Lasswade High School Centre
Biology Intermediate 1
Health and Technology Short Notes
Healthy Lungs • • •
The passage of air from the nose is – nose ------- windpipe -------- left and right bronchus --------- bronchioles ----------- air sacs ---------- blood The job of the lungs is to take oxygen from the air into the blood and to get rid of waste carbon dioxide from the blood into the air sacs. To help them do this the air sacs have very thin walls and a very good blood supply (capillaries) surrounding the air sacs.
Breathing Rate and Lung Capacity • • • • • • • • • • •
Measured by counting the number of breaths /minute Exercise increases the breathing rate The rate and depth of breathing return to normal during recovery time Tidal volume – volume of air breathed in and out in one breath This is measured using a breath volume kit Vital capacity – maximum volume of air that a person can breath in and out This is measured using a tank of water, a bell jar and a tube. Peak flow – maximum rate at which air can be forced from the lungs Measured by using a peak flow meter Asthma sufferers have narrower air passages and therefore a lower peak flow – improved by using an inhaler Tidal volume, vital capacity and peak flow all depends on body size, age, sex and level of fitness
Effect of Smoking on the Lungs • • • •
Tar in cigarette smoke increases the risk of lung cancer Carbon monoxide in cigarette smoke stops the blood carrying as much oxygen which means the heart has to work harder to pump enough around the body and can lead to heart disease. Smoking in pregnancy can harm the unborn baby. The baby may be lighter, unhealthier and not as intelligent.
Body Fat and Health • • • •
The body needs a balanced diet of the three main food types Fats and carbohydrates for energy Protein for growth and tissue repair Vitamins and minerals are also required to keep the body healthy
Body fat can be measured using skin fold callipers. BMI – body mass index is an indication of whether a person’s is a healthy weight BMI takes into account height as well as their weight. • •
Overweight people may suffer heart disease, diabetes and arthritis Underweight people may suffer anorexia or cancer.
Regular exercise maintains the size and strength of the muscles. Reaction time is the time taken for the body to respond to a stimulus It is affected by drugs and alcohol. A slow reaction time can indicate diabetes, a brain disorder or arterial disease. Alcohol • • •
Alcohol is absorbed across the stomach. It travels in the blood It affects brain activity making reaction time slower, and the person more relaxed and uninhibited. Co-ordination and judgement are poorer. • Excessive drinking can cause liver and brain damage. Drinking during pregnancy can damage the health of the baby and affect brain development.