Anatomy: Skull, Scalp and Face Flashcards
What are the two parts of the frontal bone?
The vertical aspect (forehead)
The horizontal aspect (roof of orbits)
Where is the ethmoid bone?
Between the eyes
What two vessels meet to form the straight sinus?
The inferior sagittal sinus and great cerebral vein/great vein of galen
Describe the course of the superficial temporal artery
Branches of the external carotid artery
Travels up the lateral aspect of the face, in front of the ear, towards the temple
Describe the arrangement of the LNs of the face?
They form an arch underneath the mandible and ear
Where is the mastoid process located on the temporal bone?
Posteriorly
What is the general structure of the parietal bone?
Flat and rectangular - follows the structure of the brain
Where does the straight sinus run?
Along the meeting point of the tentorium cerebelli and falx cerebri
What holes does the middle cranial fossa have?
The crescent pattern:
- The superior orbital fossa
- The foramen rotunda
- The foramen ovale
- The foramen spinosum
Others:
- Optic canal
- Hypophysial fossa
What is trigeminal neuralgia characterised by?
Brief periods of pain in one of the divisions of the trigeminal nerve dermatome
What structures are run in/are located in the parotid gland?
CN 7
Retromandibular vein
External carotid artery
Parotid LNs
How does the layered structure of the face differ from that of the scalp?
There is no loose connective tissue layer
The aponeurosis layer is replaced by facial muscles
What do you need to know about the veins of the face?
They follow their arteries
What is the course of CN7 in the face?
It exits the stylomastoid foramen
Gives of the post. auricular nerve
Enters the parotid
Forms the parotid plexus aka pes anserinus
What is the shape and position of the petrous of the temporal bone?
Wedged shape forming a floor for the brain
What do the 5 terminal nerves of the parotid plexus do?
Supplies muscles of facial expression
Blood from where drains into the epidural space?
Meningeal arteries
What are the processes of the temporal bone called?
Zygomatic
Mastoid
Styloid
Petrous
Where does the middle meningeal artery lie in the skull?
Between the skull and dura
What supplies the dermatome in front of the ears?
The trigeminal nerves - three branches
- Opthalmic (forehead and eyes)
- Maxillary (in between nose and mouth)
- Mandibular (jaw line)
How can you tell the meningeal arteries?
They groove the skull vault
Describe the cross-sectional structure of the bones of the cranial?
Spongy bone sandwiched between two tables of compact bone
What holes does the posterior cranial fossa have?
The internal auditory (or acoustic) meatus
Jugular foramen
Hypoglossal canal
(Foramen magnum)
What separate the cortex and cerebellum laterally?
Tentorium cerebelli
What are the facial branches of the internal carotid artery and where do they sit?
The supratrochlea above the trochlea
The supraorbital above the eyes
The Pterion is a landmark for which blood vessel?
The middle meningeal artery
What does the zygomatic process of the temporal bone articulate with?
Zygoma
Which dura septa lies between the two hemispheres?
Falx cerebri
Through which foramen does the middle meningeal artery enter the skull?
Foramen spinosum
What is the function of the holes of the cribiform plates?
Nerves passage through them
What is the general structure of the occipital bone?
Moulded around the skull with prominent protuberance (external occipital protuberance)
What forms of the posterior cranial fossa?
The occipital bone
What are the bones of the cranium?
Frontal
Parietal
Temporal
Occipital
Sphenoid
Ethmoid
What other bones of the cranium does the ethmoid articulate with?
The frontal and sphenoid
Where does the neurovascular plane of the scalp lie?
In the connective tissue layer
T/F the subdural space is only a potential space
True
What does the coronal suture divide?
The frontal and parietal bones
What is the middle meningeal artery a branch of?
The maxillary artery
What does the sphenoid bone resemble?
A bat with outstretched wings
What are the two patterns of arrangement facial muscles exhibit?
They surround orifices and act as sphincters
Or they radiate out from orifices and act as dilators
What is the epidural space?
Potential space between the skull and dura
What does the posterior auricular artery do?
Branches off the external carotid and travels posterior to the ear
How does the appearance of the facial vein differ from the facial artery?
Its course is less tortuous
What separates the left and right cerebellar hemispheres?
The falx cerebelli
What supplies the dermatome behind the ears?
Dorsal rami of cervical spinal nerves - C2 behind face and C3 behind neck
What demarcates the division between the vertical and horizontal aspect of the frontal bone?
Supraorbital margin
What are the 4 sutures of the cranial?
