Respiratory System

The respiratory system is the body system that provides body cells with oxygen and removes carbon dioxide that cells produce as waste.

Respiratory System• The respiratory system works with the

cardiovascular system. We breathe in air which your blood circulates to all parts of the body

• Goal of respiratory system is to deliver oxygen to body and take away carbon dioxide from body

• Inspiration = air flowing into lungs (inhaling)• Expiration = air flowing out of lungs (exhaling)

Stages of Respiration1. Pulmonary ventilation – actual movement of air

in and out of lungs2. External respiration - gas exchange (oxygen and

carbon dioxide) between blood and lungs3. Respiratory gas transport – movement of gases

throughout the body via the blood in the cardiovascular system (hemoglobin carries oxygen)

4. Internal respiration – gases exchange between blood and the cells of the body

Breathing• Air enters through your nose and mouth when you

inhale • Mucus in the nasal passages warms, moistens, and

filters the air • Cilia – tiny hairs that protect the nasal passageways

filtering out dust and other particles that enter the nose

• Mucus is a thick secretion that moistens, lubricates, and protects mucous membranes.

• A mucous membrane is a type of tissue that lines body cavities and secretes mucus.

Path of Respiration

1. Nose and Mouth2. Pharynx (throat)3. Larynx (voice box)4. Epiglottis (flap that covers the entrance to

the trachea when you swallow, the flap opens when you breathe to allow air to enter trachea)

5. Trachea (windpipe, tube connects throat to bronchi and lungs)

Path of Respiration (continued)

6. Bronchi (trachea splits into 2 smaller tubes leading to lungs)

7. Lungs8. Bronchioles (bronchi branch into smaller

tubes as they enter each lung)9. Alveoli (microscopic air sacs covered with

blood vessels)

Alveoli• The walls of the alveoli are so thin that oxygen

and carbon dioxide can easily pass through them

• Clusters are in direct contact with pulmonary capillaries

• Two exchanges take place in the alveoli1. Oxygen passes from alveoli into capillaries 2. Carbon dioxide passes from your capillaries into

the alveoli

Diaphragm• Sheet of muscles that lies across the bottom of

the chest cavity• Separates the chest from the abdomen• Function is to help pump carbon dioxide out

of the lungs and pull oxygen into the lungs

Diaphragm Muscle

• Inhaling - Diaphragm contracts when you breathe in – pulling downward and creating more space for

your lungs to expand (like a balloon)

• Exhaling - Diaphragm relaxes when you breathe out – the space for the lungs is reduced and air is forced

out of the lungs

Lungs• The lungs are covered by a thin tissue layer

called the pleura• The PLEURA are the two membranes, that

surround each lobe of the lungs and separate the lungs from the chest wall

• the lung on the left side of your body is a bit smaller than the lung on the right. This extra space on the left leaves room for your heart.

Disease and Disorders• Asthma – constriction of airways• Emphysema - damage to air sacs walls causing

loss of elasticity• Bronchitis - inflammation of bronchial tubes• COPD – Chronic Obstructive Pulmonary

Disease - lung disease causing shortness of breath

• Lung Cancer -malignant tumors that develop in lung tissue

How to Keep your Respiratory System Healthy

• Do not smoke• Avoid breathing secondhand smoke• Do not inhale harmful drugs• Avoid breathing polluted air• Exercise regularly• Avoid inhaling harmful chemicals• Seek medical help for respiratory infections