Anatomy

Question 1

What does the falx cerebri separate?

Answer 1

Right and left cerebral hemispheres

Question 2

What are the anterior and posterior attachments of the falx cerebri?

Answer 2

Anterior attachement –> Crista galli

Posterior attachement –> continuous with the tentorium cerebelli

Question 3

What does the tentorium cerebelli?

Answer 3

Separates occipital lobes of cerebrum from cerebellar hemisphere in posterior cranial fossa

Question 4

What are the anterior/posterolateral attachments of tentorium cerebelli?

Answer 4

Anterior: Posterior clinic process and petrous part of temporal bones
Posterolateral: parietal and occipital bones

Question 5

What is a tentorial herniation?

Answer 5

Increased pressure within middle cranial fossa squeezes part of temporal lobe through tentorial notch

Question 6

What nerve can be damaged in a tentorial herniation? What does this lead to?

Answer 6

Oculomotor nerve (CN III)
Leads to fixed pupil dilation due to loss of parasympathetic activity

Question 7

Where is the confluence of sinuses located?

Answer 7

Posterior edge of tentorium cerebelli

Question 8

What sinuses form a junction at the confluence of sinuses?

Answer 8

Superior sagittal, straight, occipital, transverse

Question 9

Where does superior sagittal sinus run? Where does it end?

Answer 9

Runs in superior border of falx cerebri

Ends in confluence of sinuses

Question 10

Where does inferior sagittal sinus run? Where does it end?

Answer 10

Runs in free inferior edge of falx cerebri

Ends in straight sinus

Question 11

Where does the straight sinus run?
Which structures does it receive?
Where does it end?

Answer 11

Runs in space formed by union of falx cerebri and tentorium cerebelli
It receives inferior sagittal sinus, and great cerebral vein
It ends in confluence of sinuses

Question 12

Where do the transverse sinuses run?
Where do they end posteriorly?
Where do they end anteriorly?

Answer 12

Run along attached posterolateral margins of tentorium cerebelli
End posteriorly in confluence of sinuses
End anteriorly in sigmoid sinus

Question 13

Where do sigmoid sinuses run?

Where do they end?

Answer 13

They run in the grooves of occipital and temporal bones

End into the internal jugular veins

Question 14

Where does the occipital sinus run?

Where does it end?

Answer 14

Runs in free edge of falx cerebelli

Ends in the confluence of sinuses

Question 15

Where are the cavernous sinuses located?

Answer 15

Located on either side of the sella turcica

Question 16

Which structures are associated with the cavernous sinuses?

Answer 16

Internal Carotid Artery
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Ophthalmic (V1) and maxillary (V2) divisions of CN V
Abducent nerve (CN VI)

Question 17

What do the cavernous sinuses recieve?

Answer 17

Superior/Inferior ophthalmic veins
Sphenoparietal sinuses
Superficial middle cerebral veins
Central veins of retina

Question 18

Cavernous sinus drains into what inferiorly?

Posteriorly?

Answer 18

Inferiorly: Pterygoid Venus plexus
Posteriorly: Superior/inferior petrosal sinuses

Question 19

What do the intercavernous sinuses do?

Answer 19

Connect the right and left cavernous sinuses

Question 20

What is Cavernous thrombophlebitis?

What nerves can it effect?

Answer 20

Blood from danger triangle of face can drain through cavernous sinuses. So infections can travel from the danger triangle of the face and can spread effected thrombi to the cavernous sinus.
This can effect the nerves, CNIII, CNIV, CNV1, CNV2, CNVI
Leading to acute meningitis

Question 21

Where do the superior petrosal sinuses travel?
What do they drain?
Where do they end?

Answer 21

Along the petrosal(temporal) attachment of the tentorium cerebelli
They drain the cavernous sinuses
They end in the sigmoid sinuses

Question 22

Where do the inferior petrosal sinuses run?
What do they drain?
Where do they end?

Answer 22

Travel in groove between petrous part of temporal bone and basilar part of occipital bone
Drain the cavernous sinuses
End in sigmoid sinuses

Question 23

What additional structure do the inferior petrosal sinuses communicate with? How do they do this?

Answer 23

Vertebral venous plexus through the basilar plexus

Question 24

What is an epidural hemorrhage?

The cause?

Answer 24

Bleeding in the epidural space

Caused by a torn middle meningeal artery

Question 25

What are subdural hemotomas?

The cause?

Answer 25

Bleeding in the subdural space
Due to tearing of bridging veins that traverse the gap between dural sinuses and cerebral cortex
Higher risk in elderly, B/c brain shrinks increasing gap between dural sinuses and cerebral cortex

Question 26

What is a subarachnoid hemmorage?

Cause?

Answer 26

Bleeding into the subarachnoid space
Causes by rupture of aneurysms of the vessels of the circle of Willus and vessels of anterior cerebral circulation
Start with headaches, stiff neck can lead to coma