Arachnoid Mater Anatomy (including introduction to haemorrhage)

Question 1

What are the three layers of the meninges superficial to deep.

Answer 1

1. Dura mater
2. Arachnoid mater
3. Pia mater

Question 2

What comprises the arachnoid mater?

Answer 2

Numerous irregularly arranges fibroblasts arranged into trabeculae.

Question 3

What layers of meninges are either side of the subarachnoid space?

Answer 3

The arachnoid mater is superficial > subarachnoid space > pia mater is deeper and attaches to the surface of the brain (cerebral parenchyma).

Question 4

What circulates within the subarachnoid space?

Answer 4

Cerebrospinal fluid circulates within the subarachnoid space. Via arachnoid granulations SCF reenters the circulation via the dural sinuses.

Question 5

Within the meninges where do the cerebral blood vessels run?

Answer 5

Within the sub arachnoid space.

Question 6

How many subarachnoid cisterns are located within the brain?

Answer 6

5:

Question 7

What is a subarachnoid cistern?

Answer 7

Subarachnoid cisterns are areas within the subarachnoid space where the the arachnoid mater and the pia mater are further apart forming larger pockets/ collections of CSF.

Question 8

List as many subarachnoid cistern’s as you can.

Answer 8

Cisterna magna,
Pontine cistern,
Quadrigeminal cistern,
Inter-peduncular / basal cistern,
Suprasellar cistern

Question 9

Describe the location of the cisterna magna

Answer 9

The Cisterna magna, the largest subarachnoid cistern is located between the cerebellum and the dorsal surface of the lower posterior regions of the medulla.

Question 10

Describe the location of the Pontine cistern.

Answer 10

The Pontine cistern is located anterior to the ventral aspect of the pons and contains the BASILAR artery.

Question 11

Describe the location of the Quadrigeminal cistern.

Answer 11

The Quadrigeminal cistern is located dorsal to the midbrain colliculi, inferior to the splenium of the the corpus callosum and superior to the cerebellum.
The Quadrigeminal cistern contains the GREAT CEREBRAL VEIN.
*self study note enclosed by brain tissue on all 4 sides (quad).

Question 12

Describe the location of the inter-peduncular or basal cistern.

Answer 12

The Inter-peduncular / basal cistern is located anterior to the ventral aspect of the midbrain between the cerebral peduncles.
The Inter-peduncular cistern contains the posterior part of the CIRCLE OF WILLIS.

Question 13

Describe the location of the Suprasellar cistern.

Answer 13

The Suprasella cistern is located above the sella turcica (boney depression containing the pituitary gland), and inferior to the hypothalamus; and anterior to the basal cistern.
The Suprasella cistern contains the anterior part of the CIRCLE OF WILLIS, the optic chiasm and the pituitary stalk.

Question 14

List all of the subarachnoid cisterns shown in this image (1-5).

Answer 14

1. Cisterna magna
2. Pontine cistern
3. Quadrigeminal cistern
4. Inter-peduncular cistern
5. Suprastella cistern