HNS Anatomy 1 - Cranium, meninges and brain

Question 1

List the sutures in the skull

Answer 1

• 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

Question 2

List the characteristics of cervical vertebrae

Answer 2

• Small bodies
• Bifid spinous processes
• transverse processes that contain a foramen

Question 3

Which structures pass through the supra-orbital foramen?

Answer 3

Supraorbital nerve and vessels

Question 4

Which structures pass through the infra-orbital foramen?

Answer 4

Infra-orbital nerve and vessels

Question 5

Which structures pass through the mental foramen?

Answer 5

Mental nerve and vessels

Question 6

Which structures pass through the zygomaticofacial foramen?

Answer 6

Zygomaticofacial nerve

Question 7

Which structures pass through the parietal foramen?

Answer 7

Emissary veins

Question 8

Which structures pass through the incisive foramen?

Answer 8

• Nasopalatine nerve

- Spheopalatine vessels

Question 9

Which structures pass through the greater palatine foramen?

Answer 9

Greater palatine nerve and vessels

Question 10

Which structures pass through the lesser palatine foramen?

Answer 10

Lesser palatine nerves and vessels

Question 11

Which structures pass through the pterygoid canal?

Answer 11

Pterygoid nerve and vessels

Question 12

Which structures pass through the foramen ovale?

Answer 12

• Mandibular nerve [V3]

- Lesser petrosal nerve

Question 13

Which structures pass through the foramen spinosum?

Answer 13

Middle meningeal artery and vein

Question 14

Which structures pass through the foramen lacerum?

Answer 14

Internal carotid artery

Question 15

Which structures pass through the carotid canal?

Answer 15

Internal carotid artery and nerve plexus

Question 16

Which structures pass through the foramen magnum?

Answer 16

• Continuation of brain and spinal cord
• Vertebral arteries and nerve plexuses
• Anterior spinal artery
• Posterior spinal arteries
• Roots of accessory nerve [XI]
• Meninges

Question 17

Which structures pass through the condylar canal?

Answer 17

Emissary veins

Question 18

Which structures pass through the hypoglossal canal?

Answer 18

Hypoglossal nerve [XII] and vessels

Question 19

Which structures pass through the jugular foramen?

Answer 19

• Internal jugular vein
• Inferior petrosal sinus
• Glossopharyngeal nerve [IX]
• Vagus nerve [X]
• Accessory nerve [XI]

Question 20

Which structures pass through the stylomastoid foramen?

Answer 20

Facial nerve

Question 21

Which structures pass through the cribiform plate foramina?

Answer 21

Olfactory nerve fibres

Question 22

Which structures pass through the optic canal?

Answer 22

• Optic nerve (inc. central artery of retina)

- Opthalamic artery

Question 23

Which structures pass through the superior orbital fissure?

Answer 23

• Oculomotor
• Trochlear
• Opthalamic division of vagus
• Abductent
• Subopthalamic vein

Question 24

Which structures pass through the foramen rotundum?

Answer 24

Maxillary division of vagus

Question 25

Which structures pass through the internal acoustic meatus?

Answer 25

- Facial - Vestibulocochlear - Labyrinthine artery

Question 26

Which structures pass through the hypoglossal canal?

Answer 26

Hypoglossal nerve

Question 27

List the layers of tissue that make up the scalp

Answer 27

- Skin - Connective tissue - Aponeurosis - Loose areolar connective tissue - Periosteum

Question 28

What is present in each of the cranial fossae?

Answer 28

- 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

Question 29

What is the clinical significance of the tentorial notch?

Answer 29

- 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

Question 30

What is the importance of the pteryon?

Answer 30

- 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

Question 31

Describe the blood flow through the arteries in the circle of Willis

Answer 31

- 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

Question 32

Describe the venous drainage of the dura

Answer 32

- 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)

Question 33

List the fontanelles of the neonatal skull

Answer 33

- Anterior fontanelle (forms the bregma - between frontal and parietal bones) - Posterior fontanelle (forms the lambda, between occipital and parietal bones) - These are soft spots

Question 34

How are the cranial fossa in the skull split?

Answer 34

- 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