In Sickness and in Health

MR N GREWW

Move
Reproduce
Nutrients
Grow
Respond
Exchange gases
Waste
Water

Plants

Multicellular, structured

Animals

Multicellular, no structure

Fungi

Unicellular or Multicellular

Bacteria

Unicellular

Cellular Respiration

glucose + oxygen --> water + energy + carbon dioxide

Photosynthesis

water + carbon dioxide --> light + chlorophyll --> glucose + oxygen

Mitosis

Cell division for growth and repair

Osmosis

Fluid movement from high to low concentration

Diffusion

Fluid movement in cells from high to low concentration

Hypotonic

High concentration outside of cells; cell swells

Isotonic

Equal concentration in and out of cell; no change

Hypertonic

Low concentration outside of cell; cell shrinks

Homeostasis

Organism's ability to maintain a steady state when the external environment changes

Set Point

Target value in homeostasis

Normal Range

Values surrounding the set point in homeostasis

Negative Feedback

Reversus a stimulus change in homeostasis

Stimulus Response Pathway

Stimulus, receptor, control centre, effector, response

Nervous System

Senses environment and controls actions (localised)

Central Nervous System (CNS)

Brain and spinal chord

Peripheral Nervous System

Nerves branching throughout the body

Neurons

Transmit messages throughout the body

Sensory Neurons

Sensory organs to CNS

Interneurons

Sensory neurons to effectors

Motor Neurons

CNS to effectors

Endocrine System

Chemical hormone glands throughout the body, which release hormones that target specific organs by matching with its receptors (throughout the body)

Hypothalamus

Brain, controls reflex

Pineal Gland

Brain, released melatonin

Pituitary Gland

Brain, controls growth and development

Parathyroid Gland

Neck, releases parathormone (calcium and bones)

Thyroid Gland

Neck, releases thyroxine (cell growth/activity)

Thymus Gland

Spine, releases thymosin (white blood cells)

Adrenal Gland

Kidneys, releases adrenaline

Pancreas

Releases insulin and glucagon

Ovaries

Releases oestrogen and progesterone (puberty and development)

Testes

Releases testosterone (puberty and development)

Reasons Why Pregnancy Cannot Occur

Damage or blockage, gametes (insufficiently produced sperm/egg), repeated miscarriage

Artificial Insemination

Sperm injected into the uterus; sperm can come from partner or donor

Donor Egg and Sperm

Sperm collected from a partner or donor and kept frozen until required. Donor eggs are uncommon as they require careful hormonal and medical treatment. Sometimes a uterus cannot support a pregnancy, so eggs can be taken out and placed in a surrogate

IVF

In-Vitro Fertilisation: Hormones injected into the body which causes eggs to mature quickly which as then removed through a procedure. The egg is placed in a petri dish and has a needle containing sperm injected into it, and it is then placed into the uterus where pregnancy can occur

Pathogens

Organisms that cause infectious disease eg bacteria, virus, fungi

Non-infectious disease

Caused by environment, genetics, and lifestyle

First Line of Defence

Generalised, external reaction made up of physical barriers such skin, tears, and mucus

Second Line of Defence

Generalised reaction once pathogen has entered body. Blood is directed to source so white blood cells can fight and consume bacteria, which causes inflammation. Things such as fever are used to slow down and kill foreign bacteria

Third Line of Defence

Specific reaction that identifies pathogen and develops resistance to it. B Cells produce antibodies which bind specifically to pathogens with the same markers, and produces millions of matching antibodies to fight pathogen

Vaccine

Introduce a dead or weakened pathogen so the third line of defence matches B Cells with matching antibodies to the pathogen and retains memory cells of the pathogen. Vaccine development usually takes years as they are incredibly complex, must be tested on organisms, and must be approved by scientists and the government before being released to the public

Herd Immunity

When enough people are vaccinated, a disease can't spread through the population. This is called herd immunity, which protects vulnerable people with weaker immune systems such as babies, the elderly, and people with cancer