Meningeal Coverings and CSF

Question 1

What are the 3 layers of the meningeal coverings?

Answer 1

Dura Mater
Arachnoid
Pia Mater

Question 2

The dura mater is pain sensitive. What innervates these sensory parts?

Answer 2

Front: Trigeminal Nerve
Back: Cervical Nerves

Question 3

What is the main function of the dura mater?

Answer 3

Provides mechanical strength

Question 4

What is located beneath the tentorium cerebella?

Answer 4

Cerebellum

Question 5

What is the danger with infections of the skin on the head?

Answer 5

Infections have a chance of spreading to the CNS because blood vessels run from the skin through the skull into the dura mater.

Question 6

What is the arachnoid mater and its function?

Answer 6

It is thin, avascular, and several layers of cells adhering to the dura and it has its main function as a barrier.

Question 7

What are the arachnoid trabeculae?

Answer 7

They are strands of collagenous connective tissue and scattered cells and function to suspend the brain.

Question 8

What is the subarachnoid space?

Answer 8

Space between the arachnoid and the pia mater

Question 9

How does the CSF enter the venous system?

Answer 9

Through the arachnoid villi

Question 10

What is the pia mater?

Answer 10

It closely covers the surface of the brain and is very thin

Question 11

What cells lie directly underneath the pia mater?

Answer 11

Astrocytes

Question 12

Where are the two places where the pia mater thickens?

Answer 12

Dentate Ligaments

Filum Terminale

Question 13

Where do vessels enter and leave the brain?

Answer 13

Perivascular Space (Virchow-Robin Space)

Question 14

What holds the spinal cord in place?

Answer 14

Dentate Ligaments

Question 15

What is the cranial epidural space?

Answer 15

There is none in normal cases

Question 16

What is the spinal epidural space?

Answer 16

It is the space between the periosteum and the dura and it is filled with connective tissue and vertebral venous plexus.

Question 17

Where do the spinal dura and arachnoid end?

Answer 17

S2

Question 18

What is a subarachnoid cistern? Where is the large subarachnoid cistern located?

Answer 18

It is a surface irregularity of the arachnoid space. The large cistern is located at the lumbar cistern.

Question 19

Describe the ventricular system of the brain.

Answer 19

The lateral ventricle is tubular and empties into the 3rd ventricle which is like a slit and it empties into the 4th ventricle which then goes down the central canal.

Question 20

What connects the lateral ventricle and the 3rd ventricle?

Answer 20

Interventricular Foramen (Foramen of Monro)

Question 21

What connects the 3rd and 4th ventricle?

Answer 21

Cerebral Aqueduct (Sylvius)

Question 22

What is the canal of the median aperture and what does it connect?

Answer 22

Canal of Magendie and it connects the 4th ventricle and the subarachnoid space

Question 23

What is the canal of the lateral aperture and what does it connect?

Answer 23

Canal of Luschka and it connects the 4th ventricle and the subarachnoid space

Question 24

Where is the CSF made?

Answer 24

Choroid Plexus

Question 25

What are some important features of the choroid plexus?

Answer 25

It acts as a CSF-blood barrier with the choroid epithelium, which is a specialized ependyma.

Question 26

What makes up the choroid plexus?

Answer 26

Capillaries Pia Choroid Epithelium

Question 27

What is the difference between the ependyma and the choroid epithelium?

Answer 27

The choroid epithelium has cells connected by tight junctions that form the CSF-blood barrier

Question 28

Where is the choroid plexus found?

Answer 28

The choroid plexus occurs near the central ventricles where the pia is close to the choroid epithelium. It is found in all of the ventricular components except for the cerebral aqueduct, frontal horn of the lateral ventricle, and occipital horn of the lateral ventricle.

Question 29

What are the functions of the CSF?

Answer 29

Mechanically supports the brain by making it lighter. Acts as a medium for neuroactive hormones to travel through.

Question 30

What is the most common cause of hydrocephalus?

Answer 30

Malfunction in the resorption of CSF

Question 31

What is a sensory circumventricular organ?

Answer 31

Area Postrema

Question 32

What is a secretory circumventricular organ?

Answer 32

Neurohypophysis

Question 33

What are tanycytes?

Answer 33

They are specialized ependymal cells that overlie circumventricular organs; barrier between organ and ventricular CSF

Question 34

What kind of brain herniation pushes the dura away from the skull?

Answer 34

Epidural