CNS and Blood Supply Flashcards
1
Q
what is the brain made up of?
A
over 100 billion neurons (mostly inter-neurons = associative) and 1 trillion neuroglia
2
Q
what are the 5 vesicles of the brain?
A
- Telencephalon
- Diencephalon
- Mesencephalon (midbrain)
- Metencephalon
- Myelencephalon
3
Q
what parts of the brain are in the Telencephalon?
A
- Cerebral hemispheres
- basal ganglia
- limbic system
4
Q
what parts of the brain are in the Diencephalon?
A
- thalamus
- hypothalamus
- epithalamus
5
Q
What parts of the brain are in the Mesencephalon (midbrain)?
A
- cerebral peduncle
- corpus quadrigemina
- Superior colliculi
- inferior colliculi
- CN3 and CN4 nucleus
- Red nucleus
- Substantia nigra
6
Q
what parts of the brain are in the Metencephalon?
A
Pons
7
Q
what parts of the brain are in the Myelencephalon?
A
- Medulla oblongata
8
Q
what are the components of the brain stem?
A
- medulla oblongata
- pons
- midbrain (mesencephalon)
Mesencephalon, Metencephalon and Myelencephalon
9
Q
what does SCALP stand for?
A
skin
connective tissue
aponeurosis
lipid
periosteum
*protective coverings of the brain
10
Q
what are the protective coverings of the brain?
A
- cranial bones (skull)
- epidural space with fat
- dura mater
- subdural space w/interstitial fluid
- arachnoid mater
- subarachnoid space w/CSF
- pia mater
11
Q
name the folds of dura mater that hold the brain in place
A
- falx cerebri
- falx cerebelli
- tentorium cerebelli
12
Q
what is the falx cerebri?
A
a sagittal fold between cerebral hemispheres
13
Q
what is the falx cerebelli?
A
a sagittal fold between cerebellar hemispheres
14
Q
what is the tentorium cerebelli?
A
a transverse fold between cerebrum and cerebellum
15
Q
what are the 3 components of the blood brain barrier?
A
- tight junctions between blood vessel endothelial cells
- continuous endothelial cell basement membrane
- astrocytes wrapped around the endothelial cell basement membrane
16
Q
T/F: the BBB allows free passage of hydrophillic substance into the brain?
A
FALSE
allow free passage of lipid soluble, hydrophobic substances
17
Q
what are the components of the medulla oblongata?
A
- nerve tracts (both sensory ascending and motor descending)
- pyramids
- decussation of pyramids
- olives
- dorsal medulla
- fasciculus gracilis
- fasiculus cuneatus
- decussation of the medial lemniscus
- nuclei
- cranial nerve nuclei for CN, 8 - 12
18
Q
what is the overall function of the brain stem?
A
- contains nuclei for vital centers and cranial nerves
- signal propagation via ascending (sensory signals) and descending (motor signals) tracts
19
Q
what are the pyramids in the medulla oblongata?
A
paried ventral surface ridges that contain motor descending tracts
20
Q
what are the decussation of pyramids?
A
where motor tracts from R/L brain cross to control muscles on the opposite side
21
Q
what are the olives in the medulla oblongata?
A
paired bulges lateral to pyramids which contain the inferior olivary nuclei
these link the brain and spinal cord motor signals to the cerebellum for perception of time
22
Q
what do the fasciculus gracilis and cuneatus do?
A
relay sensory ascending input to the opposite side of the brain
23
Q
what is the decussation of the medial lemniscus?
A
crossover of ascending sensory input to the contralateral brain hemisphere
24
Q
What is contained within the Pons?
A
- cranial nerve nuclei for CN 5, 6, and 7
- ascending and descending tracts
25
what is the function of the Pons?
information relay for cerebellar hemmispheres
26
what is located in the midbrain?
1. cerebral peduncles
2. corpora quadrigemina
3. cranial nerve nuclei for CN 3, 4
4. red nucleus and substantia nigra
27
what are the cerebral peduncles?
they contain descending motor axaon tracts from cerebral hemispheres to spinal cord, medulla, and pons
and
ascending sensory axons going to the cerebrum
28
what is the corpora quadrigemina made up of?
