Exploring and Understanding Concepts

Example

Name the basic job of the digestive, respiratory, circulatory and skeletal systems.

1. Digestive: breaks food down into nutrients the body can use. Respiratory: takes in oxygen and lets carbon dioxide out.
2. Circulatory: moves blood, with its oxygen and nutrients, around the body. Skeletal: supports the body and protects the soft parts inside.

Example

Name the basic job of the nervous and muscular systems.

1. Nervous: carries messages between the brain and the rest of the body. Muscular: moves the body by pulling on its bones.

Example

For the heart and lungs, say what each does and how its structure fits the job.

1. Heart: pumps the blood around the whole body; it is made of muscle that squeezes and relaxes without resting, so the blood keeps moving.
2. Lungs: pass oxygen from the air into the blood; soft and stretchy, so they fill and empty with every breath.

Example

For the intestines and bones, say what each does and how its structure fits the job.

1. Intestines: absorb the nutrients out of broken-down food; a long, folded tube gives food a long path. Bones: hold the body up and shield the soft parts; stiff and strong.

Example

Name the systems that cooperate when you sprint and when oxygen reaches every part of the body.

1. Sprint: muscular and skeletal — muscles pull on bones, and the bones carry the body's weight.
2. Oxygen everywhere: respiratory and circulatory — the lungs load oxygen into the blood, and the heart sends that blood around.

Example

Name the systems that cooperate when you catch a ball.

1. Catch: nervous and muscular — the eyes and brain judge the ball, and nerves tell the hand's muscles when to close.

Example

Match each to the system it affects: asthma, heart disease, a broken bone, a cavity, the flu, a concussion.

1. Asthma narrows the airways — respiratory. The flu — respiratory.
2. Heart disease — circulatory. A broken bone — skeletal.
3. A cavity decays a tooth, where digestion's first bite happens — digestive. A concussion bruises the brain and scrambles its signals for a while — nervous.

Summary

• Six systems, six basic jobs.
• Each organ's structure fits its function.
• Systems cooperate: muscles with bones, lungs with heart, nerves with muscles.
• A disease is named by the system it affects.