Skull and cranial cavity

Question 1

How many layers does the scalp consist of?

Answer 1

5

Question 2

Describe the innervation of the scalp

Answer 2

Trigeminal nerve(V) and spinal cutaneous nerves

Question 3

What are the bones of the neurocranium?

Answer 3

Occipital, two temporal, two parietal, sphenoid, ethmoid and frontal

Question 4

What are the bones of the viscerocranium?

Answer 4

Two nasal conchae, two nasal bones, two maxilla, two palatine, two zygomatic, two lacrimal, vomer and mandible

Question 5

What are the extra bones in the skull called?

Answer 5

Wormian bones(sutural bones)

Question 6

Why are wormian bones also called sutural bones?

Answer 6

They are called sutural bones because they can occur within a suture(joint) in the cranium

Question 7

What is the base of the skull divided into in terms of foramina?

Answer 7

Anterior, middle and posterior cranial fossa

Question 8

Name the main foramina of the skull

Answer 8

• Cribiform plate
• Optic canal
• Superior orbital fissure
• Foramen rotundum
• Foramen ovale
• Foramen spinosum
• Internal acoustic meatus
• Stylomastoid foramen
• Foramen lacerum
• Jugular foramen
• Hypoglossal canal
• Foramen magnum

Question 9

What are the names of the meningeal layers?

Answer 9

• Dura mater
• Arachnoid mater
• Pia mater

Question 10

What are the functions of the meninges?

Answer 10

• Protection
• Support network for blood vessels
• Form a fluid-filled cavity for cushion and nourish the brain

Question 11

What are the two layers of the dura mater?

Answer 11

• Endosteal layer

- Meningeal layer

Question 12

What does the meningeal layer of the dura mater surround?

Answer 12

• The brain and spinal cord

Question 13

What does the endosteal layer surround?

Answer 13

• Only the skull

Question 14

What is the dura mater innervated by?

Answer 14

• CN V, X, C1-3 and sympathetic

Question 15

What does the middle meningeal artery enter through?

Answer 15

• Foramen spinosum

Question 16

Where is the foramen spinosum located?

Answer 16

• The base of the human skull on the sphenoid bone

Question 17

How is trauma to the head likely to affect the middle meningeal artery?

Answer 17

Can cause an extradural hematoma

Question 18

What is an extradural haematoma?

Answer 18

• Also known as epidural haematoma
• Is a collection blood between the endosteal layer of the dura and the inner surface of the skull
• They are usually associated with a history of head trauma and frequently associated skull fracture

Question 19

What can the dura mater split to form?

Answer 19

A venous dural sinus

Question 20

How is the meningeal layer of dura arranged?

Answer 20

• Arranged in a series of folds/septa which divide the cranial cavity
• Folds or reflections prevent/restrict movement of the brain

Question 21

Purpose of falx cerebri

Answer 21

• Separates cerebral hemispheres

Question 22

Purpose of tentorium cerebelli

Answer 22

• Separates cerebellar hemispheres from cerebral hemispheres

Question 23

Purpose of falx cerebelli

Answer 23

• Separates cerebellar hemispheres

Question 24

What causes a dural headache?

Answer 24

• The dura is sensitive to stretching which can cause a headache
• Extraction of CSF can cause strain on the dura resulting in a dural headache

Question 25

What is a tentorial herniation?

Answer 25

- caused by space occupying lesion which causes a herniation of temporal lobe

Question 26

What is the arachnoid mater?

Answer 26

- Thin avascular layer between pia and dura | - It is loosely applied layer with projections

Question 27

What do all structures passing to/from the brain pass through?

Answer 27

The subarachnoid space

Question 28

What space should not exist unless there is a pathology

Answer 28

The subdural space should not exist unless there is a pathology

Question 29

What are arachnoid granulations

Answer 29

- Arachnoid granulations from the arachnoid layer project into the venous sinus(for filtration of CSF)

Question 30

What does the subarachnoid space(real space) contain?

Answer 30

- Contains CSF: produced by choroid plexus in brain ventricles

Question 31

Purpose of arachnoid granulations

Answer 31

- Arachnoid granulations affect the transfer of CSF to venous sinuses

Question 32

What is the pia mater?

Answer 32

- Very delicate vascular membrane(nourish) - Closely invests brain following gyri/sulci - Cerebral arteries enter brain carrying sheath of pia mater with them

Question 33

What gives the brain a slightly shiny appearance?

Answer 33

- Pia mater

Question 34

What is meningitis an infection of?

Answer 34

- Leptomeningitis is an infection and inflammation in the arachnoid and pia mater(the lepto

Question 35

What is a complication of meningitis?

Answer 35

- The infection may enter into the subarachnoid space and enter into blood(septicemia)

Question 36

Where are dural sinuses located?

Answer 36

- Positioned in the dural fold

Question 37

What do the dural sinuses contain?

Answer 37

- Drained blood and CSF from the brain via cerebral veins

Question 38

Describe the walls of the dural sinuses

Answer 38

- Thick walled endothelium | - No valves or smooth muscle

Question 39

Where does blood from the dural sinuses drain into?

Answer 39

- Internal jugular vein