1. The Respiratory System
Ms. Cohen
Anatomy & Physiology

2. The Basic Functions Organs of respiratory system are designed to:
Serve as air distributor
Gas exchanger for the body
Filters, warms and humidifies air we breathe
Accessory organs influence speech, sound, smell

3. Organs of the respiratory system
Upper respiratory tract - Nose, pharynx, larynx
Lower respiratory tract - trachea, all segments of bronchial tree, lungs

4. Respiratory Mucosa
Membrane that lines most of the air distribution tubes in the system.
Main function is to cleanse, warm and humidify inspired air.
Mucous blanket covers lining of tubes.
Microscopic cilia move materials along.

5. The NOSE Air enters thru nostrils/nares Flows into nasal cavities.
Moist from mucus and warm from blood flowing underneath.
Nerve endings in nasal mucosa smell
4 sinuses drain into nasal cavity
When nasal mucosa is inflamed - sinusitis

6. The Pharynx Often called the “throat”
Hallway for digestive and respiratory system
12.5 cm long, 3 sections
Nasopharynx - upper
Oropharynx - behind mouth
Laryngopharynx -lower

7. Pharynx, continued…
Right and left auditory or eustachian tubes open into the nasopharynx; they connect middle ears with pharynx.
Permits equalization of air pressure b/t middle and exterior ear.
Tonsils, which contribute to lymph system (defense) are embedded in mucous membrane.

8. Larynx/voice box Located just below pharynx
Composed of several pieces of cartilage
Largest is “Adams apple” (thyroid cartilage)
Vocal cords stretch across larynx
Epiglottis (cartilage) trapdoor for larynx

9. Trachea A.K.A. “windpipe” 11cm long From larynx to bronchi
Furnishes part of open passageway thru which air can reach the lungs.

10. Trachea

11. THE LUNGS!! Large organ R. lung - L. lung - R - 3 lobes, L - 2 lobes
Covered by pleura - thin, slippery membrane covering lungs (visceral pleura) and lines thoracic cavity (parietal pleura)

12. Bronchi, bronchioles, alveoli
Right and left bronchi branch from trachea -
Secondary bronchi -
Eventually branch into tiny tubes containing smooth muscle only -
primary bronchi
in each lung, bronchi branch
bronchioles

13. Alveoli Structure
Basic tube with many branches ending in millions of extremely tiny, very thin-walled sacs called ALVEOLI that specialize in gas exchange via diffusion.

14. Why do alveoli work so well?
The wall of each alveolus is made up of
Capillaries are also made up single cell layer
RESPIRATORY MEMBRANE
How many alveoli are there?
a single layer of cells
This thin layer b/t blood and air is less than 1 micron
Millions of alveoli which makes enormous SA (100 sq. meters)

15. Respiration
Pulmonary ventilation is the process that moves air into and out of the lungs.
Makes possible external respiration-
Also makes possible internal respiration,
Cellular respiration,
the exchange of gases b/t air in the lungs and blood.
exchange of gases b/t blood and cells in the body.
refers to the actual use of oxygen by cells in the process of metabolism!

16. Pulmonary Ventilation
Two phases: Inspiration - inhalation moves air into lungs and Exhalation - moves air out of lungs.
Changes in thoracic cavity result in changes in the air pressure w/i cavity and lungs
Air moves from an area where pressure is high to an area where pressure is lower.
Respiratory muscles are responsible for the changes in shape of thoracic cavity.

17. Inspiration Diaphragm contracts Increasing volume of thoracic cavity
Decreases pressure
Causes air to rush into lungs.

18. Expiration Diaphragm returns to an upward position
Reduces the volume in thoracic cavity
Air pressure increases
Forces air out of lungs

19. What about Carbon Dioxide?
Most carbon dioxide is carried as bicarbonate ion (HCO3-) in the blood
Some combines with hemoglobin to form carbaminohemoglobin
As cells remove oxygen from circulating blood, they add the waste product to it
Follows rules of diffusion

20. Air exchange
Spirometer is used to measure amount of air exchanged in breathing
This amount is referred to as the TIDAL VOLUME (TV)
We take in 500ml (pint) of air into our lungs with each inspiration and expiration

21. Ventilation Terms Vital Capacity(VC) - In normal young adults = 4800ml
Inspiratory reserve volume (IRV) -
As TV increases, the ERV and IRV decreases.
VC = TV+IRV+ERV
Residual volume (RV) =
Vital Capacity(VC) -
In normal young adults = 4800ml
Expiratory reserve volume (ERV) -
VC largest amount of air that we can breathe out in one expiration
ERV amount of air that can be forcibly exhaled after expiring TV
IRV amount of air that can be forcibly inspired over and above a normal inspiration
RV air that remains in lungs after the most forceful expiration.

22. Pulmonary Ventilation Volumes

23. Regulation of Respiration
The body makes automatic adjustments in respiration and circulation rates when it needs to
Heart beats faster, harder = pumps more blood/min.
RBC make more round trips thru body

24. How is it regulated?
Cerebral cortex can influence by modifying the rate at which neurons fire in the insp. & exp. Centers.
I.E.holding breath
Muscle control - stimulated by nervous impulses originated in respiratory control centers in medulla & pons

25. Types of Breathing Eupnea - normal respiratory rate
Hyperventilation - very rapid respiration
Hypoventilation - slow/shallow respiration
Dyspnea- labored or difficult breathing associated with hyperventilation
Orthopnea - dyspnea that is relieved by moving into an upright position
Apnea - when breathing stops

26. Chronic Obstructive Pulmonary Disease (COPD) Disorders
Chronic Bronchitis:
Emphysema:
Asthma:
chronic (ongoing) inflammation of bronchi and bronchioles
torn walls of alveoli
periodic constriction of bronchioles, often due to inflammation, triggered by stress, heavy exercise, infection, or inhaling allergens

27. ASTHMA