W1: Cranial Nerves Flashcards
List the cranial nerves derived from pharyngeal arches
nerves providing motor supply to the pharyngeal arches
V3, VII, IX, X
Arches 1, 2, 3 and 4/6 respectively
The nerves are called branchiomotor efferents.
List the 12 cranial nerves in order
List the cranial nerves derived from rostral somites, (pre-otic)
III, IV, VI
Extraocular muscles
List the cranial nerves classfied as somatic
III, IV, VI, XII
List the cranial nerves derived from caudal somites, (post-otic)
XI, XII
innervate the tongue and sternocleidomastoid & trapezius
Describe the cranial nerves involved in special senses
I, II, VIII, IX, Chorda Tympani
How are the cranial nerve nuclei grouped?
Based on…
Grouped by embryological origin
Do the extraocular rectus muscles insert anterior of posterior to the midline?
Rectus insert anterior to the midline. Oblique insert posterior to the midline
Name the action of the extraocular muscle, superior rectus
Elevation and Adduction
Name the action of the extraocular muscle, superior oblique
Abduction and Depression
List the nerves that supply each extraocular muscle
What nerve lesion might explain this pathology? Link this to the symptoms seen
Test
3rd Nerve Palsy
What nerve lesion might explain this pathology?
Test
VI nerve palsy
Which nerves exit the skull through the superior orbital fissure
V1, III, IV, VI
Which nerve carries proprioceptive fibres (positioning and movement of the eyes) from the extraocular muscles centrally
III (Oculomotor) sensory component carries proprioceptive fibres from the extraocular muscles - fibres then join the opthalmic divison of the trigeminal nerve (hitches ride)
Describe the differences between the Autonomic nervous system and Somatic nervous system
Past Exam Q
ANS: unconcious control, SNS: concious control
Describe the sympathetic innervation of the head and the neck - specifically referring to the pre- and post- ganglionic fibre locations.
Three gnaglia in the neck divided into superior, middle and inferior cervical ganglia
The post-ganglionic sympathetic nerves that innervate the head and neck arise from the superior cervical ganglion. These fibres travel with arteries and form the cephalic periarterial nerves.
What are cephalic periarterial nerves.?
post-ganglionic sympathetic nerves that leave the superior cervical ganglion forming the cephalic periarterial nerves - the fibres wrap around and follow the arteries (ex. carotid) to innervate visceral effectors associated with the skin of the face (sweat glands, blood vessels ect.) & visceral structures of the head (lacrimal gland, eye, nasal mucosa, salivary glands)
Describe the parasympathetic innervation of the head and the neck - specifically referring to the pre- ganglionic fibre locations.
Cell bodies of pre-ganglionic parasympathetic nerves are in nuclei of four of the cranial nerves (3rd, 7th, 9th, 10th) & 2nd-4th sacral segments of spinal cord
‘cranio-caudal divison of the ANS’
The pre-ganglionic parasympathetic nerves - travelling with the cranial nerves (3rd, 7th, 9th, 10th) correspond to which ganglia?
3rd: Ciliary ganglion
7th: Pterygopalatine ganglion
7th: Submandibular ganglion
9th: Otic ganglion
Where is the ciliary ganglion located? What role do the post-ganglionic fibres (that have synapsed in the ciliary ganglion) have?
Posterior to the eye
Fibres from ciliary ganglion supply parasympathetic innervation responsible for lens accommodation, pupilary light reflex
What other types of fibres travel through the ciliary ganglion/nerve
Describe the autonomic innervation to the eye (including the muscles and reflex)
Regulate diameter of the pupil of the eye by S.M
Constrictor muscles - circumferential/circular muscles (sphincter pupillae) - innervated by parasympathetic nerves. contraction = pupil constriction
Dilator muscles - radial muscles (dilator pupillae) - innervated by sympathetic nerves. contraction = pupil dilation
Pupillary reflex - constriction of the pupil in response to bright light - mediated by oculomotor nucleus (parasympathetic)
Lens accommodation - parasympathetic innvervating ciliary muscles
Where is the pterygopalatine ganglion located? What fibres enter the ganglion (what nerve is associated with this ganglion) and exit? What do they innervate?
Located lateral to the sphenopalatine foramen - between the sphenoid and palatine bones
Recieves pre-ganglionic fibres from the facial nerve (VII)
Post-ganglionic fibres asend to maxilary nerve (V2)
= parasympathetic innervation of the nasal mucosa, palate, pharynx and lacrimal glands