Lecture 10 - Intracranial Anatomy

Question 1

What two parts make up the neurocranium?

Answer 1

Cranial vault/calavaria (top) & Cranial base (bottom)

Question 2

How does the cranial vault form?

Answer 2

intramembranous ossification

Question 3

How does the cranial base form?

Answer 3

endochondral ossification

Question 4

What makes up the viscerocranium?

Answer 4

face & mandible

Question 5

What two types of bone comprise the cranial vault?

Answer 5

Compact bone: hard, inner & outer layers

Diploe: middle, spongy bone

Question 6

Cranial sutures

Answer 6

Fibrous joint held together by Sharpey’s fibers (collagen type III)

Question 7

Sutural (wormian) bones

Answer 7

small, irregular bones that develop within sutures

Question 8

Emissary veins

Answer 8

external veins that drain through diploic veins to internal dural sinuses

Question 9

Dural sinuses

Answer 9

A potential route of infection from the scalp into the cranial cavity

Question 10

What are the 4 paranasal sinuses & the cells that act as another “sinus”

Answer 10

Frontal, ethmoidal, sphenoidal, maxillary (antrum)

mastoid air cells

Question 11

Semilunar hiatus

Answer 11

Drains frontal, maxillary, and anterior ethmoidal sinuses into the nasal cavity

Question 12

Where do the posterior ethmoidal and sphenoidal sinuses drain into?

Answer 12

The nasopharynx

Question 13

What nerve runs through the maxillary sinus?

Answer 13

maxillary nerve (2nd branch of trigeminal CN V)

Question 14

What are the 3 meningeal layers?

Answer 14

Dura mater, arachnoid mater, pia mater

Question 15

What is the order of the tissue layers on the cranium?

Answer 15

Skin, periosteum, bone, dura mater, arachnoid mater, pia mater

Question 16

What artery supplies the meninges?

Answer 16

middle meningeal artery branch from the maxillary artery

Question 17

What is the modality & innervation of the meninges in the anterior & middle cranial fossae?

Answer 17

GSA, Trigeminal (CN V)

Question 18

What is the modality & innervation of the meninges in the posterior cranial fossa?

Answer 18

GSA, Glossopharyngeal (CN IX), Vagus (CN X), & C1-C3

Question 19

What structures does the dura mater form?

Answer 19

The folds around the parts of the brain including: tentorium cerebelli & falx cerebri

Question 20

What sinuses do the dural folds contain?

Answer 20

Dural sinuses

Question 21

Falx cerebri

Answer 21

Separates the left and right cerebral hemispheres

Question 22

Tentorium cerebelli

Answer 22

Separates the cerebrum and cerebellum

Question 23

What meningeal layer allows for CSF to enter the dural sinuses and return to systemic circulation?
Bonus: What are these structures called?

Answer 23

Arachnoid mater

Bonus: arachnoid granulations

Question 24

Pia mater

Answer 24

Impermeable to CSF fluid and forms perivacular spaces which act as the brains’ lymphatic system

Question 25

Where is the superior & inferior sagittal sinuses?

Answer 25

In the falx cerebri

Question 26

Where is the straight sinus?

Answer 26

At the junction of falx cerebri & tentorium cerebelli

Question 27

Where is the transverse sinus?

Answer 27

In tentorium cerebelli

Question 28

Where does the sigmoid sinus drain into?

Answer 28

It drains into the internal jugular vein

Question 29

What does the cavernous sinus surround?

Answer 29

The internal carotid artery

Question 30

Where does the internal jugular vein exit the skull?

Answer 30

The sigmoid sinus

Question 31

Where do the vertebral veins exit the skull?

Answer 31

Through the vertebral venous plexuses through the foramen magnum

Question 32

Where does the maxillary vein exit the skull?

Answer 32

It exits through the cavernous sinus and pterygoid venous plexuses

Question 33

What is located in the anterior cranial fossa?

Answer 33

Frontal lobes & olfactory bulbs

Question 34

What is located in the middle cranial fossa?

Answer 34

Temporal lobe, pituitary gland, and the cavernous sinus

Question 35

What is located in the posterior cranial fossa?

Answer 35

Cerebellum, medulla, & pons

Question 36

What vessels are located in the middle cranial fossa?

Answer 36

The internal carotid artery, ophthalmic arteries, and middle meningeal vessels

Question 37

What nerves are located in the middle cranial fossa?

Answer 37

Meningeal nerves, CN II, II, IV, V, VI, Trigeminal ganglion, greater facial nerve, and lesser petrosal nerves

Question 38

Anastomosis

Answer 38

An alternative route for vascular flow commonly found in joints or organs with high vascular requirements

Question 39

What does the external carotid artery supply?

Answer 39

face, scalp, skull, & meninges

Question 40

What does the internal carotid artery supply?

Answer 40

brain & eyes

Question 41

What does the carotid sinus measure?

Answer 41

Blood pressure

Question 42

What does the carotid body measure?

Answer 42

Blood oxygen content

Question 43

What connects the cavernous sinus to the facial vein?

Answer 43

Ophthalmic veins