Human Body Systems Lesson 11 Terms and Definitions

Characteristics of the lungs Elastic – they can expand and contract Inside is like a sponge –Contains bronchi and alveoli –Alveoli surrounded by capillaries Diffusion of gases occur between the alveoli and the capillaries.

Oxygen and Carbon Dioxide Exchange

Q: How much air can you exhale?

Tidal Volume Tidal Volume – The volume of air that is moved in and out of your lungs with each breath. –Avg. adult breath – 500mL of air in and out

Average Adult Male Lungs Lungs of avg. adult male –Hold 3000 mL air –Can forcibly inhale an additional 3000 mL Total lung capacity – 6000 mL air

Vital Capacity Vital Capacity – the amount of air that a person can forcibly exhale after breathing in as much air as possible. –Avg. adult male – 4800 mL

Residual Volume Residual Volume – the amount of air still in the lungs after you force out as much as possible. –Avg adult male – 1200 mL

Total Lung Capacity Total Lung Capacity – the sum of vital capacity and residual volume. –The total volume of air the lungs can hold. Avg. healthy adult male 6000 mL.

4800 mL – Vital Capacity mL – Residual Volume 6000 mL – Total Lung Capacity

What affects Vital Capacity? Body size, age, strength of respiratory muscles… Older you get – lungs are less elastic –70 yr old persons 2/3 the vital capacity of a healthy young adult

Respiratory Rate The amount of time it takes to breath in and out. –Often determined by respirations per minute Active person – higher respiratory rate Inactive person – lower respiratory rate

Macrophages Macrophages – Cells that clean the respiratory tract. –Destroy dust and other harmful things we inhale.