chapter 14- brain & cranial nerves Flashcards
1
Q
the cerebrum is the largest part of the human brain & easily identifiable by the elevated ridges called what & the depression called sulci?
A
gyri (plural) or gyrus (singular)
2
Q
at the base of the longitudinal fissure is the what which contains axons that pass between the two cerebral hemispheres?
A
corpus callosum
3
Q
the central sulcus is the division line between the frontal lobe & the what lobe?
A
parietal
4
Q
what is the fifth cerebral lobe which is located at the base of the lateral sulcus?
A
insula
5
Q
the left & right hemispheres of the cerebellum are connected by a ridge of material called the what?
A
vermis
6
Q
the three regions of the what are the epithalamus, thalamus & hypothalamus?
A
diencephalon
7
Q
what contains CSF, is located between the pons & cerebellum and connects to the central canal of the spinal cord?
A
fourth ventricle
8
Q
what is a fold of dura mater that is located in the longitudinal fissure to prevent lateral movements of the brain?
A
falx cerebri
9
Q
what is the innermost cranial meninge that is shrink-wrapped to the surface of the brain and held in place by astrocytes?
A
pia mater
10
Q
cerebrospinal fluid is produced by the what?
A
choroid plexus
11
Q
what describes the fact that capillaries of the CNS are less permeable than capillaries elsewhere in the body & the movement of most substances to and from the blood is controlled by astrocytes?
A
blood-brain barrier
12
Q
the part of the brain that is connected to the spinal cord is the what?
A
medulla oblongata
13
Q
what kind of info. does the solitary nucleus integrate & relay?
A
visceral sensory info.
14
Q
in what part of the brainstem are the apneustic & pneumotaxic centers located?
A
pons
15
Q
what nuclei of cranial nerves are located in the mesencephalon?
A
III & IV (3 & 4)
16
Q
what is the reticular activating system important for?
A
maintaining consciousness
17
Q
the what is the part of the diencephalon that has the pineal gland & choroid plexus?
A
epithalamus
18
Q
the what is the part of the diencephalon that makes up the walls of the third ventricle?
A
thalamus
19
Q
what are the parts of the hypothalamus that control feeding reflexes?
A
mammillary bodies
20
Q
disruption to the major function of the cerebellum is called what?
A
ataxia
21
Q
in the limbic system, what is important for fear response initiating fight or flight behavior?
A
amygdala
22
Q
the what of the cerebrum is responsible for prediction, estimation & related emotions?
A
prefrontal cortex
23
Q
in which lobes of the cerebrum are visual info. processed?
A
occipital
24
Q
what is the fatal genetic disorder where the brain fails to develop above the mesencephalon?
A
anencephaly
25
brain & cranial nerves:
-spinal cord -> reflex = immediate response
-brain -> thinking = adaptable but slower
26
cerebrum structure:
-largest part of human brain
-2 cerebral hemispheres covered in cerebral
(neural) cortex
-surface convoluted to increase surface area
for neurons (~3ft 2 )
-longitudinal fissure separates left and right
hemispheres
-hemispheres divided into five lobes each
27
gyri
elevated ridges of cerebrum
28
sulci
depression in cerebrum
29
fissures
big sulci
30
corpus callosum
make up the base of fissure, axons to connect neurons of hemispheres
31
central sulcus
divides frontal lobes from
parietal lobes
32
lateral sulcus
divides frontal lobes from
temporal lobes
33
parieto-occipital sulcus
divides parietal lobes
from occipital lobes
34
insula
located at base of lateral sulcus beneath frontal and temporal lobes
35
cerebellum structure:
-second largest part
-consists of right and left hemispheres connected by the vermis
-covered in cerebellar cortex
-folia instead of gyri
-each hemisphere divided into anterior and posterior lobes by the primary fissure
36
diencephalon
-links cerebral hemispheres to brain stem
-3 parts: epithalamus, thalamus, hypothalamus
37
brainstem
-connects to spinal cord
-consists of mesencephalon, pons & medulla oblongata
38
ventricles
holes in brain that circulate CSF
39
lateral ventricle
in each cerebral hemisphere & circulates CSF
40
third ventricle
in diencephalon & circulates CSF
