Brian and his cranial nerves Flashcards
1
Q
What makes up the brainstem?
A
medulla oblongata, pons, and midbrain
2
Q
What makes up the diencephalon?
A
thalamus, hypothalamus, and epithalamus
3
Q
What is the largest part of the brain?
A
cerebrum
4
Q
What is the difference between the cranial and spinal meninges?
A
pia mater of the cranial meninges has to layers: the periosteal and meningeal
5
Q
What is the main source of blood to the brain and how does it leave the brain?
A
internal carotid and vertebral arteries and the dural venous sinuses drain into the internal jugular veins to return the to heart
6
Q
How much of the bodies oxygen and glucose does the brain consume?
A
20%
7
Q
How many minutes without blood flow causes permanent injury?
A
4 mins
8
Q
Blood-brain barrier
A
consists mainly of tight junctions that seal together the endothelial cells of brain blood capillaries and a thick basement membrane that surrounds the capillaries
9
Q
What substances pass the BBB?
A
lipid soluble substances (O2, CO2), steroid hormones, alcohol, barbiturates, nicotine, and caffeine; and water molecules
10
Q
CSF
A
consists mostly of water, small amounts of gluose, proteins lactic acid, urea, cations and anions; carries same to/from neurons and neuroglia
11
Q
Gracile and cuneate nuclei
A
nuclei in the medulla associated with sensations of tough, pressure, vibration, and conscious proprioception
12
Q
What ascending sensory axons synapse with the cuneate and gracile nuclei
A
12
Q
What ascending sensory axons synapse with the cuneate and gracile nuclei?
A
gracile and cuneate fasciculus
13
Q
Medial lemniscus
A
band of white matter in the medulla that ascends to the thalamus; relays sensory info from the cuneate and gracile nulcei
14
Q
Posterior column-medial lemniscus pathway
A
tracts of the posterior columns and the axons of the medial lemniscus
15
Q
Gustatory necleus
A
nucleus in the medulla that receive input from the taste buds
16
Q
Cochlear nuclei
A
in the medulla, receive auditory input from the inner ear
17
Q
Vestibular nuclei
A
in the medulla, receive sensory input from the inner about equilibrium and proprioception
18
Q
5 Cranial nerves that contain nuclei in the medulla
A
vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal
19
Q
Pons
A
a bridge that connects parts of the brain with one another
20
Q
Pontine nuclei
A
large synaptic relay station in the pons consisting of scattered gray centers
21
Q
Pontine respiratory group
A
together with the medullary respiratory center helps regulate breathing
22
Q
4 Cranial nerves with nuclei in the pons
A
trigeminal, abducens, facial, vestibulocochlear
23
Q
Cerebral peduncles
A
paired bundles of axons in the midbrain; consist of axons of the corticospinal, coticobulbar, and corticopontine tracts
24
Tectum
posterior part of the midbrain; contains superior and inferior colliculi
25
Superior colliculi
nuclei in the midbrain that serve as reflex centers fro certain visual activities
26
Inferior colliculi
nuclei in the midbrain that relay impulses from the receptors for hearing in the inner ear to the brain, also startle reflex
27
Substantia nigra
nuclei in the midbrain that contain neurons that release dopamine into the basal nuclei
28
Red nuclei
in the midbrain, where axons from the cerebellum and cerebral cortex form synapses
29
2 Cranial nerves with nuclei in the midbrain
oculomotor, trochlear
30
Reticular formation
broad region where white matter and gray matter exhibit a netlike arrangement; contain neurons with both sensory and motor functions
31
Reticular activation system
consists of sensory axons that project to the cerebral cortex; functions in consciousness, arousal, attention, muscle tone, and prevents sensory overload
32
Transverse fissure
separates the cerebellum from the cerebrum
33
Tentorium cerebelli
supports the posterior part of the cerebrum
34
Vermis
central constricted area of the cerebellum
35
Cerebellar hemispheres
lateral wings or lobes of the cerebellum
36
Which lobes of the cerebellum govern subconsious aspects of skeletal muscle movement?
anterior and posterior lobes
37
Cerebellar cortex
superficial layer of the cerebellum; consists of gray matter in a series of slender, parallel folds (folia)
38
Folia
series of slender, parallel folds of gray matter in the cerebellar cortex
39
Arbor vitae
tracts of white matter in the cerebellum that resemble branches of a tree
40
Cerebellar nuclei
regions of gray matter that give rise to axons carrying impulses from the cerebellum to other brain centers
41
Cerebellar peduncles
bundles of white matter that attach the cerebellum to the brainstem
42
Superior cerebellar peduncles
contain axons that extend from the cerebellum to the red nuclei of the midbrain and to several nuclei in the thalamus
43
Middle cerebellar peduncles
axons that carry impulses for voluntary movements from the pontine nuclei into the cerebellum
44
Inferior cerebellar peduncles
consist of (1) axons of the spinocerebellar tracts that carry sensory info into the cerebellum from the proprioceptors in the trunk and limbs; (2) axons from the vestibular apparatus of the inner ear and from the vestibular nuclei of the medulla and pons that carry sensory info into the cerebellum from the proprioceptors in the head; (3) axons from the inferior olivary nucleus of the medulla that enters the cerebellum and regulates the activity of cerebellar neurons; (4) axons that extend from the cerebellum to the vestibular nuclei fo the medulla and pons; and (5) axons that extend from the cerebellum to the reticular formation
45
What is the primary function of the cerebellum?
