LAB 9 CRANIAL SPINAL NERVES AND REFLEX PHYSIOLOGY Exercises 18 19 21 and 22 Teacher Course Evaluations TCEs will be available ONLINE from April 21st and will CLOSE on May 7th If 80 of the lab sections complete these surveys there will be a free question on the practical essentially automatic 2 pts Reminders will be on D2L as well Agenda Pre Labs Quiz Exercise 21 Cranial Nerves Exercise 18 Spinal Nerves Exercise 19 Somatic Reflexes Exercise 22 Autonomic Reflexes Few things to clear up EXERCISE 21 CRANIAL NERVES Before we start Remember that NERVES are part of the PNS while TRACTS are part of the CNS Nerve bundle of axons in PNS Tract bundle of axons in CNS CNs therefore can be sensory motor or both afferent efferent or both Cranial Nerves are numbered with roman numerals I to XII Olfactory I Action Smell Function Sensory Optic II Action Vision Function Sensory Oculomotor III Action Movement of eyelid and eyeball accommodation of lens and pupillary constriction Function Motor Trochlear IV Action Movement of eyeball Function Motor Trigeminal V Action Cutaneous sensations from opthalmic maxillary and mandibular areas chewing Function Both Abducens VI Action Movement of eyeball Function Motor Facial VII Action Taste facial expression tear secretion and salivation Function Both Vestibulocochlear VIII Action Equilibrium and hearing Function Sensory Glossopharyngeal IX Action Taste swallowing speech saliva secretion Function Both Vagus X Action Taste and somatic sensation from pharynx and epiglottis swallowing coughing and voice production smooth muscle contraction of GI tract slow heart rate secretion by digestive glands Function Both Accessory XI Action Cranial portion Swallowing Spinal portion Movement of head and shoulders Function Motor Hypoglossal XII Action Speech and swallowing Function Motor Mnemonics for Cranial Nerves Mnemonic for Order of Cranial Nerves I XII On Old Olympus Towering Top A Friendly Viking Grew Vines And Hops Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Spinal Accessory Hypoglossal Mnemonic for Function of Cranial Nerves Some Say Marry Money But My Brother Say Big Brains Matter Most S Sensory M Motor B Both Information to Skip Skip Table 21 1 on pg 322 foramen Skip Activity 2 and Table 21 3 on pg 326 Skip the distribution column of Table 21 2 you need to know the rest Activity Time Sheep Brains and Models Specimen pg 312 314 Review Need to identify CN I II and V on the sheep brain Must be able to identify ALL CNs on the models and their functions EXERCISE 18 SPINAL NERVES Introduction Send information between the PNS and CNS Peripheral sensory receptors to the spinal cord From the spinal cord to various effectors 31 pairs of spinal nerves Emerge bilaterally from spinal cord Help to mediate spinal reflexes as well more on this later Connective Tissue Coverings of Spinal Nerves Epineurium Surrounds whole nerve Perineurium Surrounds each fascicle Endoneurium Covers myelinated and unmyelinated axons Spinal Nerve Divisions and Spinal Plexus Divisions 8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal Cervical plexus Cervical nerves Brachial plexus Thoracic nerves Plexus braided network of spinal nerves Cervical Brachial Lumbar Sacral Lumbar nerves Lumbar plexus Sacral plexus Sacral nerves Coccygeal nerves CERVICAL PLEXUS C1 C5 Lesser occipital nerve Great auricular Ansa cervicalis Transverse cervical nerve Supraclavicular nerve Phrenic nerve BRACHIAL PLEXUS C5 T1 Musculocutaneous nerve Axillary nerve Median nerve Radial nerve Ulnar nerve Intercostal thoracic nerves Subcostal nerve intercostal nerve 12 LUMBAR PLEXUS L1 L4 Iliohypogastric nerve Ilioinguinal nerve Genitofemoral nerve Lateral femoral cutaneous nerve Femoral nerve Obturator nerve SACRAL PLEXUS L4 S4 Superior gluteal nerve Inferior gluteal nerve Sciatic nerve Common fibular nerve Tibial nerve C1 C2 C3 C4 C5 C6 C7 C8 T1 T2 T3 T4 T5 T6 T7 CERVICAL NERVES 8 pairs THORACIC NERVES 12 pairs T8 T9 T10 T11 T12 L1 LUMBAR NERVES 5 pairs L2 L3 L4 L5 S1 S2 S3 S4 S5 Posterior view of entire spinal cord and portions of spinal nerves SACRAL NERVES 5 pairs COCCYGEAL NERVES 1 pair Cervical Plexus A plexus of the first 4 spinal nerves C1 C4 Nerves exit lateral to transverse processes Form anastomoses Nerves are deep to the SCM muscle Cervical Plexus Paired nerve Phrenic Receives info from respiratory centers in medulla and pons Innervates diaphragm Brachial Plexus Plexus of the lower 4 cervical spinal nerves and the first thoracic spinal nerve C4 T1 Innervates the upper limb Muscular and cutaneous innervation Exception of trapezius XI Brachial Plexus Brachial Plexus Axillary Deltoid and teres minor muscles Musculocutaneous Anterior muscles of arm Ulnar Flexor carpi ulnaris flexor degitorum profundus most hand muscles Median Muscles of anterior forearm except muscles supplied by ulnar nerve some hand muscles Radial Muscles of posterior arm and forearm Lumbar Plexus This plexus is located in the lumbar region L1 L4 Also some contribution from subcostal nerve T12 Helps to innervate area of the pelvis and thigh Both cutaneous and muscular Nerves exit to the lower limb under inguinal ligament or through obturator foramen Lumbar Plexus Femoral Iliacus quadriceps femoris sartorius pectineus Obturator Adductor longus brevis and part of magnus gracilis Sacral Plexus Originates in the lower lumbar spine and terminates at the coccyx L5 S4 Some contribution from L4 Branches innervate the leg and posterior thigh Sacral Plexus Pudendal Muscles of perineum Sciatic Biceps femoris semimembranosus semitendinosus Tibial Gastrocnemius soleus tibialis posterior flexor digitorum longus plantaris flexor hallicus longus Common fibular Fibularis longus tibialis anterior extensor digitorum longus DERMATOMES AND SHINGLES By John What is a dermatome Area of skin supplied by a single spinal nerve 8 cervical 12 thoracic 5 lumbar 5 sacral Transmit sensation from region of skin to brain Exact areas supplied by nerve is individualized much like fingerprints Clinical Significance Pain or rash at dermatome may signify a nerve related pathology i e somatic dysfunction Problems in this area are usually diagnosed by D O Doctor of Osteopathic Medicine Dormant chicken pox Varicella zoster virus lies in nerves During immune deficiency may present with a rash or pain Shingles Waz dat Reactivation a latent virus Varicella zoster Viral infection Varicella zoster which is the virus that causes chicken