1. The muscular System
What do skeletal muscles do?
How do muscles work?

3. Functions of Muscle Tissue
Produce movement
Muscle pulls tendons to move the skeleton
Maintain posture and body position
- Continuous muscle contraction
Support soft tissue
-Support weight of visceral organs
Movement of substance around the body
- Encircle openings to digestive and urinary tracts: sphincters
- Regulate blood flow, movement of food, enzyme, propel urine….
Maintain body temperature
Energy from contraction is converted to heat

4. Types of muscles tissue

5. Skeletal Muscle Muscles are bundles of cells and fibres.
Muscles work in a very simple way; all they do is contract or relax.
Muscles can only pull, they never push.
Muscles generally work in pairs to produce movement: when one muscle contracts the other relaxes.
There are 630 active muscles in your body

6. Muscle Action
Skeletal muscles produce movement by exerting force on tendons, which pull bones.
When muscle contracts it shortens and pulls two jointed bones together.
However the two bones do not move equally in response to the force, one is held in place by other muscles which brace it so that the other bone will move towards it.

7. Muscles which cause the movement of a joint are connected to two different bones; muscle contraction pulls them together.
An example would be the contraction of the biceps and a relaxation of the triceps. This produces a bend at the elbow, an action called flexion
The contraction of the triceps and relaxation of the biceps produces the effect of straightening the arm.

8. Muscle contractions require energy
Blood vessels deliver oxygen and nutrients to produce ATP
ATP is the cellular energy molecule produce in the mitochondria
Muscle contractions are under stimulation from the CNS
Voluntary control
Axons connect to individual muscle fibers

9. Anterior View

10. Posterior View

11. The muscular system
BBC MUSCLE GAME