AMA 177 - Anatomy & Physiology/Medical Terminology/Pathology 8 Musculoskeletal System

1. AMA 177 - Anatomy & Physiology/Medical Terminology/Pathology 8 Musculoskeletal System

2. Function: • Made up of bones, muscles and joints. • Bones are the framework that protect and support internal organs. • Bones manufacture red blood cells in the marrow and store minerals necessary for growth. • Muscles are responsible for the movement of the body. • Joints are the places where bones come together; the type of joint depends on the need for more or less movement.

3. Structure of the Musculoskeletal System: Bones Bones: composed of connective tissue (osseous tissue) as well as blood vessels and nerves. • Bones need calcium and phosphorus to grow. • Bone cells called osteoblasts and osteoclasts work together to build bones and breakdown excess bone tissue; bones are living tissues that constantly rebuild and renew as a response to the mechanical stress of movement.

4. Bones: • There are 206 bones in the body. • Long bones, such as the femur, are every strong and have large surface areas for muscles to attach. • Short bones, such as the carpals in the hand, are grouped together to help provide movement. • Flat bones, such as the ribs, cover and protect soft body parts. • Sesamoid bones, such as the kneecap, are small and rounded; they are found near joints to increase the efficiency of the muscles near that joint. • Study all the different types of bones and their locations and function in the body.

5. Parts of the bone: • Diaphysis: middle region of long bones • Epiphysis: each end of the long bones • Epiphyseal plate: cartilage tissue that is constantly replaced as bone grows; disappears when bone is fully grown, very obvious in children • Metaphysis: flared portion of bone between diaphysis and epiphysis • Periosteum: strong, fibrous, vascular covering of long bones; has extensive nerve supply

6. Parts of the bone continued: • Articular cartilage: ends of long bones and surface of any bone that meets another to form a joint; cushions the joint, allowing fluid movement • Compact bone: layer of hard dense bone under the periosteum; contains canals of blood vessels that nourish the bone and remove waste products • Haversian canals: channels in compact bone that contain blood vessels • Medullary cavity: central shaft of long bones that contains yellow bone marrow that is made up of mostly fat cells • Cancellous bone: spongy, porous bone tissue in the center of bones that contain spaces that contain red bone marrow; this is where red blood cells are made.

8. Bone processes: • Enlarged areas that extend out from bones that function as attachments for muscles and tendons • Bones also contain openings and hollow areas that help join bones together and serve as passages for blood vessels and nerves: • Fossa: shallow cavity in a bone • Foramen: opening in a bone for blood vessels and nerves • Fissure: deep, narrow slit in a bone • Sinus: hollow cavity in a bone

22. Structure of the Musculoskeletal System: Muscles Three types of muscles: • Striated: made up of voluntary or skeletal muscles that move all bones, facial expressions and eye movement; we control these muscles. Muscle fibers are arranged in bundles. There are more than 600 muscles in the body. Muscles attached to bones contract and relax in groups to cause movement; tendons connect the muscles to the bones • Smooth: involuntary or visceral muscles that move internal organs, such as the digestive tract; we do not control these. Muscle fibers are arranged in sheets that wrap around vessels • Cardiac: heart muscles; we do not control these. Arranged in branching fibers • Study all the different types of muscles and their locations and function in the body as well as the types of movements they create.