1. The Respiratory System
Bio 20

2. THE RESPIRATORY TRACT
The respiratory tract is what brings air from the atmosphere to the lungs
RECALL - Your body needs oxygen from the air to undergo aerobic cellullar respiration to create energy
There is both an upper and a lower respiratory tract

3. UPPER RESPIRATORY TRACT
Air enters through the mouth and nostrils
Nasal passages will warm, moisten and clean incoming air
Are lined with cilia
Air is warmed to protect later structures

4. The pharynx is the passageway for air into the respiratory system (also for food and water)
epiglottis – flap that covers the glottis (opening to the trachea) when food is swallowed

6. The larynx is our voice box and is made from cartilage
Contains vocal cords
When you speak the muscles around the larynx contract drawing the vocal cords together

8. From the pharynx air enters the trachea
The trachea is strengthened by cartilaginous arches
This cartilage prevents the trachea from collapsing

9. LOWER RESPIRATORY TRACT
The trachea will branch into two pathways called bronchi
These bronchi lead to the left and right lungs
Once they reach the lungs the bronchi split into even smaller tubes called bronchioles
Both the bronchi and bronchioles are lined with cilia and mucus-producing cells

10. Each bronchiole ends with a bunch of tiny sacs called alveoli
In the alveoli is where gas exchange between the lungs and the circulatory system takes place
Each alveoli is surrounded by many capillaries

13. during inhalation the alveoli are bulb shaped
when one exhales, the sacs collapse and the membranes touch
need to have a lipoprotein layer to avoid staying stuck together
respiratory distress syndrome

14. Our lungs are divided into lobes; the right lung has 3 lobes and the left has 2 lobes (to leave space for the heart)
The lungs are surrounded by a membrane called the pleural membrane which is found on the outer surface of the lung and the inner wall of the chest cavity
these membranes stick to each other

17. BREATHING AND RESPIRATION
Air needs help to flow in and out of the lungs
The diaphragm and the intercostal muscles (rib muscles) help the air move in and out
These two structures work together during inhalation and exhalation
They control the air pressure in the lungs

18. INHALATION
To help us breathe in the intercostal muscles and the diaphragm contract
This increases the space in the chest cavity which decreases the air pressure around the lungs
The lungs are drawn outwards and the air pressure in the lungs decreases
Air moves from an area of high pressure to low pressure so moves from the environment to the lungs

19. INHALATION

20. EXHALATION
The intercostal muscles and the diaphragm relax which makes the space in the chest cavity smaller
This causes the lungs size to decrease which increases the air pressure inside the lungs
The pressure is now greater inside the lungs than in the environment so the air wants to move out

21. EXHALATION

23. Exhalation
The intercostal muscles and the diaphragm relax which makes the space in the chest cavity smaller
This causes the lungs size to decrease which increases the air pressure inside the lungs
The pressure is now greater inside the lungs than in the environment so the air wants to move out

24. GAS EXCHANGE AND RESPIRATION
Respiration is a combination of external and internal respiration
External respiration happens in the lungs where gases are exchanged between the alveoli and the blood in capillaries
The air in the alveoli has a higher O2 content than the air in the blood so O2 diffuses into the blood
The air in the blood has a higher CO2 content than the air in the alveoli so CO2 diffuses into the alveoli

25. Internal respiration occurs between the blood and tissue cells in our body
O2 moves into the tissues and CO2 moves into the blood

26. Most oxygen in the blood is carried by hemoglobin which is only found in red blood cells
Very little carbon dioxide, 23%, is carried by hemoglobin (carboaminohemoglobin)
Most carbon dioxide is carried in the blood as bicarbonate ion (HCO3-), 70%
The final 7% is carried in the plasma

27. Respiratory Volume
Spirograph – graph representing the amount of air that moves into and out of the lungs

28. Tidal volume – volume of air inhaled and exhaled during a normal breath at rest
Inspiratory reserve volume – additional volume of air that can be taken in beyond a tidal inhalation
Expiratory reserve volume – additional volume of air that can be forced out beyond a tidal inhalation
Vital capacity = Tidal volume + inspiratory reserve volume + expiratory reserve volume
Residual volume – amount of gas remaining in respiratory system after full exhalation

29. GAS EXCHANGE AND RESPIRATION
Respiration is a combination of external and internal respiration
External respiration happens in the lungs where gases are exchanged between the alveoli and the blood in capillaries
The air in the alveoli has a higher O2 content than the air in the blood so O2 diffuses into the blood
The air in the blood has a higher CO2 content than the air in the alveoli so CO2 diffuses into the alveoli

31. Respiratory Disorders

32. Tonsillitis Infection of the tonsils Viral infection is more common
Tonsils can be removed through surgery

33. Laryngitis Inflammation of the larynx
Caused by viral infection, allergies and over-straining of the voice
Reduces the ability to speak normally

34. Bronchitis Inflammation of the bronchi; filled with mucus
Bacterial infection; treated by antibiotics
Exposure to irritants over a long period of time can kill the cilia causing the bronchi to be even more inflammed

35. Pneumonia Alveoli fills with liquid and becomes inflamed
Interferes with gas exchange
Bacterial and viral infection

36. Pleurisy Swelling and irritation of the pleura
Caused by viral or bacterial infections; a blood clot or cancer
Sharp, stabbing pain in the chest

37. Emphysema Walls of the alveoli break down and lose their elasticity
Affects gas exchange; breathing becomes labored
Caused by smoking; permanent and incurable

38. Cystic Fibrosis Genetic condition
Causes there to be an increase in mucus and liquids in the lungs
Contract many infections
Treated with medications, an inhaler, gene therapy

39. Asthma Obstructive lung disease of the bronchi and bronchioles
Makes breathing difficult
No cure; treated with inhalers and various medications

40. Lung Cancer Uncontrolled and invasive growth of abnormal cells
Reduce gas exchange
Most types of lung cancer are caused by smoking