1. The Digestive System

2. What is the purpose of the digestive system?

3. Purpose of the Digestive System
To break down food to provide nutrients and water to the body, and expel waste
What is the toughest food that the human body might try to break down?
Fibre – made from plants (vegetables and grains)

4. How does food get broken down?
Mechanically
Mouth chews food to break it into smaller pieces
Stomach churns
Chemically
Liver produces bile to mix water and fat together for digestion
Gastric acid is produced by the cells of the stomach lining (it would burn your hand!)

5. Mouth
Esophagus
Liver
Stomach
Gall Bladder
Pancreas
Large Intestine
Small Intestine
Colon
Rectum/Anal Sphincter

6. Parts of the Digestive System
Liver
Filters blood and releases enzymes
Stomach
Break down food into microscopic nutrients through the use of acid
Esophagus
Performs peristalsis
Pushes food/water into stomach

7. http://www.youtube.com/watch?v=NddZ5ftQb 0Q

8. Parts of the Digestive System
Large intestine
Diffuses water into blood stream
Gall bladder
Produces bile to help break down fat
Pancreas
Produces enzymes to assist digestion and to help absorb nutrients in small intestine

9. Parts of the Digestive System
Mouth/ Teeth/ Tongue
Performs mechanical digestion and starts chemical digestion
Small Intestine
Diffuses nutrients into blood stream

10. Stomach Cells – How would these help the stomach lining?
Mucus

11. How do these stomach cells work?
Fit tightly together to provide a barrier to substances
Columnar epithelial cells secrete mucus which provides a lining in the interior of the stomach which protects against acid

12. Take a minute… Complete the flow chart using your organ system diagram
Start with the stomach
End with the blood stream/Out of the body
What organs do the water/nutrients/waste have to go through to get to the bloodstream/exit?

13. How does the digestive system give nutrients to the blood stream?
What do we call exchange points in the circulatory system?
Capillaries
Where do nutrients get absorbed?
Intestines (Small – Food, Large – Water)
Where else do these exchange points exist?
Every cell and the lungs

14. The Process of Nutrient Absorption
Food is broken down in the stomach to microscopic nutrients and released into small intestine dissolved in water
As the nutrients pass the villi, diffusion occurs through the extremely thin walls of the villi
Nutrients enter the capillaries and then start to circulate through the blood stream

16. The Importance of the Sphincter
Without a sphincter, the digestive track is really just a hole through your body
Sphincter – a ring of muscle that holds a biological opening closed
Over 50 different sphincters in the human body

17. Two Types of Sphincter’s
Voluntary - Controllable
Rectum – both voluntary and involuntary sphincter’s
Sphincter Urethrae - Urinary sphincter

18. 2 Types of Sphincter’s
Involuntary - Not in your control
Ileocecal valve – closes off the small intestine so that food that has not fully broken down may not pass
Sphincter pylori – Holds food in the stomach until it is thoroughly mixed with stomach acid

19. Olestra Fat substitute used in the 1980’s
zero calories, zero grams of cholesterol and zero grams of fat
gastrointestinal symptoms — including diarrhea, loose stools, nausea, gas
Olestra sometimes causes underwear staining
“greasy, hard-to-wipe-off fecal matter”
anal leakage (leakage of liquid olestra through the anal sphincter).

20. My Roomate He did not have an esophogeal sphincter
Always got heart burn (acid moving up from your stomach into your esophagus)
Had a muscle from his leg fashioned into a sphincter to prevent it

21. Demo
Digestion of Fat -

22. What’s wrong with me Doc?
Day 1:
Pain in stomach area
Answers:
Lot’s of fibre, good amount of veggies, not too much red meat
2 days of on and off pain
Bowel movements – 1-2/day (regular)

23. What’s wrong with me Doc?
Day 2: Pain moves down and to the right side
Excrutiating pain when I walk
Some nausea and vomiting
Answers:
I know I have collitis. Do I have collitis? How could I test for it?

24. The Circulatory System

25. Purpose of the Circulatory System
Transports nutrients and oxygen to cells
Transports waste and carbon dioxide away from cells

26. Getting Around the Body
The heart pumps blood through the body
It pumps blood to the lungs to exchange gases and comes back to the heart
The heart then pumps blood around the rest of the body to transport gases to the cells

27. Veins vs. Arteries Arteries – Pumps blood AWAY from the heart
Veins – Brings blood back to the heart

28. Capillaries – Act as an exchange point for gases and nutrients
These happen in the:
Lungs
Intestines
Every single cell in the body

29. Structure of the Circulatory System
Video

30. Respiratory System

31. Purpose of the Respiratory System
To provide all cells in the human body with Oxygen and remove Carbon Dioxide produced as waste by each cell

32. Fact
You breathe 15 times per minutes and move 10,000L of air in and out of your lungs each day
With every breath, you breath in at least one particle of air that Gandhi breathed in when he was alive

33. Respiratory System Structure

34. Gas Exchange

35. Carbon Monoxide Poisoning
When we breathe in Carbon monoxide, it takes the place of oxygen on the red blood cells
Since RBC’s cannot carry oxygen, the tissues in the human body start to malfunction
The brain relies on oxygen and is one of the first organs affected
You will feel nausea, head aches, loss of consciousness and more

36. Breathing You breath without having to ask your body to do so
If you hold your breath too long, when you fall unconcious, your body will start to breathe again

37. Musculoskeletal System

38. Purpose
The musculoskeletal system supports the body, protects delicate organs and makes movement possible

39. Muscles Bundles of long cells.
Contract and expand when signalled by nerve cells.
Skeletal muscle attached to bone by tendons

40. Muscles
Muscles contract – get shorter and thicker.

41. Muscles
Voluntary
Involuntary

42. Osteoporosis

43. Nervous System

44. Purpose of the Nervous System
To sense the environment and coordinate an appropriate response

45. Nervous System
The nervous system is made up of the brain, spinal cord, and peripheral nerves.
It senses the environment and coordinates an appropriate response.
The core of the nervous system is the brain and the spinal cord. This is called the central nervous system.

46. Nerves are bundles of special cells called neurons, surrounded by connective tissue.
Neurons are communication specialists that send information around the body using electrical signals.
There are approximately 100 billion neurons in the human brain.

47. Neuron Facts
Human brain has over 100 billion neurons If lined up, they’d make a line over 600 miles long Neurons do not undergo mitosis Signals can be sent as high as 180 miles/hour

48. The peripheral nervous system consists of the nerves that carry the signals between the central nervous system and the body.

49. Human Body is an Electrical Circuit
Let-go Voltage

50. Reflexes
Reflexes are actions that do not require the involvement of the brain: they occur without conscious thought.
The spinal cord acts as a short cut for reflexes.

51. Functional MRI (Magnetic Resonance Imaging)
Detects electrical activity in the brain

52. Congenital Analgesia Congenital Insensitivity to Pain
Malfunction of path of pain signals to the brain or the brain’s failure to interpret them
Very dangerous for children because they can hurt themselves without knowing it.
We feel pain so we don’t injure ourselves