15
Skeletal Muscle Contraction 1. Neurotransmitter must stimulate muscle. This happens at the neuromuscular junction. Axon of neuron, ‘Synaptic bulb’ Muscle AcH Formed by Muscle fiber membrane

Skeletal Muscle Contraction

  • Upload
    pilar

  • View
    65

  • Download
    3

Embed Size (px)

DESCRIPTION

Skeletal Muscle Contraction. Neurotransmitter must stimulate muscle. This happens at the neuromuscular junction. The space = synapse, synaptic cleft. Neurotransmitter = Acethylcholine. Stored in vesicles on the distal end of the axon. - PowerPoint PPT Presentation

Citation preview

Page 1: Skeletal Muscle Contraction

Skeletal Muscle Contraction

1. Neurotransmitter must stimulate muscle.This happens at the neuromuscular junction.

Axon of neuron,‘Synaptic bulb’

Muscle

AcH

Formed byMuscle fibermembrane

Page 2: Skeletal Muscle Contraction
Page 3: Skeletal Muscle Contraction
Page 4: Skeletal Muscle Contraction

The space = synapse, synapticcleft

ContainAcH

Page 5: Skeletal Muscle Contraction

Neurotransmitter = Acethylcholine. Stored in vesicles on the distalend of the axon.1. A nerve impulse/action potential reaches the synaptic bulb2. Calcium ions diffuse into the terminal.3. This causes the vesicles to move to the cell membrane, fuse with itand release AcH into the synaptic cleft.4. AcH binds to receptor proteins on the muscle side of the junction.5. This causes an impulse in the muscle that travels along and around the muscle.

Page 6: Skeletal Muscle Contraction

Receptorproteins

Motor end plate = membrane of muscle fiber.

Page 7: Skeletal Muscle Contraction

6. This muscle impulse/action potential moves along the sarcolemma, into transverse tubules and into the sarcoplasmicreticulum.

Action potential = A spike ofelectricaldischarge thattravels along the membraneof a cell

Depolarizes = becomes less negative

Page 8: Skeletal Muscle Contraction
Page 9: Skeletal Muscle Contraction
Page 10: Skeletal Muscle Contraction
Page 11: Skeletal Muscle Contraction
Page 12: Skeletal Muscle Contraction

7. Calcium ions are released into sarcoplasmic reticulum8. Calcium ions expose binding sites on actin.9. Myosin heads bind to the binding sites and form cross bridges.10. Myosin heads lose ADP and P, change shape and pull actin to the center of the sarcomere… this results in the contraction of the muscle.11. ATP forms, binds to myosin head, cross bridges break and muscle relaxes

Muscle relaxes

Muscle contracts

Page 13: Skeletal Muscle Contraction
Page 14: Skeletal Muscle Contraction
Page 15: Skeletal Muscle Contraction

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__breakdown_of_atp_and_cross-bridge_movement_during_muscle_contraction.html

http://www.dnatube.com/video/5034/Contraction-of-muscle-function-of-neuromuscular-junction

http://highered.mheducation.com/sites/0072495855/student_view0/chapter10/animation__action_potentials_and_muscle_contraction.html

http://www.sumanasinc.com/webcontent/animations/content/muscle.html

http://www.wiley.com/college/pratt/0471393878/student/animations/actin_myosin/actin_myosin.swf