Basic Human Anatomy, Physiology and Hygiene
This domain tests the structure and function of the major body systems and the everyday hygiene practices that prevent disease. Questions are factual: name the chamber, name the organ of absorption, pick the correct hygiene step.
Organisation of the body
- Cell, tissue, organ, organ system, organism; the adult skeleton has 206 bones.
- Systems tested: skeletal, muscular, digestive, respiratory, circulatory, excretory, nervous, endocrine, reproductive and the skin.
- Skin is the first defence barrier; intact skin and short clean nails are practical infection control, not cosmetics.
Physiology essentials
- Heart has four chambers: right atrium, right ventricle, pulmonary artery, lungs, pulmonary veins, left atrium, left ventricle, aorta.
- Digestion begins in the mouth with salivary amylase; most chemical digestion and absorption occur in the small intestine; the large intestine absorbs water.
- The nephron filters blood and forms urine; a healthy adult passes about 1.5 litres of urine a day.
- Gas exchange happens in the alveoli, where oxygen crosses into the capillaries.
Hygiene in practice
Daily bath, twice-daily brushing, short nails, clean clothing, safe drinking water (boil, filter or chlorinate), use of a sanitary latrine, and menstrual hygiene with a clean absorbent changed every 4 to 6 hours.
Worked example
Trace one drop of deoxygenated blood from the leg to the lung. Reasoning: veins carry blood toward the heart, so it enters the right atrium through the inferior vena cava; the right ventricle pumps it into the pulmonary artery, the one artery carrying deoxygenated blood; in the lungs it is oxygenated and returns through the pulmonary veins to the left atrium. A vessel is named by direction, not by oxygen content.
Traps that cost marks
- Calling the pulmonary artery oxygenated.
- Saying the stomach is the main site of absorption.
- Using 300 bones for an adult, which is the newborn count.