1. Increase in scientific understanding and technology advances have broadened options for maintaining humans as functioning organisms. * Identify parts of the body and the biomaterials and biomedical devices that can be used to replace damaged or diseased body parts including:
- pins, screws and plates. These are used to repair bone fractures. They are almost all made from metallic alloys.
- artificial joints. These replace joints that have been largely destroyed by degenerative diseases such as arthritis or damaged badly in an accident. Common examples are knee, hip and shoulder joints
- pacemakers. These are used to correct arrhythmias, that is, when the heart beats too fast, too slowly or irregularly. A pacemaker is a battery-operated device designed to stimulate contraction of the heart at a certain rate.
- artificial valves. These valves can be used to replace damaged valves in the body that are no longer functioning to keep blood flowing in one direction only.
- crowns, dentures. A crown is a tooth cap that is placed over an artificial or natural root system. Crowns have traditionally been constructed from ceramic materials, which have relatively low strength. Dentures (false teeth) are generally made from acrylic for ease of fabrication.
- lenses. Artificial lenses restore function in the eye where a cataract has caused the previous lens to go cloudy. Artificial lens are commonly made from PMMA, silicone rubber, copolymer blends; nylon; Dacron; or polypropylene
- prosthetic limbs. These are artificial limbs that are commonly used to replace entire limbs, or part limbs on amputees. Materials that are sometimes used include silicone or silicone matrix (for liners), and titanium, aluminium, stainless steel or carbon fibre composites.
- cochlear implants. This is an artificial hearing device that can replace a damaged cochlea. It is designed to stimulate nerves inside the inner ear, thus produce a hearing sensation. They are made of a head set inside the skull and a pocket speech processor
* gather and process information from secondary sources to trace the historical development of one of the following cochlear implants, replaces the function of the ear, sound is detected by micro phone, 1950 first electrical stimulation of auditory nerve, 1957 first stimulation of acoustic nerve via an electrode, biocompatible material made, 1972 speech processor developed, 1970 single cochlear implant used, 1978 first implant of multi channel.
Pacemaker, early 1950’s first external pacemaker, requires main power supply, mid 1950’s battery developed so patient can be mobile, early 1960’s internal pacemaker, mid 1970’s titanium casing no more electromagnetic radiation, 1990’s programmable pacemakers and ones that compensate for physical activity. 2. The regular beating of the heart and continuity of the flow of blood through the heart and around the body is needed to maintain good health * Explain the relationship between the structure and function of the following parts of the heart
- valves. These are structures present in the heart and in veins that allow blood to flow in one direction only. Valves consist of flaps of tissue that are oriented to allow this unidirectional flow.
- atria. The function of the atria in the heart is to receive blood from the veins before passing it on to the ventricle. About 80% of the blood received in the atria flows into the ventricles while the heart is relaxed.
- ventricles. These ventricles receive blood from the atrium. The function of the ventricles is to pump the blood either to the lungs for re-oxygenation (right ventricle) or to the body for distribution to cells (left ventricle).
- major arteries and veins. Arteries carry blood away from the heart and veins carry