T1L2 skull and cranial cavity

Question 1

layers of the scalp

innervation

Answer 1

• skin
• connective tissue
• aponeurotic layer
• loose connective tissue
• pericranium

innervated by trigeminal nerve and spinal cutaneous nerve

Question 2

2 types of skull bones and how many

Answer 2

neurocranium (cranium) - 8

viscerocranium (facial bones) - 14

Question 3

foramina in skull to learn

Answer 3

• cribiform plate
• optic canal
• superior orbital fissure
• foramen rotundum
• foramen ovale
• foramen spinosum
• internal acoustic meatus
• stylomastoid foramen
• foramen lacerum
• jugular foramen
• hypoglossal canal and foramen magnum

Question 4

skull divided into 3

Answer 4

cranial fossa
see s5
anterior, middle and posterior cranial fossa

Question 5

3 layers of meninges and its role

Answer 5

1. dura mater
2. arachnoid mater
3. pia mater

role to protect, support network of vessels, cushion and nourish the brain

Question 6

dura mater

Answer 6

2 layers of dm around brain:

• endosteal layer
• meningeal layer

the 2 are closely applied to each other

• meningeal layer around brain and spinal chord
• endosteal layer just lines skull

nerve supply: CN5,10, C1-3 and sympathetic
blood: middle meningeal

Question 7

meningeal layer of dura

Answer 7

• arranged in folds/septa which divide cranial cavity. these restrict the movement of the brain

1. falx cerebri separates cerebral hemispheres
2. tentorium cerebelli - separates cerebellar hemispheres from cerebral hemispheres
3. falx cerebelli - separates cerebellar hemispheres

sensitive to stretching - headaches

Question 8

arachnoid mater

Answer 8

• thin avascular layer between pia and dura
• loosely applied layer with projections
• everything passing into or out of brain pass through the subarachnoid space

subdural space (Above)
arachnoid mater
subarachnoid space (below)

see s10,11

subarachnoid space contains csf (produced by choroid plexus in brain ventricles)

• provides buoyancy for protection
• arachnoid granulations affect transfer of csf to the venous sinuses

Question 9

pia mater

Answer 9

• delicate vascular membrane
• close to brain. follows gyri and sulci
• cerebral arteries enter brain carrying sheath of pia mater with them

leptomeningitis is an infection and inflammation in the arachnoid and pia mater. this may enter subarachnoid space and get into the blood

Question 10

dural sinuses

Answer 10

• sit between the dural fold
• drained blood and csf from brain via cerebral veins
• communicate with veins of skull and scalp
• thick walled endothelium with no valves or smooth muscle
• drain into internal jugular vein

Question 11

blood supply to brain

Answer 11

• internal carotid and vertebral artery
• anastomose at circle of willis

Inside the skull there are two terminal branches: the anterior cerebral and middle cerebral artery
Vertebral arteries passes within cervical vertebrae and enter foramen magnum where they unite to form the basilar artery.
s16

Question 12

circle of willis

Answer 12

learn s17

Question 13

cerebral artery

Answer 13

• each cerebral artery has its own pattern of supply to the brain
• the anterior cerebral supplies medial and superior surfaces of brain and frontal pole
• the middle cerebral supplies the lateral surfaces and temporal pole
• The posterior cerebral supplying the inferior surfaces and occipital pole.