Neuromuscular Junction (NMJ). Neuromuscular junction Neuromuscular junction : the synapse between motor neuron and muscle fibre Motor neurons : are the.

Slides:

Advertisements

Similar presentations

Advertisements

SYNAPSES AND DRUGS.

Muscles and Muscle Tissue

Figure 10.6 Structure of the Neuromuscular Junction Process Diagrams Step-by-Step Copyright © 2007 by John Wiley & Sons, Inc.

Anatomy and Physiology I

Sliding Filament Mechanism

How does a muscle work? Remember, muscles can only contract so they can only pull, not push. And it needs certain parts to do this.

Histology of Muscle.

{ Nerve Stimulus and Action Potential Bella Veri Brandon Richter Haily Walker Deva Ramos Jenny Le Period 4.

How Does A Motor Unit Illicit A Muscular Contraction.

The Neuromuscular Junction Chapter 10 Anatomy and Physiology Mr. Knowles Liberty Senior High School.

Signals Passing Through Neuromuscular Junction 4 th Period: Breanne Gomez, Haleigh Eary, Hanna Hollman, Yazmin Baldonado.

Skeletal Muscles. Anatomy and innervation of skeletal muscle tissue Connective tissue components: –Fascia (“bandage”) –sheet or band of fibrous C.T. under.

Contraction of skeletal muscle. Learning objectives What evidence supports the sliding filament mechanism of muscle contraction? How does the sliding.

BY: STEPHANIE MARTELLA THE CHEMISTRY OF A MUSCLE CONTRACTION.

The Muscular System What do skeletal muscles do? How do muscles work?

Stimulation and Contraction of Single Skeletal Muscle Cells

Muscle Contraction. Muscle Movement Muscle fiber must be stimulated: – By an electrical signal called muscle action potential (AP) – Delivered by motor.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Contraction.

Pages  Stimulus generated capabilities: ◦ Irritability (also called responsiveness)—ability to receive and respond to a stimulus ◦ Contractility—ability.

Nerve Supply to Skeletal Muscle. Nerve Supply The outside of the nerve plasma membranes contain a slightly positive charge (Na+). The inside of this same.

Contraction of skeletal muscles. Energy Needed for Contraction 1. Aerobic Respiration (oxidative phosphorylation) Majority of ATP comes from this process.

Neuromuscular transmission Motor Unit Motor Unit :Motor Unit : is the motor neuron and all the muscle fibers it supplies all of these fibers will have.

Motor Unit: A motor neuron and all the muscle fibers it innervates. *Powerful movements use more fibers *Fine movements use fewer fibers.

Flash Cards Chapter

THE SYNAPSE Where nerve impulses convert to neurotransmitters The Sanger Institute.

Muscle Physiology: Cellular Mechanisms of Muscle Contraction Review of Membrane Permeability Resting Potential of Muscle Cells Local Membrane Potentials.

Neuromuscular transmission

Ch : Contraction and Metabolism of Skeletal Muscle

Neuromuscular transmission. Synaptic transmission *** Synapse is the junction between two neurones where electrical activity of one neurone is transmitted.

Filaments Resting state Electrical impulse (Action Potential) reaches axon terminal.

Synapse – The site of connection between a neuron and a cell. Neurotransmitter – A chemical released at the neuron’s synapse that communicates with the.

Skeletal Muscle Contraction

The Neuromuscular Junction

Neuromuscular Junction and Major Events of Muscle Contraction Quiz Review.

Chapter 9 Muscular System.

Action potential 1. Action potentials arriving at the presynaptic terminal cause voltage- gated Ca2+ channels to open. Ca Presynaptic terminal.

09.12 Function of the Neuromuscular Junction Slide number 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Muscle Contraction. 1.Acetylcholine (Ach) is released from the axon terminal (nerve) into the synaptic cleft and binds to Ach receptors in the sarcolemma.

Neuron Function The Membrane Potential – Resting potential Excess negative charge inside the neuron Created and maintained by Na-K ion pump Copyright ©

The Muscular System What do skeletal muscles do? How do muscles work?

