Beginning nervous system

• Olfactory nerve
• Sense of smell
• exits brain through olfactory foramina

• Optic Nerve
• Visual acuity, visual fields
• Exits brain through optic canal

• Occulomotor N.
• -Innervates levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, inferior oblique extraocular muscles
• -Provides parasympathetic innervation that constrict the eye and change lense shape

Exits brain through superior orbital fissure

• Trochlear n.
• Controls: Superior oblique muscles (Down and inward motion)
• Exits brain through superior orbital fissure

• Trigemnian Nerve
• - receives sensation from face
• -responsible for corneal reflex
• -innervates muscles of mastication
• Goes through superior orbital fissure, foramen rotundum, and foramen ovale

• Abducens nerve:
• -innervates lateral rectus muscle (allowing ABduction of eye)
• Exits brain through superior orbital fissure

• Facial nerve
• - Motor innervation to: Facial expression muscles, posterior belly of digastric m., stapedius muscle
• -taste on anterior 2/3 tongue
• -secretomotor innervation to salivary glands (except parotid), lacrimal gands,
• -located and goes through internal acoustic canal to facial canal and exits sckull at styylomastoid foramen
• Branches: temproaly, zygamatic, buccal, mandibular, cervical

• Vestibulocochlear n.
• -senses sound, rotation, gravity
• -carries impulses for equlibrium (in terms of being level)
• - Chochlear branche carries hearing impulses
• -located in internal acoustic canal

• Glossopharyngeal N.
• Taste: posterior 1/3 tongue
• Secretemotor innervation to parotid gland
• -motor innervation to stylopharyngeus
• -sensory innervation from palatine tonsils
• -Exits brain through jugular foramen

• Vagus n.
• -motor innervation to most laryngeal and al pharyngeal muscles
• -parasmpathetic innervation to heart, GI tract, lungs
• -Leaves skulll through jugular foramen

• Cranial Accessory n
• - overlaps some vagus fxn
• -innervates sternocleidomastoid and trapezius
• -Damage= inability to shrug, weak head movements
• -leaves skull through jugular foramen

• Hypoglossal nerve
• -motor innervation to tongue muscles (except palatoglossus) and other glossal muscles
• -important to swallowing and speech
• -leaves skull through hypoglossal canal

• The primary motor cortex (in the precentral gyrus)
• -Corticospinal tract starts here

Premotor cortex; in charge of motor planning, immediately anterior to Brodman area 4

• Postcentral gyrus
• -contains primary somatosensory cortex
• - pain, touch, vibration, position

• Somatosensory association area
• -Assocation area
• -immediately posterior ot primary somatosensory cortex (Brodman 1,2,3)
• -combine senses to be recognized by the frontal lobe: stereognosis, graphestesia

• Divided into anterior and lateral corticospinal tract.
• -Lateral corticospinal (pyramidal) tract: found near dorsal horn
• -Anterior (ventral) corticospinal tract:

• innervates fine motor: esp upper extremities
• --crosses over at the cervicomedullary jxn
• --R brain injuries (before cervicomedullary jxn) cause L lateral corticospinal tract deficits in the peripbery

- Controls postural/trunk muscles

• Sensory: vibration, position, fine touch (2 pt)
• Divided into:
• - Gracile fasciculus
• -Cuneate fasciculus

• -part of dorsal column system
• - fine touch, position, and vibration BELOW T6

• -component of dorsal column system
• - Fine touch, position, and vibration ABOVE T6

• Includes:
• Spinothalamic tract
• spinoreticular tract
• spinomesencephalic tract (spinotectal)
• spinohypothalamic fibers

• - pain and temperature sensation
• -contralateral sensation: "crosses over" at the vertebrae where it enters the spinal cord or at most 2 vertebrae above that

Pertaining to motor neurons in the CNS (Brain and spinal cord)

Pertains to nerves that begin in brainstem/spinal cord that exit as cranial/spinal nerves to muscles

starts in cortex of brain, goes to brainstem

• Contributes to the upper motor neurons.
• -injuries to corticobulbar and corticospinal tracts may not result in hypertonicity of rubrospinal tract remains intact

• -largest motor tract
• -voluntary, highly skilled fractionated movement tract
• -decussation at cervicomedullary jxn