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Flashcards in CNS and Blood Supply Deck (144)
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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
  1. Telencephalon
  2. Diencephalon
  3. Mesencephalon (midbrain)
  4. Metencephalon
  5. Myelencephalon
3
Q

what parts of the brain are in the Telencephalon?

A
  1. Cerebral hemispheres
  2. basal ganglia
  3. limbic system
4
Q

what parts of the brain are in the Diencephalon?

A
  1. thalamus
  2. hypothalamus
  3. epithalamus
5
Q

What parts of the brain are in the Mesencephalon (midbrain)?

A
  1. cerebral peduncle
  2. corpus quadrigemina
    1. Superior colliculi
    2. inferior colliculi
  3. CN3 and CN4 nucleus
  4. Red nucleus
  5. 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
  1. Medulla oblongata
8
Q

what are the components of the brain stem?

A
  1. medulla oblongata
  2. pons
  3. 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
  1. cranial bones (skull)
  2. epidural space with fat
  3. dura mater
  4. subdural space w/interstitial fluid
  5. arachnoid mater
  6. subarachnoid space w/CSF
  7. pia mater
11
Q

name the folds of dura mater that hold the brain in place

A
  1. falx cerebri
  2. falx cerebelli
  3. 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
  1. tight junctions between blood vessel endothelial cells
  2. continuous endothelial cell basement membrane
  3. 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
  1. nerve tracts (both sensory ascending and motor descending)
  2. pyramids
  3. decussation of pyramids
  4. olives
  5. dorsal medulla
    • fasciculus gracilis
    • fasiculus cuneatus
  6. decussation of the medial lemniscus
  7. nuclei
  8. cranial nerve nuclei for CN, 8 - 12
18
Q

what is the overall function of the brain stem?

A
  1. contains nuclei for vital centers and cranial nerves
  2. 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
  1. cranial nerve nuclei for CN 5, 6, and 7
  2. ascending and descending tracts
25
Q

what is the function of the Pons?

A

information relay for cerebellar hemmispheres

26
Q

what is located in the midbrain?

A
  1. cerebral peduncles
  2. corpora quadrigemina
  3. cranial nerve nuclei for CN 3, 4
  4. red nucleus and substantia nigra
27
Q

what are the cerebral peduncles?

A

they contain descending motor axaon tracts from cerebral hemispheres to spinal cord, medulla, and pons

and

ascending sensory axons going to the cerebrum

28
Q

what is the corpora quadrigemina made up of?

A
  1. superior colliculi
  2. inferior colliculi
29
Q

what does the superior colliculi control?

A

reflex movement of eye, head, and neck to visual and other stimuli

30
Q

what do the inferior colliculi control?

A

reflex movement of head and neck to auditory stimuli

31
Q

what is the function of the red nucleus and substantia nigra?

A

modify motor signals

32
Q

what is the overall function of the midbrain?

A
  1. relay motor impulses from cerebral cortex
  2. relay sensory impulses from spinal cord to thalamus
33
Q

what is the reticular formation?

A

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
Q

what is the function of the reticular formation?

A
  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
Q

what is the cerebellum (metencephalon) comprised of?

A
  1. vermis (worm)
  2. cerebellar hemispheres
  3. peduncles
36
Q

describe the cross section anatomy of the cerebellum

A
  1. cortex = gray matter
  2. folia ridges
  3. arbor vitae (nerve tracts = white matter)
  4. cerebellar nuclei
37
Q

what is the function of the cerebellum?

A
  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
Q

what makes up the Diencephalon?

A
  1. thalamus
  2. hypothalamus
  3. epithalamus
  4. subthalamus
39
Q

describe the structure of the thalamus

A

composed of paired masses of mixed gray (nuclei) and white (tracts) matter that are connected by intermediate mass (crossover point)

40
Q

what is the function of the thalamus?

A
  1. relay sensory info to correct region of cerebral cortex
  2. refine motor signals with the basal nucleus
41
Q

describe the composition of the hypothalamus

A

composed of:

  1. dozen nuclei
  2. mammillary bodies (visible on inferior surface)
  3. infundibulum (connects pituitary to the hypothalamus)
42
Q

what is the overall function of the hypothalamus?

A

control of body activities to maintain homeostasis

43
Q

T/F: the hypothalamus is a circumventricular organ?

