Body Systems Bones and Muscles. Skeletal Systems 4 functions Key role in movement Provides a strong,...
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Transcript of Body Systems Bones and Muscles. Skeletal Systems 4 functions Key role in movement Provides a strong,...
Body SystemsBody SystemsBones and MusclesBones and Muscles
Skeletal Systems
4 functions
Key role in movement
Provides a strong, stable, and mobile framework on which muscles can act
Supports and protects internal organs
Storage center for essential body materials (ex: calcium and phosphorous)
Manufactures blood cells
Structure of Skeletal System
206 bones
Axial skeleton
80 bones around the core of the body:
examples: skull, spine, ribs, and sternum
Appendicular skeleton
126 bones outside the core frame (appendicular - appendices)
examples: shoulders, arms, hands, hips, legs, and feet
Types of Bones
Four types of bones:
Long - femur
Short - wrist
Flat - rib
Irregular - vertebrae
Cartilage and Joints
Cartilage: strong, flexible connective tissue (tip of your nose)
Joints: the point at which two bones meet
Ball and socket joint: shoulder
Pivot joint: head and shoulders
Ellipsoidal joint: wrist
Hinge joint: elbow
Ligaments and tendons
Ligaments
Tough bands of fibrous, slightly elastic tissue that bind the bone ends at the joint
Tendons
Fibrous cord that join muscle to bone or to other muscles
Types of Muscles
Cardiac Muscles:
Special type of striated tissue that forms the walls of the heart
Smooth Muscles:
Concerned with internal movements of internal organs (involuntary, like intestines)
Skeletal Muscles:
Striped muscles (striated) that are attached to bones that cause body movements (voluntary)
Flexors: muscles that close a joint
Extendors: muscles that open out a joint
Muscles: Use it or lose it
Atrophy: unused muscles waste away
Muscle tone: the natural tension in the fibers of a muscle