3: Dural Sinuses and Meninges Flashcards
Two layers of dura mater
- Periosteal layer: attaches to periosteum
2. Meningeal layer
Dural venous sinuses
Gaps between periosteal and meningeal layer of dura mater, are filled with blood
Arachnoid trabeculae
Web of collagen and elastin in arachnoid mater
Space between arachnoid and dura mater
Subdural space
Space between arachnoid and pia mater
Subarachnoid space
Artery that supplies bulk of meninges
Middle meningeal A
Innervation of the meninges (5 parts)
V1, V2, V3, C2, C3
Cranial dural septa
Dura mater extensions deep into cranial cavity for support and stability
Four dural septa
Falx cerebri, falx cerebelli, tentorium cerebelli, diaphragm sellae
Nine dural venous sinuses
- Inferior petrosal
- Superior petrosal
- Confluence of sinuses
- Straight sinus
- Transverse sinus
- Sigmoid sinus
- Inferior sagittal sinus
- Superior sagittal sinus
- Cavernous sinus
Structures in the cavernous sinus
- Pituitary gland
- Internal carotid A
- Nerves: CN 3, 4, 5, 6
Which nerve is freely located in cavernous sinus while other nerves are embedded in CT?
Abducens (CN 6)
Cavernous sinus thrombosis cause
Pt has trauma to face -> thrombus forms, moves through sinuses to the cavernous sinus
Clinical signs of cavernous sinus thrombosis
Edema and erythema around eye, high fever, periorbital edema, cranial nerve palsy of abducens N, decreased visual acuity
Possible tx options for cavernous sinus thrombus
IV Abx, heparin, surgical consult
What forms CSF?
Ependymal cells in choroid plexus in each ventricle
How is CSF similar to blood plasma?
Similar but…
Greater: Na, H, Ca
Less: K
How does CSF drain into dural venous sinuses?
Through arachnoid granulations (villi)
What can cause hydrocephalus
Obstruction in CSF flow that restricts reabsorption into venous bloodstream
Two treatment options for hydrocephalus
- Ventriculoperitoneal shunt -> drain to abdominal cavity
2. Ventriculostomy: hole in floor of 3rd ventricle -> drains to subarachnoid space
Three major veins that drain craniofacial structures
IJV, EJV, facial V
What two veins join to form the retromandibular V?**
Superficial temporal V + maxillary V
What gland does the retromandibular vein run deep with?
Parotid gland
What two veins join to form the EJV?
Retromandibular V + posterior auricular V
What does the facial V create a confluence with?
Retromandibular V
What does the facial V drain into?
IJV
Which four superficial veins form anastomoses with intracranial veins?
Supratrochlear V, supraorbital V, angular V, facial V
What is the importance of superficial veins anastomosing with intracranial veins?
Potential spread of infection into cranium
Two veins that drain the orbit and eyeball
Superior and inferior ophthalmic veins
Main vein that drains the anterior neck
Anterior jugular V