A

TRUE

44
Q

what are the specific functions of the hypothalamus?

A
  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
Q

describe the structure of the epithalamus

A

composed of:

  1. pineal gland
  2. habenular nuclei (paired structure)
46
Q

what is the function of the epithalamus?

A

more of a modulator

functions in:

  1. melatonin production (at pineal gland)
  2. habenular nuclei involved in the emotional response to smell
47
Q

what is the subthalamus composed of?

A
  1. subthalamic nuclei (paired)
  2. parts of red nuclei (paired)
  3. parts of substantia nigra (paired)
48
Q

what is the function of the subthalamus?

A

connects to cerebellum and motor cortex for control of body movement

49
Q

what are circumventricular organs?

A

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
Q

where are circumventricular organs found?

A
  1. hypothalamus
  2. pineal
  3. pituitary (hypophysis)
51
Q

what region of the brain are the basal ganglia in?

A

Telencephalon

52
Q

what are the basal ganglia?

A

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
Q

what region of the brain is the limbic system in?

A

Telencephalon

Diencephalon

54
Q

what is the limbic system comprised of?

A
  1. paired nuclei
  2. tracts
  3. cortex (parts of frontal, parietal, and temporal lobes)
55
Q

what is the function of the limbic system?

A

“primitive brain” function in emotion aspects of behavior and memory-pain, pleasure, affection, and anger → to determine feelings

56
Q

What portion of the brain is the cerebrum in?

A

Telencephalon

57
Q

describe the composition of the cerebrum

A
  1. cerebral cortex (gray matter)
  2. cerebral white matter
58
Q

what is cerebral cortex (gray matter)?

A

10s of billions of associate (inter) neurons

typically arranged in 6 layers to allow vertical integration

59
Q

what is cerebral white matter made of?

A

3 types of neurons:

  1. association fibers
  2. commissural fibers
  3. projection fibers
60
Q

what do association fibers in the cerebral white matter do?

A

connect different gyri in same hemisphere

61
Q

what do commissural fibers in cerebral white matter do?

A

connect different gyri in opposite hemisphere (found in corpus collosum)

62
Q

what do projection fibers in the cerebral white matter do?

A

connect the cerebrum to rest of body (sensory and motor tracts)

63
Q

Cerebrum is the highest of the brain regions, what are it’s functions?

A
  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
Q

describe the surface anatomy of the cerebrum

A
  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
Q

what is the corpos callosum?

A

large collection of commissural tracts connecting R/L hemispheres

66
Q

what is the central sulcus of the cerebrum?

A

separates frontal and parietal lobes

67
Q

what is the precentral gyrus of the cerebrum?

A

anterior to central sulcus

voluntary (somato-) motor area

68
Q

what is the postcentral gyrus of the cerebrum?

A

posterior to central sulcus

conscious (somato-) sensory area

69
Q

what is the lateral cerebral fissure (sulcus) of the cerebrum?

A

separates frontal and temporal lobes

70
Q

what is the parieto-occipital sulcus of the cerebrum?

A

separates parietal and occiptal lobes

71
Q

Name the Lobes of the cerebrum

A
  1. Frontal
  2. Parietal
  3. Temporal
  4. Occipital
  5. Insula
72
Q

where is the frontal lobe?

A

anterior of central sulcus and medial to lateral sulcus

73
Q

what are the different sections of the frontal lobe?

A
  1. precentral gyrus
  2. premotor area (supplemental motor area)
  3. frontal eye field
  4. Broca’s area
  5. prefrontal cortex
  6. cingulate gyrus
74
Q

what are the components of the precentral gyrus?

A
  1. primary motor cortex
    1. somatotopic
    2. homunculus
75
Q

what does the primary motor cortex do?

A

control voluntary movement on contralateral side of the body

76
Q

what does the term somatotopic mean?

A

refers to specific regions of the precentral gyrus that control muscles in specific body regions

77
Q

what is a homunculus?

A

it depicts somatotopic organization of precentral gyrus and relative cortical contributions to a particular body region

78
Q

what is the premotor area (supplemental motor area) of the frontal lobe?

A

associative area next to precentral gyrus functions to initiate and sequence motor activity

79
Q

what is the function of the frontal eye field of the Frontal lobe?

A

coordinated R and L eye movement = conjugate eye movements

80
Q

What is Broac’s area on the Frontal Lobe?

