Respiratory and Circulatory System Functions

What is the primary function of the respiratory and circulatory systems working together?

• To digest food and absorb nutrients.

• To produce hormones for growth.

• To bring oxygen into the body and remove carbon dioxide.

• To fight off infections and diseases.

Why do large animals like mammals and birds need lungs instead of relying on simple diffusion for oxygen intake?

• Lungs help them stay constantly moist.

• Simple diffusion is too slow for their large bodies and high energy needs.

• Lungs allow them to absorb dissolved oxygen from water.

• Simple diffusion only works for exhaling carbon dioxide.

What is the correct order of structures air passes through when entering the human body?

• Larynx, Trachea, Bronchus, Bronchioles, Alveoli

• Trachea, Larynx, Bronchioles, Bronchus, Alveoli

• Bronchus, Trachea, Larynx, Alveoli, Bronchioles

• Alveoli, Bronchioles, Bronchus, Trachea, Larynx

How does the thoracic diaphragm help us breathe in?

• It pushes up on the lungs, decreasing their volume.

• It contracts and flattens, increasing lung volume.

• It relaxes and expands, increasing lung pressure.

• It directly absorbs oxygen from the air.

What is the main function of the heart in the circulatory system?

• To oxygenate the blood.

• To filter waste from the blood.

• To pump blood throughout the body.

• To produce red blood cells.

Which type of blood vessel carries blood away from the heart?

• Veins

• Capillaries

• Arteries

• Vena Cava

Why do veins have valves?

• To increase blood pressure.

• To prevent blood from flowing backward.

• To help oxygenate the blood.

• To filter impurities from the blood.

What is a key difference between endotherms and ectotherms?

• Endotherms have slower metabolisms than ectotherms.

• Ectotherms maintain a steady internal body temperature.

• Endotherms generate their own body heat, while ectotherms rely on external sources.

• Ectotherms require more oxygen than endotherms.