Anatomy - Skull, Face, Arterial Supply to Brain Flashcards
What bones articulate to form the coronal suture?
Frontal bone articulates with parietal bone
What are the bones of the skull made of?
External and internal tables of compact bone Spongy bone (diploë bone) in between the external and internal tables
What bones articulate to form the sagittal suture?
Left and right parietal bones articulate
What grooves the internal surface of the pterion?
Middle meningeal artery
What bones articulate to form the pterion suture?
Frontal, parietal, temporal and sphenoid bones
What demarcates the vertical and horizontal plates of the frontal bone?
supraorbital margin
What bones articulate to form the lambdoid suture?
Left and right parietal bones articulate with occipital bone
What is the supraorbital margin?
Demarcation between vertical and horizontal plates of the frontal bone
What is the flat aspect of the temporal bones?
Squamous part of temporal bones
What are the projections that come off the squamous part of the temporal bone?
- zygomatic process anteriorly which articulates with zygoma
- mastoid process posteriorly which gives attachment to SCM
- styloid process inferiorly which give attachment to muscles of oral cavity and pharynx
- petrous part projects into cranium and forms part of cranial floor
What structure sits between the cribiform plates?
Cristagalli
Which bone sits between the eyes?
Ethmoid bone
What is transmitted through the cribiform plate of the ethmoid bone?
Olfactory nerve fibres
Through what structure do the olfactory nerve fibres travel through?
Cribiform plate of the ethmoid bone
Where does the pituitary sit?
Within the body of sphenoid bone - sella turcica
What are the main features of sphenoid bone?
Superior orbital fissure separates lesser and greater wings
Lesser wing sits anterosuperior to greater wing
What bones form the anterior cranial fossa?
Horizontal plate of frontal bone
Cribiform plate of ethmoid bone
Lesser wings of sphenoid bone
What bones form the middle cranial fossa?
Greater wings of sphenoid bone
Body of sphenoid bone (sella turcica)
Petrous part of temporal bone
What are the components of the frontal bone?
Vertical plate forms the forehead and horizontal plate forms the roof of the orbits
What bones form the posterior cranial fossa?
Occipital bone
What structures transmit through optic canal?
Optic nerve
Ophthalmic artery
Which structures transmit through the superior orbital fissure?
CN III, IV, VI and V1 of trigeminal
Which structures transmit through foramen rotundum?
V2 of trigeminal nerve
Which structures transmit through foramen ovale
V3 of trigeminal
Which structures transmit through foramen spinosum?
Middle meningeal artery
Which structures transmit through the internal acoustic meatus?
CN VII and VIII
Which structures transmit through the jugular foramen?
CN IX, X, XI, and internal jugular vein
Which structures transmit through the hypoglossal canal?
CN XII
Where is the optic canal located?
Between the body of sphenoid and lesser wing of sphenoid
Which foramenae are located in the middle cranial fossaa?
- Optic canal
- Superior orbital fissure
- Foramen rotundum
- Foramen ovale
- Foramen spinosum
Which foramenae are located in the posterior cranial fossa?
- Internal acoustic meatus
- Jugular foramen
- Hypoglossal canal
- Foramen magnum
Where is the internal acoustic meatus located?
Petrous part of temporal bone
Where is the jugular foramen located?
Between petrous part of temporal bone and occipital bone
Where is the extradural/epidural space?
Between skull and dura
If meningeal arteries rupture, where will blood collect?
Extradural space
Where is the subdural space?
Between dura and arachnoid mater
If venous haemorrhage occurs, where will blood collect?
Subdural space
Where is the subarachnoid space?
Between arachnoid and pia mater
Which space is occupied by CSF?
Subarachnoid space
What is the function of dural petitions?
Restrict rotatory displacement of brain
What are the 4 dural petitions?
- Tentorium cerebelli
- Falx cerebelli
- Falx cerebri
- Diaphragma sellae
Where is the falx cerebri and what are its margins?