A

on L hemisphere only

coordinates motor speech

81
Q

where is the prefrontal cortex?

A

rostral most part of the frontal lobe

primary target of lobotomy

82
Q

significance of the prefontal cortex?

A

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
Q

what is the cingulate gyrus of the frontal lobe?

A

medial surface (within longitudinal fissure) of frontal and parietal lobes

limbic cortex for emotional behavior, autonomic reponse, and learning

84
Q

where is the Insula lobe located?

A

within the lateral sulcus where frontal, parietal and temporal lobes come together

85
Q

what is the function of the Insula Lobe?

A

integration of sensory input for:

  1. taste and olfaction
  2. viscerosensation (interoreceptors)
  3. pain
86
Q

what are the sections of the Parietal Lobe?

A
  1. post central gyrus
  2. supramarginal and angular gyrus
  3. Wernicke’s area
  4. superior parietal lobe
87
Q

what part of the Parietal Lobe is located at the post central gyrus?

A

Somatosensory Cortex

primary sensory area for tactile and proprioceptive sensation → end destination for conscious somatosensory signals

88
Q

what does the supramarginal and angular gyrus do?

A

receive visual and auditory input for perceptional discrimination and integration

89
Q

where is Wernicke’s area and what does it do?

A

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
Q

what is the superior parietal lobe?

A

an association area integrating sensory and motor areas to program complex motor responses

91
Q

where is the occipital lobe of the cerebrum located?

A

caudal to the parietal-occipital sulcus on the medial border

92
Q

what is located in the occipital lobe?

A

primary visual cortex

visual association cortex

93
Q

name the structures at the temporal lobe

A
  1. primary auditory cortex
  2. superior temporal gyrus
  3. middle temporal gyrus
  4. inferior temporal gyrus
  5. parahippocampal gyrus and uncus
94
Q

where is the primary auditory cortex located?

A

medial aspect of superior temporal gyrus → transverse gyri Heschl

95
Q

what is located at the superior temporal gyrus?

A

auditory association cortex

96
Q

what is the function of the middle temporal gyrus?

A

perception and analysis of motion in the visual field

97
Q

what is the function of the inferior temporal gyrus?

A

facial recognition in response to visual input

98
Q

where is the parahippocampal gyrus and uncus and what is it’s function?

A

located on the inferior surface of temporal lobe

function w/limbic system

99
Q

how are hemispheres in the cerebrum divided?

A

separated by longitudinal fissure and connected by commissural fibers

100
Q

what is hemispheric localization?

A

refers to the functional differences that exist between hemispheres = cerebral dominance

101
Q

what is the left hemisphere primarily responsible for?

A
  1. language interpretation and execution
  2. numerical and scientific skills (abstract)
  3. reasoning
102
Q

what is the right hemisphere primarily responsible for?

A
  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
Q

what is cerebral dominance due to?

A
  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
Q

describe the course of the internal carotid through the skull

A
  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
Q

what are the branches of the internal carotids proximal to distal?

A
  1. opthalmic
  2. posterior communicating
  3. anterior choroidal artery
  4. anterior cerebral artery
  5. middle cerebral artery
106
Q

where does the opthamic artery run?

A

with CN2 supplying blood to the choroid/retina of the eye

via central artery of the retina

107
Q

what does the posterior communicating artery connect the internal carotid to?

A

Circle of Willis

108
Q

what does the posterior communicating artery eventually supply?

A

Circle of Willis which supplies:

  1. diencephalon
    1. pituitary
    2. infundibulum
    3. hypothalamus
    4. thalamus
109
Q

where is the anterior choroidal artery and what does it supply?

A

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
Q

where does the anterior cerebral artery run?

A

runs in longitudinal fissure above corpus callosum to medial aspect of frontal and parietal lobes

111
Q

what is the anterior communicating artery?

A

an anastomosis between R/L anterior cerebral arteries

112
Q

what does the middle cerebral artery supply?

A

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
Q

after the vertebrals pass through the foramen magnum where do they head next?

A

they ascend the clivus and then fuse into basilar artery

114
Q

what are the branches of the vertebral arteries from proximal to distal?

A
  1. anterior spinal artery - medial medulla
  2. posterior inferior cerebellar - lateral medulla
  3. posterior spinal artery - dorsal medial medulla
115
Q

what are the branches of the basilar artery from proximal to distal?