Section Sarcolemma- plasma membrane of a muscle fiber 2. Sarcoplasm- cytoplasm 3. Sarcoplasmic reticulum- smooth ER that stores Ca Myofibrils-

Nerve Supply to a Muscle. Nerve Supply Motor Neuron: Nerve that stimulates a muscle cell. A single nerve (motor neuron) will supply approximately 150.

Skeletal Muscle Blank.

Muscles Skeletal muscles are stimulated to contract by nerves and act as effectors.

The Muscular System PP # 3 Contraction

The Muscular System What do skeletal muscles do? How do muscles work?

2. Striation Pattern of Sarcomere

LECTURE 15 NEUROMUSCULAR JUNCTION

9 Muscles and Muscle Tissue: Part B.

MUSCLE CONTRACTION © 2016 Paul Billiet ODWS.

The Muscular System What do skeletal muscles do? How do muscles work?

Introductory Skeletal Muscle – Histology Flash Cards

Chapter 3 Support and locomotion – muscles and movement.

The Sliding-Filament Mechanism

The Neuromuscular Junction

1. An action potential arrives at the

SYNAPSES AND DRUGS.

SYNAPSES AND DRUGS.

Communication Between the Nervous System and Skeletal Muscles

1. An action potential arrives at the

Muscle Innervation Skeletal muscles are acted upon by somatic motor neurons (neurons that take thought) Motor unit: axon terminal branches of the neuron.

How do Muscles Contract?

Module 4 Responding to the environment

Neuromuscular Junction

SYNAPSES AND DRUGS.

Contraction of Skeletal Muscle

Nerves and Muscles.

Presentation transcript:

Neuromuscular Junction (NMJ)

Neuromuscular junction Neuromuscular junction : the synapse between motor neuron and muscle fibre Motor neurons : are the nerves that innervate (power) muscle fibres Motor unit : single motor neuron and the muscle fibre it innervates Axon: nerve fibre that is a long, slender projection of a nerve cell, or neuron 2

As an axon approaches muscle, it divides into many terminal branches Each of these axon terminal forms special junction  a neuromuscular junction with one or more muscle fibre 3

5

Synaptic Terminal Contains molecules of Acetylcholine (ACh) ACh ACh is a neurotransmitter  chemical released by neurons to change the membrane properties of other cells.

Synaptic Cleft narrow space A narrow space that separates the synaptic terminal of the neuron from the sarcolemma surface. (AChE) Ach Contains Acetylcholinesterase (AChE) which breaks down Ach

Motor End Plate ACh The surface of the sarcolemma that contains membrane receptors that bind ACh

Nerve Stimulus to Muscles Neuromuscular junctions – association site of nerve and muscle

Nerve Stimulus to Muscles Synaptic cleft – gap between nerve and muscle – Nerve and muscle do not make contact – Area between nerve and muscle is filled with fluid

Sequence of events 1.An action potential arrives at the end of a motor neurone, at the neuromuscular junction. 2.This causes the release of the neurotransmitter acetylcholine.

Sequence of events 3.This initiates an action potential in the muscle cell membrane (Sarcolemma). 4.This action potential is carried quickly into the large muscle cell by invaginations in the cell membrane called T-tubules.

Sequence of events 5.The action potential causes the sarcoplasmic reticulum to release its store of calcium into the myofibrils. 6.Ca 2+ causes tropomoysin to be displaced uncovering myosin binding sites on actin. 7.Myosin cross bridges can now attach and the cross bridge cycle can take place. 8.Relaxation is the reverse of these steps

Neuromuscular junction: Note Ach = Acetylcholine

In Summary…

Sequence Of Events At Neuromuscular Junction 29 Action potentials arrives at the presynaptic terminal  causes voltage-gated Ca 2+ channels to open.

Sequence Of Events At Neuromuscular Junction 30 Ca2+ uptake into the terminal causes release of the neurotransmitter acetylcholine into synaptic cleft, which has been synthesized & stored into synaptic vesicles

Sequence Of Events At Neuromuscular Junction Ach travels across the synaptic cleft to postsynaptic membrane which is also known as motor end plate. 31