Between the cerebral hemispheres in a sagittal plane
Upper margin attaches to skull
Attaches to crista galli anteriorly
Attaches to internal aspect of occipital protuberance posteriorly
Where is falx cerebelli?
Beneath tentorium cerebelli in the posterior cranial fossa
Lodges between left and right cerebellar hemispheres in sagittal plane
Where is the tentorium cerebelli?
Separates the occipital lobes from the cerebellum
Roof over posterior cranial fossa in a horizontal plane
What are the dural venous sinuses?
Endothelial-lined spaces existing between inner and outer layers of dura
Which veins drain the scalp?
Emissary veins
What do emissary veins drain?
Scalp
What do diploic veins drain?
Drain the layer of spongy bone between the 2 layers of compact bone in the skull
Which veins drain the spongy bone within the skull?
Diploic veins
What are the main dural venous sinuses?
- Superior sagittal sinus
- Inferior sagittal sinus
- Great cerebral vein
- Straight sinus
- Confluence of sinuses
- Transverse sinus
- Sigmoid sinus
- Cavernous sinus
Which veins drain into the superior sagittal sinus?
Diploic veins and emissary veins
Where is the superior sagittal sinus located?
Above falx cerebri
Where is the inferior sagittal sinus located?
Inferior margin of the falx cerebri
What forms the straight sinus?
Great cerebral vein and inferior sagittal sinus
Where does straight sinus run?
Along the junction between falx cerebri and tentorium cerebelli
What forms the confluence of sinuses?
Superior sagittal sinus meets with the straight sinus (formed by inferior sagittal sinus and Great cerebral vein)
Where is confluence of sinuses located?
Internal aspect of occipital protuberance
Which sinuses come off the confluence of sinuses?
Left and right transverse sinuses
What is the sigmoid sinus?
Transverse sinus becomes sigmoid sinus when it leaves the tentorium and snakes down to the jugular foramen
Which sinus exits the jugular foramen as the internal jugular vein?
Sigmoid sinus
What does the sigmoid sinus become when it exits the jugular forman?
Internal jugular vein?
What foramen does the sigmoid sinus travel through?
Jugular foramen?
Where is the cavernous sinus?
On either side of the body of sphenoid
What is the middle meningeal artery a branch of?
Maxillary artery
Through which foramen does the maxillary artery enter the cranium?
Foramen spinosum in the middle cranial fossa
Where does the middle meningeal artery lie?
Lies in the extra/epidural space immediately deep to pterion
What are the margins of the scalp?
Occipital protuberance to supraorbital margins (posterior to anterior)
Level of zygomatic arches (laterally)
What are the 5 layers of the scalp?
Skin and hair follicles Connective tissue (dense) Aponeurosis of occipitofrontalis Loose connective tissue Pericranium
What is the origin and insertion of muscles of facial expression?
- Arise from bone or fascia
- Attach to skin of face
What is the embryological origin of the muscles of facial expression?
Derived from the second pharyngeal arch
What is the sensory innervation of the face and scalp anterior to the ear?
CNV
What is the sensory innervation of scalp, head posterior to the ears and neck?
Dorsal rami of C2 and C3 (neck)
Which division of trigeminal exits the superior orbital fissure?
V1
Which division of trigeminal exits foramen rotundum?
V2
Which division of trigeminal exits foramen ovale?
V3
Where does trigeminal ganglion lie?
Apex of petrous part of temporal bone
Which arteries supply the superficial face?
Branches of internal and external carotid arteries
Which arteries supply the centre of the forehead?
Supratrochlear branches of ICA (more medial)
Supraorbital branches of ICA (more lateral)
Which artery supplies the side of the scalp?
Superficial temporal artery (branch of ECA)
What structure does superficial temporal artery pass over?
Zygomatic arch
What is the main arterial supply to the face?
Facial artery (branch of ECA)
What is the course of the facial artery?
Winds over inferior angle of the mandible onto the face
Tortuous course over the face to the medial angle of the eye
What are 4 branches of the external carotid artery?
