Skull and cranial nerves Flashcards
Skull bones
- Zygomatic
- Maxilla
- Nasal
- Mandible
- Frontal
- Parietal
- Temporal
- Occipital
- Sphenoid
- Ethmoid
Which cranial nerves are associated with the temporal bone?
7 and 8
5 parts on temporal bone
Styloid process, zygomatic process, typamic part, squamous part, petromastoid part
How many wings does the sphenoid bone have?
6
What are sutures?
Join parts of the skull
Which suture takes longest to close?
Frontal
Why do the anterior fontanels pulsate?
Bones haven’t closed - raised pressure in brain means skull keeps growing
What is hydrocephalus?
Accumulation of CSF in brain
Name the sutures
- Coronal
- Sagittal
- Squamous
- Lamdoid
- Occipitomastoid
Main aspects of anterior skull surface
- Frontal eminence
- Supra-orbital ridges
- Supra-orbital notches
- Nasal aperture
Main aspects of lateral skull surface
- Inferior end of nasal bone
- Zygomatic arch
- Mastoid process
- Head of mandible
- Pterion
Function of superior orbital fissure
Nerve supply to eye muscles and eye ball
What does inferior orbital fissure do?
Intra-orbital neurovascular supply
What does optic canal do?
Nerve and artery supply to retina
What is the foramen spinousum?
Course of middle meningeal artery
Contains grooves for arteries
On lateral side, they run deep to pterion
Connects greater wing of sphenoid to frontal/parietal/temporal bone
Which artery runs to pterion?
Middle meningeal artery
Where do the muscles of mastication attach?
Lateral pterygoid plate
Sensory supply of cranial nerve 7
Tiny area on ear
Somatic supply of cranial nerve 7
Muscles of facial expression
Parasympathetic motor supply of cranial nerve 7
Lacrimal, submandibular and sublingual glands
Course of cranial nerve
Medullopontine junction → internal acoustic foramen → stylomastoid foramen to exit skull → parotid gland → splits into 5 branches
What does the greater petrosal branch of the 7th cranial nerve do?
Parasympathetic lacrimal glands and mucous glands of nose
What does the nerve to stapedius muscle do?
Dampens loud noises
What does the chords tympani branch of the 7th cranial nerve do?
Parasympathetic submandibular and sublingual glands, taste of anterior 2/3 tongue
Conditions when born without 7th cranial nerve
Bell’s palsy, Tarsorrhaphy, Moebius syndrome
What does somatic sensory branch of 7th cranial nerve do?
Patch of skin on pinna (Ramsay-Hunt syndrome)
Sensory supply of 8th cranial nerve
Hearing, equilibrium, detect motion
Where does 8th cranial nerve enter skull?
Internal acoustic meatus - doesn’t exit skull
What do the utricle and saccule detect?
Linear acceleration
What doe the three semi circular canals detect?
Rotational acceleration
