Intracranial Vasculature And Meninges

Question 1

Losing what % of blood volume will lead to loss of neuron function?

Answer 1

10-25%

Question 2

2 sources of blood supply to the brain?

Answer 2

Internal carotid artery and vertebral artery

These are both paired - so on both sides of brain

Question 3

What is the cerebral arterial circle?

Answer 3

Circle of willis- anastomosis formed by vertebral and internal carotid arteries

Question 4

Vertebral arteries give off which artery? What does it supply?

Answer 4

Posterior inferior cerebellar artery supplies inferior part of cerebellum

Question 5

2 vertebral arteries join together to form?

What 3 arteries does this give off and what do they supply

Answer 5

Basilar artery - gives off anterior inferior cerebellar artery which supplies top of inferior cerebellum
Also gives off superior cerebellar artery which supplies top part of cerebellum
Also gives off posterior cerebral artery which supplies posterior cerebrum

Question 6

What arteries form the “circle”

Answer 6

Posterior communicating arteries connect posterior cerebral artery to internal carotid artery

Question 7

What arteries come off the the internal carotid artery laterally?

Answer 7

Middle cerebral arteries

Question 8

The “horns” of the circle are what arteries?

What artery is in between these 2 “horns”

Answer 8

Anterior cerebral arteries

Anterior communicating artery

Question 9

What are pontine arteries?

Answer 9

Little arterial branches coming off the pons

Question 10

What 4 structures do the anterior cerebral supply?

Answer 10

Olfactory bulb, frontal/parietal lobes (medial), corpus callosum, and basal ganglia

Question 11

What 3 structures does the middle cerebral artery supply?

Answer 11

Temporal pole, lateral surface of cerebral hemispheres, and basal ganglia

Question 12

What 4 structures that the posterior cerebral artery supplies

Answer 12

Occipital lobe, inferior surface of temporal bone, thalamus, and third ventricle

Question 13

5 arteries that provide blood supply to the cerebellum?

Answer 13

Superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery, basilar artery and vertebral artery

Question 14

Subclavian steal syndrome:

1. Result of ?
2. What 2 things will happen because of it?
3. Symptoms?

Answer 14

1. Occlusion/stenosis of subclavian artery
2. Retrograde blood flow in vertebral artery and upper limb receives blood at the expense of vertebrobasilar circulation
3. Ischemia/fainting, different blood pressures in both limbs

Question 15

Function of meningeal spaces?

Answer 15

Has spaces for circulation of CSF

Question 16

Dura:

1. What are its 2 layers
2. What do the dural reflections form?

Answer 16

1. Periosteal (outer) and membranous (inner)

2. Venous sinuses

Question 17

How is the arachnoid held against dura?

Answer 17

By CSF pressure

Question 18

Difference between sucli and gyri

Answer 18

Sulci are the hollows

Gyri are the hills

Question 19

Meninges get their blood supply from 3 arteries branches

1. What is the main artery/branches that supply meninges?
2. What are the other 2 arteries and their branches that supply meninges?

Answer 19

1. External carotid: middle and posterior meningeal arteries

2. Internal carotid: anterior meningeal arteries; vertebral artery: meningeal branches

Question 20

Sensory innervation of dura?

Answer 20

CN V and cervical nerves

Question 21

Define dural reflections

Answer 21

Inner/outer layers that separate and partition the intracranial space

Question 22

1. Cerebral falx is ?
2. Location?
3. Anchored anteriorly to what 2 things?
4. Anchored posteriorly to what?

Answer 22

1. One of the dural reflections
2. In longitudinal fissure; between cerebral hemispheres
3. Frontal crest and crista galli
4. Internal occipital protuberance

Question 23

Cerebellar tentorium:

1. Location
2. Forms roof of?
3. Attached to?
4. What is the tentorial notch

Answer 23

1. Runs horizontally; between cerebrum and cerebellum
2. Forms roof of posterior cranial fossa
3. Attached to petrous ridge of temporal bone
4. Gap for brainstem to pass from posterior to middle cranial fossa

Question 24

Cerebellar falx:

1. Location
2. Partially separates?

Answer 24

1. Runs vertically through posterior cranial fossa

2. Cerebellar hemispheres

Question 25

Sellar diaphragm: 1. Location 2. Roof of? 3. Has small opening for what to pass through? 4. Function?

Answer 25

1. Suspended between clinoid processes 2. Roof of sella turcica 3. Infundibulum (pituitary stalk) 4. Holds the pituitary in the sella turcica

Question 26

What is houses within those dural reflections?

Answer 26

Major structures of venous drainage system

Question 27

Venous return from the brain flows in two directions: towards __ and towards __

Answer 27

Towards dural sinuses and towards the great cerebral vein (of Galen)

Question 28

5 major sinuses? (Veins)

Answer 28

Superior sagittal, inferior sagittal, straight sinus, transverse sinus, and sigmoid sinus

Question 29

1. Epidural hematoma are slow or fast occuring? Arterial or venous blood? 2. Subdural hematoma are slow of fast occuring? Arterial or venous blood?

Answer 29

1. Fast; arterial | 2. Slow; venous (slow because blood is at a lower pressure)

Question 30

CSF: 1. Produced by __ which is located where? 2. Fills which space?

Answer 30

1. Choroid plexus within the ventricles of the brain | 2. Subarachnoid space

Question 31

Choroid plexus: 1. Lined with cells that do what? 2. What directs the flow of CSF? 3. Where does it get its blood supply?

Answer 31

1. Facilitate CSF production 2. Cilia 3. Anterior choroidal artery (from middle cerebral artery) and posterior choroidal artery (from posterior cerebral artery)

Question 32

1. CSF flows through ventricles to where? | 2. CSF gets absorbed into __ via __

Answer 32

1. Surfaces of cerebellum/brain stem, up through tentorial notch to surface of cerebrum 2. Into dural venous sinuses via arachnoid granulations

Question 33

1. What is hydrocephalus caused from (3)? 2. What can it lead to in infants? 3. Adults?

Answer 33

1. Overproduction, poor absorption or blockage (in adults mostly) of CSF flow 2. Enlarged neurocranium 3. Enlarged ventricles

Question 34

Cavernous sinus 1. 1 artery and 5 nerves pass through this space, what are they 2. Location of this sinus? 3. Infection of which vein can pool in this space and cause problems?

Answer 34

1. Internal carotid artery; abducens nerve, V1, V2, trochlear and oculomotor 2. On each side of the sella turcica 3. Ophthalmic veins (which drain the orbit)

Question 35

1. What parts of the head/face drain into the internal jugular vein 2. What parts of the head/face drain into the external jugular vein 3. How are the cavernous sinus and facial venous complex of IJV connected to each other (2)

Answer 35

1. Cranial cavity and superficial face/neck 2. Exterior cranium and deep face 3. Via ophthalmic veins and pterygoid venous plexus