• (a) distinguish between signs of a disease, e.g. rash, high temperature, which can be seen or measured, and symptoms, e.g. pain, which can only be described by the patient• (b) distinguish between transmissible and non- transmissible diseases• (c) state the chief signs and symptoms for each of the following transmissible diseases; influenza;severe acute respiratory syndrome(SARS) and dengue fever
• (d) state the chief signs and symptoms for each of the following non-transmissible diseases: colon cancer, coronary hear disease and diabetes• (e) list general disease prevention measures such as personal hygiene, healthy lifestyle and regular medical check-ups
• (f) state that genes determine many of the characteristics that are passed on from parents to offspring, e.g. physical appearance, personality• (g) state that some diseases are hereditary by nature, i.e. passed through the parents’ genes, e.g. thalassemia and sickle cell anaemia
1. Introduction• How does our body parts protect ourselves from getting diseases?• Mucus traps dust and germs in the air that we breathe in• Tears contain an antiseptic liquid that kills germs• Glands in the skin make an antiseptic oil that kills many germs
1. Introduction• How does our body parts protect ourselves from getting diseases?• Acid in the stomach kills germs in your food• Blood clots stop the germs from getting in• Skin forms a barrier to germs
(a) distinguish between signs of a disease, e.g. rash, high temperature, which can be seen or measured, and symptoms, e.g. pain, which can only be described by the patient • Signs of a disease • Rash • A high temperature • Runny nose • Watery nose • High blood pressure
• Some symptoms of diseases• Pain in joints• Loss of appetite• Stiffness in neck• Headache
• Diseases can be broadly classified as • 1) Transmissible • 2) non-transmissible
1. Transmissible disease• Transmissible diseases are diseases that are transmitted among people by• disease-causing microorganisms or pathogens.
• Transmissible Diseases and their Main signs and symptoms
Transmissible disease Main signs and symptomsInfluenza ( or flu ) Starts with headache, chills, coughSevere acute respiratory Starts with a feversyndrome ( SARS ) higher than 38.0o C Followed by cough, and difficulties in breathing, chills, headache, muscular aches, sore throat and diarrhoea
Transmissible disease Main signs and symptomsDengue fever Starts with a sudden high fever up to 40.5oC, severe headache, pain behind the eyes, severe joint pains, muscular pains and muscular aches
• Types of pathogens• And• Transmissible disease caused
Spreading of Transmissible Diseases• Transmissible diseases can be transmitted or spread by• People ( those infected with transmissble diseases)• Animals (e.g mosquitoes)• Non-living things ( such as contaminated food, water and air)
• Pathogens are commonly spread through coughing, sneezing or using common objects such as infected needles.
3. Non-transmissible diseases• Non-transmissible diseases are generally diseases that are not caused by pathogens and cannot be spread among people.• Non-transmissible diseases are also known as non-infectious or non- communicable diseases.
Non- Main signs and symptomstransmissiblediseaseColon cancer No symptoms in early stages Bleeding of gut wall, anaemia, traces of blood in faeces, diarrhoea or constipationCoronary heart Chest pain and shortness ofdisease breath in early stages Heaviness, tightness, pain, burning, pressure or squeezing, usually behind the breastbone, arms, neck, jaws
Non-transmissible Main signs anddisease symptomsDiabetes Loss of weight, excess urine production, weakness, extreme hunger and thirst
• General disease prevention measures:• Practising personal hygiene• Leading a healthy lifestyle• Having regular medical check-ups
• Personal hygiene includes: 1) washing your hands before meals, after going to the toilet and before handling food or drinks• 2) taking regular baths or showers especially in hot weather or after sweating• 3) cooking food properly, covering it to keep flies away and eating it before it turns bad• 4) boiling water before drinking it during any outbreak of transmissible diseases
Leading a healthy lifestyle• There are two types of white blood cells in our immune system to defend our bodies against diseases.• One type of white blood cells ‘eats’ and destroys pathogens.• One type of white blood cells makes antibodies that kill pathogens.
Having regular medical check-ups• To detect visible signs of diseases, a doctor• Looks out for rashes, watery eyes and running nose• Looks out for signs of diseases on the skin, tongue, hair and fingernails• Use a thermometer to measure the body temperature
5. Hereditary and Diseases• The passing of characteristics from parents to their offspring is called heredity.
• Chromosomes are found inside the nucleus of every cell in the human body.• Each chromosome is composed of an extremely long thread of a compound called deoxyribonucleic acid or DNA. The DNA molecule looks like a spiral staircase with pairs of bases forming the steps on the spiral staircase.
• A gene is made up of a short length of DNA. Different genes are made up of different lengths of DNA with different bases• Each gene contains instructions that determine the characteristics to be passed on from parents to their offspring.• The offspring can inherit physical characteristics such as hair, eye and skin colour from the parents
• Some examples of inherited diseases are shown in the table below. Inherited diseases Sign and symptoms Sickle cell - Sickle-shaped red anaemia blood cells -Pale skin -Low count of healthy red blood cells (anaemia) -Breathing difficulties