5

1
Why do we eat?

• 5º grade
• 2012

2
Food

• Type

• Use

• Carbohydrate
• Fat
• Protein
• Sugars

• Long term energy
• Protecting organs and long term energy store
• Making muscle, enzymes, skin, hair
• Fast energy

3
Primary Producers (Plants)

• Plants can make their own food using
• Sunlight
• Chlorophyll
• Water
• Carbon dioxide
• How are all the consumers and producers linked?

4
The Digestive System
(Breaking food down into smaller pieces)
Lets find out what happened to your breakfast
today!

• Mouth
• Oesophagus
• Stomach
• Small Intestine
• Liver
• Large Intestine
• Gall Bladder
• Pancreas
• Rectum
• Anus

5
Mouth

• Teeth
• (mechanical breakdown)
• Incisors used for cutting
• Canines used for stabbing and holding
• Molars large surface area used for grinding
• Saliva
• (chemical breakdown)
• Enzyme (speeds up reactions in the body)
• Breaks down carbohydrate

6
Esophagus

• Approximately 25cm long
• Moves food from the throat to the stomach
• Muscle movement called peristalsis
• If acid from the stomach gets in here thats
  heartburn.

7
Stomach

• Stores the food you eat
• Chemically breaks it down into tiny pieces
• Mixes food with digestive juices
• Acid in the stomach kills bacteria

8
Small Intestine

• Small intestines are roughly 6 metres long.
• Enzymes and bile are added.
• Villi increase the surface area to help
  absorbtion.
• Nutrients from the food pass into the bloodstream
  through the small intestine walls.

9
Liver

• Directly affects digestion by producing bile
• Bile is an enzyme that helps dissolve fat
• Processes nutrients in the blood, filters out
  toxins and waste.
• Is often called the bodys energy factory

10
Gall Bladder

• Stores bile from the liver
• Delivers bile when food is digested
• Fatty diets can cause gallstones

11
Pancreas

• Produces compounds to digest fats and proteins
• Neutralizes acids that enter small intestine
• Regulates blood sugar by producing insulin

12
Large Intestine

• About 1.5 metres long
• Accepts what small intestines dont absorb.
• Absorbs water and minerals from the waste matter.
• Absorption means taking into the body via the
  blood stream.

13
Rectum and Anus

• Rectum
• About 15cm long
• Stores waste before egestion.
• Anus
• Muscular ring that controls egestion.

14
Write the name of each colored organ

• Green
• Red
• Pink
• Brown
• Purple
• Green
• Yellow

15
Answers

• Green Oesophagus
• Red Stomach
• Pink Small Intestine
• Brown Large Intestine
• Purple Liver
• Green Gall Bladder
• Yellow Pancreas

16
Circulatory System
What is it for ?
We need 2 pumps because 1 would not have enough
energy to push blood through the lungs and then
around the body.
17
Anatomy of the Heart

• Oxygenated blood
• To the body
• LHS thicker
• Deoxygenated blood
• To the lungs

18
Blood Vessels
19
Structure of Arteries

• Oxygenated blood leaving heart
• High pressure
• Thick muscular walls

20
Structure of Capillaries

• Carry blood to cells
• Remove waste
• Deliver oxygen
• Deliver food
• Single file r.b.c.
• Very thin walls (single cell thick)

21
Structure of Veins

• Deoxygenated blood returning to heart
• Thin walls
• Low pressure
• Valves allow flow of blood in one direction
• Muscle contraction

22
Blood

• Plasma
• Liquid carries other components
• Nutrients
• Waste like carbon dioxide
• Red Blood Cells
• Carry oxygen and carbon dioxide
• White Blood Cells
• Fight disease
• Platelets
• Clotting