SLHS 261Exam # 1 Study Guide Lectures: 1 - 3Lecture 1 (January 21st)NeuronsHow do neurons communicate? How does chemical communication occur? How does an AP occur? What has been linked to a deficit in electrical communication? Neurons communicate chemically and electrically. Chemical communication occurs when the cell becomes depolarized. A neurotransmitter is released and latches onto the receptors on the next cell. AP begins with a cell in resting state. Na+ channel opens and the influx of Na+ leases to depolarization. An AP is released and K+ channels reopen and repolarizes the cell. K+ overshoots and the cell becomes hyperpolarized. Lecture 2 (January 23rd) What are the two important muscle proteins and what are their roles in the sliding filament theory? What are motor units? What is spasmodic dysphonia? What is afferent? What is efferent?Myosin and actin coming together shorten the sarcomere. This makes up the sliding filament theory. Motor Units are functional units for producing muscle action- consists of a nerve cell (lower motor neuron in gray matter of spinal cord) and all the muscle fibers served by the cell. Spasmodic dysphonia is sustained laryngeal muscle contractions that result in hyperadduction of vocal folds and hurts speech abilities. The treatment is surgical route that partially or fully de-enervates the muscle or the injection of botox into vocal folds reduces the release of acetylcholine at the neuromuscular junction and decreases muscle contractions. Afferent is from the periphery to the CNS (incoming). Efferent is signals which move from CNS to periphery (motor signals). Lecture 3 (January 28th)List all 12 of the cranial nerves and whether or not they are sensory, motor or both. Also list the function of each nerve. Discuss relevant disorders. Number Name Sensory, Motor, BothFunction Branches (if applicable)I Olfactory S SmellII Optic S VisionIII Oculomotor M Eye movementIV Trochlear M Eye movementV Trigeminal B Mastication, face, mucous membranes, teeth, tongueOphthalmic , Maxillary, MandibularVI Abducens M Eye MovementVII Facial B Face and stapedius, liquid related thingsVIII Vestibulocochlear S Hearing and balanceIX Glossopharyngeal B stylopharyngeus, tongue, pharynx; salivary gland (just one),carotid bodyX Vagus B velopharyngeal, pharyngeal, laryngealmuscles. Pharyngeal, Superior, ReccurentXI Accessory M Spinal branch (sternocleidomastoid,trapeziusmuscles)Cranial branch- pharyngeal musclesXII Hypoglossal M General efferent- innervates muscles ofthe tongueTrigeminal Neuralgia- feel pain, touch, and temperature changes in different portions of face- Nerve damage causes severe facial pain - Caused by a blood vessel that presses on the trigeminal nerve as it exits the brain stem leading to the wearing away of the myelin sheath- Occurs with multiple sclerosis- Treatment: cutting nerve or taking drugs to block nerve firing Bell’s Palsy: Damage to the facial nerve that results in droopy eyelid, facial paralysis, twitching or weakness; droopy corner of mouth, dry mouth, and impaired taste Glossopharyngeal damage: difficulty swallowing- damage includes severe pain in tongue, throat, ear tonsils- causes include tumors and infections- Treatment: surgery or anticonvulsant/antidepressant Vagus Damage: Vagal Nerve Injury/ Vocal Cord ParalysisMotor division of vagus nerve innervates laryngeal nerve supplying muscles involved in swallowing- dysphagia