)
58
describe the pineal gland and habenular nuclei of the epithalamus
Pineal gland
Endocrine gland, size of small pea
Secretes melatonin during darkness
Promotes sleepiness and sets
biological clock
Habenular nuclei
Involved in olfaction, especially
emotional responses to odors
59
what are circumventricular organs and what do they do (CVOs)
Structures that lie in the wall of the third ventricle and lack a blood-brain barrier
◦ Include hypothalamus, pineal gland, pituitary gland, and a few other nearby
structures
Can monitor chemical changes in the blood
Coordinate homeostatic activities of endocrine and nervous systems
◦ Regulation of blood pressure, fluid balance, hunger, and thirst
CVOs are thought to be the sites of entry into the brain of HIV
60
Which of the following is true about the
thalamus?
a) It is the major relay center for just motor impulses
b) It is a component of the diencephalon
c) It precisely locates sensations of pain, temperature, pressure
and sound
d) A and B
a) it is the major relay center for just motor impulses
61
Are hypothalamic axons part of the nervous
system or endocrine system?
a) Nervous system
b) Endocrine system
c) Both
d) Neither
c) both
62
describe and locate major anatomical featues of the cerebrum
63
64
what are some characteristics of the cerebral hemispheres
Each hemisphere receives sensory input
and generates motor outputs to the
opposite side of the body
◦ Anatomically the same, with
functional differences
The assignment of function to a
particular region is not exact, because
lobe boundaries are indistinct.
65
what are the 3 kinds of tracts in cerebral white matter
1. association tracts run between
gyri in the same hemisphere
2. commissural tracts run from gyri
of one hemisphere to
corresponding gyri of the other
hemisphere
3. projection tracts form descending
& ascending tracts
66
what is the corpus striatum
The Corpus Striatum are involved in the execution of movements – They control
muscular movements by influencing the cerebral cortex rather than via direct
descending pathways
They communicate with the cerebral cortex (sensory area and motor area), the
thalamus and the midbrain (substantia nigra)
They help regulate the initiation and termination of movements (activity in
basal ganglia is detected prior to muscle movements)
They help control muscle tone, subconscious movements, posture (with
substantia nigra)
◦ eg swinging of arms when walking, true spontaneous laughter
66
Which of the following tracts connect different
parts of the brain within the same hemisphere?
a) Commissural tracts
b) The Corpus Callosum
c) Projection tracts
d) Association tracts
d) association tracts
67
A projection tract is one which:
a) Consists of axons that conduct nerve impulses to or from the
cerebrum
b) Consists of axons that conduct impulses between ipsilateral gyri
c) Includes the corpus callosum as an example
d) Is also known as a commissural tract
e) Conducts nerve impulses to a different area of the same
hemisphere
a
68
what is the limbic system?
The limbic system is a circle of
structures forming the floor of the
diencephalon and wrapping up
and around the corpus callosum
It is involved in the establishment
of emotional states - pain,
pleasure, docility, affection, anger…
Also involved in memory storage
and retrieval
69
Which component of the brain is referred to
as the “emotional brain,” as it plays a primary
role in a wide range of emotions?
a) basal nuclei
b) frontal lobe of the cerebrum
c) corpus callosum
d) limbic system
e) cerebral cortex
d) limbic system
70
Which statement is true?
a) the central sulcus separates the parietal lobe from the temporal
lobe
b) the postcentral gyrus contains the primary motor area
c) the insula lies within the precentral gyrus
d) the lateral cerebral sulcus separates the frontal lobe from the
temporal lobe
d) the lateral cerebral sulcus seperates the frontal lobe from the temporal lobe
71
primary somatosensory area location and function
The primary somatosensory area
is in the postcentral gyrus
(posterior to the central sulcus)
touch, pain, cold, warmth,
tickle, itch and proprioception
the main function is to
localize the origin and
intensity of the sensation
72
what happens if you get a lesion in the primary somatosensory area
A lesion causes contralateral
loss of sensations
patient can perceive the sensation
but can’t tell the degree of warmth,
or where the touch comes from, or
evaluate the weight of objects
73
describe location and function of the primary visual area
The primary visual area is
in the posterior tip of the
occipital lobe
The primary visual area
receives visual information
and is involved in visual
perception
74
what happens if u get a lesion in the primary visual area
A lesion causes complete or partial
blindness (blind spot), depending
on the size of the lesion
75
location and function of primary auditory area. what happens if get lesion there?
The primary auditory area
is in the superior portion of
the temporal lobe, near the
lateral sulcus
The primary auditory area receives
information for sound and is
involved in auditory perception
A lesion causes partial deafness,
and difficulty to locate sounds
76
describe primary gustatory area
The primary gustatory area
is in the insula
The primary gustatory area
receives information for
taste and is involved in
gustatory perception
77
describe the primary olfactory area
the primary olfactory area
receives information for
smell and is involved in
olfactory perception
The primary olfactory area
is located on the medial
side of the temporal lobe
78
The primary visual area is in which lobe of
the brain?
a) frontal
b) occipital
c) parietal
d) flocculonodular
e) posterior
b
79
what are the motor areas
The motor areas are the regions that govern muscular movement.
