The skeletal system has several functions including protection of organs, providing levers for movement, and storing minerals. It is divided into the axial skeleton which includes the skull, vertebrae, and ribs, and the appendicular skeleton comprising the upper and lower limbs. Bones are classified as long, short, flat, or irregular. Bone formation occurs through ossification by osteoblasts and osteoclasts. Osteoporosis is the thinning of bones which can be prevented by sufficient calcium, vitamin D, weight bearing exercise, and good nutrition. Synovial joints like the ball-and-socket hip joint allow a wide range of movement. Connective tissues like cartilage, tendons, and ligaments support the skeletal system.
3. THE FUNCTIONS OF THE SKELETON Protection of vital organs Levers for Movement Provide a bony framework for Support To Produce blood cells (red and white) To provide surfaces for Muscle attachment To Store minerals (calcium and phosphorus)
5. BONE CLASSIFICATION Long ->Humerus, Tibia Short -> Carpals, Tarsals Flat -> Ribs, Sternum Irregular -> Vertebrae, Facial bones Sesamoid-> Patella
6. BONE FORMATION-OSSIFICATION Ossification Osteoblasts- These are bone Building cells Osteoclasts- These break down & Clean old bone Factors Affecting Bone Formation Nutrition Exposure to sunlight Hormonal secretions Physical exercise
8. OSTEOPOROSIS Factors that cause Osteoperosis- Insufficient Calcium Intake. Insufficient Vitamin D. Poor Nutrition and dieting. Amenorrhea: Loss of periods. Menopause. Weight Bearing exercise increases bone density.
11. THE SPINE Intervertebral Discs- The Vertebrae are separated by discs which are made of fibrocartilage. The function of the discs is to absorb shock.
17. TYPES OF JOINT Synovial Joints Also known as Freely moveable joints They allow a wide range of movement. There are 6 types of Synovial Joints: Ball & Socket Gliding Pivot Ellipsoid/Condyloid Saddle Hinge
30. KINESIOLOGY Flexion- To reduce the angle of the joint, or to bend a limb. Extension-To return from Flexion, or straightening the limb. Rotation-A rotary movement, inward & outward about a long axis, i.e. thoracic vertebrae.
31. KINESIOLOGY Abduction-To take away from the mid-line of the body, i.e. raising the leg/arm to the side. Adduction-To move towards or across the mid-line of the body, i.e. drawing the arm/leg across the front of the body.
32. KINESIOLOGY Horizontal flexion-A forward movement in a horizontal plane, i.e. pec dec arms. Horizontal extension-A backward movement in a horizontal plane, i.e. swinging the arms away from the body.
33. KINESIOLOGY Lateral flexion-To bend sideways with the trunk or neck, i.e. sidebends. Circumduction-To circle part of the body. Elevation-Upward movement of the shoulder girdle. Depression- Downward movement of the shoulder girdle.
34. KINESIOLOGY Protraction-Forward movement of the shoulder girdle Retraction-Backward movement of the shoulder girdle Pronation-Palm of the hand facing downward Supination-Palm of the hand facing upward
35. KINESIOLOGY Dorsiflexion- To pull the toes up towards the body, i.e. heel dig. Plantarflexion-To point the toes down to the floor, away from the body. For example- standing on the tip toes.
37. Effects of Exercise on Skeletal System SHORT TERM (whilst exercising) Increase synovial fluid production LONG TERM (after training for period of time) Stronger ligaments Increased bone density