1. superior colliculi
2. inferior colliculi
29
what does the superior colliculi control?
reflex movement of eye, head, and neck to visual and other stimuli
30
what do the inferior colliculi control?
reflex movement of head and neck to auditory stimuli
31
what is the function of the red nucleus and substantia nigra?
modify motor signals
32
what is the overall function of the midbrain?
1. relay motor impulses from cerebral cortex
2. relay sensory impulses from spinal cord to thalamus
33
what is the reticular formation?
a diffuse structure, composed of areas of gray matter interspersed among areas of white matter in central portions of the Diencephalon, brain stem, and spinal cord
34
what is the function of the reticular formation?
1. alerting cerebral cortex to sensory signals
2. reticular activating system → functions in maintaining consciousness and awakening from sleep by stimulating the cortex
3. filter sensory input to remove unimportant input (prevents sensory overload)
4. efferent motor function in maintaining muscle tone
35
what is the cerebellum (metencephalon) comprised of?
1. vermis (worm)
2. cerebellar hemispheres
3. peduncles
36
describe the cross section anatomy of the cerebellum
1. cortex = gray matter
2. folia ridges
3. arbor vitae (nerve tracts = white matter)
4. cerebellar nuclei
37
what is the function of the cerebellum?
1. smooth and coordinate (refine) cerebral control of skeletal muscle movements to facilitate complex muscle activity
2. regulate muscle tone
3. posture and balance
38
what makes up the Diencephalon?
1. thalamus
2. hypothalamus
3. epithalamus
4. subthalamus
39
describe the structure of the thalamus
composed of paired masses of mixed gray (nuclei) and white (tracts) matter that are connected by intermediate mass (crossover point)
40
what is the function of the thalamus?
1. relay sensory info to correct region of cerebral cortex
2. refine motor signals with the basal nucleus
41
describe the composition of the hypothalamus
composed of:
1. dozen nuclei
2. mammillary bodies (visible on inferior surface)
3. infundibulum (connects pituitary to the hypothalamus)
42
what is the overall function of the hypothalamus?
control of body activities to maintain homeostasis
43
T/F: the hypothalamus is a circumventricular organ?
TRUE
44
what are the specific functions of the hypothalamus?
1. control of ANS: heart, gut, bladder
2. control of endocrine system via control of the pituitary gland
3. regulates emotional behavior (part of limbic system)
4. regulates eating and drinking
5. control body temp
6. regulates circadian rhtyhms and states of consciousness
45
describe the structure of the epithalamus
composed of:
1. pineal gland
2. habenular nuclei (paired structure)
46
what is the function of the epithalamus?
more of a modulator
functions in:
1. melatonin production (at pineal gland)
2. habenular nuclei involved in the emotional response to smell
47
what is the subthalamus composed of?
1. subthalamic nuclei (paired)
2. parts of red nuclei (paired)
3. parts of substantia nigra (paired)
48
what is the function of the subthalamus?
connects to cerebellum and motor cortex for control of body movement
49
what are circumventricular organs?
areas of the brain that do not have a BBB, therefore they are able to monitor chemical changes in the blood
tend to be endocrine organs
50
where are circumventricular organs found?
1. hypothalamus
2. pineal
3. pituitary (hypophysis)
51
what region of the brain are the basal ganglia in?
Telencephalon
52
what are the basal ganglia?
consist of paired nuclei (gray matter)
function in control of skeletal muscle movement and muscle tone. Refine movement from uncoordinated jerky motion to smooth motion
53
what region of the brain is the limbic system in?
Telencephalon
Diencephalon
54
what is the limbic system comprised of?
1. paired nuclei
2. tracts
3. cortex (parts of frontal, parietal, and temporal lobes)
55
what is the function of the limbic system?
"primitive brain" function in emotion aspects of behavior and memory-pain, pleasure, affection, and anger → to determine feelings
56
What portion of the brain is the cerebrum in?
Telencephalon
57
describe the composition of the cerebrum
1. cerebral cortex (gray matter)
2. cerebral white matter
58
what is cerebral cortex (gray matter)?
10s of billions of associate (inter) neurons
typically arranged in 6 layers to allow vertical integration
59
what is cerebral white matter made of?