Two important motor areas are:
Primary motor area
Controls voluntary contractions of skeletal muscles on other side
Broca’s speech area
Production of speech
Control of tongue and airway
80
describe the location and function of the primary motor area
he primary motor area is
in the precentral gyrus,
directly anterior to the
central sulcus
The primary motor area is
divided into regions controlling
voluntary contractions of
skeletal muscles
81
what happens if you get a lesion in the primary motor area
results in contralateral paralysis (like stroke)
82
describe Broca's speech area
Broca’s speech area is in the
frontal lobe, close to lateral
sulcus. It is in the left hemisphere
in 97% of people
Broca’s speech area is
involved in the planning
and production of speech
- motor signals to muscles
in larynx, pharynx, mouth
and breathing muscles
83
what happens if you get a stroke in Broca's speech area
A stroke in Broca’s speech area causes loss of
speech → patient knows what he wants to say
but can’t produce the words. Reading, writing,
understanding are normal
84
what are association areas
The association areas are concerned with complex integrative functions such as
memory, emotions, reasoning, will, judgment, personality traits, and intelligence.
Different association areas are connected to each other by association tracts
Nerve impulses are transmitted from primary areas to association areas
85
what are the somatosensory association area
the somatosensory
association area is located
directly posterior to the
primary somatosensory area
It receives information from
the primary somatosensory
area (as well as other parts
of the brain)
The main function is to put together and interpret
sensory data. Storage of past sensory experiences
86
what does somatosesory area allow us to do and what happens if u get a lesion there
- Can tell just by touch the
shape, size and texture of
an object, and can recognize
that object (stereognosis).
- Can tell where one part of
body is relative to another
A lesion causes astereognosis: can’t
recognize an object if eyes are closed
87
describe the visual association area. what happens if you get lesion there
receives data from the primary
visual area and the thalamus
The visual association area is
in the occipital lobe, next to
the primary visual area
- Compares past and
present visual experiences
- Allows recognition
A lesion causes an inability to recognize
objects, even though you can see them
88
describe facial recognition area
allows for the
recognition of faces
The facial recognition area
is in the inferior part of the
temporal lobe
89
describe the auditory association area and what happens if there is a lesion
located inferior and posterior to the primary auditory area
receives data from the primary auditory area, interprets sounds (talking, music, noise)
a lesion causes an inability to interpret sounds
90
describe the orbitofrontal cortex
receives data from the primary olfactory areas
is involved in identifying odors and discriminating among different odors
the orbitofrontal cortex is in the lateral part of the frontal lobe
91
describe Wernicke's Area. what happens if lesion
Wernicke’s area is in the temporal and
parietal lobes; like Broca’s area, it is in
the left hemisphere. It interprets the
meaning of speech.
A lesion causes incoherent speech
→ fluent speech, but words don’t
make sense (word salad). Patient is
not aware of it. Patient cannot
understand what other people say,
or written words
The regions in the right hemisphere that correspond to Broca’s
and Wernicke’s areas give emotional content to speech
92
a) one cannot detect any sensation
b) one can detect a sensation, but cannot make sense of the
sensation
c) a and b
a
93
describe the common integrative area
The common integrative area is
surrounded by somatosensory,
visual and auditory association areas
It gets information from the
aforementioned areas, as well as
gustatory, olfactory, thalamus,
and parts of brainstem
It puts together all sorts of information, interprets the data, and signals
different parts of the brain for appropriate actions, and forms thoughts.
94
describe the premotor area
The premotor area is located
anterior to the primary motor area
It communicates with the
p.m.a., different sensory a.a.,
basal nuclei and thalamus
It deals with learned, complex, sequential actions (e.g., writing, typing, playing
piano) → it sends signals to specific groups of muscles in specific order to produce
a sequence of contractions
95
describe the prefrontal cortex
Many connections with other areas
of the brain (cerebral cortex,
thalamus, hypothalamus, limbic
system, and cerebellum)
Personality, intellect, complex learning
abilities, information recall, initiative,
judgement, foresight, reasoning,
conscience, intuition, mood, future
planning, development of abstract ideas
96
The cerebral area indicated is:
a) Primary somatosensory area
b) Broca’s area
c) Facial recognition area
d) Primary visual area
e) Primary motor area
e) primary motor area
97
The region of the brain responsible for predicting
the consequence of events or actions is the
a) prefrontal cerebral cortex.
b) occipital association cortex.
c) reticular formation.
d) temporal lobe.
e) cerebral ganglia.
a) prefrontal cortex
98
right hemisphere vs left hemisphere. whats there
right hemisphere is visual and speech skills, left is language
99
what is Electroencephalogram (EEG) and what is it used for. what are the 4 different kinds of brain waves
Measures electrical activity = brain waves = millions of nerve action potentials in
cerebral cortex (close to surface)
An EEG may be used to diagnose a variety of nervous system disorders
There are 4 kinds of brain waves that can be recorded from normal individuals
◦ Alpha – awake & resting
◦ Beta – mental activity
◦ Theta – emotional stress
◦ Delta – deep sleep
100
The presence of which type of brain waves might
indicate a brain injury in an awake adult?
