Cranial Cavity & Scalp Flashcards
5 layers of the scalp
Skin
Connective tissue (dense)
epicranial Aponeurosis
Loose connective tissue
Pericranium
skin
contains hair follicles, sweat and sebaceous glands. is thickest over occipital bone
dense connective tissue
subcutaneous layer richly vascularised & with cutaneous nerves
epicranial apeneurosis
tendon and muscle of occipito-frontalis which prevents superficial wounds from gaping open
loose connective tissue
loose areolar tissue that allows free movement of outer layers over underlying calvaria
pericranium
external periosteum of the skull
boundaries of the scalp
from superior nuchal line of occipital bone to supraorbital margins of the frontal bone and laterally over the temporal fascia to the zygomatic arch
cutaneous / sensory innervation is supplied by
CN V & cervical nerves C2, C3
CN V1 includes (5)
supraorbital
supratrochlear
infratrochlear
external nasal
lacrimal
CN V2 includes (3)
zygomaticotemporal
zygomaticofacial
infraorbital
CN V3 includes (3)
auriculotemporal
buccal
mental
what supplies the skin over the angle of the mandible
the cervical plexus with the great auricular nerve (C2 and C3), not CN V
C2 and C3 includes
greater and lesser occipital
third occipital
great auricular
how does CN V1 exit the skull
superior orbital fissure
how does CN V2 exit the skull
foramen rotundum
how does CN V3 exit the skull
foramen ovale
arterial supply to the scalp is via 2 main arteries
ICA - anterior scalp
ECA - lateral & posterior scalp
3 branches of the ECA involved in arterial supply of the scalp
- occipital
- posterior auricular
- superficial temporal
2 branches of ICA involved in arterial supply of the scalp
2 branches of the ophthalmic which are:
1. supraorbital
2. supratrochlear
venous drainage of the scalp
via veins of the same name as the arteries i.e. superficial temporal, posterior auricular, occipital, supraorbital, supratrochlear
which vein is the exception and why
occipital as it drains into the IJV while the rest drain to the EJV
anterior cranial fossa is bounded by
sphenoid crest
middle cranial fossa bounded by
sphenoid crest and superior border of petrous temporal bone
what bones are in the anterior cranial fossa (3)
frontal, ethmoid and sphenoid bones
anterior cranial fossa is occupied by
frontal lobes
bones of middle cranial fossa (2)
sphenoid and temporal bones
middle cranial fossa is occupied by
temporal lobes
where is the pituitary gland found
in the pituitary fossa in the deepest part of the sella turcica
bones of posterior cranial fossa (3)
sphenoid, occipital and temporal bones
posterior cranial fossa is occupied by
cerebellum and brainstem (medulla oblongata)
internal view of the skull is called
calvaria
what is a buttress
thicker portion of cranial bone that transmits forces around weaker regions of the cranium
frontonasal buttress
from the region of the canine teeth between the nasal and orbital cavities to the central frontal bone
zygomatic buttress
from region of molars to the lateral, frontal and temporal bones
occipital buttress
transmit forces received lateral to the foramen magnum from the vertebral column
cranial meninges are
membranous layers that help in the protection of the brain
what are the cranial meninges
dura mater (2 layers)
arachnoid mater
pia mater
subarachnoid space
2 layers of dura mater
inner meningeal layer - in contact with arachnoid mater
outer periosteal layer - attached to bone
arachnoid mater
lines the dura mater
trabeculae project from the internal surface, across the subarachnoid space and are continuous with the pia materb
subarachnoid space
fluid filled space
contains CSF + blood vessels
villi here will reabsorb CSF into the venous system
villi can be found in sagittal sinus and lateral lacunae - known as arachnoid granulations
pia mater
membrane attached to surface of brain
as it adheres to brain surface it enters sulci of the brain
dura mater folds limit movement within the brain cavity (4)
- falx cerebri
- tentorium cerebelli
- falx cerebelli
- diaphragma sellae
dura and calvaria are supplied by what arteries in the periosteal layer
anterior meningeal arteries
middle & accessory meningeal arteries
posterior meningeal arteries