Functions of the Skeletal System

Functions of the Skeleton

• Provides structure and support for the body
• Provides protection for organs
• Works with muscles to create movement

Joints and Their Functions

• Cartilage: smooth white tissue at the end of bones, absorbs shock
• Synovial membrane: absorbs shock, produces synovial fluid
• Synovial fluid: lubricant to reduce friction between bones
• Ligaments: connects bone to bone
• Tendons: connects muscle to muscle
• Antagonistic muscles: work in pairs, move opposite each other to create movement

Types of Joints

• Hinge joints: elbow, knee, ankle
• Ball and socket joints: hip, shoulder
• Fixed joints: skull, mandible

Functions of Blood Components

• Plasma: liquid carrying dissolved food, minerals, and hormones
• Red blood cells: carry oxygen and haemoglobin
• White blood cells: attack bacteria, produce antibodies
• Platelets: produce scabs when you are cut

Gas Exchange

• Oxygen-rich blood travels down the lungs to the alveoli
• Oxygen diffuses into the bloodstream through capillaries due to thin walls
• Oxygen-poor blood diffuses from capillaries into the alveoli to be breathed out

Blood Vessels

• Arteries: carry blood away from the heart, have thick muscular walls, elasticity, and are red
• Veins: have less pressure, thinner muscles, and thinner walls, carry deoxygenated blood back to the heart, have valves to prevent backflow
• Capillaries: have thin walls for nutrient and oxygen diffusion, smallest blood vessel
• Valves: prevent backflow of blood, ensure blood travels in the right direction

Respiratory System

• Trachea: allows air to flow into the lungs
• Cartilage rings: keep the trachea open
• Bronchi: branches leading from the trachea to bronchioles
• Bronchioles: pathways from bronchioles to alveoli
• Alveoli: site of gas exchange
• Diaphragm: muscle that expands and contracts to allow space for the lungs to expand and then forces air out of the lungs

Breathing and Respiration

• Breathing: air coming in and out of the lungs
• Respiration: energy being produced in cells
• Aerobic respiration equation: CO2 + glucose = H2O + CO2 (+38 ATP)
• Anaerobic respiration equation: glucose = lactic acid (+2 ATP)