Cross-System Connections + Data Analysis (LG 1)

Why is surface area important in biological systems like the circulatory, respiratory, and digestive systems?

It increases the rate of exchange (diffusion or absorption) of substances such as gases, nutrients and wastes between systems and cells.

How does surface area affect the respiratory system?

Alveoli in the lungs increase surface area to maximize oxygen and carbon dioxide exchange

How does surface area affect the digestive system?

Villi and microvilli in the small intestine increase surface area for maximum nutrient absorption.

How does surface area affect the circulatory system?

Capillaries are thin and numerous, providing a large surface area for efficient exchange of gases, nutrients, and waste with tissues.

How has the respiratory system evolved to increase surface area?

Lungs evolved with millions of alveoli, creating a large surface area in a small volume.How has the digestive system evolved to increase surface area?

How has the digestive system evolved to increase surface area?

The small intestine is long and contains folds, villi, and microvilli to increase surface area for nutrient absorption

How has the circulatory system evolved to increase surface area?

Extensive networks of capillaries and branching blood vessels increase contact area with tissues.

Which structure is common to all three systems for maximizing surface area?

Thin, folded, and highly branched structures (e.g., alveoli, villi, capillaries).

How might a disease affecting alveoli (like emphysema) impact the respiratory system?

It reduces surface area for gas exchange, causing shortness of breath and low oxygen levels.

How does a blocked artery affect the circulatory system?

It decreases blood flow, leading to tissue damage or heart attack due to lack of oxygen.

What happens when villi are damaged in the digestive system (as in celiac disease)?

Nutrient absorption decreases, leading to malnutrition and digestive issues.

What would happen if multiple systems are affected simultaneously (e.g., in severe trauma)?

Body’s ability to exchange gases, circulate blood, and absorb nutrients is impaired, leading to systemic failure.

What is diffusion?

The movement of particles from an area of high concentration to low concentration.

What factors increase the rate of diffusion?

Increased surface area, thin membranes, high concentration gradient, and short diffusion distance.

How do biological systems maximize diffusion?

By using thin, moist, and large-surface-area structures (e.g., alveoli, capillaries, villi).

Why is diffusion essential for life?

It enables the exchange of gases, nutrients, and wastes between cells and their environments.