evaluate how well movements initiated by motor areas in the cerebrum are actually being carried out; help correct errors, smooth movements, and coordinate complex muscle contractions
46
What does the thalamus consist of?
paired oval masses of gray matter organized into nuclei with interspersed tracts of white matter
47
Interthalamic adhesion
joins the right and left halves of the thalamus
48
Internal medullary lamina
divides the gray matter of the right and left sides of the thalamus
49
Internal capsule
a thick band of white matter lateral to the thalamus that axons that connect the thalamus and cerebral cortex pass through
50
How does the thalamus contribute to motor functions?
transmits info from the cerebellum and basal nuclei to the primary motor area of the cerebral cortex
51
What are the 7 major groups of nuclei on each side of the thalamus?
anterior nucleus, medial nuclei, lateral group, ventral group, intralaminar nuclei, midline nucleus, and reticular nucleus
52
Anterior nucleus
in thalamus; receives input from the hypothalamus and sends output to the limbic system; functions in emotions and memory
53
Medial nuclei
in thalamus; receives input from the limbic system and basal nuclei and send output to the cerebral cortex; functions in emotions, learning, memory, and cognition
54
Lateral group
in thalamus; receive input from the limbic system, superior colliculi, and cerebral cortex, and sends output to the cerebral cortex; functions in expression of emotions
55
Ventral group
in thalamus; receives input from basal nuclei and cerebellum and sends output to motor areas of cerebral cortex; functions in movement control, and relays impulses for somatic sensations and visual and auditory impulses
56
Intralaminar nuclei
make connections with the reticular formation, cerebellum, basal nuclei, and wide areas of the cerebral cortex; function in arousal and integration of sensory and motor info
57
Midline nucleus
presumed function in memory and olfaction
58
Reticular nucleus
monitors, filters, and integrates activities of other thalamic nuclei
59
4 Major regions of hypothalamus
mammillary, tuberal, supraoptic, and preoptic
60
Mammillary region
in hypothalamus; contain mammillary bodies that act as relay stations for reflexes related to sense of smell and posterior hypothalamic nuclei
61
Tuberal region
in hypothalamus; contains infundibulum which connects the pituitary gland to the hypothalamus and the median eminence (encircle infundibulum)
62
Preoptic region
in hypothalamus; regulates certain autonomic activities
63
Which region of the brain contain receptors that monitor osmotic pressure, blood glucose levels, and temperature of blood?
hypothalamus
64
5 Important functions of the hypothalamus
control of ANS, production of hormones, regulation of emotional and behavioural patters, regulation of eating and drinking, control of body temp, and regulation of circadian rhythms
65
Which two hormones are produced in the hypothalamus?
oxytocin and antidiuretic hormone
66
What makes up the epithalamus?
pineal gland and habenular nuclei
67
Habenular nuclei
in the epithalamus; involved in olfaction, especially emotional responses to odors
68
Circumventricular organs
lie in the wall of the 3rd ventricle; can monitor chemical changes in the blood because they lack a BBB; coordinate homeostatic activities of the endocrine and nervous systems
69
What is the cerebral cortex?
a region of gray matter that forms the outer rim of the cerebrum
70
What are the folds on the cerebral cortex called?
gyri or convolutions
71
What are the shallower grooves between folds called?
sulci
72
Longitudinal fissure
separates the cerebrum into right and left hemispheres
73
Corpus collosum
broad band of white matter that connects cerebral hemispheres; formed by 3 groups of commissural tracts
74
Central sulcus
separates the frontal lobe from the parietal lobe
75
What does the the precentral gyrus contain?
primary motor area of the cerebral cortex
76
What does the postcentral gyrus contain?
primary somatosensory are of the cerebral cortex
77
Lateral cerebral sulcus
separates the frontal lobe from the temporal lobe
78
Parieto-occipital sulcus
separates the parietal lobe from the occipital lobe
79
Where does the insula lie?
