Musculoskeletal system Concepts to Master Bones – Joints - Muscles

Bones Definition: A Bone is a hard solid organ that forms part of the skeleton. Fact: 206 Bones divided into 3 regions. Head Trunk Limbs Types of Bone: spongy and compact

Bones Categories of Bones Long Bones: longer than wide thin body (diaphysis) rounded ends (epiphysis) Short Bones: cubic in shape, mostly spongy bone – wrists and ankles Flat Bones: Thin flat and curved – a sandwich of spongy and compact bone. – skull, ribs scapula Irregular Bones: not covered by the other categories because of their irregular shape – spine

Bones Femur Wrist Hip Scapula

Bones Function of Bones Support: Keeps us vertical: supports soft organs (heart, lungs, liver, intestines) Protection: Organ protection – brain, heart, lungs Movement: bones act as levers during muscle movement. Storage: fat storage – mineral storage – calcium, phosphorus Production of Blood Cells: in the bone marrow – red blood cells, white blood cells, platelets.

Joints Mobility of Joints Mechanics of a Joint Fixed: skull, hip Semi movable: vertebrae Freely Movable: shoulder A junction between two or more bones Mechanics of a Joint Extension/Flexion Abduction / Adduction Rotation

Muscles Muscles have the ability to contract causing our bodies OR our internal organs to move. Muscle Functions: Movement Posture Maintenance Joint Stabilization Heat Release

Muscles Three distinct types of muscles carry out the functions described on the previous slide. Muscle Types: Smooth Muscles Cardiac Muscle Skeletal Muscle

Muscle Properties: Skeletal Muscles: Voluntary muscles that are attached to the skeleton. Can react with great force for short periods of time. Composed of bundled muscle fibers. Muscle is fibers and bundles are covered with connective tissue. Connective tissue fuses at the ends of muscles for form tendons. Tendons attach bone to muscle. Smooth Muscles: Involuntary muscles that make up the wall of internal organs. The help move substances from place to place. Work slower than skeletal and tire less easily. Cardiac Muscle: A unique muscle that makes up the heart. Involuntary muscle like smooth muscle. Structure similar to skeletal muscle. Great strength and endurance. Contraction causes blood to flow throughout the body.