Lecture 7Olfactory Nerve—CN 1—sensoryDamage to olfactory nerve results in loss of sense of smell in ipsilateral nostril. Very inconsequential, most people go their whole lives without knowingOptic Nerve—CN2--- sensory visualDamage to optic nerve results in complete blindness in ipsilateral eyeOculomotor Nerve—CN3---innervates ipsilateral medial rectusDamage results in ipsilateral eye drifting outward (because medial rectus is weak, lateral rectus takes over)—ipsilateral pupil also stays dilated when light is shown on the eyesEx. This lady has damage to the right oculomotor nerveTrochlear Nerve—CN4--innervates superior obliqueDamage results in diplopia, and inability to intort the eye—so the patient manually intorts it by tilting head so that damaged eye is upwardTrigeminal Nerve—CN5—primarily facial sensation (some chewing)Damage results in ipsilateral loss of sensory perception—inflammation of trigeminal nerve by herpes zoster will present with specific dermasome representation on the faceAbducens Nerve—CN6—innervation of lateral rectusDamage results in ipsilateral eye drifting medially---innervation to lateral rectus is damaged so medial rectus takes overFacial Nerve—CN 7—motor innervation of the faceDamage results in ipsilateral face weakening, ex. Bell’s Palsy—UMN lesion does not involve foreheadAuditory—CN 8—hearingDamage results in ipsilateral hearing lossGlossopharyngeal–CN 9---tasteDamage results in loss of tasteDoesn’t really present telling physical symptoms of damageVagus–CN 10—guttural signals (parasympathetic) and soft palette motor controlDamage results in deviation of uvula AWAY from lesion (towards the strong side)Ex. Damage to left vagus; left palette is drooping (weak)Accessory–CN11—innervation of neck and shoulder musclesDamage results in shoulder paresis, so affected shoulder droopsEx. Damage to right accessoryHypoglossal –CN 12—motor innervation of tongueDamage results in tongue deviating to side of lesionThis lady has damage to the right hypoglossal nerveLecture 8Functions of long projections*Pain/ sensory perception*Posture*Wakefulness/ arousal (RAS)reticular activating system*Filters incoming stimuli to block irrelevant stimuliVentral pons is dominated by transverse fibers that originate in the pons and pass through contralateral middle cerebellar peduncle to the cerebellar hemisphereVentral surface of the midbrain contains a huge column of descending motor fibers, the crus cerebri (in red) (corticospinal tract)Caudal MedullaRostral Medulla:Pons:Midbrain:Midbrain Nuclei:1. Red nucleus - motor control, especially for posture. Receives signals from motor cortex, they cross and descend through the rubrospinal tract2. Superior colliculus – visual control of eyes (reflex) -> tectospinal tract3. Inferior colliculus – receives auditory input -> thalamus (to assist in visual reflex)4. PAG - pain processing5. Medial lemniscus – rostral sensory path (axons of nucleus gracilis and nucleus cuneatus form this)6. Substantia nigra – movement control -> caudate and putamen (striatum)NSC 4366 1nd EditionExam # 2 Study Guide Lectures: 7-10Lecture 7Olfactory Nerve—CN 1—sensoryDamage to olfactory nerve results in loss of sense of smell in ipsilateral nostril. Very inconsequential, most people go their whole lives without knowingOptic Nerve—CN2--- sensory visualDamage to optic nerve results in complete blindness in ipsilateral eyeOculomotor Nerve—CN3---innervates ipsilateral medial rectusDamage results in ipsilateral eye drifting outward (because medial rectus is weak, lateral rectus takes over)—ipsilateral pupil also stays dilated when light is shown on the eyes Ex. This lady has damage to the right oculomotor nerveTrochlear Nerve—CN4--innervates superior obliqueDamage results in diplopia, and inability to intort the eye—so the patient manually intorts it by tilting head so that damaged eye is upwardTrigeminal Nerve—CN5—primarily facial sensation (some chewing)Damage results in ipsilateral loss of sensory perception—inflammation of trigeminal nerve by herpes zoster willpresent with specific dermasome representation on thefaceAbducens Nerve—CN6—innervation of lateral rectusDamage results in ipsilateral eye drifting medially---innervation to lateral rectus is damaged so medial rectus takes overFacial Nerve—CN 7—motor innervation of the faceDamage results in ipsilateral face weakening, ex. Bell’s Palsy—UMN lesion does not involve foreheadAuditory—CN 8—hearingDamage results in ipsilateral hearing lossGlossopharyngeal–CN 9---tasteDamage results in loss of tasteDoesn’t really present telling physical symptoms ofdamageVagus–CN 10—guttural signals (parasympathetic) andsoft palette motor controlDamage results in deviation of uvula AWAY fromlesion (towards the strong side)Ex. Damage to left vagus; left palette is drooping(weak)Accessory–CN11—innervation of neck and shouldermusclesDamage results in shoulder paresis, so affectedshoulder droopsEx. Damage to right accessory Hypoglossal –CN 12—motor innervation of tongueDamage results in tongue deviating to side of lesionThis lady has damage to the right hypoglossal nerveLecture 8MIDBRAIN-Mesencephalic Trigeminal Nucleus (CN V)-sensory-jaw proprioception-Oculomotor Nucleus (CN III)-motor-innervates medial lemniscus Edinger Westphal Nucleus (CN III)-sympathetic-Trochlear Nucleus (CN IV)-exits midbrain dorsally and wraps around-“trauma nerve”-intorts eye-Red Nucleus-extrapyramidal—rubrospinal—movement coordination-Dopamine synthesis at ventral tegmental area and substantia nigra PONS-Abducens Nucleus (CN VI)-innervates the lateral lemniscus-Chief Sensory Nucleus of Trigeminal Nerve (CN V)-fine touch and vibration to the face-Primary Motor Nucleus of Trigeminal Nerve (CN V)-“jaw-jerk” reflex—motor control of the jaw-Facial Nerve Nucleus (CN VII)-motor control of the face-Vestibular and Cochlear Nuclei (CN VIII)-auditory response and balance-Norepinephrine synthesis-locus coeruleus in dorsal ponsMEDULLA-Solitary Nucleus (CN X and CN IX)-Nucleus Ambiguus (CN X and CN IX)-innervates pharynx, larynx and soft palette-Dorsal Motor Nucleus of the Vagus (CN X)-parasympathetic responses of internal organs-Hypoglossal Nucleus (CN XII)-motor control of the tongue-Spinal Trigeminal Nucleus (CN V)-crude pain and temperature to faceLecture 9Reticular Formation:Functions of long projections *Pain/ sensory perception *Posture