- superficial temporal a.
- facial a.
- posterior auricular a.
- occipital a.
What is the main venous drainage of the face?
Facial vein
What is the course of the facial vein?
Runs posterior to facial a.
Has a straighter course and is more superficial
Where do all the lymph nodes of the face drain into?
Deep cervical node
Where does the parotid gland sit?
- below zygomatic arch of temporal bone
- in front of ear and mastoid process of temporal bone
- above the angle of the mandible
- behind masseter
- superficial to styloid process
What is the neurovascular bundle that runs within the parotid gland?
Nerve, vein, artery (superficial to deep)
- CNVII
- retromandibular vein
- external carotid artery
What is the course of the parotid duct?
Emerges from anterior border of parotid gland onto masseter
Turns inwards at the anterior edge of masseter, pierces buxinator and enters oral cavity near 2nd upper molar
What is the course of facial nerve?
Exits cranium via internal acoustic meatus
Travels through temporal bone
Exits via stylomastoid foramen
Gives off posterior auricular branch to innervate occipitalis
Enters posteromedial surface of parotid gland
Forms parotid plexus (pes anserinus)
What are the 5 terminal branches of facial nerve?
Temporal Zygomatic Buccal Mandibular Cervical
What veins form the retromandibular vein?
Superficial temporal and maxillary veins
Where does external carotid artery divide into its 2 terminal branches?
within parotid gland
What branches does external carotid artery give off in the parotid gland?
Maxillary artery
Superficial temporal artery
Which arteries form the circle of Willis?
Vertebro-basilar system and internal carotid artery
What does anterior cerebral artery supply?
Medial parts of frontal and parietal lobes
What territories does the anterior cerebral artery supply?
Motor and sensory cortices for lower limb
Medial part of precentral gyrus and postcentral gyrus
What are the consequences of a stroke in ACA territory?
- Contralateral hemisensory loss
- Contralateral hemiparesis
What territories does the MCA supply?
Motor and sensory cortices for most of body (excl. lower limb) Language areas (Broca's and Wernicke's)
What are possible consequences of a stroke in MCA territory?
- Contralateral hemisensory loss for body and upper limbs
- Possible contralateral hemisensory loss in face
- Contralateral hemiparesis
- Aphasias
What territories does posterior cerebral artery supply?
Medial and inferior surfaces of temporal and occipital lobes including visual cortex
What are the possible consequences of a stroke in PCA territory?
- Visual disturbances
- Contralateral homonymous hemianopia
What arteries supply deep structures?
Small perforating arteries
Which arteries supply the basal ganglia and internal capsule?
Lenticulostriate arteries
Which arteries unite to from the basilar artery?
Vertebral arteries
What arteries supply the cerebellum?
Posterior inferior cerebellar a.
Anterior inferior cerebellar a.
Superior cerebellar a.
Which artery supplies most of the midbrain?
Posterior cerebral artery
Which artery supplies the ventro-medial aspect of the pons?
Basilar artery
Which artery supplies the dorso-lateral aspect of the medulla?
Posterior inferior cerebellar artery
Which artery supplies ventrolateral aspect of medulla (olives)?
Vertebral artery
Which artery supplies medial strip of the medulla?
Anterior spinal artery
What are possible consequences of a cerebrovascular event to anterior spinal artery (medial medullary syndrome)?
- Loss of function of hypoglossal nerve will cause ipsilateral paralysis and atrophy of the tongue
- Loss of function of medial lemniscus will cause contralateral hemianaesthesia
- Loss of function of pyramids affecting the cortiospinal tract will cause contralateral hemiparesis
What structures does the anterior spinal artery supply?
- Hypoglossal nerve
- Medial lemniscus
- Pyramids
Which artery supplies most of the ventral surface of the spinal cord?
Anterior spinal artery
Which arteries do the posterior spinal arteries originate from?
Vertebral arteries
Which arteries supply the posterolateral surface of the spinal cord?
Posterior spinal arteries
Segmental arteries branching from the aorta