1. The Muscular System

2. Functions of muscles What comes to mind when you think of muscles?
A muscle is made of strong tissue that contracts in an orderly way
4 main functions of muscles:
Movement
Stability
Protection
Temperature regulation

3. Movement Most of the muscles involved in moving the body work in pairs
The skeletal and muscular system work together to help the body move
Bones move when muscles contract or shorten
Some movement can be fast (run) or slow (stretch)
Muscles that aren’t attached to the skeleton contract to push blood and food through the body, as well as other things

4. Stability
Muscles that are attached to bone also help with stability, balance, and posture
The cordlike structures that you see moving under the skin are tendons, which attach muscle to bone
Tendons help keep joints in place as well as help the body maintain its shape
Most muscles are always contracted a little

5. The only time muscles that help maintain posture relax completely is when you are asleep
Your muscles make constant adjustments to keep you sitting or standing upright automatically without you thinking about it

6. protection
Muscles protect the skeleton and cover the majority of the organs in the body
They offer layers of padding
Muscles also surround the abdomen, chest, and back while also protecting the internal organs

7. Temperature regulation
What does the body do when you are cold?
When the body shivers, the muscles contract rapidly and change chemical energy to thermal energy (heat) which raises the body’s temperature
In order for the body to function properly, it has to maintain a normal body temperature of 98.6°F
Muscles contract, releasing heat to help the body maintain this body temperature

8. Skeletal muscles
Skeletal muscles are those that attached to your skeleton; they are also called voluntary muscles you can consciously move them
Pull on bones and must work in pairs
Change throughout your lifetime and increase in size if you exercise

9. Cardiac muscle
The heart is made of cardiac muscle is found only in the heart
The cardiac muscle is involuntary, meaning you cannot consciously control it
When they contract/relax, they pump blood through the body

10. Smooth muscles Smooth muscles line blood vessels and organs
They are involuntary muscles named for their smooth appearance
Contraction of smooth muscles helps push food through the stomach and control blood movement through the vessels

11. Sprain vs. strain