41
fourth ventricle
-in between pons & cerebellum
-connects to central canal of spinal cord
42
cranial bones (protection of the brain)
-form the skull
-occipital, frontal, sphenoid, ethmoid, parietals, temporals
43
cranial meninges (protection of the brain)
-hold brain in place
-prevent contact with skull
-three layers
44
dura mater of cranial meninges
-two layers
-no epidural space: fused to periosteum
-forms dural folds deep into fissures
45
falx cerebri (dura mater of cranial meninge)
between cerebral hemispheres in longitudinal fissure
46
tentorium cerebelli (dura mater of cranial meninge)
between cerebrum
& cerebellum
47
falx cerebelli (dura mater of cranial meninge)
between cerebellar
hemispheres
48
arachnoid of cranial meninges
1. arachnoid membrane
2. arachnoid trabeculae: span subarachnoid space which contains CSF
49
pia mater of cranial meninges
-adheres to brain via astrocytes
-follows topology of gyri and sulci
50
cerebrospinal fluid (CSF)(protection of the brain)
-functions: cushion brain, support brain & diffusion medium
-produced by choroid plexus (= ependymal cells plus capillaries in brain ventricles)
-volume of CSF in brain & cord turned over every 8hrs
-choroid plexus secretes ~500ml/day
-CSF reabsorbed at arachnoid granulations
51
hydrocephalus
(infants) failure to reabsorb
CSF, fluid expands cranium & crushes brain
52
blood-brain barrier (protection of the brain)
-capillaries of CNS less permeable:
-endothelial cells linked by tight junctions
-astrocytes cover capillary surface
-only lipid-soluble compounds diffuse into
CNS, all others actively transported by astrocytes
-inflammation (infection, cancer) can break
down blood-brain barrier
53
brain stem structure
-connects brain & spinal cord
-consists of three parts: medulla oblongata, pons & mesencephalon
54
medulla oblongata
connects the top of spinal cord, serves as a relay center for sensory information, controls many autonomic reflexes & many visceral functions
55
white matter of the medulla oblongata
ascending & descending tracts, link brain to spinal cord
56
gray matter of medulla oblongata: group 1 nuclei
sensory & motor nuclei of cranial nerves VIII-XIII (8-12)
-motor: to muscles of pharynx, neck, visceral organs of thoracic & peritoneal cavities
-sensory: from inner ear (hearing, balance)
57
gray matter of medulla oblongata: group 2 nuclei
autonomic nuclei controlling visceral activities (autonomic reflex center)
58
cardiovascular center of medulla oblongata (gray matter group 2 nuclei)
cardiac center: adjusts heart rate & strength of contraction
59
vasomotor center of medulla oblongata (gray matter group 2 nuclei)
adjusts blood flow through tissues
60
respiratory rhythmicity centers of medulla oblongata (gray matter group 2 nuclei)
sets pace of respiration
61
nucleus gracilis & nucleus cuneatus of medulla oblongata (gray matter group 3 nuclei)
transmit somatic sensory (skin, proprioception) info to thalamus (filter & relay center)
62
gray matter of medulla oblongata: group 3 nuclei
relay stations along sensory & motor pathways
63
olivary nuclei of medulla oblongata (gray matter group 3 nuclei)
transmit sensory info about muscle stretch & joints & info about somatic motor commands from cerebral motor centers to cerebellum (coordination)
64
solitary nucleus of medulla oblongata (gray matter group 3 nuclei)
integrates & relays visceral sensory info to autonomic centers in medulla & other brain areas
65
pons
-means "bridge"
-connects cerebellum & the rest of brain, connects higher & lower brain centers
66
white matter of pons
-conduction pathway between high & lower brain centers
67
ascending tracts of the pons (white matter)
sensory from medulla (nucleus cuneatus & nucleus gracilis) to thalamis
68
descending tracts of the pons (white matter)
motor from cerebrum or cerebellum to cranial or spinal nerves
69
gray matter of the pons
-relay centers for info to (sensory) & from (motor) cerebellum
-sensory & motor nuclei of cranial nerves V-VII (5-7), innervate jaw muscles, anterior surface of face, mouth
70
apneustic & pneumotaxic centers of the pons (gray matter)
