The Human Body and Health: Systems, Hygiene, First Aid
The human body is studied by anatomy (structure) and physiology (function); hygiene studies health preservation. Organ systems must be known by function: musculoskeletal (support, movement), digestive (breakdown and absorption), respiratory (gas exchange in alveoli), circulatory (transport; heart with four chambers, systemic and pulmonary circuits), excretory (kidneys filter blood, form urine), nervous (regulation, reflexes), endocrine (hormones), reproductive, and immune/lymphatic defence.
Health topics test hygiene rules (handwashing, food safety, posture, sleep, avoidance of smoking and alcohol) and first aid: stopping bleeding with pressure and tourniquet, immobilising fractures, cooling burns, positioning an unconscious person, and calling emergency services. Vaccination introduces weakened antigens to build immunity; antibiotics act on bacteria, not viruses.
Traps
Confusing arteries and veins (arteries carry blood away from the heart, veins toward it - not defined by oxygen content), mixing vaccination with treatment, and applying a tourniquet without noting the time. Also, alcohol and nicotine are not "nutrients" and antibiotics do not cure influenza.
Rule of thumb
For first aid: safety → assess → call help → act (bleeding, breathing, fractures, burns in that priority).
Worked example
"A person has a deep cut with heavy bleeding from the forearm." Correct action: apply direct pressure, elevate the limb, and if bleeding continues apply a tourniquet above the wound and record the time - not to wash with antiseptic only or to wait.