Notes 14-3

Respiratory System

The Air You Breathe• The air you breathe in

contains several different gases, shown in the circle graph on the left. The air you breathe out contains the same gases, but in the amounts shown in the circle graph on the right.

The Air You Breathe

– Percent of a gas breathed in or out

• Reading Graphs:

– What does each wedge of the graphs represent?

The Air You Breathe

– Oxygen; less oxygen is breathed out than breathed in—meaning that some must have been used by the body.

• Interpreting Data:

– Based on the data, which gas is used by the body? Explain.

The Air You Breathe

– There is a higher percentage of carbon dioxide in exhaled air. Carbon dioxide is a waste product of cellular activity.

• Drawing Conclusions:

– Compare the percentage of carbon dioxide in inhaled air with the percentage in exhaled air. How can you account for the difference?

The Air You Breathe

– Nitrogen is not used by the body and is not a waste product.

– Inferring:

– Explain why the percentage of nitrogen is the same in both inhaled air and exhaled air.

Functions of respiratory system

• Takes in oxygen (and glucose)

• Removes carbon dioxide and water

= CELLULAR RESPIRATION

Systems Working Together• Oxygen from the air and glucose from

digested food are both carried to the cells by the blood. During respiration, oxygen reacts with glucose to release energy.

The Path of Air

• As air travels from the outside environment to the lungs, it passes through the following structures: nose, pharynx, trachea, and bronchi.

• The bronchi branches into smaller tubes

• At the end of these tubes are the alveoli

How You Breathe• When you breathe, the

actions of your rib muscles and diaphragm expand or contract your chest. As a result, air flows in or out.

Breathing and Speaking• Two vocal cords, folds of

connective tissue that produce your voice, stretch across the opening of the larynx. Air moving over the vocal cords causes them to vibrate and produce sound.

Health Problems and Smoking

• Tobacco smoke damages the respiratory system and strains the circulatory system, resulting in such diseases as emphysema, cancer, and chronic bronchitis.

Respiratory Diseases • During an asthma attack, air passages narrow

and breathing is more difficult.

• Colds, influenza, pneumonia