1. Chapter 2
Human Body Systems

2. Lesson 1: Digestive System
Main Idea:
To function properly, living things need the nutrients found in food. The digestive system breaks down food to release these nutrients.

3. 1. blood-
A system of fluid and cells that carries nutrients and oxygen to cells in the body

4. 2. Digestive system -
The major organ system that breaks down food into nutrients that the body’s cells can use

5. 3. esophagus-
A muscular tube that pushes food toward the stomach

6. 4. Large intestine-
The organ where water and minerals from food are removed and absorbed into the blood

7. 5. Small intestine-
The long, coiled organ where most digestion takes place

8. 6. stomach-
A muscular organ that mixes and stores food and continues the process of digestion

9. Notes 4 main kinds of nutrients:
carbohydrates- main energy source (ex: potatoes)
proteins- helps replace, repair, and grow cell tissue (ex: beans and meat)
Vitamins and minerals- helps nerves work (ex: fruits and vegetables)
fats- provide energy; keep skin healthy; cushion organs (ex: butter and oil)

10. Notes Digestion is the process of breaking down food.
The stomach is a muscular organ that squeezes food and mixes it with digestive juices.
Food leaves the stomach, then enters the small intestine, which is where most digestion takes place.

11. Notes
In the small intestine, liquids from the pancreas and liver help to digest fats and carbohydrates.
The large intestine is where water and minerals from food are removed and stored in the blood.

12. Lesson 2: Respiratory and Circulatory Systems
Main Idea:
The respiratory system brings oxygen into the body and removes wastes. The circulatory system carries oxygen to the cells and carries away wastes.

13. 1. artery-
A blood vessel that carries blood away from the heart

14. 2. capillary-
A tiny blood vessel that connects arteries and veins

15. 3. Circulatory system-
Organs that transport oxygen, nutrients, water, and wastes

16. 4. heart-
A muscular pump that pushes blood through the blood vessels

17. 5. Respiratory system-
Organs that work together to take air into the body and push it back out

18. 6. vein-
A blood vessel that carries blood to the heart

19. Notes
You take air in your nose and mouth when you inhale (breathe in). The air moves to the trachea, then to the lungs(main organs of respiratory system).
Red Blood Cells (RBCs) pick up oxygen at the alveoli (air sacs) in the lungs.
The diaphragm is a dome-shaped muscle that helps you breathe.

20. Notes
The heart is a muscular pump that works all the time. It pushes the blood through the blood vessels (arteries, capillaries, veins).
An artery is a blood vessel that carries blood away from the heart to the capillaries.
A vein carries blood back to the heart.
Blood carries oxygen to the cells and takes away carbon dioxide.
3 Types of blood cells:
Platelets- help heal injuries by forming blood clots
Red Blood Cells- carry oxygen
White blood cells- help body fight disease

21. Notes
The heart has 4 chambers (sections). The 2 upper chambers receive blood from the veins and are the left and right atrium.
Oxygen-poor blood enters the heart in the right atrium. It is coming from the body.
Ventricles (left and right) pump blood out of the heart into the arteries.

22. Lesson 3: Skeletal and Muscular Systems
Main Idea:
The skeletal and muscular systems protect and support the body and allow it to move.

23. 1. muscular system-
Body system made of muscle that makes body parts move

24. 2. skeletal system-
Body system that gives the body its shape, protects organs inside the body, and works with the muscles to move the body

25. 3. cartilage-
A flexible material that is softer than bone and cushions bones where they meet

26. 4. ligament-
Connect bones to cartilage and holds the joint together

27. 5. joints- Where bones come together

28. Ball-and-Socket joint
Hinge Joint
Ball-and-Socket joint
Pivot Joint

29. 6. Skeletal muscle-
Voluntary muscles that moves your bones by pulling on the bone it is attached to, but cannot push

30. 7. Cardiac muscle-
Involuntary muscle found only in the heart

31. 8. Smooth muscle-
Involuntary muscle found in blood vessels and other organs

32. Notes
Cartilage is a flexible material that cushions most bones and is softer than bone.
Your spine (backbone) is a column of small bones that runs down your back to keep it straight.
Your ribs form a cage of curved bones that protect your heart, lungs, and other organs.
Ligaments connect bones to cartilage.
The human skeleton has 206 bones.
Some joints work like hinges, which allow bones to move back and forth. (ex: knee)

33. Notes
7. Skeletal muscles work in pairs. They can only pull on the bone they are attached to. They cannot push. 8. The muscles in the upper part of your arm are biceps and triceps. 9.The muscles in the upper part of your leg are quadriceps and hamstrings. 10.The muscle in the lower part of your leg is the calf.