CNS Anatomy Flashcards

1
Q

CNS vs. PNS

A

CNS - brain and spinal cord
PNS - all the nerves that go from CNS to take impulses out to create effects and fibers that bring info back
EXCEPTION: optic nerve and retina and olfactory nerve are considered part of the CNS - described as outpatchings of the brain

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2
Q

weight of brain vs. energy consumption

A

brain is only 2% of body weight but uses 20% of the blood circulation
-body expends a lot of energy keeping the brain viable

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2
Q

size of brain in infant

A

young brain lacks insulation that adult brain does since it is still developing and much bigger proportional to the body

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3
Q

legal definition of death

A

brain death - analysis of brain waves is considered for death

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4
Q

color of brain during surgery

A

pink tissue perfused with a lot of blood vessels
arteries supply blood and veins take it away

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4
Q

what does brain do during surgery?

A

beating like the heart since the blood is coursing through and around the brain and the heart beating is changing pressure of cerebrospinal fluid (CSF)

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5
Q

variability in brain size

A

we all have different head and skull sizes and brain fills in

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6
Q

features of brain

A

similar to fingerprints and faces where there are consistent structures that may look different

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7
Q

gyri

A

folds in brain that increase the surface area for the gray matter

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8
Q

sulci

A

-gaps/valleys in-between the gryi
-vessels pass through these to go from one part of the brain to another

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9
Q

fissure vs sulcus

A

fissure - open to another part of the brain
sulcus - has a dead end…insert probe and you would hit brain matter

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10
Q

sylvian fissure/lateral sulcus

A

-labelled differently depending on where it is identified
-in one part is considered a sulcus but in another it is considered a fissure
-it is the division between frontal and temporal
-need to go through this to get to the midbrain or brainstem

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11
Q

cerebrum

A

-whole brain
-divided into lobes that are paired except for occipital lobe
-frontal - problem solving, word production, behavioral control and emotion
-temporal (2 lobes that run into fossa behind eye) - memory and emotion plus word understanding
-occipital - vision

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12
Q

sphenoid wing

A

corresponds with sylvian fissure and forms sulcus

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13
Q

cerebellum

A

-little brain
-coordination of movement and allows us to choreograph complex movements
Ex. DOES NOT fire skeletal muscles to walk/dance but coordinates movement

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14
Q

motor strip

A

-anterior to central fissure in the temporal lobe
-controls fine motor movements

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15
Q

somatosensory strip

A

-controls sensory feeling in fingers and toes
-posterior to central sulcus and located in temporal lobe

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16
Q

homunculus (little man)

A

-components of the motor and somatosensory strips
-motor strip has a lot of fibers to control fingers and face
-looking at coronal slice of brain

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17
Q

sagittal fissure

A

separates the brain

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18
Q

ventricles

A

parts of brain that are filled with cerebrospinal fluid (CSF)

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19
Q

brainstem

A

consists of the pons, medulla oblongata, and midbrain
-nerves, tracts, and dendrites are passing through the midbrain and medulla oblongata

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20
Q

midbrain

A

gives rise to two important nerves:
-ocular motor (CN 3)
-trochlear nerves (CN 4)
-forms the top of the brainstem

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21
Q

pons

A

controls three nerves:
-trigeminal nerve (CN 5), which transmits sensory info to the skin, sinuses, and mucous membranes in the face
-abducens nerve (CN 6) that controls the lateral movement of the eye
-facial nerve
-tracts run throughout the pons and midbrain
-connection between the right and left cerebellum

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22
Q

medulla oblongata

A

gives rise to three nerves:
-vestibular cochlear nerve (CN 8), which controls balance and hearing
-glossopharygneal (CN 9) for movement of the tongue
-vagus nerve (CN 10) which is called the vagabond since it sits very high up then branches down and helps with homeostasis —> works with the digestive and respiratory systems plus the heart
-accessory nerve (CN 11), located in the neck and helps with motor innervation to the muscles of the neck and upper back
-hypoglossal nerve (CN 12) and controls the innervation of the tongue

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23
Q

diencephalon

A

-upper portion of the brainstem
-forms the conduit between the brainstem, body, and brain
-contains pineal gland, thalamus, and hypothalamus

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24
Q

cerebral aquaduct

A

-narrow-like tube structure that connects the third ventricle to the fourth ventricle of the brain
-allows cerebrospinal fluid to flow between these ventricles

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25
Q

pineal gland

A

tiny endocrine gland in the middle of your brain that helps regulate your body’s circadian rhythm

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26
Q

clinical correlate: Andre the Giant

A

-neoplasm surrounding his pituitary gland, which caused giantism
-anesthesiologists would use his alcohol consumption to gauge how much sedative to give him for medical procedures