a) Alpha waves
b) Beta waves
c) Theta waves
d) Delta waves
d
101
describe the cranial nevres
12 pairs of cranial nerves (I to XII)
Part of PNS
Indicated by roman number & name
CN I, II and VIII are sensory nerves, because they contain Sensory axons
only/mostly
CN III, IV, VI, XI and XII are motor nerves, because they contain Motor axons
only/mostly
CN V, VII, IX and X are mixed nerves, because they contain Both sensory &
motor neurons
102
only need to know 12
103
describe the olfactory nerve
CNI relays odorous stimuli to the brain
The olfactory tract ends in the primary
olfactory area of the cerebral cortex
Neurons originate in the olfactory
epithelium and the bundle of axons
form the olfactory nerve
The olfactory nerve is a
sensory nerve
104
describe the optic nerve
CNII relays visual
stimuli to the brain
the optic nerves is a sensory nerve
axons end in the thalamus, and
synapse with neurons whose
axons extend to the primary
visual area in the cerebral cortex
Axons originate in the retina and
bundle up to form the optic nerve
A few axons go to the midbrain to
control eye movements
105
describe Oculomotor Nerve (CN III), Trochlear Nerve (CN IV),
Abducens Nerve (CN VI)
All three nerves are motor nerves
(mostly). All three control
movements of the eyeballs and CN
III and IV control eyelids
CN III and IV originate in the midbrain
CN VI originates in the pons
106
describve the trigeminal nerve
he sensory portion of the
trigeminal nerve is involved
in relaying touch, pain and
thermal sensations from
the face/forehead
The motor portion of
the trigeminal nerve is
involved in mastication
The cell bodies for
motor neurons
are located in the
pons
The cell bodies for
sensory neurons
are located in the
trigeminal ganglia
107
describe the facial nerve
The motor portion of the
facial nerve innervate
muscles of the face, as well
as salivary, nasal and
lacrimal glands
The sensory portion of the
facial nerve is involved in
taste (taste buds on
anterior 2/3 of tongue)
108
where are the cell bodies of the facial nerve located
The cell bodies for
motor neurons
are located in the
pons
The cell bodies for sensory
neurons are located in the
geniculate ganglia
109
describe the vestibular nerve
The cochlear branch of CN
VIII carries impulses for
hearing (synapse in medulla)
The vestibular branch of CN
VIII carries impulses for
equilibrium (synapse in pons)
mostly a sensory nerve
110
where are the cell bodies of the vestibulocochlear nerve
The cell bodies for neurons of
vestibular branch are in the
vestibular ganglia (synapse in pons)
The cell bodies for neurons of
cochlear branch are in the spiral
ganglia (inside the cochlea)
(synapse in medulla)
111
describe the CN IX – Glossopharyngeal Nerve
The sensory portion of CN IX relays
information from taste buds
(posterior 1/3 of tongue),
proprioceptors of swallowing
muscles, baroreceptors and
chemoreceptors in blood vessels
(for blood pressure and breathing)
The motor portion of CN
IX innervates swallowing
muscles, and parotid
gland for salivation
112
where are the motor neurons and cells bodies of the glossopharyngeal nerve
The motor neurons for CN IX originate
in the medulla
The cell bodies for sensory neurons of CN IX form the superior and inferior ganglia,
and synapse in the medulla
113
describe the vagus nerve
The vagus nerve is for the
sensory and motor
functions of head, neck
and thoraco-abdominal
region (heart, respiratory
tract and GI tract)
114
where is the sensory portion of the vagus nerve and what does it do
The sensory portion relays information
from baroreceptors and chemoreceptors
in aorta, proprioceptors in neck and
throat, sensory receptors in visceral
organ (medulla and pons)
115
where is the moto portion of the vagus nerve and what does it do
The motor portion innervates the pharynx,
larynx and soft palate (swallowing,
coughing, voice), and is involved in
autonomic functions of heart and lungs,
glands of GI tracts, and smooth muscles of
respiratory and digestive tracts (medulla)
116
where are the motor neurons and cells bodies of the vagus nerve
the motor neurons for
CN X originate in the
medulla oblongata
The cell bodies for sensory
neurons of CN X form the
superior and inferior ganglia, and
synapse in the medulla and pons
117
describe the CN XI – Accessory Nerve
mostly a motor nerve
the cranial portion originates from the medulla; the spinal portion originates from the spinal cord
the cranial portion innervates msucles of the throat and soft palate for swallowing
the spinal portion innervates muscles for head movements
118
describe the CN XII – Hypoglossal Nerve
mostly a motor nerve
The CN XII innervates
muscles of tongue
during speech and
swallowing
119
Which nerve controls movement of eye muscles?
a) CN III
b) CN IV
c) CN V
d) CN VI
e) More than one of the above
e 3,4 and 6
120
Which statement is true regarding cranial nerves?
a) They pass through intervertebral foramina
b) They are part of the peripheral nervous system
c) They all contain sensory and motor axons
d) They originate from the brainstem, cerebellum and cerebrum
e) They lack connective tissue coverings
b)
121
what is an accronym to remeber the 12 cranial nerves
idk google it
