H&n B3: Venous Drainage Of The Brain And Circulation Of Csf Lecture 12 Handout

Front 1

What are the four main bony sinuses? What happens when fluid collects in them?

Back 1

Maxillary, ethmoid, frontal, sphenoid. Sinus headaches.

Front 2

What do diploic veins drain? Emissary? What do they both drain into?
Where does CSF drain into?

Back 2

Diploic = scalp bones. Emissary = scalp. Both drain into superior sagittal sinus.

CSF from subarachnoid space drains into superior sagittal sinus through arachnoid villi.

Front 3

Superior sagittal sinus:

1) What drains into it?
2) What does it run with?
3) What does it merge with?

Back 3

1) CSF (through arachnoid villi), diploic and emissary veins, superior cerebral veins
2) Falx cerebri
3) Confluence of sinuses in posterior aspect of skull in occipital lobe.

Front 4

Where does blood from the superior aspect of the cerebrum drain into?

Back 4

Superior cerebral vein -> superior sagittal sinus -> confluence -> transverse sinus -> sigmoid sinus -> internal jugular vein

Front 5

What does the inferior sagittal sinus drain into?

Back 5

Straight sinus -> confluence of sinuses -> transverse sinus -> sigmoid sinus -> internal jugular vein

Front 6

Where does blood from the middle portion of the lateral aspect of hte brain and the inferior aspect of the brain drain into?

Back 6

Inferior cerebral vein -> middle cerebral vein -> cavernous sinuses -> inferior or superior petrosal sinus

Front 7

Where does blood from the internal aspect of the brain drain into?

Back 7

Deep cerebral veins -> straight sinus -> confluence of sinuses -> transverse sinus -> sigmoid sinus -> internal jugular vein

Front 8

Where are the cavernous sinuses located? What do they drain into?

What are superior to the sinuses? What structures abut them?

Back 8

Bilaterally, surrounding the pituitary, lateral to the sella turcica.

Drain into internal jugular vein through two pathways:

1) Cavernous sinus -> inferior petrosal sinus -> internal jugular vein

2) Cavernous sinus -> superior petrosal sinus -> transverse sinus -> sigmoid sinus -> internal jugular vein

Optic nerve/optic chiasm superior
Internal carotid artery, oculomotor, abducens, trochlear, V1 (opthalmic nerve) and V2 (maxillary nerve) of trigeminal.

Front 9

Where does venous drainage of the face occur? What is a potential problem?

Back 9

Facial vein -> retromandibular vein -> jugular veins.

However, blood from superior opthalmic vein, inferior opthalmic vein, pterygoid plexus (via emissary) drain into cavernous sinus. (If infections in the face gain access to venous drainage of face, can go to cavernous sinus and cause cavernous sinus thrombosis - fatal)

Front 10

Where is CSF made? What is the lining called? Cells?

How much CSF is produced per hour?

Where does CSF go?

Back 10

Ventricles. Ependymal cells = ventricular lining. Choroid plexus makes CSF.

30 ml/hr

Circulates around nervous system, then drains into veins via superior sagittal sinus.

Front 11

What lobes are the ventricles found in?

What are the two largest ventricles, where are they found, what lobes do they span and what are they divided into?

Back 11

Frontal, parietal, temporal, occipital.

Lateral ventricles, one of each side of the cerebrum. Span the four major cerebral lobes, divided into body, posterior, anterior, and inferior horns.

Front 12

What lies adjacent to the lateral ventricles in the brain?

Back 12

For the most part, caudate nucleus, then hippocampus in the temporal lobe.

Front 13

What is the third ventricle surrounded by?

Where is the fourth ventricle located?

Back 13

Thalamus and hypothalamus.

Posterior aspect of pons and medulla, surrounded on three sides by the cerebellum.

Front 14

What is CSF produced by and where? What is its function?

Map the pathway of CSF.

Back 14

Choroid plexus in lateral, third, and fourth ventricles. Lubricate/protect CNS.

Let Me Think Cause Falling Madly in Love Sounds Awfully Stupid & Vain

Lateral ventricles -> foramen of Monroe -> third ventricles -> cerebral aqueduct -> fourth ventricle -> foramen of Magendie/foramen of Lushka -> subarachnoid space -> arachnoid villi -> superior sagittal sinus -> venous system

Front 15

What are the two cisternae in the subarachnoid space?

Back 15

Cisterna magna, pontine cistern.

Front 16

How does CSF compare to blood plasma?

How much CSF is there in the ventricles normally? What is the rate of production per day? Where does blockage normally occur?

