Cerebral Blood Flow, Ventricles, meninges and CSF

Question 1

What is the magnum foramen?

Answer 1

Big hole, located at the bottom of the skull.

Space where spinal cord passes thru.

Important location where motor/sensory pathways crossover (decussate- important for speech production).

Question 2

What are the 3 layers of the meninges?

Answer 2

1. Dura Mater- outermost, tough
2. Arachnoid- middle, weblike
3. Pia Mater- innermost, tender

Question 3

Define sulcus and gyrus:

Answer 3

Sulcus= valley
Gyrus= bump

Question 4

Function of the meninges:

Answer 4

Provides buffering/coating to lobes, Provides stability, Anchoring

Question 5

What is the innervation of Dura Mater?

Answer 5

Trigeminal nerve (CN 5)

Question 6

What are 2 important branches in CN5?

Answer 6

1. Opthalmic
2. Mandibular

**See slide 18 in PPt.

Question 7

Dura Mater blood supply?

Answer 7

Meningeal arteries- supplies bone marrow, spreads over inner surface of temporal & parietal bones

Question 8

Describe outer and inner layers of arachnoid:

Answer 8

Outer layer- composed smooth tightly fitting cells impermeable to CSF

Inner layer- Arachnoid trabeculae – delicate strains of connective tissue that loosely connect arachnoid to pia mater

Question 9

What is subdural space?

Answer 9

potential space that could exist between meningeal layer of dura mater and arachnoid layer

Question 10

What is the subarachnoid space composed of?

Answer 10

filled with CSF, blood vessels and cisterns

Question 11

What are arachnoid granulations?

Answer 11

pockets of arachnoid membrane, extend through dura mater into dural venous sinuses

Function: allows CSF to absorb into the bloodstream

Question 12

What is the function of CSF?

Answer 12

Provides mechanical protection/cushioning “bubble wrap”
Facilitates homeostasis (removes waste)
Facilitates communication between CNS & Peripheral nervous system & Immune system

Question 13

Where is CSF found?

Answer 13

ventricular system, cerebral, spinal, & arachnoid, spaces and perivascular spaces in CNS

Question 14

What is the primary source of CSF?

Answer 14

choroid plexus

Question 15

What are the 2 types of CSF flow?

Answer 15

1. Connective flow (unidirectional)
2. Pulsatile Flow (bidirectional)

Question 16

What is hydrocephalus?

Answer 16

Excess CSF builds up in ventricles; enlarging one or more

Question 17

How many cerebral ventricles are there?

Answer 17

4

Question 18

How many lateral ventricles and what shape are they?

Answer 18

2, they are c-shaped

Question 19

What are the 3 big components of the aorta?

Answer 19

1. Brachiocephalic trunk/artery (may be labeled innominate)
2. Left Common Carotid artery
3. Left Subclavian Artery

Question 20

What is the circle of willis?

Answer 20

Meeting of bilateral internal carotids, basilar (formed by merging of vertebral arteries), Posterior communicating artery.

Question 21

Anterior Cerebral artery supplies what?

Answer 21

1. Medial Frontal
2. Medial
3. Superior Parietal

Question 22

Middle cerebral artery supplies what?

Answer 22

Majority of lateral surface of frontal, temporal, parietal

Question 23

Posterior Cerebral artery supplies what?

Answer 23

the occipital lobe,
the inferomedial surface of the temporal lobe,
midbrain,
thalamus and
choroid plexus of the third and lateral ventricles.

Question 24

Which artery supplies the midbrain?

Answer 24

Posterior Cerebral Artery (PCA)

Question 25

Which 2 arteries supply the pons?

Answer 25

Basilar, AICA

Question 26

Which artery supplies the medulla?

Answer 26

posterior & anterior spinal, Basilar

Question 27

Which 3 arteries supply the cerebellum?

Answer 27

1. PICA, 2. AICA, 3. SCA

Question 28

Which 2 arteries supply the spinal cord?

Answer 28

posterior and anterior spinal

Question 29

Define ischemia

Answer 29

inadequate blood perfusion to the tissue, associated with the area of the brain served by the compromised vessel

Question 30

Define hypoxia

Answer 30

inadequate oxygenation

Question 31

Define anoxia

Answer 31

no oxygen

Question 32

Define infarct

Answer 32

A stroke...brain tissue that has died as result of ischemia and thus decreased oxygen to the tissue

Question 33

What are the 3 types of aneurysm?

Answer 33

1. Saccular/berry - pouching of one side of artery 2. Fusiform – ballooning of all sides artery 3. Mycotic – infection weakens the artery

Question 34

What are the Central arteries

Answer 34

Anterior Choroidal Ophthalmic Anteromedial Medial striate artery Medial and lateral lenticulostriate Posterior choroidal Posteromedial All Orphans Are Motherless Making Paternal Problems