1. Muscles

2. Types of Muscle Smooth - involuntary Skeletal - voluntary
Cardiac - involuntary

3. Smooth Muscle Involuntary Lines digestive system Lines blood vessels
Contracts bladder
Contracts uterus
Few nuclei, no striations
Movements involve many muscles at a time

4. Skeletal Muscle Under voluntary control Moves arms, legs, head
Allows us to change body position, move
Produces most of body heat
Many striations, many nuclei
Pull on bone

5. Structure of Skeletal Muscle
Draw figure in your notes here.
Muscles are made of individual bundles.
Each bundle is enclosed by a sarcolemma
Within each sarcolemma are many sarcomeres

6. Skeletal Muscle Structure

7. Skeletal Muscle (cont.)
Each sarcomere is bounded by two Z lines
Each sarcomere is made of actin and myosin strands

8. Sliding Filament Theory
Basic theory of muscle contraction.
Two filaments, actin & myosin, interact within the sarcomere
Length of A band doesn’t change.
I-band and H-zone shorten during contraction.
Filaments slide past each other but do not shorten themselves.

9. Cardiac Muscle Found only in heart Striated like skeletal muscle
Involuntary like smooth muscle
Pushes blood out of the heart