respiratory

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Jessie

Cards (10)

Function of the Gas Exchange System
2. The circulatory system (to): transports the blood high in oxygen and low in carbon dioxide from the lungs to the tissues.
4. The circulatory system (back): transports the blood high in carbon dioxide and low in oxygen to the lungs.
Function of the Gas Exchange System
External gas exchange: brings air into the lungs. Here, gases are exchanged between the air and the blood. Oxygen diffuses from the air → capillaries and carbon dioxide from the capillaries diffuse from blood → air.
3. Internal gas exchange: The diffusion of oxygen into the body cells. In the cells during cellular respiration, oxygen is used to break down glucose to produce energy. The CO2 released diffuses from cells → blood.
Parts of the Gas Exchange System
The organs of external gas exchange can be divided into 2 groups:
The passages through which air travels to get to the capillaries in the lungs.
-nasal passage
-pharynx
-trachea
-bronchi
-bronchiole tubes
-alveoli

2. The structures that produce the mechanics of breathing.
-ribs
-intercostals muscles (rib muscles)
-diaphragm
-abdominal muscles
-pleural membranes
Pathway of Air Movement - Nose and Nasal Passage
The air enters the nose through two nostrils.
2. Many animals can also inhale through the mouth (not as beneficial)
3. From the nostrils, air enters the nasal passages.
4. The nasal passages are lined with a mucous membrane, which is made up of ciliated cells that produce mucus (snot).
5. This mucus helps to filter particles such as dust and bacteria out of the air. The nasal cavity also warms and moistens the air that passes through them (done through nose hair).
Pathway of Air Movement - Trachea
From the nasal passages, air goes through the pharynx down the trachea (windpipe).
2. The upper end of the trachea is protected by the epiglottis flap, which is a flap of cartilage. When we swallow, this flap covers the trachea.
Pathway of Air Movement - Trachea
3. The upper end of the trachea holds the voice box or the larynx. This forms a lump outside the neck called the Adam's Apple.
Vocal cords are located inside the larynx. Our vocal cords are used to make sounds as air moves past them.
Pathway of Air Movement - Trachea
4. Rings of cartilage support the trachea to keep it open for the passage of air.
5. The trachea and its branches are all lined with mucus and tiny hairs called cilia. The cilia is constantly beating, acting like a broom.
6. Cilia carry inhaled dirt and foreign particles upwards into the mouth, into the pharynx where they are swallowed.
The Lungs
Two lungs fill most of the chest cavity (thoracic cavity)
2. The lower trachea divides. It forms two branches called bronchi for each lung.
3. each bronchus divides and forms many small bronchial tubes. These divide again into even smaller bronchioles.
4. The bronchioles end in air sacs. Each air sac is made of tiny sacs in clusters called alveoli.
Path:
nostril → nasal passages (mucous membrane) → pharnyx → epiglottis flap → larnyx →
trachea (mucus + cilia) → bronchi → bronchial tubes → bronchioles → air sacs → alveoli
The Lungs - Alveoli
Lung tissue is mostly made of alveoli.
The walls of the alveoli are very thin, elastic, and moist.
2. The water-air division is covered in a phospholipoprotein (surfactant) that increases surface tension and allows inhalation to be easier
3. Less pressure is needed to keep the sacs open.
Respiratory distress syndrome is common in babies due to a lack of surfactant.
The Lungs - Capillaries and Alveoli
Covering the outside of the alveoli is a network of capillaries from the pulmonary (lung) circulation.
2. Erythrocytes (red blood cells) in the capillaries pass through in a single file.
3. Gases are exchanged through the thin moist walls of the alveoli and capillaries by diffusion SEPARATE from one another.
4. The blood in the capillaries unloads CO2 and picks up O2.
5. All the tiny alveoli provide the great amount of surface area needed for this exchange of gases.