HNS Anatomy 1 - Cranium, meninges and brain Flashcards
List the sutures in the skull
- Coronal suture (coronal plane)
- Sagittal suture (sagittal plane)
- Lamboid suture
- Lambda is where the lamboid suture and sagittal suture meet
- Bregma is where the coronal suture and sagittal suture meet
List the characteristics of cervical vertebrae
- Small bodies
- Bifid spinous processes
- transverse processes that contain a foramen
Which structures pass through the supra-orbital foramen?
Supraorbital nerve and vessels
Which structures pass through the infra-orbital foramen?
Infra-orbital nerve and vessels
Which structures pass through the mental foramen?
Mental nerve and vessels
Which structures pass through the zygomaticofacial foramen?
Zygomaticofacial nerve
Which structures pass through the parietal foramen?
Emissary veins
Which structures pass through the incisive foramen?
- Nasopalatine nerve
- Spheopalatine vessels
Which structures pass through the greater palatine foramen?
Greater palatine nerve and vessels
Which structures pass through the lesser palatine foramen?
Lesser palatine nerves and vessels
Which structures pass through the pterygoid canal?
Pterygoid nerve and vessels
Which structures pass through the foramen ovale?
- Mandibular nerve [V3]
- Lesser petrosal nerve
Which structures pass through the foramen spinosum?
Middle meningeal artery and vein
Which structures pass through the foramen lacerum?
Internal carotid artery
Which structures pass through the carotid canal?
Internal carotid artery and nerve plexus
Which structures pass through the foramen magnum?
- Continuation of brain and spinal cord
- Vertebral arteries and nerve plexuses
- Anterior spinal artery
- Posterior spinal arteries
- Roots of accessory nerve [XI]
- Meninges
Which structures pass through the condylar canal?
Emissary veins
Which structures pass through the hypoglossal canal?
Hypoglossal nerve [XII] and vessels
Which structures pass through the jugular foramen?
- Internal jugular vein
- Inferior petrosal sinus
- Glossopharyngeal nerve [IX]
- Vagus nerve [X]
- Accessory nerve [XI]
Which structures pass through the stylomastoid foramen?
Facial nerve
Which structures pass through the cribiform plate foramina?
Olfactory nerve fibres
Which structures pass through the optic canal?
- Optic nerve (inc. central artery of retina)
- Opthalamic artery
Which structures pass through the superior orbital fissure?
- Oculomotor
- Trochlear
- Opthalamic division of vagus
- Abductent
- Subopthalamic vein
Which structures pass through the foramen rotundum?
Maxillary division of vagus
Which structures pass through the internal acoustic meatus?
- Facial
- Vestibulocochlear
- Labyrinthine artery
Which structures pass through the hypoglossal canal?
Hypoglossal nerve
List the layers of tissue that make up the scalp
- Skin
- Connective tissue
- Aponeurosis
- Loose areolar connective tissue
- Periosteum
What is present in each of the cranial fossae?
- Anterior fossa contains the frontal lobe
- Middle cranial fossa contains the temporal lobe
- Posterior cranial fossa contains the brainstem and cerebellum
- Occipital lobe sits above the tentorium cerebelli
What is the clinical significance of the tentorial notch?
- If intracranial pressure superior to the tentorium cerebelli is increased, it may force part of the temporal lobe through this notch
- This is called a tentorial brain herniation
What is the importance of the pteryon?
- The weakest part of the skull, where the frontal, temporal, parietal and sphenoidal bones meet
- If hit, the middle meningeal artery will rupture causing an epidural haemorrhage
Describe the blood flow through the arteries in the circle of Willis
- Vertebral arteries join to form the basillar artery
- Basillar artery gives off the superior cerebellar artery, anterior inferior cerebellar artery. It splits to form the posterior cerebral artery
- The posterior inferior cerebellar artery comes from the vertebral arteries
- Posterior cerebral artery supplies the occipital lobe. it forms two posterior communicating arteries, which give ride to the middle cerebral artery and interal carotid artery
- The middle cerebral artery (supplies the lateral areas of the frontal, parietal and temporal bones) forms the anterior cerebral artery.
- The two anterior cerebral arteries (supplies the midline frontal lobes and parietal lobe) are joined by a single anterior communicating artery
Describe the venous drainage of the dura
- The confluence of sinuses is formed by the superior sagittal sinus, straight sinus (from the inferior sagittal sinus) and temporal sinuses.
- Temporal sinuses form the sigmoid sinus and these form the internal jugular vein
- Two cavernous sinuses above the lesser wings of the sphenoid bone, joined by intercavernous sinus
- The petrosal sinuses are at the margin of the petrous process of the temporal lobe (superior and inferior)
List the fontanelles of the neonatal skull
- Anterior fontanelle (forms the bregma - between frontal and parietal bones)
- Posterior fontanelle (forms the lambda, between occipital and parietal bones)
- These are soft spots
How are the cranial fossa in the skull split?
- Anterior is bound by the lesser wings of the sphenoid bone and the limbus
- Middle is between the anterior and posterior
- Posterior is from the petrous part of the temporal bone
