Musculoskeletal system Flashcards
musculoskeletal system function
to support the body, protect delicate organs, and make movement possible
bone: connective tissue
- hard and dense
- made of bone
- cells within a matrix (Structure made of many different building blocks) of minerals (mainly calcium and phosphorus)
- Canals in bones contain nerves and blood vessels
ligaments: connective tissue
- tough, elastic connective tissues (collagen) that hold bones together at the joints.
- made up mostly of long fibres of collagen
Cartilage: connective tissue
- special cells in a Matrix of collagen fibres (strong, flexible and resistant to stretch)
- provides a strong, flexible, low-friction support for bones and other tissues
How do bones grow?
At birth, a baby’s body has about 300 bones. These eventually fuse (grow together) to form the 206 bones that adults have. Some baby bones are made entirely of a special material called cartilage (say: kar-tel-ij). Other baby bones are partly made of cartilage. This cartilage is soft and flexible. During childhood, as you grow, the cartilage grows and is slowly replaced by bone, with help from calcium.
By the time you are about 25 years old, this process is complete. After this point, no more growth occurs—the bones are as big as they will ever be. All of these bones make up a skeleton that is both very strong and very light.
Ribs
Cage of bones around the chest. Come in pairs, ppl have 12 pairs of ribs.
Skull
Protects the brain, smallest bone in entire body is the stirrup bone behind the eardrum on .1 to .13 inches.
Legs
Legs attached to circular group of bones called the pelvis. Pelvis is a bowl-shaped structure that supports the spie. Leg bones are large and strong to help support weight of body.
Comparative anatomy
vertebrates: animals w backboens
invertebrates: no rigid frame to give them structure like worms and jellyfish
exoskeleton: skeletal systems on the outside like insects
Muscle
bundles of long cells called muscle fibres that contain specialized proteins that proteins cause the muscle to contract when signalled by nerve cells
Skeletal muscle tissue
- voluntary
- attached to bones by tendons, allowing the movement of body parts
- Tendon: similar to ligaments but are less elastic and connect muscles to bones
- Muscles can pull, but they cannot stretch
- When muscles contract, they get shorter and thicker
- skeletal muscles always work in opposing pairs or groups
Smooth muscle tissue
involuntary, located in intestines
Cardiac muscle tissue
in the heart
Problems: osteoporosis and tear
- loss of bone tissue making bones brittle and weak
- Common among older women
- Does not cause pain
- Diagnosed by a bone density test
- Linked to a loss of calcium in bones
Tearing ligaments, tendons and muscle tissue and broken bones (due to extreme movements)
