Recall the way in which muscles, tendons, the skeleton and ligaments interact to enable movement including antagonistic muscle pairs, extensors and flexors. Cartilage: a tissue made from collagen, which protects bone ends A muscle: an organ that produces movement by contraction A joint: the junction between two bones A tendon: joins muscle to bone A ligament: joins bone to bone to stabilise a joint Muscles work in pairs.
One muscle produces the opposite movement from the other muscle, therefore, the pairs are called antagonistic pairs. Muscles which cause a joint to extend are called extensors, muscles which cause a limb to retract are called flexors. Possible disadvantages of exercising too much (wear and tear on joints, suppression of the immune system) and exercising too little (increased risk of obesity, CHD and diabetes) A moderate level of exercise improves health & well-being. However, over-training can result in the opposite effect. This is the phenomenon known as “burn-out” Positive effects of exercise include;
- Increased BMR
- Decreased blood pressure
- Increased HDL
- Decreased LDL
- Maintaining healthy BMI
- Decreased risk of diabetes
- Increased bone density
- Improved well being
- Decreased adrenaline levels
- Less stress
- Decreased risk of CHD
Moderate exercise increases levels of Natural Killer cells, which secrete apoptosis-inducing chemicals in response to non-specific viral or cancerous threat Negative effects of exercise (over-training) include;
- Decreased levels of Natural Killer Cells, Phagoctyes and B & T Cells. This decreses immune response.
- Increased muscle inflammation
- Muscle tears and sprains
- Increased adrenaline levels
- Increased cortisol levels, which also decreases the immune response
- Increased stress
- Damaged cartilage
- Tendinitis
- Ligament damage
- Swollen bursae.
How medical technology, including the use of key-hole surgery and prostheses, is enabling those with injuries and disabilities to participate in sports Key-hole surgery is a technique which allows doctors to conduct surgery with the minimum possible damage to the patient. The surgeon makes a small incision (a “key-hole”) and uses a fibre-optic camera to view the damaged area.
If required, the surgeon can make a second incision and use a number of small, remote operated tools to repair the damage. Because the incisions are small and only the damaged area is targeted, the patient recovers quickly. There is also less chance of infection. Unfortunately, the procedure requires a high degree of training, expensive equipment and can only be used on certain types of surgery. Prosthetics allow people with amputations to participate in many activities, including sports.
Whether the use by athletes of performance enhancing substances is morally and ethically acceptable. Drug Effect on physiology Effect on performance Side-effects Erythropoietin EPO causes the bone Extra blood cells mean the Increased haemocrit marrow to generate extra blood can carry extra oxygen. increases blood (EPO) red blood cells. This increases the level of work the body can sustain through aerobic respiration (aerobic threshold). viscosity. This causes strain on the heart and can lead to infarction Creatine Creatine combines with phosphate to form Creatine Phosphate (CP). CP can phosphorylate ADP, regenerating ATP.
Describe the structure and function of sensory, relay and motor neurones including the role of Schwann cells and myelination Sensory nerve: Motor nerve: Relay nerve: carries electrical message from receptor to spine carries electrical message from spine to effector. connects sensory and motor nerves. Also relays message to the brain. wrap around the axon of the long nerves, creating a thick layer of membrane, which insulates the nerve and allows for much faster conduction speed.
