Transcript Chapter 21 - Cloudfront.net

Chapter 21
The Respiratory System
Structures of Respiratory System
1. Palate
• The floor of the nose and roof of mouth.
• Two parts: Hard and soft
– Hard Palate is the bone toward the
anterior of mouth.
– Soft Palate ends with the uvula in the
posterior of the mouth.
Structures of Respiratory System
2. Pharynx
• The throat!
• Muscular tube lined with ciliated
epithelial tissue.
• Part of respiratory and digestive
system.
• Has 7 openings! 2 for nose, 2 for middle
ear, opening for esophagus, entrance to
larynx!
3.Larynx
• Voice box.
• Contains vocal cords.
Structures of Respiratory System
4. Epiglottis
• Flap the closes the glottis when you
swallow to keep substances out of your
lungs.
5. Trachea
• Extends from Larynx to Bronchi which
lead to the lungs.
• Lined with ciliated mucous membrane.
6. Bronchi
• Resemble structure of trachea, but
smaller in diameter.
• One leads to each side of your lungs.
Structures of Respiratory System
7. Lungs
8. Alveoli
• Site of gas exchange between external
environment and blood.
• Right lung has 3 lobes and left has 2
lobes.
• Inside lobes of lungs, bronchi divide into
smaller bronchial tubes and finally even
smaller bronchioles.
• All bronchioles end in alveoli.
• Most of lung tissue is alveoli! (300
million of them!)
• Capillaries surround each alveoli
allowing the blood to exchange gas with
the environment.
Structures of Respiratory System
• Pluera
• Delicate membrane that lines the
thoracic cavity and covers the lungs.
• Between the two layers there is fluid
(pluera fluid).
• The fluid functions to reduce friction
between the walls of the thoracic cavity
and the lungs!
• If air or fluid (other than the pluera fluid)
fills this space, it must be removed
immediately or the lungs cannot inflate!
Gas Exchange!!!
• The alveoli have capillaries that allow for
the carbon dioxide and the oxygen to be
exchanged!
3 Phases of Respiration
• External Respiration: Exchange of gases
between air and alveoli.
• Internal Respiration: Exchange of gases
between the blood and body cells.
• Cellular Respiration: The use of oxygen to
break down glucose and convert it to
energy! Carbon Dioxide is the bi-product
of this.
Mechanisms of Respiration
• Inspiration: Lungs are filled with air!
• Expiration: Air is forced out of lungs!!!
Mechanisms of Respiration
• Diaphragm contracts and allows air to flow
in to the lungs.
• When the diaphragm relaxes, the air is
pushed out.
The Gas Exchange Process!
• 98% of the oxygen in the blood is attached
to hemoglobin.
• As oxygen moves in to the alveoli, it
combines with the hemoglobin to form
oxyhemoglobin.
• When the oxygen is released in to the cell
through diffusion, carbon dioxide enters
the blood cell.
Role of Carbon Dioxide!
• Carbon dioxide regulates respiration!
• When there is a build up of Carbon
Dioxide, it becomes Carbonic Acid.
• Carbonic Acid triggers the parts of the
brain that control breathing.
• Respiration increases as carbonic acid
increases.