1. Muscular & Skeletal Systems

2. Muscular System Muscles are the organs that move body parts.
Bones and joints
have no power to
move on their own.
More than 600
muscles in the body
35–40% of body mass
is muscle

3. Muscular System
The muscle organ contracts and becomes shorter or expands and becomes longer
Result = Body parts move, energy is used, and work is done.

4. Muscular System Two Groups of Muscles Voluntary—You can control these.
Arms, legs, hands, face
2. Involuntary—You can’t control
these; you don’t have to decide to
make these muscles work.
Muscles around the heart

5. Muscular System Three Types of Muscle Tissue 1. Skeletal Muscle
Most numerous in body
Looks striped (striated)
Attached to the bones by
tendons
Tendons—thick bands that pull on
the bone as the muscle contracts
Voluntary
Contract quickly, tire easily

6. Muscular System Three Types of Muscle Tissue (cont.) 2. Smooth Muscle
Involuntary
Found in: walls of stomach,
intestine, uterus, etc.
Contracts and relaxes slowly
No striations

7. Muscular System Three Types of Muscle Tissue (cont.) 3. Cardiac Muscle
Only found in heart
Involuntary
Has striations
Contracts 70 times per minute (heartbeat)

8. Muscles at Work Skeletal muscle movements are
results of pairs of muscles
working together.
One muscle contracts while
the other muscle relaxes.
Muscles always pull;
they never push.

9. Muscles at Work Results of Muscle Action Muscles contract
This produces thermal energy, and it uses chemical energy.
Thermal energy produces heat that helps keep body temperature constant.
Chemical energy is from glucose. (When glucose is used up, muscles are tired and need to rest.)

10. Muscles at Work Results of Muscle action (cont.)
Over time, muscles become larger or smaller, depending on how much work they do.

11. Skeletal System Made up of all of the bones in your body,
it is the framework
of the body.
Each bone in your body
is a living organ, made
of different tissues.
Cells in bones take in
food and use energy.

12. 5 Functions of The Skeletal System
#1. Framework gives shape
& support to the body.

13. 5 Functions of The Skeletal System
#2. Bones protect the
internal organs.

14. 5 Functions of The Skeletal System
#3. Helps the body to move.
Major muscles of the body are attached to the bones.

15. 5 Functions of The Skeletal System
#4. Blood cells are formed
in red marrow of some
bones.

16. 5 Functions of The Skeletal System
#5. Stores minerals and chemical energy.
Skeleton is a place where major quantities of calcium and phosphorus compounds
are stored.

17. Bones The adult skeleton has 206 bones (baby have around 305).
Babies have more bones than adults because as they grow up, some of the bones fuse together to form one bone. This is because babies have more cartilage than bone. New born babies have around 305 bones.

18. Joints & Ligaments Joints: Any place where two or more bones meet.
Ligaments: tough
bands of tissue that
hold bones together
at the joints.