NBSS Flashcards
CN I
Olfactory nerve:
olfactory nerves –> olfactory bulb (cribriform plate) –> olfactory tract –> olfactory cortex (anterior ends of temporal cortex; olfactory tubercle and piriform process)
CN II
Optic nerve:
optic nerve –> optic chiasm –> optic tract –> lateral geniculate nucleus of thalamus –> optic radiation to visual cortex
CN III
Oculomotor nerve:
exits between crus cerebri from oculomotor and Edinger-Westphal nucleus (superior colliculi level)
Superior orbital fissure
Innervates most muscles of the eye + levetator palpebrae muscle; parasympathetics –> accommodation reflex through edinger-westphal nucleus
CN IV
Trochlear nerve:
exits posteriorly beneath inferior colliculi of mid-brain from trochlear nucleus (superior oblique muscle of eye)
Superior orbital fissure
Innervates superior oblique muscle (purely motor)
CN VI
Abducens nerve:
exits between pons and medulla oblongata from abducens nucleus (floor of fourth ventricle), lateral rectus muscle
Superior orbital fissure
Innervates lateral rectus muscle
CN V
Trigeminal nerve:
biggest CN, attaches to lateral pons
Sensory nucleus: mesencephalic nucleus, chief main nucleus, spinal nucleus
Motor nucleus: pons, floor of 4th ventricle at level of cerebellar peduncles, muscle of mastication innervation
Ophthalmic branch: superior orbital fissure
Maxillary branch: foramen rotundum
Mandibular branch: foramen ovale
What are the roles of Aalhpa, beta, delta and C fibers?
Aalpha: proprioception, myelinated
Abeta: touch, myelinated
Adelta: pain, myelinated
C: pain, unmyelinated
CN VII
Facial nerve:
Facial motor nucleus: stapedius + muscles of facial expression (stylomastoid foramen)
Nucleus solitarius: sensory (bodies in geniculate ganglia)
Superior salivatory nucleus: parasympathetic fibers (salivation and tears)
Internal auditory meatus (together with CN VIII)
CN VIII
Vestibulocochlear nerve:
Cerebello-pontine angle
Vestibulo and cochlear nuclei (lateral to the floor of 4th ventricles, pons)
CN IX
Glossopharyngeal nerve:
Root at medulla, lateral to olives
Nucleus ambiguus: motor fibers to stylopharyngeus muscle
Inferior salivatory nucleus: parasymp fibers to parotid gland
Nucleus solitarius: taste from 1/3 of tongue, blood pO2/CO2
Spinal nucleus of trigeminal nerve: pain, temperature and general sensation from inner ear, upper phraynx and posterior 1/3 of tongue
CN X
Vagus nerve:
root at medulla, lateral to olives
Nucleus ambiguus: motor fibers to larynx, pharynx and upper oesophagus + parasympathetic input to heart
Sensory fibers:
1. Spinal nucleus of trigeminal nerve: general sensation from phar, lar, oes, ear
2. Nucleus solitarius: chemo and mechano receptors from viscera, some taste
Dorsal nucleus of vagus nerve: parasympathetic fibers to viscera
CN XI
Accessory nerve (motor only): Cranial root: from nucleus ambiguus, splits from spinal root to join vagus at jugular foramen, innervates muscle of pharynx and larynx Spinal root (C1-6): enters through foramen magnum, innervates sternocleidomastoid and trapezius muscles
CN XII
Hypoglossal nerve (motor only): hypoglossal nucleus, innervates intrinsic and extrinsic muscles of the tongue, exits from hypoglossal canal (next to foramen magnum)
What is the neurocranium made of?
Calvaria (skull cap), basicranium and intracranial region
8 bones: frontal, ethmoidal, sphenoidal and occipital + temporal and parietal (paired)
What is the viscerocranium made of?
Facial bones in anterior part of the cranium
Single: mandible and vomer
Paired: maxillae, inferior nasal conchae, zygomatic, palatine, nasal and lacrimal
Through which structure does the medulla oblongata pass?
Foramen magnum
Where is the pterion situated?
At the level of the sphenoparietal suture
Which structures sit in each cranial fossa?
Anterior: frontal lobe
Middle: temporal lobe
Posterior: occipital lobe
Which cranial nerves pass through the jugular foramen?
IX, X, XI
What are the dura and arachnoid mater made of?
Dura: collagen fibers
Arachnoid: non-vascular connective tissue
What is the middle meningeal artery and where does it run?
largest of three paired arteries supplying the meninges; branch of maxillary artery (terminal branch of external carotid); runs through foramen spinosum; supplies dura mater and calvaria; runs beneath the pterion
Which are the cerebral ventricles?
Lateral ventricles (anterior, posterior and inferior horns), interventricular foramen, third ventricle, cerebral aqueduct, lateral aperture (allows CSF to go into subarachnoid space (cisterna magna), central canal
How is CSF re-absorbed into systemic veins?
Through arachnoid granulations (into superior sagittal sinus)
In between which two structures does the superior sagittal sinus run?
Periosteal and meningeal layers of the dura mater