B7 Flashcards
To be awesome at B7 (OCR 21st Century)
Name and describe the four main components of blood.
Red blood cells transport oxygen around the body.
White blood cells fight infection
Plasma carries nutrients and waste
Platelets help blood to clot
How are red blood cells adapted to their job?
They have a biconcave shape to increase surface area so they can exchange oxygen efficiently.
They don’t have a nucleus so they can be packed full of oxygen.
What is meant by the term double circulatory system?
Blood passes through the heart twice during each ‘circuit’.
How is tissue fluid produced and what does it do?
As blood passes through the capillaries small molecules are forced out to form tissue fluid which allows cells to get rid of waste and to obtain what they need without ridiculous amounts of capillaries.
Discuss the key parts of a joint.
Ligaments stabilise joints but don’t stop movement.
Cartilage reduces friction between the bones.
The synovial fluid lubricates the joints.
Describe how muscles allow bones to move.
Muscles work in antagonistic pairs. When one muscle contracts, e.g. a biceps, it pulls on a tendon which moves a bone. The antagonist muscle relaxes. This also works vice versa.
What do fitness practitioners need to know before designing an exercise regime?
Health problems Current medication Previous fitness regimes Lifestyle factors Medical history Physical activity
How does your heart rate change during exercise?
It increases during exercise and decreases after. How long it takes to return to resting level can show fitness levels.
How is BMI calculated?
Body mass (kg) / height^2 (m^2)
Describe four common sporting injuries.
A sprain is damage to a ligament.
Dislocations are when a bone comes out of its socket.
Torn ligaments are when a ligament is torn.
Torn tendons are when a tendon is torn.
What four stages are used to treat sprains?
Rest - avoid any further damage
Ice - to reduce swelling
Compression - to reduce swelling and movement
Elevation - to make it easier for blood to flow back to the heart
Where in the brain is temperature detected and what does it do if temperature is not optimal?
The hypothalamus.
If it is too high, the body sweats and vasodilation occur, both to increase heat loss.
If it is too low, the body shivers (to generate energy) and vasoconstriction occurs (to stop heat loss).
How does insulin control blood sugar levels?
Blood sugar level can be affected by diet. If the level is too high, then insulin is released so glucose can leave the bloodstream and enter body cells. The opposite occurs when the level is too low.
What is the difference between type 1 and type 2 diabetes?
Type 1 diabetes is where the body stops producing insulin. It is controlled by regular insulin injections.
Type 2 diabetes is where the body stops responding to insulin. It is controlled by exercising and eating a carefully controlled diet with many complex carbohydrates.
Describe a perfect closed loop system. Why are ecosystems rarely perfect closed loop systems?
In perfect closed loop systems all outputs are recycled. There are no inputs nor outputs.
In ecosystems there are almost always outputs or inputs. Outputs include waste gases and dead organic matter.