3 types of neurons:
1. association fibers
2. commissural fibers
3. projection fibers
60
what do association fibers in the cerebral white matter do?
connect different gyri in same hemisphere
61
what do commissural fibers in cerebral white matter do?
connect different gyri in opposite hemisphere (found in corpus collosum)
62
what do projection fibers in the cerebral white matter do?
connect the cerebrum to rest of body (sensory and motor tracts)
63
Cerebrum is the highest of the brain regions, what are it's functions?
1. conscious sensation
2. voluntary motor activity
3. higher brain functions
* cognition
* association of sensory input with memory to produce more memory
* language
* astract though
64
describe the surface anatomy of the cerebrum
1. gryi = ridges
2. sulci = shallow grooves
3. fissures = deep grooves
4. longitudinal fissures = separate R/L hemispheres
5. hemispheres = R/L side of cerebru
6. corpus callosum
7. lobes
8. central sulcus
9. precentral gyrus
10. lateral cerebral fissure (sulcus)
11. parieto-occipital sulcus)
65
what is the corpos callosum?
large collection of commissural tracts connecting R/L hemispheres
66
what is the central sulcus of the cerebrum?
separates frontal and parietal lobes
67
what is the precentral gyrus of the cerebrum?
anterior to central sulcus
voluntary (somato-) motor area
68
what is the postcentral gyrus of the cerebrum?
posterior to central sulcus
conscious (somato-) sensory area
69
what is the lateral cerebral fissure (sulcus) of the cerebrum?
separates frontal and temporal lobes
70
what is the parieto-occipital sulcus of the cerebrum?
separates parietal and occiptal lobes
71
Name the Lobes of the cerebrum
1. Frontal
2. Parietal
3. Temporal
4. Occipital
5. Insula
72
where is the frontal lobe?
anterior of central sulcus and medial to lateral sulcus
73
what are the different sections of the frontal lobe?
1. precentral gyrus
2. premotor area (supplemental motor area)
3. frontal eye field
4. Broca's area
5. prefrontal cortex
6. cingulate gyrus
74
what are the components of the precentral gyrus?
1. primary motor cortex
1. somatotopic
2. homunculus
75
what does the primary motor cortex do?
control voluntary movement on contralateral side of the body
76
what does the term somatotopic mean?
refers to specific regions of the precentral gyrus that control muscles in specific body regions
77
what is a homunculus?
it depicts somatotopic organization of precentral gyrus and relative cortical contributions to a particular body region
78
what is the premotor area (supplemental motor area) of the frontal lobe?
associative area next to precentral gyrus functions to initiate and sequence motor activity
79
what is the function of the frontal eye field of the Frontal lobe?
coordinated R and L eye movement = conjugate eye movements
80
What is Broac's area on the Frontal Lobe?
on L hemisphere only
coordinates motor speech
81
where is the prefrontal cortex?
rostral most part of the frontal lobe
primary target of lobotomy
82
significance of the prefontal cortex?
input from all regions of cortex and limbic system
output to wide variety ⇒ subcortical nuclei-thalamus, basal ganglia, brain stem
functions to regulate visceral, emotional, and cognitive processes
83
what is the cingulate gyrus of the frontal lobe?
medial surface (within longitudinal fissure) of frontal and parietal lobes
limbic cortex for emotional behavior, autonomic reponse, and learning
84
where is the Insula lobe located?
within the lateral sulcus where frontal, parietal and temporal lobes come together
85
what is the function of the Insula Lobe?
integration of sensory input for:
1. taste and olfaction
2. viscerosensation (interoreceptors)
3. pain
86
what are the sections of the Parietal Lobe?
1. post central gyrus
2. supramarginal and angular gyrus
3. Wernicke's area
4. superior parietal lobe
87
what part of the Parietal Lobe is located at the post central gyrus?