nuclei to control rate & depth of respiration, act to modify activity of respiratory rhythmicity center in medulla
71
midbrain/mesencephalon
processes visual & auditory input, generates somatic motor reflexes, maintains consciousness
72
white matter of mesencephalon/midbrain
cerebral peduncles, conduction between higher & lower brain center
73
ascending tracts of mesencephalon/midbrain (white matter)
sensory to thalamus
74
descending tracts of mesencephalon/midbrain (white matter)
voluntary somatic motor to cerebellum (via pons) & spinal cord
75
superior colliculi of mesencephalon/midbrain (gray matter)
integrate visual info, initiate reflex response to visual stimuli
76
inferior colliculi of mesencephalon/midbrain (gray matter)
integrate auditory info, intimate reflex response to auditory stimuli
77
red nuclei & substantia nigra of mesencephalon/midbrain (gray matter)
house subconscious somatic motor centers to affect upper limb position & control background muscle tone
78
reticular formation of mesencephalon/midbrain (gray matter)
contains reticular activating system (RAS) headquarters to trigger alertness & attentiveness to maintain consciousness
79
gray matter of mesencephalon/midbrain
houses motor nuclei for cranial nerves III & IV (3-4), eye movements
80
diencephalon
functions in integration of conscoius & subsonscious sensory info & motor commands: consists of epithalamus, thalamus & hypothalamus
81
pineal gland (in epithalamus -> diencephalon)
produces melatonin; regulates day-night cycel & reproductive function
82
choroid plexus (top of third ventricle) (in epithalamus -> diencephalon)
CSF production
83
thalamus
-process, relay & filter sensory info
-some memory processing
-houses some parts of limbic system (emotion, motivation, memory)
84
thalamic nuclei of thalamus
-relay sensory info to appropriate cerebral cortex for interpretation
-relay motor info from cerebellum & basal nuclei to somatic motor areas of cerebral cortex
-connect emotion centers in hypothalamus with frontal cortex of cerebrum for awareness of emotional states
85
hypothalamus
-control autonomic functions, control hormone release from pituitary, produce emotions/drives
-control subconscious somatic motor to face: facial expressions with emotions
86
autonomic centers in hypothalamus
-control autonomic nuclei in medulla & pons: heart rate, blood pressure, respiration, digestive activity
-coordinate voluntary & autonomic functions
87
tuberal nuclei of hypothalamus
releases hormones that control pituitary gland (coordinates activities of nervous & endocrine systems)
88
supraoptic nucleus of hypothalamus
produces antidiuretic hormone (ADH): promotes water retention
89
paraventricular nucleus of hypothalmus
produce oxytocin: controls smooth muscle or labor & delivery, sperm emission
90
mammillary bodies of hypothalmus
control feeding reflexes
91
preoptic areas of hyopthalmus
regulate body temp., triggers reflexes in other brain areas to retain or shed heat
92
suprachiasmatic nuclei of hypothalamus
circadian rhythms (day-night cycles, 24-hour clock)
93
cerebellum function:
maintain balance & equilibrium through motor centers in brainstem, refines learned movement patterns
94
arbor vitae of cerebellum (white matter)
connects cortex & nuclei to peduncles
95
superior peduncles of cerebellum (white matter)
link cerebellum to midbrain, diencephalon & cerebrum
96
middle peduncle of cerebellum (white matter)
link cerebellum to pons
97
inferior peduncle of cerebellum (white matter)
link cerebellum to medulla oblongata & spinal cord
98
gray matter of the cerebellum
-cerebellar cortex consisting of Purkinje cells
-cerebellar nuclei
-both function provide involuntary coordination of ongoing body movements & monitor all proprioceptive, visual, tactile, balance & auditory sensations
99
cerebellar cortex (Purkinje cells) & cerebellar nuclei (gray matter of cerebellum)
1. adjust the postural muscles of body: coordinate rapid autonomic adjustments that maintain balance & equilibrium
2. program & fine tune movements controlled at conscious & subconscious levels
100
what do cerebellar cortex (Purkinje cells) & cerebellar nuclei (gray matter of cerebellum) refine?
