《生理学》课程教学资源（PPT课件讲稿）Chapter 9 Motor System（Muscle Contraction and Motor Unit）

Chapter 9 Motor System -1 Muscle contraction and motor unit

Chapter 9 Motor System - 1 Muscle Contraction and Motor Unit

Content Skeletal muscle contraction · Motor unit

Content • Skeletal Muscle Contraction • Motor Unit

Reference -Text Book DY5TESO7n ①…+:· 的二 GUYTON AND HALL Textbook of The Nervous System Medical Physiology secoND eDmoN 生理学 Aum Mdmek-Ttbe Puros Reves 3酯 E EDUCA HALL SAUNDERS P160-163 P71-82 UNIT XI The Nervous System: C P482-483 Motor and Integrative Neurophysiology

Reference – Text Book P160-163 P71– 82 P482-483 UNIT XI The Nervous System: C. Motor and Integrative Neurophysiology

Section i skeletal muscle contraction Signal Transmission Through Neuromuscular Junction Molecular mechanism of muscle Contraction Factors that affect the efficiency of muscle Contraction

Section I Skeletal Muscle Contraction • Signal Transmission Through Neuromuscular Junction • Molecular Mechanism of Muscle Contraction • Factors that Affect the Efficiency of Muscle Contraction

Part l Signal Transmission Through the Neuromuscular junction

Part I Signal Transmission Through the Neuromuscular Junction

Skeletal muscle innervation Path of action neuron Neuromuscular Axon junction e Motor end plate Supporting cell Synaptic terminal Sarcolemma Mitochondrion Myofibril Muscle b

6 Skeletal Muscle Innervation

Illustration of the neuromuscular Junction(NMJ Motor neuron fiber Nerve fiber branches Muscle fiber nucleus Motor end plate Myofibril of muscle fiber m e Mitochondria Synaptic vesicles Synaptic cleft Folded sarcolemma Motor end plate

7 Illustration of the Neuromuscular Junction (NMJ)

New lon Channel Players Voltage-gated ca2+ channel >in presynaptic nerve terminal >mediates neurotransmitter release P Nicotinic Acetylcholine receptor channel >in muscle neuromuscular junction (postsynaptic membrane or end plate) >mediates electrical transmission from nerve to muscle Nerve fiber branches Muscle fiber nucleus Motor end plate Myofibril of muscle fiber Motor end plate

8 New Ion Channel Players ➢Voltage-gated Ca2+ channel ➢in presynaptic nerve terminal ➢mediates neurotransmitter release ➢Nicotinic Acetylcholine Receptor Channel ➢in muscle neuromuscular junction (postsynaptic membrane, or end plate) ➢mediates electrical transmission from nerve to muscle

Neuromuscular transmission Axon Axon terminal Skeletal Muscle

9 Neuromuscular Transmission Skeletal Muscle Axon Axon Terminal

Depolarization Neuromuscular Nerve出i Transmission opens ca nnels potential invades Step by step axon terminal Look here

10 Neuromuscular Transmission: Step by Step Nerve action potential invades axon terminal - + - - - - - - + + + + + + + - - - + + Depolarization of terminal opens Ca channels Look here + +