Cranium, Meninges, etc... Flashcards
What passes through the optic canal and what does it do?
CNII (Optic Nerve)…carries visual information from the retina of the eye back to the brain
What passes through the superior orbital fissure?
CN III (occulomotor), IV (Trochlear), VI (Abducens), and the V1 branch of CN V (Trigeminal)
Occulomotor, trochlear, and abducens allow for control of the orbital muscles which move the eye and constrict the pupil
What passes through the foramen ovale
V3
What passes through the foramen spinosum?
Middle meningeal arteryenters the skull
Internal carotid artery gains entry into the skull by entering through which pathway?
Carotid foramen, passes through a bony canal, and then enters the skull via the carotid canal
CN VII exits the skull via
Stylomastoid foramen
CN VIII exits skull via
external auditory meatus
The jugular foramen permits exit of what
CN IX, X, II
CN XII exits the calderium via the hypoglossal canal
ok
How many layers of meninges are there?
3
From the brain out: - Pia Mater: very thin, tight against brain surface
- Arachnoid mater: Thicker
- Dura Mater: double membrane, Meningeal layer closest to the brain and periosteal layer furthest out
The two layers of the Dura mater separate where to form what
Separate in the midline and at the lateral aspects to form large venous sinuses known as the superior sagittal sinus and the lateral sinuses.
The meningeal layer of the Dura mater creates a thick membrane called the —–, that separates left and right cerebral hemisphere. Also creates another membrane that separates the cerebral hemispheres from the cerebellum
falx cerebri
Tentorum Cerebelli
Three important spaces associated with the meninges?
- Epidural and Subdural spaces, these are called potential spaces.
- Epidural bleeding is usually arterial, subdural usually venous
- Subarachnoid: True space that is lined by the arachnoid above and the pia mater below. The bulk of the CSF, large blood vessels all lie in subarachnoid
What 2 pairs of arteries supply the brain
Right and Left Internal Carotid- Formed from division of common carotids just below the angle of jaw. Externals supply the face, scalp and meninges
Right and Left Vertebral-
Internal carotid arteries become what once they get inside the skull?
Middle Cerebral and Anterior cerebral
Opthalmic arteries branch off of what
Internal carotid, they are the first branch
Right and left vertebral arteries originate from where?
Subclavian
Why is the Circle of Willis important
It provides the potential for collateral blood flow if one or more of the four major arteries is obstructed or occluded
Note that the lesser wing of the sphenoid bone (separating the anterior fossa of the skull from the middle) and the petrous ridge of the temporal bone (sep middle from posterior) create bony ridges which the skull can rub against and be injured if it accelerates or decelerates quickly
ok
Dura mater continues out into the peripheral nerve to form what layer
epineurium
Arachnoid continues out into the peripheral nerve to form what layer?
Perineurium
