Grade: Grade 7 Subject: Science Unit: Cells and Body Systems Lesson: 5 of 6 SAT: ProblemSolving+DataAnalysis ACT: Science

System Interactions

Understand how body systems depend on and support each other.

Learn

Systems Working Together

  • Respiratory + Circulatory: Lungs get oxygen; blood delivers it to cells
  • Digestive + Circulatory: Intestines absorb nutrients; blood transports them
  • Nervous + Muscular: Brain sends signals; muscles respond
  • Skeletal + Muscular: Bones provide structure; muscles move them
  • Homeostasis: Systems maintain stable internal conditions

Practice

Question 1: How do the respiratory and circulatory systems work together?

Answer

The respiratory system brings oxygen into lungs, and the circulatory system (blood) picks it up and delivers it to body cells.

Question 2: What happens if the digestive system cannot absorb nutrients properly?

Answer

The circulatory system would have fewer nutrients to deliver, and cells throughout the body would not get enough energy to function.

Question 3: How does the nervous system interact with the muscular system when you walk?

Answer

The brain sends electrical signals through nerves to muscles, telling them when and how to contract to produce movement.

Question 4: What is homeostasis?

Answer

Homeostasis is the body's ability to maintain stable internal conditions like temperature, pH, and blood sugar levels.

Question 5: Which two systems work together to allow you to move your arm?

Answer

The skeletal system (bones) and muscular system work together. Muscles attach to bones and pull on them to create movement.

Question 6: How does the excretory system help other systems?

Answer

It removes waste products from the blood, keeping other systems healthy by preventing toxic buildup.

Question 7: When you exercise, your heart beats faster. Which systems are interacting?

Answer

Muscular (needs more oxygen), circulatory (heart pumps faster), and respiratory (breathe faster) systems interact.

Question 8: How does the skeletal system protect other organ systems?

Answer

Bones protect organs: skull protects brain, ribs protect heart and lungs, vertebrae protect spinal cord.

Question 9: What would happen if the circulatory system stopped working?

Answer

Cells would not receive oxygen or nutrients and could not remove waste, causing all other systems to fail.

Question 10: Name two systems that help regulate body temperature.

Answer

The integumentary system (skin sweats to cool) and circulatory system (blood flow to skin increases) work together to regulate temperature.