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Three different ways: Inhalation (breathing) Ingestion (eating) Absorption through skin
Breath in through nose and mouth Pharynx Trachea
Bronchial Tubes Lungs
Diaphragm contracts lungs expand air sucked in Diaphragm relaxes air forced up and
out
Bronchial tubes (bronchus) bronchiolesAlveoli capillaries • Alveoli = site of gas exchange
• Oxygen (O2)
• Carbon Dioxide (CO2)
Carried to cells in body
Smoke, bacteria, dust Nasal passage ways & bronchial tubes =
mucus and cilia Mucus = traps inhaled particles Cilia = move particles in wave like motions to
be expelled through sneezing and coughing
- Can only defend against low doses ~ no defence against VOC’s and pesticides
Ingestion = process of eating and drinking
Digestion = break down of food into smaller pieces in order to absorb chemical nutrients Carbohydrates Proteins Fats Vitamins and Minerals
Starts in mouth with chewing Teeth = break up food into smaller pieces Saliva = moistens and breakdown food
Swallow food esophagus stomach small intestine (most nutrients absorbed)
Mixed with digestive substances from liver and pancreas Liver = bile (breakdown and absorb fat) Pancreas = very important organ in digestion - breakdown carbohydrates, proteins,
fats
Intestinal walls lined with villi other side = capillaries
Nutrients absorbed through small intestine walls into circulatory system and distributed to rest of cells in body
Food not absorbed in small intestine passed to large intestine = water absorbed,
compacted into feces
Vomiting Contents from middle of intestine up forced
out through mouth Liver
Filters blood ~ removes poisons that get across villi
Skin = largest organ; first line of defence against outside world Makes Vitamin D with sunlight ~ calcium
Structure: Epidermis Dermis
Subcutaneous
Epidermis: Two layers (top = dead cells, bottom = new
cells) Dermis:
Contains nerve endings and capillaries, sweat glands
Subcutaneous Fat cells
Keeps out water and contaminants Can absorb chemicals in cleaning
products and in workplace, as well as oils, tars, alcohols, pesticides
Harm layers of skin Get into capillaries and carried to cells of
body
Heart, veins, arteries, capillaries
Carries blood to cells of body and transports nutrients and wastes
Nutrients = carbohydrates, proteins, fats, vitamins, minerals
Wastes = carbon dioxide, water, heat
Fights pathogens when skin is wounded (white blood cells)
Contaminants can get into blood through wounds from sharp objects, insect and animal bites
Carries contaminants to organs, tissues, systems