orbit

Question 1

extrinsic (extra-ocular) muscles

Answer 1

1. levator palpebrae superioris
2. superior rectus
3. inferior rectus
4. lateral rectus
5. medial rectus
6. superior oblique
7. inferior oblique

moving of eyeball and raising upper eyelids

Question 2

blood supply, venous drainage and innervation of orbital cavity

Answer 2

blood supply

• internal carotid artery
• ophthalmic artery (branch of internal carotid artery)

veins

- inferior ophthalmic vein
- superior ophthalmic vein

nerves

- optic nerve
- ophthalmic nerve and its branches (V1)
- trochlear nerve
- oculomotor
- abducens
- autonomic nerves

Question 3

extradural/epidural hemorrhage

Answer 3

meningeal arterial damage (in temporoparietal region)

forms between skull and dura mater

associated with skull fracture

biconvex/lens-shape

can shift falx cerebri

Question 4

subdural hemorrhage

Answer 4

damage to cerebral veins
(that cross this space from brain to superior sagittal sinus can cause this bleed)

forms between dura mater and arachnoid mater

can shift lateral ventricles

Question 5

subarachnoid hemorrhage

Answer 5

bleed in subarachnoid space

cerebral arterial damage/intracerebral bleed
-ruptures cerebral artery aneurysm of circle of willis

causes sudden severe headache, vomiting and loss of consciousness

Question 6

superior sagittal sinus

Answer 6

empty into right transverse sinus via confluence of sinues

located in superior border of falx cerebri

Question 7

inferior sagittal sinus

Answer 7

empty into straight sinus (joined by great cerebral vein

located in inferior border of falx cerebri

Question 8

straight sinus

Answer 8

empty into left transverse sinus via confluence of sinuses

located at the junction of falx cerebri and tentorium cerebelli

Question 9

confluence of sinuses

Answer 9

empty into transverse sinuses (recieves from superior sagittal, straight, occipital sinus)

dilated space at the internal occipital protuberance

Question 10

transverse sinus

Answer 10

empty into sigmoid sinuses

along the posterior and lateral attachments of the tentorium cerebelli

Question 11

sigmoid sinus

Answer 11

empty into internal jugular veins

groove of parietal, occipital and temporal bones

continuagtion of transverse sinus

Question 12

cavernous sinuses

Answer 12

empty into superior and inferior petrosal sinus

located at the lateral aspect of body of sphenoid

has connections with veins from outside of the skull (cerebral, ophthalmic, emissary veins) which provide connectional pathways for infections to pass from extracranial sites to intracranial locations

Question 13

what is the difference between the intracranial and intra-spinal dura mater

Answer 13

intracranial dura mater
-has both periosteal and meningeal layer

intra-spinal
-only has meningeal layer of dura mater (periosteal seals skull)

Question 14

what structures run within the cavernous sinus

Answer 14

• internal carotid artery

- abducens nerve

Question 15

what structures run within the wall of the cavernous sinus

Answer 15

• V1
• V2
• oculomotor
• trochlear