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27
Q

sella turcia (turkish saddle)

A

the pituitary gland sits here

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28
Q

corpus collusum

A

-bridge between left and right brains with tracts of white matter
-connections between the hemispheres are mixing through it
-helps left and right brains communicate

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29
Q

left brain

A

verbal tasks like speaking and writing

30
Q

right brain

A

controls spatial and movement

31
Q

falx cerebri

A

-tissue extension of tissue that covers the brain (dura)
-inferior part arcs over the corpus collusum
-crescent shape, tough stissue that sits between the hemispheres

32
Q

clinical correlate: times when the corpus collusum is cut

A

-in extreme cases of epilepsy where the seizures are life-threatening, the very last step would be to cut the corpus collusum and take out a hemisphere of the brain
-found that in hemisrectomies in young kids, they were able to do really well but there was a mismatch in what they were able to perceive, interpret, or do something somatic

33
Q

paths of vision to brain

A

left eye —> right brain
right eye —> left brain

34
Q

experiment with divided field of vision

A

-show a pic in the left eye it goes to the right brain —> they were able to pick up the picture of a rooster’s foot and match it to a rooster but they could not identify the picture
-conversely being processed in the left brain —> they could identify the picture but could not perceive what it is used for

35
Q

example of drawing with right side of brain

A

-tested theory that people who could draw were left brain sided
-when people look at a face and portrait, the left brain dominant will draw an eye that is a football shape with pupil symbol but right brain dominant people will say there is a fold with upper and lower eyelids with more observation of details

36
Q

skull

A

-main protection of brain with paired parietal bones and temporal bones a single occipital bone and single frontal bone
-important landmark: muscles attach from neck along nuchal line and external occipital protuberance

37
Q

skull base

A

-frontal fossa has frontal lobe with crista galli which divides the perforated plates
-sphenoid ridge goes to the claunoid process and the tip of the sphenoid ridge is the temporal tip, which sits in the sylvian fissure
-middle fossa has temporal lobe
-posterior fossa has occipital above and below is the cerebellum and foramen magnum with medulla oblongata above it

38
Q

petrous ridge

A

vestibular cochlear nerve –> ear –> this ridge –> internal auditory meatus

39
Q

depressions

A

-markings of the sinuses that are results of packing in soft tissue
-all give rise to something or bring something out

40
Q

venous sinuses

A

all of the blood is collected from the brain and taken down into the foreman magnum –> jugular veins –> subclavian –> superior vena cava using these sinuses

41
Q

optic foramen

A

optic nerves go through here to help us see

42
Q

thick vs. thin brain

A

-thickness of the bone varies
-thick: frontal and occipital bones are really thick without protection from muscle
-thin: temporal muscle provides protection for the temporal lobe bones
-extensor side of skull is thicker bone, which protects the corpus collusum

43
Q

meninges

A

coverings of the brain

44
Q

dura mater

A

-most external layer
-inside skull and as we get older, it becomes more adherent to the bone
-splits and creates a vascular sinus (Ex. creates the superior sagittal sinus - spent blood from the brain is collected to go to heart)

45
Q

sagittal venous sinus

A

collects blood from all over the brain and flows it down to transverse sinuses –> deeper into the sigmoid sinus –> down into the jugular veins

46
Q

arachnoid

A

-next layer underneath the dura mater
-spider-web appearance with fine filaments and the layer jumps across sulci
-all of the vasculature passes through this layer

47
Q

pia mater

A

-third layer in under the arachnoid
-very thin and goes into the sulci and comes back up over gyri

48
Q

clinical correlates: epidural hematoma

A

-meningeal artery travels and supplies meninge
-usually occurs in a skiing accident or injury that disrupts one of the vessels embedded in the dura causing the blood to go to the outside of the dura
-on the radiography, you can see how the dura adheres to the bone and a biconvex lens appears to push in on the brain and might even affect the brainstem
-lucid period followed by unconsciousness and unbeknownst to the patients they are bleeding out
-if treated immediately, the doctors will drill bur holes into the skull to release the blood and pressure then hopefully the blood in the vessels clots
-basis for concussion protocol
-often in the temporal region

49
Q

clinical correlates: subdural hematoma

A

-happens a lot with elderly since our brains get smaller as we age and they tend to drink less water —> a lot of traction on the veins and they could rupture from tension
-could also occur after trauma
-almost always involves bridging veins, which are veins that drain the brain supply and dump into the sinus —> they come from the subarachnoid space through the dura into the sinus
-arteries and veins of the brain are in the arachnoid space where the arachnoid proper is on top of the vessels and underneath is the space for veins to run through
-on the radiography, you can see a crescent shape with the brain being pushed in and the dura packed over it
-bleeding under the dura
-people usually do not lose consciousness but are confused and need to be monitored

