Organisms (Interaction and interdependence)
- Integration of body systems
- Hierarchy of subsystems
- cells, tissues, organs, systems
- emergent properties
- cheetah as predator
- Nerves, hormones and blood
- nerves: fast, specific
- hormones: slow, widespread
- blood transports materials
- Brain and spinal cord
- brain: integration, memory
- spinal cord: unconscious processes
- nerves: sensory and motor fibres
- Reflexes and the cerebellum
- pain receptor in hand
- single interneuron, grey matter
- cerebellum: coordination, balance
- Hormones
- melatonin, pineal, sleep
- epinephrine, adrenal glands
- hypothalamus and pituitary
- Feedback control
- baroreceptors: blood pressure
- chemoreceptors: pH, CO₂, O₂
- medulla: heart, ventilation
- ENS controls peristalsis
- Tropisms and auxin HL only
- positive phototropism
- angle of curvature
- efflux carriers
- H⁺ loosens cell walls
- Other phytohormones HL only
- cytokinin from root tips
- auxin from shoot tips
- ethylene: positive feedback
- Hierarchy of subsystems
- Defence against disease
- Pathogens
- viruses, bacteria, fungi, protists
- archaea: no human disease
- Primary defence
- skin: physical and chemical
- mucous membranes
- clotting: thrombin, fibrin
- Innate immunity
- broad, unchanging
- phagocytes: endocytosis, lysosomes
- Adaptive immunity
- antigens trigger antibodies
- helper T activates B-cell
- clone of plasma cells
- memory cells: immunity
- HIV and AIDS
- body fluid transmission
- kills helper T-cells
- opportunistic infections
- Antibiotics
- block bacterial processes
- useless against viruses
- resistance by natural selection
- Zoonoses
- TB, rabies
- Japanese encephalitis
- COVID-19
- Vaccines and data
- antigens or nucleic acids
- herd immunity
- percentage change, difference
- Pathogens