Transcript Body Systems Bones and Muscles Skeletal Systems 4 functions Key

Body Systems
Bones 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