Why do we need bones?
- It allows us to move and bend dynamically
- Although our muscles give us strength, the bones support our body when carrying something heavy.
- They give our organs protection (Ribcage protects the hears)
- The production of White blood cells in bone marrow
What is bone?
Bone is a composition of Calcium Phosphate and Collagen
A joint is:
Where 2 or more bones meet.
4 common types:
- Fixed Joint - Cranium (Skull)
- Hinge - Elbow, Ankle and Knee
- Pivot - Neck
- Ball and Socket - Leg, arm, hip and shoulder
Fixed Joint - These joints are immovable, these are held together by fibrous connective tissue, composed of Collagen.
Hinge Joint - Where two bones meet, but has limited movement, it can only flex and extend, or move in two dimensions
Pivot joint - It allows the neck to pivot, or rotate
Ball & Socket - The "ball" slots into a "socket". Allows the leg, arm, shoulder and hip to move in three dimensions. Surrounded by synovial fluid.
Definitions of words
Tendon - Tough cord that does not stretch, attaches the muscle across joints
Cartilage - Tough, smooth substance that covers the end of bones
Ligament - A tough band of fibres that joins bones together in a joint
Synovial Fluid - Lubricates the joint
Synovial Capsule - Encloses the fluid in the joints
Antogonistic muscles are a pair of muscles that do the opposite to each other.
An example of this is the triceps and biceps, if you straighten your arm, the biceps relax and the triceps contract.
If you bend your arm, the opposite happens, your biceps contract, and your triceps relax
Fish - Explanation
Fish swim by contracting the muscles down each side of the body in turn. The muscles pull on the vertebral column and produce wave-like undulations which travel down the length of the fish pulling sideways and backwards against the water
Fish - Fins and their uses
- Dorsal Fin (top) - Balance
- Pectoral fin (side, come in a pair) - steering
- Pelvic Fin (Bottom, towards the back) - Steering
- Anal Fin (Bottom, quite literally) - Balance
- Caudal Fin (At the back) - Forward movement
- Apidose Fin (Top, behind Dorsal Fin)
Fish - Movement
- Pitch - Up and Down
- Roll - Turning on Y axis
- Yaw - Turning on X axis
Water can support an animal with a large mass (e.g. Whale, its organs do not get crushed by water pressure)
Walkers v Sprinters - Streamlined
- Body Position - Straight, rigid
- Leg bend - Almost no bend
- Arm Swing - Small swings
- Lift off the ground - None/Very litte lift
- Body Position - Relaxed, Streamlined
- Leg Bend - A lot of bend for maximum stride length
- Arm Swing - Large Swings for minimal resistance and increased power
- Lift off the ground - A lot of lift for maximum thrust and power
Drag and Thrust
In order to run the person must generate enough thrust to overcome the effects of drag
Thrust - The action which the animal uses to push against the environment in order to move
Drag - The force which the environment exerts to resist the animal's forward movement
Support in plants
What kinds of forces do plants have to withstand?
Plants are supported by:
- Presense of lignin as the plants matures e.g. Tree trunks contain a lot of lignin
- Strong roots - Good anchorage
- Plant cells take in water into their vacuoles, pressing out against the cell wall, making the cell stiff/rigid. This is called Turgor Pressure, whickh makes the cell turgid
Food and digestion 1
We need food for:
- Growth and Repair
Food and digestion 2
Carbohydrate - Found in Bread, potato and cereal (sugar and starch are also carbs) - Needed for energy
Protein - Found in meat, fish and eggs - Needed for Growth and Repair
Fat - Found in for Cream, butter, milk and oil - Needed for a store of energy
Vitamins - Found in Vegetables and cereal - Needed to keep things 'ticking over' (Vit D means Healthy bones - Vit A means good eyesight)
Minerals - Found in Meat, milk and cereal - Needed for strong bones (Calcium keeps bones strong - Iron keeps blood good)
Fibre - Found in Fruit, Veg and cereal - Needed to keep you regular
Water - Found in Water and most foods - Needed for hydration