CO ORDINATION AND CONTROL
- Co-ordination of what happens inside your body, and responses to changes outside your body, rely on hormones and the nervous system.
- The nervous system involves neurones and impulses, which are electrical, except at a synapse.
- A reflex is rapid, automatic response to a stimuli.
- Internally controlled conditions are water content, ion content, tempreture and blood sugar level.
- Hormones are chemicals produced by glands and carried in your bloodstream.
- The menstrual cycle is controlled by 3 hormones... FSH. LH and Oestrogen.
- A healthy diet contains the right balance of different foods.
- Too little or too much food can lead to health and weight problems.
- Too much cholesterol or salt can lead to problems in your blood system.
- Cholesterol is carried in the body by low-density lipo-proteins or high-density lipo-proteins.
- LDLs are bad and HDLs are good.
- Most drugs harm the body. Even those developed to cure disease can have harmful side effects.
- Drugs can be addictive. If you try to stop taking them you may suffer from withdrawal symptoms.
Controlling Infectious Disease
- Microorganisms that cause infection are called 'pathogens'. These include bacteria and viruses.
- The body defends itself by ingesting pathogens, produces antibodies and producing antitoxins.
- We can use antibiotics and vaccination to control infection.
- Some pathogens have developed resistance to anibiotics.