Anatomy Flashcards
What does the falx cerebri separate?
Right and left cerebral hemispheres
What are the anterior and posterior attachments of the falx cerebri?
Anterior attachement –> Crista galli
Posterior attachement –> continuous with the tentorium cerebelli
What does the tentorium cerebelli?
Separates occipital lobes of cerebrum from cerebellar hemisphere in posterior cranial fossa
What are the anterior/posterolateral attachments of tentorium cerebelli?
Anterior: Posterior clinic process and petrous part of temporal bones
Posterolateral: parietal and occipital bones
What is a tentorial herniation?
Increased pressure within middle cranial fossa squeezes part of temporal lobe through tentorial notch
What nerve can be damaged in a tentorial herniation? What does this lead to?
Oculomotor nerve (CN III) Leads to fixed pupil dilation due to loss of parasympathetic activity
Where is the confluence of sinuses located?
Posterior edge of tentorium cerebelli
What sinuses form a junction at the confluence of sinuses?
Superior sagittal, straight, occipital, transverse
Where does superior sagittal sinus run? Where does it end?
Runs in superior border of falx cerebri
Ends in confluence of sinuses
Where does inferior sagittal sinus run? Where does it end?
Runs in free inferior edge of falx cerebri
Ends in straight sinus
Where does the straight sinus run?
Which structures does it receive?
Where does it end?
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
Where do the transverse sinuses run?
Where do they end posteriorly?
Where do they end anteriorly?
Run along attached posterolateral margins of tentorium cerebelli
End posteriorly in confluence of sinuses
End anteriorly in sigmoid sinus
Where do sigmoid sinuses run?
Where do they end?
They run in the grooves of occipital and temporal bones
End into the internal jugular veins
Where does the occipital sinus run?
Where does it end?
Runs in free edge of falx cerebelli
Ends in the confluence of sinuses
Where are the cavernous sinuses located?
Located on either side of the sella turcica
Which structures are associated with the cavernous sinuses?
Internal Carotid Artery Oculomotor nerve (CN III) Trochlear nerve (CN IV) Ophthalmic (V1) and maxillary (V2) divisions of CN V Abducent nerve (CN VI)
What do the cavernous sinuses recieve?
Superior/Inferior ophthalmic veins
Sphenoparietal sinuses
Superficial middle cerebral veins
Central veins of retina
Cavernous sinus drains into what inferiorly?
Posteriorly?
Inferiorly: Pterygoid Venus plexus
Posteriorly: Superior/inferior petrosal sinuses
What do the intercavernous sinuses do?
Connect the right and left cavernous sinuses
What is Cavernous thrombophlebitis?
What nerves can it effect?
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
Where do the superior petrosal sinuses travel?
What do they drain?
Where do they end?
Along the petrosal(temporal) attachment of the tentorium cerebelli
They drain the cavernous sinuses
They end in the sigmoid sinuses
Where do the inferior petrosal sinuses run?
What do they drain?
Where do they end?
Travel in groove between petrous part of temporal bone and basilar part of occipital bone
Drain the cavernous sinuses
End in sigmoid sinuses
What additional structure do the inferior petrosal sinuses communicate with? How do they do this?
Vertebral venous plexus through the basilar plexus
What is an epidural hemorrhage?
The cause?
Bleeding in the epidural space
Caused by a torn middle meningeal artery
What are subdural hemotomas?
The cause?
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
What is a subarachnoid hemmorage?
Cause?
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