A
  1. anterior inferior cerebellar
  2. labyrinthine arteries
  3. pontine arteries
  4. superior cerebellar arteries
  5. posterior cerebral arteries
116
Q

what does the anterior inferior cerebellar artery supply?

A

it is a branch of the basilar artery

supplies cerebellum and pons

117
Q

what do the labyrinthine arteries supply?

A

branch of basilar artery that enters internal acoustic meatus

supplies cochlea and vestibular apparatus

118
Q

what do the pontine arteries supply?

A

branch of basilar artery

supplies pons

119
Q

what do the superior cerebellar arteries supply?

A

branch of basilar artery

supplies cerebellum, pons, and midbrain

120
Q

what do the posterior cerebral arteries supply?

A

branch of basilar artery

supplies cortex (medial and inferior occipital, inferior temporal) and subcortical structures of midbrain, subthalamus, and thalamus

121
Q

what is the Circle of Willis?

A

an anastomosis between internal carotid arteries and basilar arteries

122
Q

what forms the Circle of Willis?

A
  1. anterior communicating arteries
  2. anterior cerebral arteries
  3. posterior communcating arteries
  4. posterior cerebral arteries
123
Q

what is the dural artery?

A

middle meningeal from the maxilary artery (from external carotid) via foramen spinosum

124
Q

what is the venous drainage of the brain?

A

Dural sinuses

125
Q

what is the path of venous blood flow in the brain?

A
  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
Q

name the venous plexi in the brain

A
  1. cavernous sinus
  2. pterygoid sinus
  3. basilar
  4. superior and inferior petrosal drain into sinuses or jugular veins
127
Q

Name the grooves in the spinal cord cross section

A
  1. anterior median fissure
  2. posterior median sulcus
128
Q

what is gray matter in the spinal cord?

A

located in an H shaped central core

contains neurons and neuroglial cell bodies as well as unmyelinated neuron processes (axons and dendrites)

129
Q

what are all the gray matter structures within the spinal cord?

A
  1. dorsal horn
  2. ventral horn
  3. lateral horn
  4. rexed’s laminae
  5. grey commissure
130
Q

T/F: the ventral horn of the spinal cord is somatotpically organized?

A

TRUE

131
Q

how is the ventral horn somatopically organized?

A
  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
Q

which regions of the spine have lateral horns?

A

Thoracic, Lumbar and Sacral

T1-L2 = sympathetic preganglionic neurons

S2-S4 = parasympathetic preganglionic neurons

133
Q

What are Rexed’s Laminae?

A

10 histological/functional regions of gray matter in the dorsal and ventral horns

134
Q

what are the lamina in Rexed’s laminae responsible for?

A
  1. Lamina 1 = marginal layer for noxious stimuli
  2. lamina 2 = substatia gelantinosa for noxious stimuli etc.
135
Q

what is the grey commissure in the spinal cord gray matter?

A

connection between R and L gray matter

allows signals to cross to the opposite side

136
Q

what is located in the white matter of the spinal cord?

A

ascending (sensory) and descending (motor) tracts (fasiciculi) which are bundles of myelinated axons with a similar origin and terminal destination

137
Q

list the organization of the white matter columns in the spinal cord

A
  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
Q

what is the central canal?

A

a continuation of the 4th ventrile of the brain, contains CSF

139
Q

what does the term funiculus mean? what about fascicula?

A

funiculus = column

fascicula = tract

140
Q

what is the function of the spinal cord?

A
  1. propagate nerve impulses between the periphery and the brain
  2. somatic reflex control center
141
Q

what is the primary arterial supply to the spinal cord?

A
  1. cervical = spinal branches from vertebral arteries
  2. thoracic = spinal branches from posterior intercostal arteries
  3. lumbar = spinal branches from lumbar arteries
142
Q

what do the spinal branches of the primary arteries of the spinal cord branch into?

A

dorsal and ventral segmental arteries

143
Q

what do the dorsal and ventral segmental arteries of the spinal cord form?

A
  1. deep anterior region = anterior spinal artery
  2. deep posterior region = 2 posterior spinal arteries
  3. superficial regions = A/P radicular
144
Q

List the veins of the spinal cord

A
  1. anterior medial spinal vein
  2. anterolateral spinal vein
  3. posteromedian spinal vein
  4. posterolateral spinal vein