Brain

Question 1

Dural Folds (Partitions):

Answer 1

are 5

1. Falx cerebri: between the two cerebral hemispheres.
2. Falx cerebelli: between the two cerebellar hemispheres.
3. Tentorium cerebelli: between the cerebrum and the cerebellum.
4. Diaphragma sellae: covers the pituitary gland. The center of the diaphragma sellae is pierced by the infundibulum of the pituitary gland.
5. Cavum trigeminal: surrounds the trigeminal ganglion.

Question 2

Function of the dural folds:

Answer 2

1. Support and prevent displacement of the brain during movement of the head.
2. Minimize the effect of vibrations on the brain.
3. Tentorium cerebelli protects the cerebellum from the weight of the cerebrum

Question 3

Relations of cavernous sinus

Answer 3

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

Question 4

Structures inside lateral wall of cavernous sinus

Answer 4

OTOM
ocuulomotor
Trochlear
Ophthalmic 
Maxillary

Question 5

Within cavernous sinus

Answer 5

ICA
abducent 6
Inferolaterally

Question 6

Tributaries of cavernous from posterior

Answer 6

inf petrosal sinuses connect it with internal jugular

Sup petrosal connect it with transverse sinus

Both connected by sigmoid sinus

Question 7

Tributaries of cavernous from anterior

Answer 7

• sphenoparietal sinus
• ophthalmic vein
• central retinal vein

Question 8

Tributaries of cavernous from medial sup and inf

Answer 8

Inf
..emissary v to pharyngeal plexus and pterygoid plexus

Sup
..superior central cerebral vein
.. inferior cerebral v

Medial
Inter cavernous sinuses

Question 9

What’s an emissary vein

Answer 9

It connects the dural sinuses with veins outside the skull

Question 10

Factors facilitating spread of infection to cavernous sinus

Answer 10

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

Question 11

Symptoms of cavernous sinus thrombosis

Answer 11

• pulging and edema of the eye
• blindness
  Due to impaired venous return from retina
  Paralysis of
  Occulomotor
  Trochlear
  Abducent
  And ophthalmic

Question 12

Parotid capsule origin

Answer 12

Drived from investing layer of deep temporal fascia

Question 13

Lateral surface of parotid

Answer 13

Skin and sup fascia contain
G auricular
Pre auricular Ln

Question 14

Relations of postero medial parotid surface

Answer 14

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

Question 15

N supply to parotid

Answer 15

Nerve Supply:

Parotid gland

1. Sensory:
   a. Capsule: great auricular nerve.
   b. Parenchyma: auriculotemporal nerve
2. Parasympathetic: inferior salivatory nucleus➡ glossopharyngeal nerve ➡ lesser

petrosal nerve otic ganglion➡ reach the gland with the auriculotemporal nerve.

3. Sympathetic: plexus around external carotid artery.

Question 16

Surface Anatomy of parotid duct

Answer 16

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.

Question 17

1. Pia Mater (the inner layer

Answer 17

⚫ 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.

Question 18

Arachnoid Membrane

Answer 18

(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.

Question 19

3. Dura Mater

Answer 19

(the outer layer):

It is a dense, strong fibrous membrane surrounding the brain and spinal cord.

• It is formed of two layers:

1. 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.
2. 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.

Question 20

Depending upon which part is affected, malocclusion can be broadly divided into؟

Answer 20

1- Malposition of individual teeth.

2- Malrelations of dental arches or dentoalveolar segments.

3- Malrelation of dental bases (skeletal malrelationship),

Question 21

Depending upon which part is affected, malocclusion can be broadly divided into؟

Answer 21

1- Malposition of individual teeth.

2- Malrelations of dental arches or dentoalveolar segments.

3- Malrelation of dental bases (skeletal malrelationship),