Lecture 16- Dural venous sinuses and ventricular system

Question 1

What are the dural venous sinuses

Answer 1

Endothelium lined spaces located between the outer periosteal and inner meningeal layers of dura mater
Receive tributaries from brain, diploe of skull, internal ear and orbit

Question 2

What is the role of the dural partitions and what are their names

Answer 2

Restrict rotary displacement

1. falx cerebri
2. tentorium cerebelli
3. falx cerebelli
4. diaphragma sellae

Question 3

Superior saggital sinus and flow

Answer 3

Sup. saggital sinus located within upper margin of F. cerebri: blood travelling within this sinus flows towards confluence of sinus and into right transverse sinus
Confluence is point where sup.saggital, straight, occipital and trasnverse sinuses meet

Question 4

Inferior sagittal sinus and flow

Answer 4

Inferior sagittal sinus located within lower margin of falx cerebri- blood travelling within it flows into STRAIGHT SINUS, into confluence of sinuses and into left transverse sinus

Question 5

Right and left transverse sinuses and flow

Answer 5

Right and left sigmoid sinuses respectively

Each sigmoid sinus will become internal jugular vein at jugular foramen

Question 6

Superior and inferoir petrosal sinuses position

Answer 6

Superior- within margin of tentorium cerebelli attached to superior broder of petrous part of temporal bone
Deliver blood from cavernous sinuses to junction between TV/ Sigmoid sinuses
Inferior- within groove between the petrous part of temporal bone and occipital bone
Drain cavernous sinuses and open into transition point of sigmoid sinus into I.Jugular v

Question 7

Cavernous sinuses

Answer 7

located on either side of sella turcica, connected by intercavernous sinus
receive number of tributaries from: Sup/ Inf ophtlamic veins
Spheno-parietal sinuses- these located along lesser wing of sphenoid bone

Question 8

What is the danger triangle of the face?

Answer 8

Area where veins contained are tributaries of facial vein- communicates w/ cavernous sinuses via sup/inf opthalmic vv, infection can spread from face into cranial cavity

Question 9

What is the choroid plexus and where is it located

Answer 9

Plexus containing choroidal epithelial cells which secrete CSF
Located in Lateral ventricles (main producer), 3rd and 4th ventricles

Question 10

Functions of CSF

Answer 10

Cushions brain within cranial cavity
Provides nutrients
Responsible for removal of waste products from brain

Question 11

What 2 structures does the interventricular foramina connect

Answer 11

Lateral ventricles and 3rd ventricle

Question 12

How does CSF flow

Answer 12

Lateral ventricle> third ventricle (through IVF) > cerebral aqueduct ( aqueduct of Sylvius) > fourth ventricle > median aperture and 2 lateral apertures > subarachnoid space

Question 13

How is CSF absorbed through arachnoid granulations?

Answer 13

Prolongations of arachnoid mater that protrude through meningeal layer of dura mater/ open into dural venous sinuses- involved in resoprtion

Question 14

Clinical relevance- what can happen if CSF flow in the ventricular system is obstructed?

Answer 14

Can be due to tumour(s), and can lead to rise in fluid pressure ( hydrocephalus)
Symptoms- headaches, unsteadiness, mental impairment
Decompression acheived by inserting a peritoneal stunt