1. 3.2 Respiratory System

2. What is Human Respiration?
The human respiratory system allows one to obtain oxygen, and eliminate carbon dioxide.
Breathing consists of two phases, inspiration and expiration
Inspiration- the process of taking in air
Expiration- the process of blowing out air

3. Functions of the Respiratory System
Breathing process
Exchange of Oxygen and Carbon Dioxide
Enable speech production

4. Internal Respiration All cells require oxygen for metabolism
All cells require means to remove carbon dioxide
Gas exchange at cellular level

5. External Respiration Ventilation Gas Exchange in pulmonary capillaries
exchange of air between lungs and atmosphere
Gas Exchange in pulmonary capillaries
Breathing largely involuntary activity

6. Structure and Function
Gas exchange
Bringing oxygen into the body
Getting rid of carbon dioxide

7. Organs in the Respiratory System
STRUCTURE
FUNCTION
nose / nasal cavity
 warms, moistens, & filters air as it is inhaled
pharynx (throat)
 passageway for air, leads to trachea
larynx
 the voice box, where vocal chords are located
trachea (windpipe)
 keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs
bronchi
 two branches at the end of the trachea, each lead to a lung
bronchioles
 a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs
alveoli
 the functional respiratory units in the lung where gases are exchanged

8. Nose nasal cavity nasal septum mucous membrane mucus cilia
olfactory receptors

9. Pharynx Nasopharynx oropharynx laryngopharynx
adenoids or pharyngeal tonsils
oropharynx
palatine tonsils
laryngopharynx
larynx

10. Epiglottis
oropharynx and laryngopharynx serve as a common passageway for both food and air
epiglottis acts as a lid or flap that covers the larynx and trachea (airway) so food does not enter the lungs.

11. Larynx voice box larynx glottis (vocal apparatus)
vocal bands or vocal cords

12. Trachea Windpipe or airway mucous membrane lining with cilia
smooth muscle with c-shaped cartilage rings
divides into two branches: bronchi
no gaseous exchange

13. Bronchi Bronchus, singular c-shaped cartilage rings with smooth muscle
each bronchi divides into bronchioles
terminate in air sacs called alveoli

14. Thoracic Cavity thoracic thorax mediastinum heart aorta esophagus
bronchi
thymus

15. Alveoli
air sacs
alveolar wall membranes one cell thick and surrounded by capillaries
gaseous exchange takes place here

16. Lungs
Right-3 lobes
Left-2 lobes
trachea

17. Pleura each lung enclosed in pleura parietal pleura (inner)
visceral pleura (outer)
pleural space or pleural cavity
lubricating fluid

18. Tissues of the Respiratory System
epithelial tissue that lines the trachea and bronchi produce mucus (traps dirt).
epithelial tissue also has cilia (microscopic hair-like structures) to move mucus and foreign material out.
trachea (windpipe) is supported by rings of cartilage (connective tissue) – keeps it open for air to flow freely

19. Breathing
involves the diaphragm (a large sheet of muscle underneath the lungs) and the muscles between the ribs.
an involuntary process that we can override while talking but only temporarily
controlled by a part of the human brain that detects the concentration of CO2 in our blood

20. Respiratory Cycle Respiration rate is the number of breaths per minute
Human respiration rate is controlled by a part of the brain called the medulla
Sends signals to adjust levels of oxygen present in your body by changing your breathing rate

21. Air Pathway
air enters through the nostrils (air is filtered by nose hair) ↓
nasal cavity (air is warmed and humidified)
pharynx (throat)
larynx (voicebox)
trachea (windpipe)
bronchi (there are 2, each leads to 1 lung)
bronchioles
alveoli (clusters of air sacs with a very large surface area, surrounded by capillaries)

22. Main Parts of the Respiratory System
Trachea (windpipe)
tube that takes air from the back of the throat down to the lungs

23. Main Parts of the Respiratory System
Bronchi
as the trachea approaches the lungs it splits into two bronchi, one bronchus leads to each lung
continues splitting into small bronchiole tubes ending in the alveoli
Label”:
nasal cavity
Mouth
pharynx
trachea
Bronchus
lung
bronchioles

24. Main Parts of the Respiratory System
Alveoli (singular: alveolus)
millions of alveoli provide a large total surface area for greater absorption of gases
a thin, single layer of flattened cells are on the wall of each alveolus to decrease the distance that gases need to diffuse across
a dense network of capillaries (tiny blood vessels) surrounding the alveolus remove CO2 from the blood and absorb O2
Hemoglobin, the protein found in red blood cells, pick up O2 from the alveoli to transport to the rest of the body

25. Gas Exchange
the circulatory system provides a good blood supply the lungs
the concentration of O2 in the blood that flows through the lungs is always less than the concentration of O2 in the air in the alveoli, therefore O2 always diffuses from alveoli into the blood.
Talk about concentration gradient.
Diffusion from area of high concentration to low concentration

26. Disorders of the Respiratory System

27. Malfunctions & Diseases of the Respiratory System
asthma
severe allergic reaction characterized by the constriction of bronchioles
 bronchitis
inflammation of the lining of the bronchioles
emphysema
condition in which the alveoli deteriorate, causing the lungs to lose their elasticity
pneumonia
condition in which the alveoli become filled with fluid, preventing the exchange of gases
lung cancer
irregular & uncontrolled growth of tumors in the lung tissue

28. Asthma
Some contaminants in some people will trigger inflammation of the airways, i.e. asthma.
People with asthma inhale corticosteroids (using “puffers”) to reduce the inflammation.

29. Tuberculosis (TB) infectious disease – easily spread
caused by bacteria in the lungs
general symptoms: fever, cough, weight loss, fatigue, and chest pain.
diagnosed by a chest X-ray.
problem: TB bacteria can remain dormant for many years – waiting for the immune system to be compromised to take over.
however, once detected, the disease can be successfully treated with medicine and/or a few weeks hospitalization

30. SARS (Severe Acute Respiratory Syndrome)
disease of the respiratory system
symptoms: flu-like (high fever), shortness of breath, dry cough, sore throat, headache, muscle pain, and exhaustion.

31. Lung Cancer
tobacco use – first and second-hand smoking is detrimental to the respiratory system
contains carcinogens (cancer-causing chemicals)

32. HOMEWORK
“What is Breathing and Respiration?” Package
Pg. 107 #1-5