Anatomy: Brain

Question 1

What is a general description of the internal surface of the brain?

Answer 1

3 step progression downwards and the floor corresponds to this shape. Cranial nerves arise from the inferior surface of the brain.

Question 2

What are the different levels of the brain called?

Answer 2

Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa

Question 3

What forms the anterior cranial fossa?

Answer 3

Horizontal part of the frontal bone with the intervening cribiform plate and the lesser wing of the sphenoid

Question 4

What is in between the ACF?

Answer 4

The ethomoid bone which consists of the cribiform plate and cristagilli.

Question 5

What is the cristagilli?

Answer 5

A vertical plate projecting from the the middle of the ethmoid.

Question 6

What is the significance of the cribiform plate?

Answer 6

It has holes where the oflactory nerves come though.

Question 7

Which cranial nerve passes through the cribiform plate?

Answer 7

The Olfactory Nerve (CNI)

Question 8

What forms the Middle cranial fossa (MCF)

Answer 8

Temporal lobes with the body and greater wing of sphenoid anterior and petrous part of sphenoid anteriorly.

Question 9

What are the foramen of the MCF and what is their significance?

Answer 9

Hypophysial fossa: pituitary gland
Optic canal: Optic nerve and opthalmic artery
Superior orbital fissure: extraocular muscles, branches of trigeminal nerve
Arc of forameniae

Question 10

What is the significance of the arc of forameniae

Answer 10

Foramen rotundum: maxillary
Formane ovale: mandibular
Foramen spinosum: middle meningeal artery

Question 11

What is the foramen lacerum?

Answer 11

Looks like a big hole in the pracs but in reality it is covered by a membrane.

Question 12

What is the posterior cranial fossa?

Answer 12

Occipital bone

Question 13

Which foramen are located in the PCF?

Answer 13

Internal acoustic meatus: facial and vestibulocochlear nerves
Jugular foramen: IX, X, XI, internal jugular vein
Hypoglossal canal: hypoglossal foramen
Foramen magnum: brain stem

Question 14

What are layers of the meninges?

Answer 14

Dura, arachnoid and pia matter

Question 15

What is the extradural space?

Answer 15

Space between the skull and the dura.

Question 16

Which kind of blood vessel is affected in the extradural space?

Answer 16

Normally a tear in the artery

Question 17

What is the subdural space?

Answer 17

Arachnoid-dura

Question 18

What is the function of the dura partition?

Answer 18

To prevent rotation of the brain.

Question 19

Where are the dura septum, there are 3 of them?

Answer 19

1 coming from above,
1 coming from behind,
1 separating left and right

Question 20

What are the different types?

Answer 20

Falx cerebri, tentorium cerebelli, falx cerebelli and diaphragma sellae.

Question 21

What is the falx cerebri ?

Answer 21

Fold of dura which has left the internal surface of the skull and projecting down between the cerebral hemispheres.

Question 22

Where is falx cerebri located?

Answer 22

Lies in the midline between left and right cerebral hemispheres

Question 23

Where does the falx cerebri run to?

Answer 23

Upper margin runs along the inside of the SAGGITAL SUTURE, extending all the way back to the external occipital protuberance.

Question 24

Where is the tentorium cerebelli?

Answer 24

Coming from behind more horizontally orientated.

Question 25

Where does the tentorium cerebelli attach?

Answer 25

Attaches to the internal surface of the cranium posterior and projecting forwards

Question 26

Where does the tentorium cerebelli lodge in between?

Answer 26

The occipital lobe and the cerebellum, roofing over the posterior cranial fossa.

Question 27

What is the falx cerebelli

Answer 27

Small projection separating right and left cerebella hemispheres

Question 28

Where does the diaphragma sella sit?

Answer 28

Sits over the the depression of the sphenoid.

Question 29

What are the 2 venous sinuses?

Answer 29

Superior saggital sinus and inferior sagittal sinus

Question 30

Where does the superior sagittal sinus run?

Answer 30

Runs in the superior border of the falx cererbri

Question 31

What is the function of the superior sagittal sinus

Answer 31

Collected venous drainage from the brain

Question 32

What is the course of the veins in the brain in re lation to the venous sinuses?

Answer 32

Emissary veins (external structures) - diploic veins - sinuses - meeting at the confluence of sinuses

Question 33

Why do we have to know the venous sinuses?

Answer 33

Infection in scalp can travel through to the meninges which can cause encephalitis and meningitis

Question 34

What is the significance of the veins subdurally?

Answer 34

The cerebral veins which enter the superior sagittal sinus can be torn easily.

Question 35

Where is the interior sagittal sinus?

Answer 35

Space between the dura in the inferior margin of the falx cerebri.

Question 36

What is the interior sagittal sinus’s course?

Answer 36

Great cerebral vein-straight sinus

Question 37

What is the arachnoid layer?

Answer 37

layer which lines the inner surface of dura. Spiderweb appearance

Question 38

What is the pia matter attached to?

Answer 38

Attached to brain tissue.

Question 39

What is the course of the veins in the brain?

Answer 39

Superior and inferior sagittal sinus → straight sinus → confluence of sinuses → right/left transverse sinus → right sigmoid sinus → jugular foramen → internal jugular vein

Question 40

What is the carvenous sinus?

Answer 40

Venous sinus which sits on either side of the sphenoid body.