Medical Laboratory Techniques Department General Anatomy Lecture (2) PDF

Medical Laboratory Techniques Department General Anatomy Lecture ( 2 ) The Skeletomuscular System Dr: Hassna Bader...

Medical Laboratory Techniques Department General Anatomy Lecture ( 2 ) The Skeletomuscular System Dr: Hassna Bader Jawad The Skeletomuscular system (locomotor system) is a human body system that provides our body with movement, stability, shape, and support. It is subdivided into two broad systems: 1.Skeletal System 2. Muscular System Skeletal system whose main component is the bone. Bones articulate with each other and form the joints. The integrity and function of the bones and joints is supported by the accessory structures of the skeletal system; articular cartilage, ligaments, and bursae. The Bones The adult human skeleton is composed of 206 bones and their associated cartilages. The bones are supported by ligaments, tendons, bursae, and muscles. Bones are rigid organs that form a part of the endoskeleton of vertebrates. Function Of Bones 1. Forms the framework that support the body. 2. Provides points of attachment for skeletal muscles. 3. Protects the organs within the body cavities (the rib cage protects the heart and lungs, the skull protects the brain). 4. Provides a storage site for inorganic salts such as calcium and phosphate and also fatty acid. 5. Contains and protects the red bone marrow, where red blood cells (or erythrocytes), white blood cells (or leukocytes) and lymph cells are formed. The human skeleton is divided into: Axial skeleton, that includes the bones along the longitudinal axis of the body. The axial skeleton consists of the vertebral column (7 cervical, 12 thoracic 5 lumbar ,5 fused sacral and 4 fused coccygeal) vertebrae, cranial and facial bones of the skull and bones of the thoracic cage. Appendicular skeleton: includes the * Bones of shoulder and pelvic girdles. *Bones of the upper extremities; clavicle, scapula, humerus ,radius ,ulna and bones of hand ( carpals, metacarpals and phalanges). *Bones of lower extremities; Hip, femur, tibia ,fibula and bones of foot ( tarsals, metatarsals and phalanges). 1  Medical Laboratory Techniques Department General Anatomy Lecture ( 2 ) The Skeletomuscular System Dr: Hassna Bader Jawad Types Of Bones Long bone: Its length is more than its width. Examples of long bones include the humerus, ulna, tibia and clavicle and phalanges. Short bone: It is cuboid or round shape. Examples include the tarsal and carpal bones. Flat bone: are thin, flattened. Examples include most of the skull bones, scapula, sternum. Sesamoid bone: are small, rounded embedded in muscle. Example the patella of knee. Irregular bone: Irregular and complex shape. Examples include the vertebrae, hip bone. The joint The joint or articulation is defined as the site where two or more bones come together. Joint is usually movable, but some joints are immovable and some shows limited movement. The joints of the human body can be classified into 3 types depending on the type of tissue that holds the neighboring bones together. 1. Synovial joint is movable joint, bones of the joint are joined together by synovial fluid as (shoulder, elbow, hip knee, wrist joints). 2. Fibrous joint; It is immovable joint, bones of the joint are joined together by with dense fibrous connective tissue as (cranial sutures, distal tibiofibular). 3. Cartilaginous joint: It shows little or limited movement. bones are joined together by cartilage as joint between the vertebral bodies and joint between first rib and sternum. 2  Medical Laboratory Techniques Department General Anatomy Lecture ( 2 ) The Skeletomuscular System Dr: Hassna Bader Jawad Muscular system: which includes all types of muscles in the body. Skeletal muscles, that act on the body joints to produce movements. Besides muscles, the muscular system contains the tendons which attach the muscles to the bones. The muscles The muscular system is composed of specialized contractile tissue called the muscle tissue. Muscle is Specialized tissue that enable the body and its parts to about 640 make up about 40 % of the body mass. There are three types of muscle tissue, based on which all the muscles are classified into three groups: 1. Cardiac muscle, which forms the muscular layer of the heart (myocardium) 2. Smooth muscle, which comprises the walls of blood vessels and hollow organs as wall of stomach. 3. Skeletal muscle, which attaches to the bones and provides voluntary movement. Skeletal muscles The skeletal muscles are the main functional units of the muscular system. There are more than 600 muscles in the human body. Function Of skeletal muscle 1.Production of Movement 2.Maintenance of posture and muscle tone 3.Heat production 4. Stabilized the joint and Protects the bones and internal organs. Each skeletal muscle is consisted of 3 parts: 1.The attachment point to the bone that does not move is called the origin. 2.Belly: is the fleshy part of the muscle between the tendons of origin and insertion. 3.The attachment point to the bone that moves is the called insertion. The muscles attaches firmly to bones by Tendon. 3  Medical Laboratory Techniques Department General Anatomy Lecture ( 2 ) The Skeletomuscular System Dr: Hassna Bader Jawad The skeletal muscles of the human body are organized into four groups for every region of the body: 1. Muscles of the head and neck, which include the muscles of the facial expression, muscles of mastication, muscles of the orbit, muscles of the tongue, muscles of the pharynx, muscles of the larynx, and muscles of the neck. 2. Muscles of the trunk, which include the muscles of the back, anterior and lateral abdominal muscles, Muscles of gluteal region and muscles of the pelvic floor 3. Muscles of the upper limbs, which include muscles of the shoulder, muscles of the arm, muscles of the forearm and muscles of the hand. 4. Muscles of the lower limbs, which include hip and thigh muscles, leg muscles and foot muscles. 4