Skeletal Muscle Contraction

p.290

Muscle Contraction

• Muscle fibers shorten and pull on their attachments

QuickTime™ and ampeg4 decompressor

are needed to see this picture.

Skeletal Muscle Contraction

How many muscle fibers are connected to motor neuron #1?

Skeletal Muscle Contraction

Motor neuron:

Neuron that attaches to a skeletal muscle

Synapse:

functional connection between axon end and muscle fiber

Skeletal Muscle Contraction

How is the message sent from the axon end to the muscle fiber??

Animation of synapse at work…

http://highered.mcgraw-hill.com/olc/dl/120107/bio_c.swf

Skeletal Muscle Contraction

Skeletal Muscle Contraction

Motor end plate:

Site where axon and muscle fiber meet

Sarcolemma folded

Nuclei and mitochondria are abundant

Skeletal Muscle Contraction

Synaptic cleft:

Small gap between membrane of neuron and membrane of muscle fiber

HW due on TUESDAY

p. 341 (6-12)