Somatosensory Cortex
primary sensory area for tactile and proprioceptive sensation → end destination for conscious somatosensory signals
88
what does the supramarginal and angular gyrus do?
receive visual and auditory input for perceptional discrimination and integration
89
where is Wernicke's area and what does it do?
located in both parietal and temporal lobes of the Left hemisphere
functions in comprehension of spoken language and works with Broca's area to formulate a verbal reponse
90
what is the superior parietal lobe?
an association area integrating sensory and motor areas to program complex motor responses
91
where is the occipital lobe of the cerebrum located?
caudal to the parietal-occipital sulcus on the medial border
92
what is located in the occipital lobe?
primary visual cortex
visual association cortex
93
name the structures at the temporal lobe
1. primary auditory cortex
2. superior temporal gyrus
3. middle temporal gyrus
4. inferior temporal gyrus
5. parahippocampal gyrus and uncus
94
where is the primary auditory cortex located?
medial aspect of superior temporal gyrus → transverse gyri Heschl
95
what is located at the superior temporal gyrus?
auditory association cortex
96
what is the function of the middle temporal gyrus?
perception and analysis of motion in the visual field
97
what is the function of the inferior temporal gyrus?
facial recognition in response to visual input
98
where is the parahippocampal gyrus and uncus and what is it's function?
located on the inferior surface of temporal lobe
function w/limbic system
99
how are hemispheres in the cerebrum divided?
separated by longitudinal fissure and connected by commissural fibers
100
what is hemispheric localization?
refers to the functional differences that exist between hemispheres = cerebral dominance
101
what is the left hemisphere primarily responsible for?
1. language interpretation and execution
2. numerical and scientific skills (abstract)
3. reasoning
102
what is the right hemisphere primarily responsible for?
1. musical, artistic
2. special pattern interpretation
3. facial recognition
4. emotional content of language
5. mental images of visual, auditory, somatic, taste, olfactory input
103
what is cerebral dominance due to?
1. unequal cortical representation of function in homologous regions of the 2 hemispheres
2. diminished commissural cross connection between the regions
* visual cortex → temporal eye field is uncrossed
* primary motor and sensory areas of distal arm and leg
104
describe the course of the internal carotid through the skull
1. external opening of carotid canal
2. carotid canal (petrous part of temporal bone)
3. internal opening of carotid canal
4. crosses over foramen lacerum
5. runs along base of sella turcica in carotid groove
6. joins the optic nerve at prechiasmatic groove
105
what are the branches of the internal carotids proximal to distal?
1. opthalmic
2. posterior communicating
3. anterior choroidal artery
4. anterior cerebral artery
5. middle cerebral artery
106
where does the opthamic artery run?
with CN2 supplying blood to the choroid/retina of the eye
via central artery of the retina
107
what does the posterior communicating artery connect the internal carotid to?
Circle of Willis
108
what does the posterior communicating artery eventually supply?
Circle of Willis which supplies:
1. diencephalon
1. pituitary
2. infundibulum
3. hypothalamus
4. thalamus
109
where is the anterior choroidal artery and what does it supply?
arises near middle cerebral artery
supplies choroid plexus of lateral ventricles, optic tract, internal capsule, globus pallidus (basal nucleus)
\*supplies deep structures of telencephalon
110
where does the anterior cerebral artery run?
runs in longitudinal fissure above corpus callosum to medial aspect of frontal and parietal lobes
111
what is the anterior communicating artery?
an anastomosis between R/L anterior cerebral arteries
112
what does the middle cerebral artery supply?
runs in lateral sulcus to:
1. lateral frontal
2. lateral parietal
3. insula
4. lateral occipital
5. M/L temporal
6. sub-cortical deep structures
1. basal ganglia
2. internal capsule
3. limbic structures
113
after the vertebrals pass through the foramen magnum where do they head next?
they ascend the clivus and then fuse into basilar artery
114
what are the branches of the vertebral arteries from proximal to distal?
1. anterior spinal artery - medial medulla
2. posterior inferior cerebellar - lateral medulla
3. posterior spinal artery - dorsal medial medulla
115
what are the branches of the basilar artery from proximal to distal?
