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