1/17 CSF, Vessels, & Higher Cortical Structure And Function

Question 1

What are the ventricles?

Answer 1

There are four interconnected ventricles
• Paired lateral ventricles (telencephalon)
• Interventricular foramen
• 3rd ventricle (diencephalon)
• Cerebral aqueduct (mesencephalon)
• 4th ventricle (metencephalon & myelencephalon)

Question 2

What are the regions that the lateral ventricles supply?

Answer 2

Inferior horn – Temporal lobe
Posterior horn – Occipital lobe
Body – Parietal lobe
Anterior horn – Frontal lobe

Question 3

Where do the lateral ventricles connect/where do they go?

Answer 3

Connected to 3rd ventricle through interventricular foramen (of Monro)

Question 4

What is the third ventricle?

Answer 4

Flat ventricle between the two halves of the diencephalon

Question 5

Where is the third ventricle?

Answer 5

Superior to the optic chiasm and midbrain

Question 6

What are the openings to the third ventricle?

Answer 6

Two superior openings – interventricular foramen
One inferior opening – cerebral aqueduct

Question 7

What are the boundaries of the fourth ventricle?

Answer 7

Anterior: pons and medulla
Posterior: cerebellum

Question 8

What are the openings to the fourth ventricle?

Answer 8

Single superior opening – cerebral aqueduct
Inferiorly open to the central canal

Question 9

What is the structure of the fourth ventricle?

Answer 9

Paired lateral apertures
Single median aperture

Question 10

What are cisterns?

Answer 10

subarachnoid space that widens in several areas

Question 11

What does the lumbar cistern consist of?

Answer 11

Cauda equina, filum terminale

Question 12

What does the cisterna magna consist of?

Answer 12

Posterior inferior cerebellar and vertebral arteries, CN IX-XII

Question 13

What does the prepontine cistern consist of?

Answer 13

Basilar and superior cerebellar arteries, CN VI

Question 14

What does the interpeduncular cistern consist of?

Answer 14

Posterior cerebral and posterior communicating arteries, CN III

Question 15

What does the quadrigeminal cistern consist of?

Answer 15

Pineal gland, great cerebral vein

Question 16

How is CSF created?

Answer 16

The choroid plexus filters the plasma from the blood to create CSF

Question 17

Where is choroid plexus found?

Answer 17

in most parts of the ventricles

Question 18

What is the composition of CSF?

Answer 18

primarily composed of water (99%) with a small amount
of chemicals and nutrients including
– Sodium
– Chloride
– Potassium
– Calcium*
– Magnesium
– Small amounts of protein and glucose

Question 19

What are the functions of CSF?

Answer 19

Physical support for the brain
Excretory functions allow for the removal of water-soluble metabolites
Channel for chemical communication

Question 20

What are the chemicals that CSF allows to communicate?

Answer 20

Serotonin
Dopamine
Noradrenaline
Vasopressin
Oxytocin

Question 21

How is CSF produced from choroid capillaries?

Answer 21

Choroid capillaries are permeable; however, they are surrounded by choroid epithelial cells that have very limited permeability.
This layer allows lipid soluble substances through (e.g. O2 and CO2)
Specialized transport selectively allows other substances through.
About 20 cc/hr are allowed through this barrier.

Question 22

What is the order of flow/pathway of CSF?

Answer 22

Lateral ventricles
Interventricular foramen
Third ventricle
Cerebral aqueduct
Fourth ventricle
Median & lateral apertures
Subarachnoid space around spinal cord and brain
Absorbed by arachnoid granulations

Question 23

What are the spaces in which CSF is produced by choroid plexus?

Answer 23

Lateral ventricles
Third ventricle
Fourth ventricle

Question 24

How is CSF reabsorbed?

Answer 24

CSF passes through the arachnoid granulations (arachnoid villi)
Recent research has also shown that absorption happens through cervical lymphatics by way of the arachnoid surrounding the cranial nerves
Reabsorption usually matches production rate (20cc/hr)

Question 25

What is hydrocephalus?

Answer 25

When there is more production than reabsorption it causes an increase in pressure

Question 26

What are the causes of hydrocephalus?

Answer 26

There are over 100 causes – Communicating – Non-communicating

Question 27

What are the symptoms of hydrocephalus?