within the lateral cerebral sulcus, deep to the parietal, frontal and temporal lobes
80
3 Tracts in cerebral white matter
association, commissural, and projection tracts
81
Association tracts
contain axons that conduct nerve impulses between gyri in the same hemisphere
82
Commissural tracts
contain axons that conduct nerve impulses from gyri in one cerebral hemisphere to corresponding gyri in the other cerebral hemispheres
83
Projection tracts
contain axons that conduct nerve impulses from the cerebrum to lower parts of the CNS or from lower parts of the CNS to the cerebrum
84
Internal capsule
a projection tract in the cerebrum that contains both ascending and descending axons
85
What 3 nuclei make up the basal nuclei?
globus pallidus, putamen, and caudate nucleus
86
Lentiform nucleus
the globus pallidus and putamen
87
Corpus striatum
the lentiform and caudate nuclei
88
Claustrum
thin sheet of gray matter in the cerebrum that may be involved in visual attention
89
Where do the basal nuclei receive input from and send output to?
receive input from the cerebral cortex and provide output to motor parts of the cortex via the medial and ventral group nuclei of the thalamus
90
Functions of the basal nuclei
help regulate initiation and termination of movemnts, control subconsious contractions of skeletal muscles, and help initiate and terminate some cognitive processes, attention, memory, and planning
91
Limbic lobe
a rim of cerebral cortex on the medial surface of each hemisphere
92
8 Main components of the limbic system
limbic lobe, dentate gyrus, amygdala, septal nuclei, mammillary bodies, 2 nuclei of the thalamus (anterior and medial), olfactory bulbs, and 5 named tracts
93
List the 5 tracts of the limbic system
fornix, stria terminalis, stria medullaris, medial forebrain bundle, and mammillothalamic tract
94
Roles of the limbic system
range of emotions (pain, pleasure, docility, affection, anger), olfaction, and memory
95
Which CNS structure is capable of mitosis?
hippocampus
96
List 5 important sensory areas
primary somatosensory, primary visual, and primary auditory, primary gustatory, and primary olfactory area
97
Where is the primary somatosensory area located?
each parietal lobe
98
Primary somatosensory area
receives nerve impulses for touch, pressure, vibration, itch, tickle, temp, pain, and proprioception and is involved in the perception of these somatic sensations
99
Where is the primary visual area located?
occipital lobe
100
Where is the primary auditory area located?
temporal lobe
101
Where is the primary gustatory area located?
insula
102
Where is the primary olfactory area located?
temporal lobe
103
List the 2 most important motor areas
primary motor and Broca's speech area
104
Where is the primary motor area located?
frontal lobe
105
Where is Broca's speech area located?
frontal lobe
106
Where does the Broca's area send its output?
the premotor regions that control the muscles of the larynx, pharynx, and mouth and also to the primary motor area to control breathing muscles while speaking
107
List the 10 association areas
somatosensory association, visual association, facial recognition, auditory association, orbitofrontal cortex, Wernicke's, common integrative, prefrontal cortex, premotor, and frontal eye field
108
Visual association area
occipital lobe, receives impulses from the primary visual area and the thalamus; essential for recognizing and evaluating what is seen
109
Facial recognition area
temporal lobe, receives impulses from the visual association area; stores info about faces (recognition)
110
Auditory association area
temporal lobe, allows you to recognize sound as speech, music, or noise
111
Orbitofrontal cortex
frontal lobe, receives sensory impulses from the primary olfactory area; allows you to identify odors
112
Wernicke's area
temporal and parietal lobes, interprets the meaning of speech by recognizing spoken words
113
Common integrative area
receives impulses from these areas and from the somatosensory, visual, and auditory association areas and from the primary gustatory, primary olfactory, thalamus, and parts of the brainstem; formation of thoughts based on a variety of sensory inputs
114
Prefrontal cortex
frontal lobe; connects with other areas of the cerebral cortex, thalamus, hypothalamus, limbic system, and cerebellum; concerned with the makeup of a person's personality, intellect, complex learning abilities, recall info, initiative, judgement, foresight, reasoning, conscience, intuition, mood, planning for the future, and development of abstract ideas
115
Premotor area
communicates with the primary motor cortex, the sensory association areas in the parietal lobe, the basal nuclei, and the thalamus; deals with learned motor activities of a complex and sequential nature
116
Frontal eye field area
frontal cortex, controls voluntary scanning movements of the eye
117
Alpha waves
rhythmic; occur when individuals are awake and disappear during sleep
118
Beta waves
appear when the nervous system is active- during periods of sensory input and mental activity
119
Theta waves
occur during emotional stress
120
Delta waves
occur during deep sleep in adults and awake infants
121
What are the special sensory nerves?
cranial nerves I, II, and VIII; carry axons of sensory neurons, unique to the head
122
What are the motor nerves?
cranial nerves III, IV, VI, XI, and XII; contain only axons of motor neurons as they leave the brainstem
123
2 Types of motor axons that innervate skeletal muscles
brachial and somatic motor axons
124
What are the mixed nerves?
