Digestive, Circulatory, Respiratory and Nervous Systems — O/L Science

What must I remember about Digestive, Circulatory, Respiratory and Nervous Systems?

• Digestive: mouth → oesophagus → stomach → small intestine → large intestine → rectum
• Circulatory: heart pumps oxygenated blood via arteries; deoxygenated returns via veins
• Respiratory: O₂ in via lungs → alveoli → blood; CO₂ reverse path
• Nervous: brain + spinal cord (CNS) + peripheral nerves; reflex arc bypasses brain

Test yourself (1 minute)

1. Digestion enzymes

   amylase (starch→sugar), protease (protein→amino acids), lipase (fat→glycerol+fatty acids)

2. Nervous system

   stimulus → receptor → sensory nerve → CNS → motor nerve → effector → response

3. Hormones (endocrine system)

   insulin (blood glucose), adrenaline (fight/flight), oestrogen/testosterone

Practise Digestive, Circulatory, Respiratory and Nervous Systems questions today

Must know

• Blood components: red cells (O₂), white cells (immunity), platelets (clotting), plasma (transport)

Source: NIE O/L Science — Unit 9: Human Body Systems

What should I study first?

What comes next?

Next in the syllabus

Where does Digestive, Circulatory, Respiratory and Nervous Systems fit in the syllabus?

Grade 10 · Term 2