Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download PNS: Somatic and Visceral
Document related concepts
no text concepts found
Transcript
PNS: Somatic and Visceral Biol. 211 Anatomy & Physiology 1 Tony Serino, Ph.D. Biology Department Misericordia University (Visceral) Cranial Nerves CN I: Olfactory Nerve CN II: Optic Nerve CN III: Occulomotor Nerve Superior Orbital Fissure Medial Rectus muscle Midbrain Superior Rectus muscle Levator Palpabrae muscle Inferior Oblique muscle Ciliary ganglion Inferior Rectus muscle Parasympathetic Motor fibers Oculomotor N. (III) Pons CN IV: Trochlear Nerve CN V: Trigeminal Nerve CN VI: Abducens Nerve CN VII: Facial Nerve CN VIII: Vestibulocochlear Nerve CN IX: Glossopharyngeal Nerve CN X: Vagus Nerve CN XI: Accessory Nerve CN XII: Hypoglossal Nerve Spinal Nerves and Plexuses Spinal Nerve Anatomy Cervical Plexus Serves neck and diaphragm Brachial Plexus and pectoral nerves Brachial Plexus Innervates most of the arm and some of the body wall. Lumbar Plexus Innervate the anterior leg. Sacral Plexus Innervates the posterior leg Dermatomes • A dermatome is the area of skin innervated by the cutaneous branches of a single sensory spinal nerve • All spinal nerves except C1 participate in dermatomes Reflex Arc Stretch Reflex Stretch Reflex •Stretching the muscle activates the muscle spindle •Excited motor neurons of the spindle cause the stretched muscle to contract •Afferent impulses from the spindle result in inhibition of the antagonist •Example: patellar reflex –Tapping the patellar tendon stretches the quadriceps and starts the reflex action –The quadriceps contract and the antagonistic hamstrings relax Golgi Tendon Reflex • The opposite of the stretch reflex • Contracting the muscle activates the Golgi tendon organs • Afferent Golgi tendon neurons are stimulated, neurons inhibit the contracting muscle, and the antagonistic muscle is activated • As a result, the contracting muscle relaxes and the antagonist contracts Flexor and Crossed Extensor Reflexes •The flexor reflex is initiated by a painful stimulus (actual or perceived) that causes automatic withdrawal of the threatened body part •The crossed extensor reflex has two parts –The stimulated side is withdrawn –The contralateral side is extended Neurotransmission Scenario ANS Divsions Parasympathetic (Craniosacral) Sympathetic (Thoracolumbar) Sympathetic Ganglia Levels of Control in ANS
Related documents