Answer 27

headaches, nausea, motor or sensory disturbances

Question 28

How is hydrocephalus traditionally treated?

Answer 28

With a ventroperitoneal shunt

Question 29

What is non-communicating hydrocephalus?

Answer 29

Indicates a blockage within the ventricular pathway

Question 30

What is communicating hydrocephalus?

Answer 30

(Non-obstructive) occurs outside of the ventricular system

Question 31

What provides the blood supply to the anterior circulation to the brain?

Answer 31

Internal carotid artery

Question 32

What provides the blood supply to the posterior circulation to the brain?

Answer 32

Vertebral arteries

Question 33

What does the anterior cerebral artery supply?

Answer 33

Medial frontal lobe Medial parietal lobe

Question 34

What does the posterior cerebral artery supply?

Answer 34

Inferior & medial temporal lobe Inferior & medial occipital lobe Posterior thalamus Cerebral peduncles

Question 35

What does the middle cerebral artery supply?

Answer 35

(Travels between frontal and temporal lobe) Lateral frontal lobe Lateral parietal lobe Lateral temporal lobe Lateral occipital lobe Insula

Question 36

What does the lenticulostriate arteries supply?

Answer 36

Basal ganglia Internal capsule Amygdala Anterior thalamus

Question 37

How does the basilar artery arise and end?

Answer 37

formed by bilateral vertebral arteries It bifurcates into the posterior cerebral arteries

Question 38

What are the branches of the basilar artery?

Answer 38

Short and paramedian pontine branches Long circumferential branches

Question 39

What do the short and paramedian pontine branches of the basilar artery supply?

Answer 39

Crus cerebri Central pons

Question 40

What do the long circumferential branches of the basilar artery supply?

Answer 40

Dorsolateral pons Superior cerebellar peduncle

Question 41

What does the superior cerebellar artery supply?

Answer 41

Cerebellum Superior dorsolateral pons Dorsal midbrain

Question 42

What does the anterior inferior cerebellar artery supply?

Answer 42

Cerebellum Inferior dorsolateral pons

Question 43

What does the posterior inferior cerebellar artery supply?

Answer 43

Cerebellum Superior dorsolateral medulla

Question 44

Where does the anterior spinal artery come from?

Answer 44

Vertebral arteries

Question 45

What does the anterior spinal artery supply?

Answer 45

Anterior 2/3 of spinal cord

Question 46

Where do the posterior spinal arteries come from?

Answer 46

Posterior inferior cerebellar arteries

Question 47

What do the posterior spinal arteries supply?

Answer 47

Posterior 1/3 of spinal cord

Question 48

What are pyramidal cells

Answer 48

Multipolar neurons (up to 600 dendritic spines) Main output neurons of the cerebral cortex

Question 49

What is the size of pyramidal cells?

Answer 49

Size of cell related to distance to target

Question 50

Where are pyramidal cells found

Answer 50

cortical layers 2, 3, 5, & 6

Question 51

What are the classifications of pyramidal cells?

Answer 51

Commissural Association Projection

Question 52

Where are commissural pyramidal cells?

Answer 52

Form the corpus callosum

Question 53

Where are association pyramidal cells?

Answer 53

To the ipsilateral cortex

Question 54

Where are the projection pyramidal cells?

Answer 54

To other parts of the CNS

Question 55

What are stellate cells?

Answer 55

Multiple processes in all directions Project to local targets in the cerebral cortex Modulates cortical activity

Question 56

Where are stellate cells found?

Answer 56

In layers 2-6

Question 57

What are the classifications of stellate cells?

Answer 57

Spiny Aspiny

Question 58

What do spiny stellate cells do?

Answer 58

release glutamate which is excitatory

Question 59

What do aspiny stellate cells do?

Answer 59

release gamma- aminobutyric acid (GABA) which is inhibitory

Question 60

What makes up the cortex layers?

Answer 60

Neocortex Allocortex

Question 61

What makes up the neocortex?

Answer 61

95% of the cortex. It has six distinct layers I-VI

Question 62

What makes up the allocortex

Answer 62

Less developed with only 3-4 layers • Archicortex • Paleocortex

Question 63

What makes up the archicortex?

Answer 63

Hippocampus/dentate gyrus

Question 64

What makes up the paleocortex?