50
Q

clinical correlates: subarachnoid hematoma

A

-one of the vessels inside the subarachnoid space ruptures
-blood diffusion in the subarachnoid space
-occurs from trauma, piercing injury, or some other method
-very often from a ruptured aneurysm
-symptoms include a “thunderclap headache” with rapid onset within seconds or minutes

51
Q

aneurysm

A

-bulge or ballooning spot the wall of a blood vessel, usually caused by a weak spot
-commonly occur in the optic chiasm with a carotid artery on the left and right side

52
Q

treatment of aneurysm

A

-if the aneurysm ruptures, it is similar to the lining of a rubber hose being cut and the water gushing out
-coiling: a catheter is placed into an artery in the groin or leg then travels up to the aneurysm and tiny platinum coils are passed through the catheter and into the aneurysm to fill it and seal it off from the main artery —> this is alternative treatment if there is no collateral circulation in the circle of willis
-clipping: a platinum clip is placed at the aneurysm’s neck to stop the blood flow

53
Q

cerebrospinal fluid (CSF)

A

-another protection of the brain that cushions it and provides some movement of brain in the skull freely
-flows through the aqueduct, so if there is a neoplasm blocking any of these areas —> there is herniation of the medulla oblongata into the foramen and blocks off CSF flow
-CSF is produced in the choroid plexus, reabsorbed in the granulations, and osmotic pressure from venous blood pulls it in a constant cycle

54
Q

hydrocephaly

A

-neoplasm in the aqueduct can cause a backup in the CSF and increase pressure
-in kids, it would cause their bones to be very flexible and have enlarged brains
-in adults, the brain takes the brunt with the neurotissue being impacted (alnocheiry syndrome)

55
Q

vasculature of brain

A

-all of the blood supply for the brain is coming from 2 paths: anterior carotid arteries or vertebrial arteries

56
Q

circle of willis

A

-vertebrial arteries coalesce into basilar artery, which splits and goes into the posterior cerebral on the right and left
-anterior arteries come up from the neck and go through the foramen then turn back on themselves
-posterior communicating arteries connect vertebrial portion to the anterior carotid arteries
-prior to surgeries that are related to these structures, you need to do a radiological study to ensure that the circle is intact otherwise you get necrosis of the tissues if not

57
Q

laden and laleh bijani

A

-vasculature was the main issue and it came down to the sagittal sinus —> sole structure collecting all of the blood supplying the cerebellum
-each sister had their own sagittal sinus but posteriorly they were fused
-took saphenous vein from leg and reconstructed the posterior sagittal sinus
-the base of the skull had cisterns like sinuses but with thin walls and one of the sisters died during the surgery

58
Q

tabea and lea block

A

-vasculature was really important
-jugular in one of the sisters but not the other and the main part was shared
-took from one confluence and the other
-jugulars for lea were intact

59
Q

ganglia

A

outposts of nerves

60
Q

where are the cell bodies of nerves?

A

CNS: in the cerebrum and cerebellum
PNS: in the ganglia

61
Q

profusion of brain

A

-consumes 20% of blood circulation = well profused
-vertebrial artery and carotid artery are responsible for profusion

62
Q

gray vs white matter

A

-gray is cell bodies
-white is axons and dendrites

63
Q

sphenoid wing

A

definition between the frontal and medial fossa

64
Q

romandy fissure (central sulcus)

A

-separates the chief motor and sensory regions of the brain
-contains neurofunctional centers on either side

65
Q

areas of the brain

A

-temporal - memory and word understanding
-frontal - problem solving, planning, word production, and behavioral control
-occipital - vision
-parietal

66
Q

tracts

A

-nerve fibers that gather in the brain
-“neuronal highways”

67
Q

back of neck muscles

A

-connect to the nuchal line
-external occipital protuberance, which is the bump on the back of the school where the neck meets the head

68
Q

openings in the skull

A

-bring something in or sends something out

69
Q

lateral ventricle

A

space in brain that is filled with CSF

70
Q

formation of sinuses

A

brain tissue leaves voids as the brain develops –> becomes the ventricles and sinuses
Ex. 1. 4th ventricle is filled with CSF
2. 3rd ventricle, between the right and left thalamus and is filled with CSF
3. aquaduct connects the 3rd and 4th ventricles and allows a passageway for CSF

71
Q

arnold-chiari syndrome

A

-medulla + cerebellum are pushed out through the foramen magnum
-often due to tumor on brain stem or hydrocephaly

72
Q

penial gland

A

secretes melatonin to help regulate the body’s circadian rhythm

73
Q

sulturasm

A

depression that the pituitary sits in