Back 16

Analogous because it has proteins and sugars. Compared to blood plasma, has much less protein, has lower pH, higher Na, Cl, Mg. Lower glucose, K, Ca, bicarb, amino acid.

150 mL normally. 450-700 ml/day, need to constantly drain to avoid hydrocephalus. Blockage normally occurs at Aqueduct of Sylvius.

Front 17

What are the cranial meninges? List all three.

Back 17

Membranes covering the brain and spinal cord.

1) Dura mater (2 layers)
2) Arachnoid
3) Pia

Front 18

Dura mater:

1) Location?
2) How many layers?
3) Primary function?

Back 18

1) Most external layer
2) 2 layers - 1) Outer (periosteal) - closely applied to inner surface of skull. 2) Inner (meningeal) - adjacent to arachnoid mater
3) Strongest of meninges, primarily protects and stabilizes the brain within the skull

Front 19

What are diploe? Describe its structure of bone.

Back 19

Bones of the skull. Compact bone, spongy bone in the middle, then compact bone on the outside. Spongy bone layer sandwich.

Front 20

What are the dural folds formed by? What are the 4 main dural folds and where are they located?

Back 20

Inner dura mater.

1. Falx cerebri - between cerebral hemispheres

2. Falx cerebelli- between cerebellar hemispheres

3. Tentorium cerebelli - separates occipital lobe from underlying cerebellum

4. Diaphragma sellae - stretches between 4 postlike structures in the skull, pierced by the infundibular stalk of the pituitary gland

Front 21

Arachnoid mater:

1) Which layer is it?
2) What are trabeculae?
3) What are villi?

Back 21

1) Middle layer of the cranial meninges
2) Delicate network of connective tissue traversing the subarachnoid space
3) Projections of arachnoid into the inner layer of the dura; contain cerebral veins that drain the brain, meningeal veins, and CSF from subarachnoid space.

Front 22

What are arachnoid granulations?

Back 22

Small collections of arachnoid villi that are commonly found along the superior sagittal sinus

Front 23

Pia mater:

1) Which layer is it?
2) What does it follow in the brain?
3) Is it vascularized?

Back 23

1) Delicate inner cranial meninx
2) Closely applied to the surface of the brain, follows the sulci and gyri
3) Vascularized tissue containing network of tiny blood vessels

Front 24

Describe the spaces of the meninges.

Back 24

1) Epidural - potential space between outer dura and skull. Contains meningeal arteries. Injury here causes epidural hematoma.

2) Subdural space - between inner layer of dura and arachnoid. Contains cerebral veins. Injury causes subdural hematoma.

3) Subarachnoid space - between the arachnoid and pia, filled with CSF.

Front 25

Where does the middle meningeal artery run? What can happen if this artery is injured?

Back 25

Runs up into skull to supply the meninges, found between the dura mater and the skull in the EPIDURAL space. If it breaks, it can rip the dura away from the diploe.

Front 26

How are the eyes related to an epidural hematoma?

Back 26

The superior colliculus can get compressed in an epidural hematoma. Look for light reflex - if you shine a light in one eye and the other doesn't constrict, it's a sign of epidural hematoma.

Front 27

Which is worse, an epidural hematoma or subdural hematoma?

Back 27

Epidural - quick bleed, enormous amount of pressure and can die in moments.

Subdural is slower, can use coagulation therapy, person doesn't have symptoms anymore.

Front 28

What are venous sinuses and where are they located?

What passes through the venous sinuses? Where is it drained?

Back 28

Enlarged veins, located in spaces between inner and outer layer of dura mater.

Deoxygenated blood passes through the venous sinuses, ultimately drained from the skull through internal jugular vein.

Front 29

If there were a cavernous sinus thrombosis, what would be the symptoms?

Back 29

Epineurium of cranial 6 is most exposed to blood in cavernous sinuses. Would see affectation of lateral rectus. So, in a cavernous sinus thrombosis, the eye would be medially deviated.

Another sign is nausea, headaches, dizziness because cavernous sinuses expand superiorly and irritate optic chiasm and optic nerve right on top of the sinuses.

Front 30

CSF:

1) Total volume of CSF in the adult
2) Ventricular volume
3) Produced at a rate of __ ml/minute
4) ___ ml produced per day
5) In adult CSF from lumbar region, contains ____ mg protein/dl fluid
6) In the adult CSF, contains ____ mg glucose/dl fluid
7) Normal CSF contains ___ mononuclear cells

Back 30

1) 150
2) 25 ml
3) .2-.7 ml/min
4) 450-700 ml (handout says 450-700, lecture says 600-700)
5) 15-45
6) 50-80
7) 0-5