Answer 64

Olfactory bulb/ pirifom cortex

Question 65

What is cortical layer I called and made of?

Answer 65

Molecular cell processes

Question 66

What is cortical layer II called and made of?

Answer 66

External granular dense stellate cells + small pyramidal cells

Question 67

What is cortical layer III called and made of?

Answer 67

External pyramidal loose stellate cells + medium pyramidal cells

Question 68

What is cortical layer IV called and made of?

Answer 68

Internal granular dense stellate cells

Question 69

What is cortical layer V called and made of?

Answer 69

Internal pyramidal large pyramidal cells

Question 70

What is cortical layer VI called and made of?

Answer 70

Multiform various sized pyramidal cells and loose stellate cells

Question 71

Where does the cells from cortical layer II travel?

Answer 71

To ipsilateral cortical areas

Question 72

Where does the cells from cortical layer III travel?

Answer 72

To contralateral cortical areas

Question 73

Where does the cells from cortical layer IV travel?

Answer 73

Input

Question 74

Where does the cells from cortical layer V travel?

Answer 74

To the striatum, brain stem, & spinal cord

Question 75

Where does the cells from cortical layer VI travel?

Answer 75

To the thalamus (output)

Question 76

What are the types of cortical communications?

Answer 76

Projection bundles Commissural bundles Association bundles

Question 77

What do projection bundles connect?

Answer 77

cortex and subcortical structures (i.e. thalamus, spinal cord)

Question 78

What do commissural bundles connect?

Answer 78

Contralateral cortical areas (layer 3)

Question 79

What do association bundles connect?

Answer 79

Ipsilateral cortical areas

Question 80

What are the different types of association fibers?

Answer 80

Superior longitudinal fasciculus Inferior longitudinal fasciculus Frontooccipital fasciculus Cingulum Uncinate fasciculus Arcuate fasciculus Short fibers

Question 81

What are brodmann’s areas?

Answer 81

52 distinct areas based on histological differences in the cortex as seen in 1905

Question 82

Do broadmann’s areas follow sulci and gyro?

Answer 82

No Don’t respect boundaries of sulci and gyri

Question 83

What do broadmann’s area 1, 2, and 3 make up?

Answer 83

Primary somatosensory cortex (Around postcentral gyrus)

Question 84

What does broadmann’s area 5 make up?

Answer 84

Somatosensory association area

Question 85

What does broadmann’s area 4 make up?

Answer 85

Primary motor cortex (Around precentral gyrus)

Question 86

What does broadmann’s area 6 make up?

Answer 86

Premotor cortex (Around precentral gyrus into some of the superior/middle/inferior frontal gyrus)

Question 87

What does broadmann’s area 17 make up?

Answer 87

Primary visual cortex (Around calcarine sulcus)

Question 88

What does broadmann’s area 18 and 19 make up?

Answer 88

Visual association cortex

Question 89

What does broadmann’s area 41 make up?

Answer 89

Primary auditory cortex (Around transverse temporal gyri)

Question 90

What are the language centers of the brain? Where are these found?

Answer 90

Broca’s area Wernicke’s area Arcuate fasiculus Primarily in the left hemisphere

Question 91

Where is Broca’s area?

Answer 91

(Brodmann 44, 45) inferior frontal gyrus (close to primary motor cortex)

Question 92

Where is Wernicke’s area?

Answer 92

(Brodmann 22, 40) superior temporal gyrus and supramarginal gyrus (close to primary auditory cortex)

Question 93

What is prosody?

Answer 93

The ability to translate/produce pitch, volume, tempo and rhythm is contained in the non- dominant hemisphere (Intonation, would be monotone without)

Question 94

Where is prosody found in the brain?

Answer 94

Broca’s and Wernicke’s on the right

Question 95

Where are the reading centers of the brain?

Answer 95

Supramarginal gyrus (40) Angular gyrus (39) Word recognition in occipitotemporal gyrus (37) Word vocalization in Broca’s area (44) Writing in premotor cortex (6)

Question 96

Where does a normal brain activate for reading?

Answer 96

Along the right hemisphere of the brain and mid-left hemisphere

Question 97

Where does a dyslexic brain activate for reading?

Answer 97

Along both hemispheres Different methods (tactile, auditory) are needed to help dyslexic readers.