BLOOD PROTECTION - blood is made in the bone marrow, particularly in the marrow of the long bones of the body. Blood contains both red and white blood cells. The red blood cells carry oxygen to muscles and the white blood cells fight infection in the body.
There are many types of joint in the body, including joints that we do not move and joints that only move slightly. The movement of joints are important factors affecting participation and performance.
most joints are synovial joints . Synovial joints are enclosed inside a capsule filled with a lubricating fluid, called synovial fluid . This fluid reduces the friction on the joint surfaces as they move against each other. A membrane seals the synovial capsule so that the fluid does not leak out.
joint surfaces are also covered by smooth, slippery hyaline cartilage . This aids the production of synovial fluid.
Joints often include another kind of cartilage, called white fibro-cartilage . This is is smooth and hard in order to help free movement, fibro-cartilage is tough and elastic . It acts as a shock absorber cushioning impact on the synovial joints. For example the knee contains fibro-cartilage to cushion the joint against the impact of walking, running and jumping.
LIGAMENTS AND TENDONS
ligaments and tendon hold together moving joints. Ligaments are very strong elastic fibres that keep joints intact.
VOLUNTARY OR SKELETAL MUSCLE (also known as ‘striped’ or ‘striated’ muscle) - mainly found attached to the skeleton, capable of rapid contraction which cause skeletal movement. It is under our conscious control.
CARDIAC MUSCLE - is only found in the heart and is also involuntary. It never stops working until we die. It pumps blood from our heart around the body.
muscles can only create movement in one direction - by becoming shorter. This means that you need two muscles at every joint to allow movement in two directions.
Therefore MUSCLES WORK IN PAIRS. For example, when your biceps CONTRACT it makes your elbow flex pulling your forearm up. To allow your elbow to extend, you need your triceps to CONTRACT and pull your arm back down. Meaning the biceps are RELAXING .
Muscles working in opposite directions like the above example are said to be working ANTAGONISTICALLY . The muscle doing the work and creating the movement is called the AGONIST or PRIME MOVER. The muscle which is relaxing and letting the movement take place, is called the ANTAGONIST .
When you flex your elbow, e.g. during a bicep curl. The bicep is the AGONIST and the tricep is the ANTAGONIST .
When other muscles assist the prime mover in creating a movement, these other muscles are called SYNERGISTS. E.g. deltoids doing a press-up.
the system consists of the heart, blood vessels and the blood.
the left hand side of the heart is the part that pumps oxygenated (oxygen rich) blood around the body. The right hand side of the heart receives deoxygenated (oxygen poor) blood that has been around the body, and pumps it back to the lungs again.
THE HEART ACTS AS A PUMP IN A DOUBLE CIRCULATORY SYSTEM.
the blood flows around a ‘figure of eight’ circuit and passes through the heart TWICE on each circuit.
blood travels AWAY from the heart through the ARTERIES and then returns to the heart through the VIENS .
The main veins and arteries of the circulatory system:
superior vena cava
inferior vena cava
Circulation and Respiration: Participation and Performance
LACTIC ACID -
muscles need oxygen to work effectively, however in anaerobic exercise muscles can work for a short time without oxygen.
if there is not enough supply of oxygen for the amount the muscles require, a new energy source must be found. This is done by converting the energy we store in our bodies (carbohydrates) into GLYCOGEN.
GLYCOGEN is a form of energy that muscles can use without needing energy.
anaerobic exercise, using glycogen rather then oxygen can only go on for a short amount of time.
when muscles have to work anaerobically they produce a waste product, a chemical called LATIC ACID. This is a poison that stops muscles working effectively.
as muscles continue to work without oxygen, lactic acid gradually builds up. The muscles will begin to ache and eventually fatigue sets in.
the cramp will not go away until the muscle is rested while the blood brings fresh oxygen to it again.
lactic acid builds up much more quickly in activities requiring all out effort than it does in endurance-based activities. Mainly because in endurance based activities the muscles are not working as hard.
the amount of oxygen that reaches our muscle can have a major effect on performance and participation.
when the rate at which muscles work is greater than the body’s ability to supply oxygen, the result is shortage of oxygen and then this will lead to fatigue.
this oxygen shortage is called OXYGEN DEBT
in order for the muscles to work again efficiently this must be repaid. This is done by taking gulps of air until enough oxygen has been taken in to allow the removal of lactic acid and the replenishment of muscle energy stores.