Scalp and Cranial Cavity

Question 1

extent of face

Answer 1

forehead to chin
ear to ear

Question 2

cutaneous nerve supply to the face

Answer 2

CNV1 - supraorbital, supratrochlear, infratrochlear, external nasal, lacrimal
CNV2 - zygomaticofacial, zygomaticotemporal
, infra-orbital
CNV3 - auriculotemporal, buccal, mental
C2 and C3 - great auricular, lesser occipital - the great auricular supplies the mandible despite it being on the facial side

Question 3

what is the scalp proper

Answer 3

first 3 layers of scalp which move as one
skin, dense connective tissue and epicranial aponeurosis

Question 4

what layer separates the scalp proper and the pericranium

Answer 4

loose connective tissue (layer 4 of the scalp)

Question 5

5 layers of scalp

Answer 5

skin
dense connective tissue
epicranial aponeurosis
loose connective tissue
pericranium

Question 6

which layer of skull cant move

Answer 6

pericranium

Question 7

extent of scalp

Answer 7

superior nuchal line of occipital bone to supraorbital margins of frontal bone
laterally to the zygomatic arch

Question 8

contents of skin

Answer 8

hair follicles
sweat and sebaceous glands

Question 9

features of the dense connective tissue

Answer 9

its subcutaneous layer (below skin) and contains many BV and nerves

Question 10

which scalp layer is known for being tough

Answer 10

epicranial aponeurosis - this stops superficial wounds gapping open

Question 11

which muscles attach to the epicranial aponeurosis

Answer 11

tendon and muscle of occipitofrontalis

Question 12

how can infection spread in the scalp

Answer 12

the loose connective tissue layer contains spaces susceptible to distension w fluid(blood) or infection
as frontal belly of occipitofrontalis inserts into skin and subcutaneous tissue not bone infection can spread to the eyelids and root of nose

there are emissary veins in the loose connective tissue which can spread infections to intracranial structures - cause of meningitis

Question 13

what tissue is the loose connective tissue layer

Answer 13

loose areolar tissue

Question 14

features of the pericranium

Answer 14

external periosteal layer of skull which is dense and firmly attached to skull where is goes into the sutures

Question 15

sensory cutaneous nerve supply of the scalp

Answer 15

C2 - greater occipital nerve
C3 - third occipital
C2 and C3 - great auricular, lesser occipital

Question 16

arterial supply of scalp

Answer 16

ICA - supraorbital and supratrochlear = anterior scalp
WCA - superficial temporal, post auricular and occipital = posterior and lateral scalp

Question 17

why is there profuse bleeding when scalp is lacerated

Answer 17

there is many arterial anastomoses

Question 18

venous drainage of scalp

Answer 18

supraorbital, supratrochlear, superficial temporal, posterior auricular which drain into EJV
occipital which drains into IJV

Question 19

lymphatic drainage of the scalp

Answer 19

posterior = mastoid and occipital nodes drain into deep cervical nodes
anterior = pre-auricular and parotid nodes

Question 20

bones of anterior cranial fossa

Answer 20

frontal
ethmoidal
sphenoid

Question 21

bones of middle cranial fossa

Answer 21

sphenoid
temporal

Question 22

bones of posterior cranial fossa

Answer 22

sphenoid
occipital
temporla

Question 23

contents and foramina of the anterior cranial fossa

Answer 23

frontal lobes of brain
crista gali - attachment site
cribriform plate - ehtmoid bone

foramina of cribriform plate - olfactory bulbs recieve nerve fibres from nasal cavity through this - fractures can be present with CSF rhinorrhoea

Question 24

contents of middle cranial fossa

Answer 24

temporal lobes of brain
pituitary gland which sits in pituitary (hypophyseal) fossa in deepest part of sella turcica
4 clinoid processes and 2 superior projections(dorsum sellae post and tuberculum sella ant) surround pituitary

Question 25

foramina of the middle cranial fossa - crescent

Answer 25

Foramen rotundum
Foramen lacerum - closed by cartilage
Foramen ovale
Foramen spinosum
Superior orbital fissure ?

Question 26

contents and foramina of the posterior cranial fossa

Answer 26

cerebellum and occipital lobes of brain
clivus which is where the brainstem enters the foramen magnum
internal occipital protuberance - at back of skull, confluence of sinuses here

jugular foramen
foramen magnum

Question 27

structure and role of meninges

Answer 27

dura matter : outer periosteal layer, inner meningeal layer
arachnoid matter
subarachnoid space
pia matter

role = protection of brain

Question 28

where do the 2 layers of the dura matter separate

Answer 28

dural folds
venous sinuses

Question 29

4 dural folds and their role

Answer 29

falx cerebri
falx cerebelli
tentorium cerebelli
diaphragma sellae

role - limit movement of brain within cavity as they go into fissures

Question 30

blood supply of dura and calvaria

Answer 30

Ant meningeal arteries - from ethmoidal arteries
Middle(from maxillary artery) and accessory meningeal arteries
Posterior meningeal arteries - from ascending pharyngeal artery

Question 31

what is the relation of the arachnoid matter to the dura matter

Answer 31

lines it but not attached just pressed against by the CSF which sits in the subarachnoid space deep to it

Question 32

arachnoid trabeculae

Answer 32

project from interal surface across subarachnoid space

Question 33

subarachnoid space contents

Answer 33

CSF
BV

Question 34

arachnoid vili

Answer 34

from subarachnoid space and reabsorb CSF into the venious system
collections of these are arachnoid granulations and are found in saggital sinus and lateral lacunae

Question 35

pia matter

Answer 35

thin membrane attached to brain where it enters the sulci