Coronal
Sagittal
Lambdoid
Pterion
What are the five terminal branches of CN7 that emerge from the parotid plexus (pes anserinus)
Temporal
Zygomatic
Buccal
Mandibular
Cervical
(Too zulu’s bear many children)
Where do the venous sinuses receive blood from?
The brain via cerebral veins
The skull via diploic vessels
The scalp via emissary veins
Where are the cribiform plates?
On the lateral aspects of the Ethmoid bone
Which layer contains the CSF?
Subarachnoid space
What happens to the transverse sinuses?
At the start of the petrous extension of the temporal bone they descend downwards in a sigmoid fashion (called the sigmoid sinuses) and exit the cranium through the jugular foramen (becoming the internal jugular veins)
Which layers on the scalp slide over the other layers?
The top 4 slide over the pericranium - this is allowed by the loose connective tissue
What are the implications of the fascia surrounding the parotid gland?
Infections that cause inflammation of the gland are very painful as there is no room for give
What forms the middle cranial fossa
Body and greater wings of the sphenoid bone
Petrous of the temporal bone
What nerve supplies the facial muscles?
Facial nerve or CN7
What is the flat, lateral part of the temporal bone called?
The squamous part
T/F the face has emissary veins that drain into the cavernous sinus
True
Where in the skull is the occipital bone?
Posterior/dorsal aspect
What is the function and course of the parotid duct?
Transmit saliva into mouth
Emerges from the ant. border - runs on the masita muscle - dives into the buccinator muscle and into the mouth
What are the borders of the scalp?
Supraorbital margin to posterior occipital protuberance and the zygomatic arches
What are the points of attachment for the falx cerebri?
Along the sagittal suture
Occipital protuberance
Crista galli
What is the diaphragma sellae?
A dura septa that rooves the body of the sphenoid bone
Where does the inferior sagittal sinus run?
In the inferior margin of the falx cerebri
What does the sagittal suture divide?
The two plates (right and left) of the parietal bone
Where does the superior sagittal sinus lie?
On top of the falx cerebri, beneath in the sagittal suture
What does the lambdoid suture separate?
The parietal and occipital bones
Where does the parotid gland sit?
Beneath the zygomatic process of the temporal bone
Ant. to mastoid process of temporal bone and ear
Superior to the angle of the mastoid bone
Posterior to the masita muscle
Superficial to the styloid process of the temporal bone
What are the five layers of the scalp?
Skin
Connective tissue
Aponeurosis of occipitofrontalis muscle
Loose connective tissue
Pericranium
Between what do the venous sinuses lie?
Inner and outer layers of dura
Where does the cavernous sinus lie?
Lateral sides of the sphenoid bone
What happens at the doral end of the straight sinus?
There is confluence of the sinuses and the two transverse sinuses extend laterally
What is the name of the major veins that drain into the superior sagittal sinus?
Superior cerebral veins
Where does the trigeminal ganglion sit in relation to the temporal bone?
At the edge of the its petrous wedge of the temporal
What does the Pterion separate?
The frontal (ant), parietal (superior), sphenoid (inferior) and temporal (posterior) bones
What is Bell’s palsy
Dysfunction of the facial nerve causing ability to use control on the affected side
What is the problem with the venous sinuses receiving blood from the scalp?
Infections of the scalp can spread to the meninges (meningitis) and brain (encephalitis)
What separates the greater and lesser wings of the sphenoid bone?
The superior orbital fissure
What forms the anterior cranial fossa?
The frontal bone
Cribiform plates
Lesser wings of the sphenoid bone
What does the external carotid artery do in the parotid gland?
Branches into the maxillary and superficial temporal a.
What is the function of the parotid gland?
Salivary production
What holes does the anterior cranial fossa have?
Just those of the cribiform plate
What three factors contribute to the heavy bleeding that occurs with scalp injuries?
- Rich vascular supply in the connective tissue layer with anastomoses between internal and external carotid arteries
- The arrangement of the occipitofrontalis muscle meaning that wounds tend to gape
- Fibrous septa in the connective tissue layer that restrict the ability of arteries to constrict
What do the meningeal arteries supply?
Bones of the vault and meninges
Which pharyngeal arch are the facial muscle derived from?
The second
Describe the course of the facial artery
Branches off the external carotid
Overlaps the mandible
Takes a tortuous course to the medial corner of the eye sending off to nose and cheek as it goes
What does the occipital artery do?
Branches off the external carotid and travels up inferior the posterior auricular artery
