1. HUMAN RESPIRATORY SYSTEM
What is Breathing?
The mechanical movement of air in
and out of your lungs

2. Functions
To provide a constant supply of oxygen to keep your body cells functioning
To remove carbon dioxide from the body cells

4. Organs of the Respiratory System
1. Mouth & Nose
Brings air into the body
This is the first line of defense for the body

5. 2. Nasal cavity Warms & moistens air
Glands that produce sticky mucus line the nasal cavity
Lined with Cilia
traps dust
sweep mucus and trapped material to the back of the throat where it can be swallowed

6. 3. Pharynx
At the lower end of the pharynx is a flap of tissue called the epiglottis
covers the trachea during swallowing so that food does not enter the lungs

7. Uvula

8. 4. Larynx
“Voice box”
The airway where two folds of tissue, called vocal cords, are attached

9. 5. Trachea ( windpipe ) to protect it from Collapse and Injury
Air-conducting tube
Connects the larynx to the bronchi
Lined with mucous membranes and cilia
Contains Strong Cartilage Rings
to protect it from Collapse and Injury

10. 5. Trachea ( windpipe ) Smoking paralyzes cilia for 20 min.
Smoking increases production of mucous

11. 6. Bronchial Tubes - Bronchi
Two short tubes that branch off the lower end of the trachea
Carries air into the lungs.
Lined with some cartilage

12. 7. Bronchioles Tiny branches of air tubes in the lungs
Connect bronchi to alveoli

13. 8. Alveoli
Tiny, thin-walled, grapelike clusters at the end of each bronchiole

14. Alveoli Where carbon dioxide and oxygen exchange take place
Lined with thin moist membranes
Surrounded by capillaries (small blood vessels)
Where carbon dioxide and oxygen exchange take place

15. Alveoli Respiratory Surface MAJOR SURFACE OF GAS EXCHANGE
About 30 million Alveoli in Lung
Each Alveolus has as many as 1,800
blood capillary contacts.
MAJOR SURFACE OF GAS EXCHANGE

16. Coordination of Circulation and Gas GAS Exchange
Blood carried to the lungs has a Low Concentration of O2 and a High Concentration of CO2 compared to the air in the alveoli

17. Gas Exchange
CO2 diffuses out through the alveoli and O2 diffuses into blood

18. CO2 O2

19. Diffusion

20. 9. Diaphragm
Muscle wall between the chest and the abdomen that the body uses for breathing

21. Inhalation Active phase Diaphragm is pulled downward
Lungs expand (oxygen fills up lungs)
Ribs are pulled up and out
Chest cavity is enlarged
Pressure within the chest is reduced

22. Exhalation Passive phase Diaphragm relaxes and pushes upward
Lungs deflate (air in squeezed out)
Size of chest cavity decreases
Rib muscles relax – ribs drop
Pressure in chest cavity increases

23. Rib cage expands as rib muscles contract Rib cage gets smaller as
Fig
Rib cage
expands as
rib muscles
contract
Rib cage gets
smaller as
rib muscles
relax
Air
inhaled
Air
exhaled
Lung
Figure Negative pressure breathing
Diaphragm
INHALATION
Diaphragm contracts
(moves down)
EXHALATION
Diaphragm relaxes
(moves up)

24. The breathing rate
Mainly an involuntary process controlled by the medulla of the brain
The medulla monitors the amount of CO2 in the blood
When CO2 increases - nerve impulses are sent to the diaphragm and chest muscles to increase the rate of breathing

25. Sensors in the aorta and carotid arteries monitor CO2 concentrations in the blood
These sensors exert control over breathing

26. Cerebrospinal fluid Pons Breathing control centers Medulla oblongata
Fig
Cerebrospinal
fluid
Pons
Breathing
control
centers
Medulla
oblongata
Carotid
arteries
Figure Automatic control of breathing
Aorta
Diaphragm
Rib muscles

27. Disorders OF THE RESPIRATORY SYSTEM

28. ASTHMA
A condition in which breathing is impaired by constriction of bronchi and bronchioles, cough, and thick mucus secretions.

29. allergens ( pollen, pets, cockroach proteins) - pollutants - Infection
Asthma
Causes:
allergens ( pollen, pets, cockroach proteins)
- pollutants
- Infection
- Emotional Stress.
Treatment:
Alleviate the symptoms -
immuno-suppressors and bronchodilators

30. Bronchitis
Inflammation of the mucous membranes of the bronchi.
Causes: Associated with smoking, pollution, and bacterial or viral infections.

31. Pneumonia
Acute inflammation of the lungs.
Symptoms: high fever, chills, headache, cough, and chest pain.
Causes: Bacterial, fungal, or viral infections.
Treatment: Antibiotics or other antimicrobials.

32. Emphysema:
Permanent and irreversible destruction of alveolar walls, resulting in ……….
Loss of lung elasticity and gas exchange surface.

33. Emphysema:
Symptoms: shortness of breath, difficulty breathing, cough, weakness, anxiety, confusion, heart failure and respiratory failure.
Causes: Smoking, pollution, old age, and infections.
Treatment: Oxygen to help breathing.
No cure.

35. Tuberculosis A specific bacteria that infects the lungs.
The formation of a Tubercle and then infection results in the loss of elasticity of the capillaries around the alveoli causing poor gas exchange.

36. Lung Cancer
Cancerous tumors grow and destroy the lung tissue.
Symptoms: bloody sputum, persistent cough, difficulty breathing, chest pain
Causes: Smoking (50% of all cases) and pollution (radon, asbestos).
Treatment: Surgery is most effective, but only 50% of all lung cancers are operable by time of detection. Other treatments include radiation and chemotherapy.