Brain Flashcards
Dural Folds (Partitions):
are 5
- Falx cerebri: between the two cerebral hemispheres.
- Falx cerebelli: between the two cerebellar hemispheres.
- Tentorium cerebelli: between the cerebrum and the cerebellum.
- Diaphragma sellae: covers the pituitary gland. The center of the diaphragma sellae is pierced by the infundibulum of the pituitary gland.
- Cavum trigeminal: surrounds the trigeminal ganglion.
Function of the dural folds:
- Support and prevent displacement of the brain during movement of the head.
- Minimize the effect of vibrations on the brain.
- Tentorium cerebelli protects the cerebellum from the weight of the cerebrum
Relations of cavernous sinus
Ant–sup orbital fissure
Post– petrous temporal bone
Lateral– temporal lobe of the brain
Medial — sphenoidal air sinus and pituitary g
Sup– optical chiasma and supra cavernous part of ICA
inf– body of sphenoid and its air sinuses
Structures inside lateral wall of cavernous sinus
OTOM ocuulomotor Trochlear Ophthalmic Maxillary
Within cavernous sinus
ICA
abducent 6
Inferolaterally
Tributaries of cavernous from posterior
inf petrosal sinuses connect it with internal jugular
Sup petrosal connect it with transverse sinus
Both connected by sigmoid sinus
Tributaries of cavernous from anterior
- sphenoparietal sinus
- ophthalmic vein
- central retinal vein
Tributaries of cavernous from medial sup and inf
Inf
..emissary v to pharyngeal plexus and pterygoid plexus
Sup
..superior central cerebral vein
.. inferior cerebral v
Medial
Inter cavernous sinuses
What’s an emissary vein
It connects the dural sinuses with veins outside the skull
Factors facilitating spread of infection to cavernous sinus
Face has no deep fascia that act as barrier against spread of infection
The veins are valveless so it allow spread to cavernous s ex squeezing an abscess in the face
Symptoms of cavernous sinus thrombosis
- pulging and edema of the eye
- blindness
Due to impaired venous return from retina
Paralysis of
Occulomotor
Trochlear
Abducent
And ophthalmic
Parotid capsule origin
Drived from investing layer of deep temporal fascia
Lateral surface of parotid
Skin and sup fascia contain
G auricular
Pre auricular Ln
Relations of postero medial parotid surface
Carotid sheath with (ICA-IJV-last 4 cranial N)
Styloid process with all attached structures
(Stylohyoid L - stylomandibular L - stylohyoid ms - stylopharyngeus ms- styloglossus ms)
Mastoid process and attached ms (sterno m - and post b of digastric)
Penetration by facial n
N supply to parotid
Nerve Supply:
Parotid gland
- Sensory:
a. Capsule: great auricular nerve.
b. Parenchyma: auriculotemporal nerve - Parasympathetic: inferior salivatory nucleus➡ glossopharyngeal nerve ➡ lesser
petrosal nerve otic ganglion➡ reach the gland with the auriculotemporal nerve.
- Sympathetic: plexus around external carotid artery.
Surface Anatomy of parotid duct
Surface Anatomy:
Middle third of a line between the tragus of the auricle and midway between the lip margin and the ala of the nose.
- Pia Mater (the inner layer
⚫ It is a highly vascular membrane closely adherent to the brain and the spinal cord. • It takes part in formation of the choroid plexus in the ventricles.
Arachnoid Membrane
(the middle layer):
• It is a nonvascular membrane located between the pia mater and the dura mater. • It forms the arachnoid granulations and villi, which project into the dural venous sinuses and permits flow of the CSF from the subarachnoid space to the venous sinuses.
- Dura Mater
(the outer layer):
It is a dense, strong fibrous membrane surrounding the brain and spinal cord.
• It is formed of two layers:
- Outer endosteal layer: is the endosteum of the cranial cavity. It is continuous with the periosteum on the outer surface of the skull at the foramena of the skull.
- Inner meningeal layer: is continuous with the spinal dura mater. The meningeal
layer is reduplicated in some areas to form five dural folds.
• The 2 layers are fused except in areas where they separate to form the dural sinuses.
Depending upon which part is affected, malocclusion can be broadly divided into؟
1- Malposition of individual teeth.
2- Malrelations of dental arches or dentoalveolar segments.
3- Malrelation of dental bases (skeletal malrelationship),
Depending upon which part is affected, malocclusion can be broadly divided into؟
1- Malposition of individual teeth.
2- Malrelations of dental arches or dentoalveolar segments.
3- Malrelation of dental bases (skeletal malrelationship),
