Lecture 5: Meninges, BBB, and CSF

Question 1

What are the meninges?

Answer 1

Dura mater
Arachnoid mater
Pia mater

Question 2

What is the enhancement the dura mater?

Answer 2

Pachymeninges

Question 3

What is the enhancement if the arachnoid mater and pia mater?

Answer 3

Leptomeninges

Question 4

What is the space between the skull and dura mater?

Answer 4

Epidural space (potential space)

Question 5

What is the epidural space like in the spine?

Answer 5

It is filled with fat

It is an actual space

Question 6

What is the space between the dura mater and arachnoid mater?

Answer 6

Subdural space (potential space)

Question 7

What is the space between the arachnoid mater and pia mater?

Answer 7

Subarachnoid space

Question 8

What is found in the subarachnoid space?

Answer 8

CSF

Question 9

What are the invaginations of dura in the brain?

Answer 9

Falx Cerebri

Tenorium cerebelli

Question 10

What does the falx cerebri do?

Answer 10

Separates the two cerebral hemispheres on the dorsal half

Houses dorsal sagittal sinus

Question 11

What does the tenorium cerebelli do?

Answer 11

Separates the cerebellum from cerebrum

Question 12

What is the path of CSF?

Answer 12

Lateral ventricle in each cerebral cortex
Interventricular foramen
Third ventricle around interthalamic adhesion
Mesencephalic aqueduct through midbrain
Fourth ventricle between pons/medulla and cerebellum
Lateral apertures to subarachnoid space OR central canal in spinal cord

Question 13

What does CSF fill?

Answer 13

The ventricles and subarachnoid space

Question 14

Where is CSF made?

Answer 14

Choroid plexus of lateral and fourth ventricles

Question 15

What is the choroid plexus?

Answer 15

Highly vascularized area of pia mater invaginate into the ventricle covered by ependymal cells

Question 16

What creates the blood-CSF barrier?

Answer 16

Tight junction between the choroid ependymal cells

Question 17

Where is CSF reabsorbed?

Answer 17

Arachnoid villi

Question 18

What does CSF do?

Answer 18

Reduces effective weigh of brain by floating it
Protects from trauma
Maintains chemical environment for neurons by removing waste and providing micronutrients
Collection and analysis of cell count/type and protein count for diagnostics

Question 19

Where do you collect CSF for analysis?

Answer 19

Cisternal or lumbar acquisition

Question 20

What should the CSF look like?

Answer 20

Clear and colorless

Question 21

What is the cell count of CSF?

Answer 21

Less than 5 total nucleated cell count

Mononuclear

Question 22

What is the protein count of CSF?

Answer 22

Less than 25 mg/dl cisternal

Less than 45 mg/dl lumbar

Question 23

What does it mean if the CSF is red tinged?

Answer 23

Xanthochromia

Previous hemorrhage

Question 24

What is red tinged CSF common with?

Answer 24

Equine herpes 1 myeloencephalopathy

Question 25

What does a high white count in CSF mean?

Answer 25

Meningitis, inflammation

Question 26

What does high protein in CSF mean?

Answer 26

Meningitis, tissue damage

Question 27

What happens to the ventral spinal artery become at the foramen magnum?

Answer 27

Basilar artery

Question 28

What does the basilar artery give off?

Answer 28

Caudal cerebellar artery and labyrinthine artery

Question 29

When the basilar artery courses rostrally, what does it branch into?

Answer 29

Right and left to join carotid arteries

Question 30

What does the arterial blood supply in the dog form?

Answer 30

Arterial circle (Circle of Willis)

Question 31

What makes up the Circle of Willis?

Answer 31

Rostral cerebral artery Middle cerebral artery Caudal cerebral artery Rostral cerebellar artery

Question 32

What is the blood supply to the arterial circle in the cat, sheep, and ox?

Answer 32

Maxillary artery to middle meningeal artery and maxillary rete

Question 33

What does the maxillary artery come from?

Answer 33

External carotid artery

Question 34

Why do you not want to use a mouth gag in cats under anesthesia?

Answer 34

It can hyperextend the jaw, which could cut off the blood supply from the maxillary artery leading to cortical blindness

Question 35

Where is the rostral cerebral artery found?

Answer 35

Medial rostral cortex

Question 36

Where is the middle cerebral artery found?

Answer 36

Lateral cortex, deep white and gray matter

Question 37

Where is the caudal cerebral artery found?

Answer 37

Medial caudal cortex, midbrain

Question 38

Where is the rostral cerebellar artery found?

Answer 38

Rostral cerebellum, midbrain

Question 39

Where is the caudal cerebellar artery found?

Answer 39

Caudal cerebellum

Question 40

Where is the labyrinthine artery found?

Answer 40

Brainstem

Question 41

What is in the occipital bone for blood drainage?

Answer 41

Dorsal sagittal sinus and transverse sinus

Question 42

What mirrors the arterial circle in blood drainage?

Answer 42

Cavernous sinus

Question 43

What does the cavernous sinus drain into?

Answer 43

Maxillary, vertebral, occipital, and internal jugular veins

Question 44

What does the blood brain barrier do?

Answer 44

Keeps blood products out of the brain/CSF

Question 45

What does the blood-brain barrier limit?

Answer 45

Pathogen exposure in the brain | Medication exposure in the brain

Question 46

What is the composure of BBB?

Answer 46

Tight junctions between capillary endothelial cells | Astrocytes foot processes surrounding capillaries