Musculoskeletal system
There are two parts to this system, the muscular and the skeletal.
The muscular system has three types of muscles.
- For muscles to function there are two proteins involved.
- When muscles overlap the area is called the sarcomere.
~Smooth Muscle- found in the walls of digestive track, bladder, various ducts, arteries, and veins.
- These muscles are controlled by the autonomic nervous system.
~ Skeletal Muscle- contains many muscle fibers, nerves, blood vessels, and connective tissue.
- These muscles are the most abundant tissue in the human body that produces movement.
- These voluntary muscles have striations.
~Cardiac (Heart) Muscle- these muscles are a cross between Smooth and Skeletal muscles
- They are found in the heart, they are involuntary muscles that are controlled by the autonomic nervous system.
The Muscular System

The Skeletal system has two parts.

~ There are 206 bones in the human body.
- There are 5 types of bones, Long, Short, Flat, Irregular, And Sesamoid.
~ Axial Skeleton - consists of bones that protects the organs of the head, neck, and trunk.
- such as, the Skull, The Sternum, The Ribs, The Vertebral Column.
~ Appendicular Skeleton - consists of bones that anchor appendages to the axial skeleton.
- such as The Upper Extremities, The Lower Extremities, The Shoulder Girdle, And The Pelvic Girdle.
~ Compostion of Bones - Bones are not completely solid, they have spaces between the hard elements.
- there are two types of bone tissue.
~ Compact Bone - this accounts of 80% of the bone, it gives the bone its smooth, solid, white appearance.
~ Spongy Bone - this accounts for 20% of the bone, but is nearly 10 times the surface area of compact bone.
- this bone allows for blood vessels and marrow to flow.
The Skeletal System