Topic 7

• The bony skeleton supports your whole body, allowing for movement due to the way the bones of your skeleton and other skeletal tissues work together.
• The main tissue of the skeleton is blank.
• Bone is strong and hard, made of bone cells fixed firmly in a matrix of collagen and calcium salts.
• Bone needs to be hard but it must be as light as possible to reduce the weight you have to move about.
• Compact bone is dense and heavy, found in the long bones of your body.
• Spongy bone has a more open structure, is much lighter, and is found in large masses of bones such as pelvis and head of the femur (thigh bone).
• The skeletal tissue, cartilage, is hard but flexible, made of cells called chondrocytes within an organic matrix made of collagen fibrils.
• Cartilage is elastic and able to withstand compression forces, serving as a shock absorber.
• Cartilage is found between bones to prevent friction during movement.
• There are two main types of cartilage found in the skeleton: Hyaline cartilage is found at the ends of bones, tip of the nose, parts of the ear and in airway passages.
• White fibrous cartilage has bundles of densely packed collagen in the matrix, has great tensile strength and is less flexible than other forms of cartilage.
• Tendons are made of white fibrous tissue, consist of bundles of collagen fibres to form a strong and inelastic tissue, and join the muscles to the bones securely.
• In the stage of ATP production known as oxidative phosphorylation, ADP is phosphorylated in a process that depends on the presence of oxygen.
• Some metabolic poisons target the electron carriers in oxidative phosphorylation, preventing them from passing on electrons, which stops electrons moving down the electron transport chain, stopping chemiosmosis.
• Reduced NAD and reduced FAD are no longer oxidized, so NAD and FAD aren’t regenerated for the Krebs cycle, causing it to stop.
• ATP synthesis in the cell ends up hugely reduced, so there’s not enough ATP to fuel ATP-requiring cellular processes, such as the contraction of heart muscle, which can be fatal for the organism.
• Oxygen acts as the final hydrogen acceptor in aerobic respiration, binding to hydrogen forming water, leading to the regeneration of oxidized NAD and FAD.
• Oxygen acts as the final electron acceptor from the electron transport chain, causing its oxidation so the electron transport chain can start accepting other electrons, leading to the production of maximum amount of energy from the breakdown of food (38 ATP).
• Without oxygen, only glycolysis takes place, producing only 2 ATP.
• The rate of respiration can be measured using a respirometer by measuring the volume of oxygen taken up or the volume of carbon dioxide produced in a given time.
• A respirometer measures the volume of oxygen being taken up in a given time, with the more oxygen taken up, the faster the rate of respiration.
• Lactate Fermentation is a type of Anaerobic Respiration that doesn’t use oxygen and doesn’t involve the link reaction, the Krebs cycle or oxidative phosphorylation.
• Ligaments hold the bones together and form a capsule around the joint, are elastic to allow movement of the bones at the joints, and are formed of yellow elastic tissue which gives strength and elasticity.
• Types of joints include Ball and socket joint, which allows a wide range of movement such as the shoulder joint, and Hinge joint, which allows a narrow range of movement as the elbow joint.
• If the joints are just bone on bone, this leads to wearing away of both bones due to friction, to prevent this, the joint is lined with a layer of cartilage to allow smooth articulation.
• Some joints produce an oily synovial fluid for lubrication to ensure friction-free movement.
• A causation can’t be established, because the link is sometimes thought to be due to obesity caused by lack of exercise not the lack of exercise itself.
• Coronary heart disease is due to factors such as obesity, DM, and sluggish circulation that increase the risk of atheroma and thrombus.
• Moderate exercise improves the immune system functionality, but vigorous exercise causes reduced immune system activity.
• The intense stresses of excessive exercise may cause temporary immune suppression by decreasing the number of phagocytes, B and T lymphocytes.
• When athletes travel to competitive sport events in other countries, they become exposed to unfamiliar pathogens.
• Overcrowdedness in some athletic events increases the risk of transmission of infections.
• Overtraining may cause two types of injuries: traumatic injuries due to a blow from single application of force as in contact sports, and overuse injuries due to wear and tear produced which may cause inflammation of joints.
• Keyhole surgery, also known as Arthroscopy, is a way of doing surgery without making a large incision in the skin.
• Surgeons make a much smaller incision in the patient, and they insert a tiny video camera and specialized medical instruments through the incision into the body.
• Keyhole surgery involves creating a small incision so the risk of infection is reduced, requires less anaesthetic so the risk of reactions to anaesthesia is reduced, and patients lose less blood and have less scarring of the skin.
• Patients are usually in less pain after their operation and they recover more quickly because less damage is done to the body.
• This makes it easier for the patient to return to normal activities and their hospital stay is shorter.
• Keyhole surgery requires high degree of training and expensive objects and can only be used in certain types of surgeries.
• Prostheses can be used to replace whole limbs or parts of limb.