Get out a sheet of paper and something to write

with.Monday, November 16, 2015

On your paper

•Think back to your homework (sliding filament videos)•What did you learn about the sliding filament theory?

Reminders

•Extra Credit due Wed.•next Monday = 1, 3, 5 block; Tuesday = 2, 4, 6

LEQ

• Microscopically, how is muscle tissue organized? • What are the roles of actin and myosin in muscle

contraction?• What are the steps of the sliding filament theory?• How do muscle cells obtain the necessary energy

for movement? • How does a signal pass across the neuromuscular

junction?

Muscle Notes (continue on same paper)

Basics

•Functions of muscles: movement, maintain posture, source of body heat•There are over 600 muscles in the body•Muscles use chemical energy to contract (shorten)

Structure

• Each muscle is an organ•Muscles are made up of skeletal muscle tissue, connective tissues, nervous tissue & blood• Fascia covers each muscle; this is connected to the tendons, that are fused to bone• Fascicles: bundle of muscle fibers (cells) Sarcolemma: cell membrane

Structure

•Myofibrils: bundle of filaments•Sarcomere: contraction unit of a myofibril; made of actin and myosin•Thin filaments: made of actin•Thick filaments: made of myosin

Thick and thin filaments

Filaments

Myofibrils

Myofibril

Muscle fibers (cells)

Muscle fiber

Sarcolemma

Nucleus Sarcoplasmicreticulum

Fascicles

Fascicle

Axon of motor neuron

Blood vessel

A skeletal muscle is composed of a variety of tissuesSlide number: 1

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

Muscle

Bone

Tendon

Fascia(covering muscle)

EpimysiumPerimysium

Endomysium

Neuromuscular Junction

•a.k.a myoneural junction•The site where the motor neuron and muscle fiber meet•Motor end plate on muscle fiber; sarcolemma is tightly folded; lots of nuclei and mitochondria•Cytoplasm of motor neuron has lots of mitochondria and synaptic vesicles that store neurotransmitters

What happens at neuromuscular junction

1. Nerve impulse travels from the brain or spinal cord

2. Impulse reaches end of motor neuron axon and causes synaptic vesicles to release neurotransmitter (acetylcholine) into the gap between the neuron and motor end plate of the muscle fiber

3. Muscle fiber contracts• One neuron may control many muscle fibers• An impulse will cause each muscle fiber to

contract at the same time

Energy Notes p. 195• Divide a sheet of paper into 3rds• Label each column

• Phosphorylation of ADP• Aerobic Respiration• Anaerobic Respiration / lactic acid formation

• In each column write a description IN YOUR OWN WORDS (you should be able to understand what you wrote)

Read pgs. 189-196

•Take notes on the following:•Nerve stimulus & action potential•How a signal passes across the neuromuscular junction• The steps of the sliding filament theory

•Have notes done & ready to go for tomorrow