Science--Chapter 1D

In science we are currently studying the Digestive, Circulatory, and Nervous Systems

Chapter 1D

1. How does the digestive system work?

  • The digestive system changes food into nutrients that body cells use for energy, for growth and repair, and for working well.
  • Food is broken down and chemically changed as it moves from the mouth through the esophagus to the stomach and small intestine.

2. How does the circulatory system work?

  • The parts of blood are plasma, red blood cells, white blood cells, and platelets, and each part does a different job.
  • The three kinds of blood vessels are arteries, capillaries, and veins, and each does a different job.
  • Blood moves through each side of the heart in one direction, from the right atrium to the right ventricle and from the left atrium to the left ventricle.

3. How does the brain get information?

  • Nerve cells are the basic units of the nervous system, which includes the brain, spinal cord, and nerves.
  • Nerve cells in the skin gather information about touch, pressure, heat, cold, and pain and send messages to the brain.
  • Nerve cells in the eyes gather information about light and send messages to the brain.
  • Nerve cells in the tongue and nose gather information about taste and smell and send messages to the brain.

Chapter 1D Vocabulary


Nutrient                      a substance in food that the body uses for energy, for growth and repair, or for working well

Digestion                    the changing of food into forms that the body can use

Saliva                          the liquid in the mouth that makes chewed food wet and begins digestion

Enzyme                      a chemical that helps your digestive system change food into nutrients

Esophagus                  the tube that carries food and liquids from the mouth to the stomach

Small Intestine          the organ of the digestive system in which most digestion takes place

Plasma                        the watery part of blood that carries nutrients, wastes, and blood cells

Red blood cell            the kind of blood cell that carries oxygen to other body cells

White blood cell         the kind of blood cell that fights germs

Platelet                       a tiny part of a cell that helps stop bleeding

Artery                          the kind of blood vessel that carries blood away from the heart

Capillary                     a tiny blood vessel with thin walls through which oxygen, nutrients, and water pass

Vein                            the kind of blood vessel tat carries blood back to the heart

Atrium                        one of two spaces in the top part of the heart that receive blood from veins

Ventricle                     one of two spaces in the bottom part of the heart that pump blood out of the heart

Sense organ               a body part that has special nerve cells that gather information about the surroundings

Nerve cell                   a cell that gathers and carries information in the body

Nerve ending             a tiny branch of a nerve cell that gathers information

Spinal cord                 a think bundle of nerves that connects the brain and nerves throughout the body.