cranial nerves V, VII, IX, and X; contain both sensory and motor axons
125
Olfactory bulbs
ends of olfactory nerves formed of masses of gray matter where the axon terminals of olfactory receptors form synapses with the dendrites and cells bodies of the next neurons in the olfactory pathway
126
Optic chiasm
merging of the 2 optic nerves
127
Axons of all ganglion cells in the retina join to form the ____ ____
optic nerve
128
Which cranial nerves control the muscles that move the eyeball?
oculomotor (III), trochlear (IV), and abducens (VI)
129
What does the oculomotor nerve innervate and where does its nucleus arise?
movements of the eyeball and upper eyelid, accommodation, and constriction
midbrain
130
What does the trochlear nerve innervate?
extrinsic eyeball muscle that controls movement of the eyeball
131
Which is the smallest cranial nerve and the only one that arises in the brainstem?
trochlear (IV)
132
What does the abducens nerve do and where does its nucleus arise?
causes abduction (lateral rotation) of the eyeball
pons
133
Trigeminal (semilunar) ganglion
swelling of the large sensory root that contains cell bodies of most of the primary sensory neurons
134
Where does the trigeminal nerve arise?
pons
135
What are the 3 branches of the trigeminal nerve?
ophthalmic, maxillary, and mandibular nerve
136
What does the ophthalmic nerve innervate?
skin over upper eyelid, cornea, lacrimal glands, upper part of the nasal cavity, side of the nose, forehead, and anterior half of the scalp
137
What does the maxillary nerve innervate?
mucosa of the nose, palate, part of the pharynx, upper teeth, upper lip, and lower eyelid
138
What does the mandibular nerve innervate?
anterior two-thirds of the tongue (not taste), cheek and mucosa deep to it, lower teeth, skin over the mandible and side of the head anterior to the ear, and mucosa of the floor of the mouth
139
What do the brachial motor neurons of the trigeminal nerve control?
chewing movements
140
Where does the facial (VII) nerve arise from?
pons
141
Geniculate ganglion
a cluster of cell bodies of sensory neurons of the facial nerve within the temporal bone
142
What do the sensory axons of the facial nerve innervate?
skin in the ear canal (touch, pain, thermal), anterior two-thirds of the tongue, proprioceptors from the muscles of the face and scalp
143
What do the brachial motor neurons of the facial nerve innervate?
middle ear, facial, scalp and neck muscles-- facial expressions; nasal glands, palatine glands, and saliva-producing glands
144
Axons of the parasympathetic motor neurons run in branches of the facial nerve and end in what 2 ganglia?
pterygopalatine and submandibular ganglion
145
2 Branches of the vestibulocochlear nerve
vestibular and cochlear
146
Where are the cell bodies of the vestibular branch located?
vestibular ganglia
147
Where are the cell bodies of the cochlear branch sensory neurons located?
spiral ganglion
148
Where do vestibular nuclei and cochlear nuclei in the brain?
vestibular-pons and cerebellum
cochlear-medulla oblongata
149
What do the motor fibers of the vestibulocochlear nerve innervate?
hair cells in the inner ear
150
5 Places axons of the sensory axons of the glossopharyngeal nerve arise from
(1) taste buds in the posterior one-third of the tongue; (2) proprioceptors from some swallowing muscles supplied by the motor portion; (3) baroreceptors in the carotid sinus; (4) chemoreceptors in the carotid bodies; (5) external ear to convey touch, pain, and thermal
151
Where are the cell bodies of the glossopharyngeal located?
superior and inferior ganglia
152
Where does the glossopharyngeal nerve end in the brain?
medulla
153
What does the brachial motor neuron branch of the glossopharyngeal nerve do?
swallowing, secrete saliva
154
Cell bodies of parasympathetic motor neurons of the glossopharyngeal branch are located in the ___ ____
otic ganglion
155
Where do the sensory axons in the vagus nerve arise from?
the skin of the external ear for touch, pain, and thermal sensations; a few taste buds in the epiglottis and pharynx; proprioceptors in muscles of the neck and throat; baroreceptors in the carotid sinus and chemoreceptors in the carotid and aortic bodies
156
Where does sensory info from the vagus nerve go in the brain?
medulla and pons
157
Where does the brachial motor neurons nuclei arise from in the brain and what do they supply?
medulla oblongota; muscles of the pharynx, larynx, and soft palate that are used for swallowing, vocalizing, and coughing
158
What do the axons of parasympathetic motor neurons in the vagus nerve supply?
lungs, heart, glands of GI, and smooth muscle of respiratory passageways, esophagus, stomach, gallbladder, SI, and most of LI
159
Where does the accessory nerves motor axons arise from?
anterior gray horn of the first 5 segments of the cervical portion of the SC
160
What does the accessory nerve do?
coordinate head movements
161
What does the hypoglossal (XII) nerve do?
supply the muscles of the tongue; speech and swallowing