-learned movement patterns: regulate activity along motor pathways at cerebral cortex, basal nuclei & motor centers in brainstem
-compare motor commands with sensory input & perform adjustments to make movements smooth
101
ataxia
loss of balance due to disruption in cerebellum (e.g. alcohol)
102
limbic system
-functional not anatomical separation
-located between cerebrum and diencephalon: parts of both
103
functions of the limbic system:
-establishes emotional states & drives
-links conscious functions of cerebrum to autonomic functions of brainstem
-facilitates memory storage and retrieval
104
amygdala (special region of limbic system)
fight or flight, initiates fear
response, links emotion with memory
105
hippocampus (special region of limbic system)
memory & learning
106
cingulate gyrus (special region of limbic system)
expressing emotions via
gestures, & resolves mental conflicts
107
cerebrum function:
localizes & interprets sensory info, controls voluntary & skilled skeletal muscle activity, performs intellectual & emotional processing
108
association fibers of cerebrum (white matter)
connect neural cortex within same hemisphere
109
commissural (crossover) fibers of cerebrum (white matter)
connect cortex between hemispheres (most in corpus callosum)
110
projection fibers of cerebum (white matter)
pass through diencephalon to lower brain centers or cord
111
basal nuclei of cerebrum (gray matter)
-at bottom
-subconscious somatic motor: control muscle tone & learned movement patterns
112
cerebral cortex (gray matter of cerebrum)
-superficial part
-primary motor cortex: somatic motor: voluntary control of skeletal muscles (in frontal lobe = precentral sulcus)
-primary somatosensory cortex: somatic sensory: conscious perception of somatic sensory info (in parietal lobes = post central sulcus)
113
visual cortex of cerebral cortex (gray matter of cerebrum)
sight (in posterior/back of occipital lobe)
114
auditory cortex of cerebral cortex (gray matter of cerebrum)
hearing (in temporal lobe)
115
olfactory cortex of cerebral cortex (gray matter of cerebrum)
smell (medial inside of temporal lobes)
116
gustatory cortex of cerebral cortex (gray matter of cerebrum)
taste (in insula)
117
association areas of cerebral cortex (gray matter of cerebrum)
integrate sensory & motor info
118
integrative centers of cerebral cortex (gray matter of cerebrum)
direct complex motor or analytical functions, collect input from association areas & initiate responses
119
Wernicke’s area (integrative center of cerebrum)
-general interpretive area
-center of left hemisphere
-gives meaning to auditory or visual cues
120
Broca’s area (integrative center of cerebrum)
-speech center
-left hemisphere superior to lateral sulcus
-coordinates motor controls for speech
121
Prefrontal cortex (integrative center of cerebrum)
-anterior frontal lobes
-prediction, estimation, and related emotions
*removal results in no remorse, what right or wrong
122
association and integration areas all over cortex carries out all levels of thought but
in general:
-left hemisphere & right hemisphere
-each hemisphere sends info to the opposite side of the body but each also has unique functions
-hemispheres communicate for whole thought
-if corpus callosum is cut, hemispheres work independently (used as treatment for seizures)
123
epileptic seizures
abnormal electrical activity
in the brain; causes loss of normal function
124
anencephaly
brain fails to develop above
mesencephalon, fatal
125
cerebrovascular accident (CVA)
“stroke”, loss of blood supply to the brain, neuron death occurs in minutes
