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Anatomy and Physiology, Sixth Edition

Rod R. SeeleyIdaho State UniversityTrent D. StephensIdaho State UniversityPhilip TatePhoenix College

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.

Chapter 12Chapter 12Lecture OutlineLecture Outline**

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Saraf tunjang dan Saraf spina

Chapter 12

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Saraf Tunjang • Bersambung dari foramen

magnum kepada vertebra lumbar kedua

• Jenis vertebra – Vertebra serviks – Vertebra toraks – Vertebra lumbar – Sakrum

• Menerbitkan 31 pasang saraf spina daripadanya

• Tidak membentuk diameter di keseluruhan panjangnya

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Meninges

• Connective tissue membranes surrounding spinal cord and brain– Dura mater– Arachnoid mater– Pia mater

• Spaces– Epidural: Anesthesia injected– Subdural: Serous fluid– Subarachnoid: CSF

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Cross Section of Spinal Cord

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Cross Section of Spinal Cord

• White matter• Myelinated axons

forming nerve tracts• Fissure and sulcus• Three columns or

funiculi– Ventral – Dorsal– Lateral

• Gray matter• Neuron cell cell bodies,

dendrites, axons• Horns

– Posterior (dorsal)– Anterior (ventral)– Lateral

• Commissures– Gray: Central canal – White

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Reflex Arc• Basic functional unit of

nervous system and simplest portion capable of receiving stimulus and producing response

• Components– Sensory receptor– Sensory neuron– Interneurons – Motor neuron– Effector organ

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• Muscles contract in response to a stretching force applied to them

Stretch Reflex

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Golgi Tendon Reflex• Prevents contracting muscles from applying

excessive tension to tendons

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Withdrawal Reflex• Function is to remove a body limb or other part from a

painful stimulus

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Withdrawal Reflex with Reciprocal Innervation

• Causes relaxation of extensors muscle when flexor muscles contract

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Withdrawal Reflex with Crossed Extensor Reflex

• When a withdrawal reflex is initiated in one lower limb, the crossed extensor reflex causes extension of opposite lower limb

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Peripheral Nerves

• Consist of– Axon bundles – Schwann cells– Connective tissue

• Endoneurium• Perineurium: Surrounds

axon groups to form fascicles

• Epineurium

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Spinal Nerves

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Dermatomal Map• Skin area supplied with sensory innervation by

spinal nerves

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Cervical Plexus

• C1-C4• Phrenic nerve

– From C3-C5 cervical and brachial plexus

– Innervate diaphragm

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Brachial Plexus

• C5-T1• Major nerves

– Axillary– Radial– Musculocutaneous– Ulnar– Median

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Axillary Nerve

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Radial Nerve

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Musculocutaneous Nerve

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Ulnar Nerve

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Median Nerve

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Lumbosacral Plexus

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Obturator Nerve

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Femoral Nerve

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Tibial Nerve

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Fibular Nerve

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PNS Disorders• General disorders

– Anesthesia: Loss of sensation• Hyperesthesia: Increased sensitivity to pain, pressure, light• Paresthesia: Tingling, prickling, burning• Neuralgia: Nerve inflammation causing stabbing pain• Sciatica: Pain radiating down back of thigh and leg

• Infections– Herpes: Skin lesions– Shingles or herpes zoster: Adult disease of chickenpox– Poliomyelitis: Infantile paralysis

• Genetic and autoimmune disorders– Myasthenia gravis: Results in fatigue and muscular

weakness due to inadequate ACh receptors