1. Muscular System

2. Types of Muscles Skeletal Smooth Cardiac
Control voluntary movements of the skeleton and body
Striated
Smooth
Control the involuntary movements of the digestive and vascular system
Not striated
Cardiac
Control the involuntary muscles of your heart

3. Types of Muscles
Skeletal
Cardiac
Smooth

4. Skeletal Muscles

5. Skeletal Muscles Skeletal muscles are made up of many muscle fibers
Those fibers are made up of many myofibrils
Those myofibrils are made up of actin and myosin, which work together to contract and relax the muscle

6. Relaxed Muscle

7. Actin and Myosin
During muscle contraction the little sticky heads on myosin filaments bind to the actin.
When ATP (energy from cellular respiration) is added the myosin changes
shape bending towards the middle and pulling the actin fibers with it.
This makes the muscle fiber shorten or contract.

8. Actin and Myosin

9. Tendons and Ligaments
The reason we move when our muscle contract is because they are attached to bones by tendons
This typically happens at joints.
Joints are where one bone meets another and movement can occur.
Ligaments attach bone to bone,
to restrict and help control our
movements

10. Joints Joints are where one bone attaches to another bone
Most joints have cartilage between them to prevent bone to bone contact and damage.
There are five different types of joints, four of which allow movement
The different joints are classified by the type of movement they allow

11. Immovable Joint
These are also referred to as fixed joints because they allow no movement
These can be found in your skull and pelvis where the different bones fuse together.

12. Ball-and-Socket Joint
Joint formed by a ball at the end of one bone that fits into a cavity in the end of another bone.
This allows free movement in almost every direction
Examples of these would be your shoulders and hips.

13. Hinge Joint
Hinge joints allow back and forth movement in one direction, and a little movement in the other direction
The bones are held in place by tough ligaments that allow more limited movement than the
ball-and socket joint.
Examples can be found in the
elbow, knee, and knuckles of
the fingers.

14. Pivot Joint Pivot joints allow rotation around one point.
The bone can twist back and forth allowing a twisting or rotating movement
Examples can be found in the radius in the forearm and in the neck, which allows us to turn our heads from side to side.

15. Saddle Joint
A saddle joint is formed when the end of one bone is the mirror image of its adjoining bone creating a saddle shape.
The two bones meet to form an X, the saddles cradle each other.
This allows a wide range of movement, or rocking movement in either direction
An example would be your thumbs.

16. Functions of the Skeletal System
Protect our soft internal organs
Provide the body with support and structure
Stores important minerals that the body needs
Works with the muscular system to allow movement
Make most of the blood cells for our circulatory system

17. Protection
There are 206 bones in the human bodies (at least for most of us)
Skull (29 bones) – protects the brain and sensory organs (eyes, ears, tongue, nose)
Spinal Column (26 bones) – protects the spinal cord
Rib Cage (25 bones) – protects the heart and lungs, and allows us to breath by supporting the diaphragm
Shoulders, Arms, and Hands (64 bones) – allow movement for survival
Pelvis, Legs, and Feet (62 bones) – allow movement for survival, so we can escape predators and find food

18. Bones There are four layers to your bones:
Pariosteum – the outer layer that is thin and dense. It contains the blood vessels and nerves.
Compact Bone – the next layer that is very smooth and hard. It is made up of round bone cells that have blood vessels running through the center of them.
Cancellous – the next layer down looks spongy, but is still very strong. It protects the bone marrow.
Bone Marrow – the inner most layer
that is like a very thick jelly and makes
the blood cells

20. Mineral Storage Bones are made up of . . .
30% living tissue
45% mineral deposits
25% water
Bones store calcium and phosphorus. As the blood needs more of these minerals they are released from the bones, but the bones need them as well to stay hard and strong.

21. Bone Marrow There are two types of marrow:
Red – this is the site for blood cell production. It makes red blood cells, white blood cells, and platelets.
Yellow – contains fatty connective tissues that can be broken down and used as energy during starvation

22. Cartilage Cartilage is the elastic, fibrous tissue that is flexible.
It can be found in joints to cushion and allow smooth movements
Some types of cartilage are used to allow flexibility, like in your ears, nose, and trachea.
Some cartilage is meant to bear weight and squish, so the bones do not crack.
Cartilage has no blood vessels running through it, but is still living tissue.
As a fetus most of your skeleton is made of cartilage.

23. Breaking Bones
There are several different types of breaks or fractures depending on their severity.
The pain is different for everyone, but usually it is a deep ache and you may feel nausea
The best thing is to not move the area that your think might be broken. Immobilize the area and get to a doctor.
Your osteocytes will start producing more bone cells and eventually your break will heal

24. Fun Facts
Bones fuse with age, so when you were a baby you had about 300 bones
Bones in the hand and feet vary, so not every one has exactly the same number of bone. It usually ranges between 206 and 216 bones
Half the bones in your body are in your hands and feet
Your femur (thigh bone) is stronger than steel rod of the same size and shape
Standing and sitting squeezes the cartilage between the discs in your spine, so you are about ½ inch shorter at the end of the day

25. Human Skeleton