Anatomy Flashcards
How much cerebral spinal fluid is circulating in you?
400-500mls
Where is CSF produced?
Choroid plexus of the ventricles
How is CSF reabsorbed?
Through the arachnoid granulations and into the dural venous sinuses
Which level should you do a lumbar puncture?
L3/L4
L4/L5 IV disc
Where does the subarachnoid space end?
Ends at the level of the S2 part of the sacrum
spinal cord ends at L1/L2
Where is the 3rd ventricle?
In the midline within the diencephalon
Where are the left and lateral ventricles?
In the cerebral hemisphere
What does the cerebral aqueduct connect?
The cerebral aqueduct connects the 3rd and 4th ventricles in the midline
Where is the 4th ventricle?
In between the cerebellum and pons
Circulation of CSF
1) secreted by choroid plexus
2) Right & left ventricles
3) 3rd ventricle
4) cerebral aqueduct
5) 4th ventricle
6) Mainly subarachnoid space (but some passes into the central canal)
7) reabsorbed from subarachnoid space via the arachnoid granulations
8) into the dural venous sinuses
Sensory supply to the dura mater?
CNV
Raised ICP and optic nerve
Raised ICP will compress optic nerve
It will also compress central artery and vein of retina
Visual symptoms of optic nerve compression and raised ICP
transient visual obscurations (graying-out of vision), transient flickering blurring of vision constriction of the visual field decreased colour perception
Which nerve might be damaged by tentorial herniation?
Occulomoter nerve (CNIII)
Which nerve supplies 4 extra-ocular muscles and eyelid and innervates the sphincter of the pupil (controls constriction of the pupil) etc?
Oculomotor
What will the eye look like if the oculomotor nerve is damaged?
“down and out”
-loose/slowness of pupillary light reflex, dilated pupils, ptosis, eye turned inferolaterally
Name two of the septa produced when the dura mater folds?
Falx cerebri
Tentorium cerbelli
Somebody has diploplia when looking down and they can’t move their eye infermedially, which nerve is damaged?
The trochlear nerve (CNIV)
Damage to which nerve results in paralysis of the superior oblique muscle?
Trochlear nerve (CNIV)
Eye cannot move laterally in horizontal plane (medial deviation of eye)
Damage to the abducent nerve
If you fracture your zygoma, what tends to happen to it?
It rotates medially
A thick fascial sling that holds the eye just above the floor of the orbit
The suspensory ligament of the eye
What lies in the infraorbital canal?
The infraorbital NVB
-This can be damaged in a zygoma fractue resulting in general sensory deficit of the facial skin
Infraorbital nerve
Large branch of V2
Supraorbital nerve
Large branch of V1
What does the superior oblique muscle do?
Intorsion of the eye
Depression in adduction
Abduction (weak)
Head tilt
CNIV
Painful third nerve palsy
Aneursym!!
What does the medial longitudinal fasciculus do?
It connects CNIII, CNIV and CNVI and carries information about which ways the eye should move
Which nerves supply the angle of the mandible?
CN2, CN3 spinal nerves
CNV1 and the eye
The upper eye lid
Cornea
The conjunctivae
The skin at the root/bridge/tip of the nose
CNV2 and the eye
the skin of the lower eyelid
the skin over the maxilla
the skin of the ala of the nose
the skin/mucosa of the upper lip
CNV3 and the eye
supplies: the skin over the mandible and temporomandibular joint (apart from the angle of the mandible – supplied by C2,3 spinal nerves)
The blink (corneal reflex)
CNV1 –> tigeminal ganglion –> trigeminal nerve (CNV) –> pons
Action potentials –> CNVII –> eyelid part of orbicularis oculi
Which nerve innervates the anterior surface of the eye so that it is sensitive to touch?
CNV1
Ciliary body
Helps the lens to focus