1. anterior inferior cerebellar
2. labyrinthine arteries
3. pontine arteries
4. superior cerebellar arteries
5. posterior cerebral arteries
116
what does the anterior inferior cerebellar artery supply?
it is a branch of the basilar artery
supplies cerebellum and pons
117
what do the labyrinthine arteries supply?
branch of basilar artery that enters internal acoustic meatus
supplies cochlea and vestibular apparatus
118
what do the pontine arteries supply?
branch of basilar artery
supplies pons
119
what do the superior cerebellar arteries supply?
branch of basilar artery
supplies cerebellum, pons, and midbrain
120
what do the posterior cerebral arteries supply?
branch of basilar artery
supplies cortex (medial and inferior occipital, inferior temporal) and subcortical structures of midbrain, subthalamus, and thalamus
121
what is the Circle of Willis?
an anastomosis between internal carotid arteries and basilar arteries
122
what forms the Circle of Willis?
1. anterior communicating arteries
2. anterior cerebral arteries
3. posterior communcating arteries
4. posterior cerebral arteries
123
what is the dural artery?
middle meningeal from the maxilary artery (from external carotid) via foramen spinosum
124
what is the venous drainage of the brain?
Dural sinuses
125
what is the path of venous blood flow in the brain?
1. superior sagittal sinus, inferior sgittal sinus (to straight sinus) and occipital sinus all drain into:
2. confluence of sinuses
3. transverse sinus
4. superficial veins
5. sigmoid sinus
6. internal jugular vein
126
name the venous plexi in the brain
1. cavernous sinus
2. pterygoid sinus
3. basilar
4. superior and inferior petrosal drain into sinuses or jugular veins
127
Name the grooves in the spinal cord cross section
1. anterior median fissure
2. posterior median sulcus
128
what is gray matter in the spinal cord?
located in an H shaped central core
contains neurons and neuroglial cell bodies as well as unmyelinated neuron processes (axons and dendrites)
129
what are all the gray matter structures within the spinal cord?
1. dorsal horn
2. ventral horn
3. lateral horn
4. rexed's laminae
5. grey commissure
130
T/F: the ventral horn of the spinal cord is somatotpically organized?
TRUE
131
how is the ventral horn somatopically organized?
1. medial ventral horn → controls axial muscles
2. lateral ventral horn → controls appendicular muscles
3. posterior section of ventral horn → controls flexors
4. anterior section of ventral horn → controls extensors
132
which regions of the spine have lateral horns?
Thoracic, Lumbar and Sacral
T1-L2 = sympathetic preganglionic neurons
S2-S4 = parasympathetic preganglionic neurons
133
What are Rexed's Laminae?
10 histological/functional regions of gray matter in the dorsal and ventral horns
134
what are the lamina in Rexed's laminae responsible for?
1. Lamina 1 = marginal layer for noxious stimuli
2. lamina 2 = substatia gelantinosa for noxious stimuli etc.
135
what is the grey commissure in the spinal cord gray matter?
connection between R and L gray matter
allows signals to cross to the opposite side
136
what is located in the white matter of the spinal cord?
ascending (sensory) and descending (motor) tracts (fasiciculi) which are bundles of myelinated axons with a similar origin and terminal destination
137
list the organization of the white matter columns in the spinal cord
1. Dorsal Column = bundle of tracts
2. Lateral Column
1. A/P lateral column
3. Anterior Column
4. Propriospinal = axons that begin and end within the cord providing interconnections between tracts and gray matter for context
138
what is the central canal?
a continuation of the 4th ventrile of the brain, contains CSF
139
what does the term funiculus mean? what about fascicula?
funiculus = column
fascicula = tract
140
what is the function of the spinal cord?
1. propagate nerve impulses between the periphery and the brain
2. somatic reflex control center
141
what is the primary arterial supply to the spinal cord?
1. cervical = spinal branches from **vertebral arteries**
2. thoracic = spinal branches from **posterior intercostal arteries**
3. lumbar = spinal branches from **lumbar arteries**
142
what do the spinal branches of the primary arteries of the spinal cord branch into?
dorsal and ventral segmental arteries
143
what do the dorsal and ventral segmental arteries of the spinal cord form?
1. deep anterior region = anterior spinal artery
2. deep posterior region = 2 posterior spinal arteries
3. superficial regions = A/P radicular
144
List the veins of the spinal cord
1. anterior medial spinal vein
2. anterolateral spinal vein
3. posteromedian spinal vein
4. posterolateral spinal vein
