Scalp and Skull Flashcards
List the layers of the scalp
S: skin C: connective tissue (dense CT) A: Aponeurosis L: loose connective CT P: pericranium (periosteum of calvarium)
Describe the blood supply and venous drainage of the scalp
Blood supply: From internal carotid (supratrochlear and supraorbital arteries of the opthalmic artery) and from external carotid (occipital and superficial temporal arteries)
Veins are similar to the arteries
Describe the innervation of the scalp
Cranial nerve 5 (V).. 3 parts; or dorsal rami C2,3
why is there profuse bleeding with scalp lacerations
because the connective tissue layer is richly vascularized and holds the vessels open, so that profuse bleeding occurs if it is cut
In what layer of the scalp do infections tend to localize and spread?
loose CT (since it is loose)
what is unique to the connective tissue layer of the scalp? (dense)
it has lots of blood vessels and nerves traversing through it (richly vascularized); it holds cut vessels open because the CT surrounds the vessels, resulting in profuse bleeding when cut
what does the aponeurosis layer of the scalp consist of?
frontalis muscle, occipitalis muscle, and the aponeurotic (flat) tendon between them
what is the function of the loose connective layer of the scalp?
facilitates the movement between the scalp proper (SCA top three layers) and the skull
what happens if pooling of blood occurs in the loose CT layer of the scalp?
localization of infection; injuries can cause pooling of blood and it may spread forward deep to the skin of the eyelids causing black eyes (since the loose CT to other loose CT)
epicranial aponeurosis
flat tendon (aponeurosis) on top of the skull that connects the occipitofrontalis muscle
what nerve supplies the forehead and the anterior scalp?
opthalamic division of CN V
what does the opthalamic division of CN V innervate?
sensory to the forehead and the anterior scalp
what does the maxillary division of CN V innervate?
sensory to the anterior temple area
what nerve supplies the anterior temple area?(sensory)
maxillary division of CN V
what does the mandibular division of CN V innervate?
sensory to the lateral temple area
what nerve supplies the lateral temple area? (sensory)
mandibular division of CN V
what nerves supply the scalp just posterior and superior to the ear? (sensory)
branches of the cervical plexus
what nerves supply the posterior scalp?
dorsal rami of CN 2 and CN 3
what arteries arise from the internal carotid artery and supply the scalp?
the supratrochlear and supraoribital arteries from the opthalamic artery
what arteries arise from the external carotid artery and supply the scalp?
occipital artery and superficial temporal artery
where does the lymph drainage of the scalp go?
to deep cervical nodes
what is the function of the skull?
to house and protect the brain and special sense organs (ear and eye); as attachments for muscles (ie: those in chewing and swallowing)
what does the skull consist of (which 2divisions/ bones):
cranium + mandible;
cranium = upper calvarium and lower facial skeleton
where is the calvarium?
surrounds the cranial cavity
what is the cranial cavity? (what does it contain?)
within the calvarium; contains the brain, meninges, blood vessels, dural sinuses, and parts of the cranial nerves
what are sutures?
fibrous joints located where the skull (cranial) bones meed
that is the pterion? what does it include?
point in the skull where the frontal, parietal, greater wing of the sphenoid, and temporal bones come together
why is fracture at the pterion dangerous?
because the middle meningeal artery lies deep to it, and fracture to the pterion can result in an extradural (epidural) hematoma
where is the lambda located?
at the intersection of the sagittal and lamboidal sutures
what bones make up the roof of the cranial cavity?
the parietal, occipital and frontal bones
is the palatine bone present in the orbit?
yes!
what is the angle of the mandible defined by?
the intersection of the mandible ramus and mandible body
what lies in the hypophyseal fossa?
the pituitary (hypophyseal) gland
what are the anterior and posterior fontanelles?
spaces where the sutures haven’t fused yet in a fetus, they are covered by a membrane (soft spots of baby’s head)
what does the anterior fontanelle give rise to? posterior fontanelle?
anterior = bregma posterior = lambda
describe the course of the internal carotid artery
arises at the bifurcation of the common carotid, passes through the neck, into the carotid canal in petrous temporal bone, across foramen lacerum, through cavernus since, next to body of sphenoid, forms carotid siphon (s-shaped), ends by giving off the anterior and middle cerebral arteries
describe the course of the middle meningeal artery
from the maxillary artery, looped by auriculotemporal nerve, through foramen spinosum, has anterior and posterior branches, leaves impression on the skull
what are paranasal sinuses?
openings within the bone
where is the sphenopalatine foramen located?
in pterygopalatine fossa
what passes through the carotid canal
internal carotid artery
what passes through the foramen magnum
spinal cord, vertebral artery, spinal portion of accessory nerve
what passes through the foramen ovale
mandibular division of trigeminal nerve, lesser petrosal nerve
what passes through the foramen rotundum
maxillary division of trigeminal nerve
what passes through the foramen spinosum
middle meningeal artery
what passes through the groove and hiatuses for greater and lesser petrosal nerves
greater and lesser petrosal nerves
what passes through the hypoglossal canal
hyperglossal nerve
what passes through the infraorbital forament
infraorbital nerve (CN V pt 2), artery and vein
what passes through the internal acoustic meatus
facial and vestibulocochlear nerves
what passes through the jugular foramen
glossopharyngeal, vagus, and accessory nerves, jugular bulb
what passes through the mandibular foramen
inferior alveolar nerve from CN V pt 3
what passes through the mental foramen
mental nerve
what passes through the olfactory foramina of cribiform plate
olfactory nerves
what passes through the optic canal
optic nerve, ophthalmic artery
what passes through the petrotympanic fissure
chorda tympani branch of facial nerve
what passes through the pterygoid canal
nerve of pterygoid canal
what passes through the sphenopalatine foramen
sphenopalatine artery
what passes through the stylomastoid foramen
motor portion of facial nerve
what passes through the superior orbital fissure
oculomotor abducen, trochlear nerve, ophthalmic division of trigeminal nerve, ophthalmic vein
what passes through the supraorbital foramen
supraorbital nerve (CN V pt1), artery and vein
what passes through the zygomaticotemporal and zygomaticofacial foramina
zygomaticotemporal and zygomaticofacial nerves
