1. CH. 15
RESPIRATORY SYSTEM

2. Organs of respiratory system

3. Nose: initial receiving station of inhaled air
External nares nostril
Vestibule small chamber that contains hair for filtration
Nasal cavity behind vestibule
Nasal Conchae/ meati increase surface area for exposure to air
Mucous membrane blood vessels warm air and mucous moistens air Mucous traps small particle & bacteria

4. Pharynx: chamber that extends from the back of the nasal cavity to the larynx
Internal nares: posterior opening of nasal cavity
Nasopharynx superior part of pharynx
Oropharynx posterior to back of mouth
Laryngopharynx below tongue to larynx
Passage for food & air

5. Larynx: connects the pharynx and trachea (voice box)
Vocal cords: production of sound by vibrations cased by air
Cartilage
thyroid cartilage- Adam’s apple
Cricoid cartilage-below thyroid
Epiglottis cartilage-tongue shaped piece that covers larynx when swallowing

6. Trachea: tubular air duct located in front to the esophagus
Cartilage rings
provide support for tube
C shaped, open in back
Allows for expansion of esophagus when swallowing food.
Ciliated mucous membrane
move mucous that contains microorganisms & particles

7. Bronchial tree: branching of trachea that extends into the lungs
Primary bronchi: right & left branches goes to lungs
Bronchioles: smaller branches off the bronchus
Alveolar ducts: smallest tubes that end in the alveoli

8. Alveoli: round pouches that allow for the exchange of materials
million in the lungs
-Large surface area for gas exchange
-Surfactant & water allow alveolus to open & close with little effort
respiratory membrane: capillaries & alveoli together to allow for rapid gas exchange

9. Lungs: the bronchiole tree, capillary networks and supporting tissue
Characteristics
soft spongy organs
Occupy most of thoracic cavity
Apex narrow superior portion
Base broad inferior portion next to diaphragm
Root attachments of bronchus, blood vessels and nerves

10. Serous membranes surround each lung “pleurae”
Lungs cont.
Serous membranes surround each lung “pleurae”
Parietal pleura
outer layer, lines thoracic wall & mediastinum
Visceral pleura
surrounds and is firmly attached to the lung
Pleural cavity potential space between layers
Contains serous fluids that
lubricates membranes to reduce friction

11. Lungs cont. Divisions Lobes
right lung contains 3 lobes left has 2 ( heart)
Each gets one branch of bronchial tree
Divides further into segments, and lobules

12. Mechanisms of breathing

13. Pressure normal air pressure is 760mmHg
Air moves from high to low pressure
alveoli opening causes a change in air pressure
1-3 mmHg decrease allows for air to rush inward filling lungs

14. Inspiration: inhalation or breathing in
Process
diaphragm & muscle contract
2. thoracic cavity expands
3. pleural cavity pressure drops
4. lung surface is pulled outward causing lung volume to increase
5. alveolar pressure falls below normal atmospheric pressure
6. air rushes into lungs

15. Expirations: passive process of expelling or exhaling air
diaphragm and muscles relax
thoracic cavity decrease in size
pleural cavity pressure increases
alveolar pressure becomes grater than atmospheric pressure
air flow outward

16. Respiratory Volumes

17. Lung volumes Factor influencing Measurement activities
Physical differences between individuals
Health
Measurement
Spirometer
Dry vs. wet

18. Volumes
(TV)Tidal volume (500ml): amount of air moving in/out during regular breathing
(IRV) Inspiratory Reserve (3100ml): max. amount of sir that can be inhaled forcibly over TV
(ERV) Expiratory reserve (1200ml): max amount of air that can be exhaled forcibly over TV
(RV) Residual volume( 1200ml): amount of air remaining in lung after forced exhale
(VC) Vital capacity (4800ml): total amount of exchangeable air determined by the sum of the TV+ IRV + ERV= VC
(TLC)total lung capacity (6000ml): total of air in fully inflated system VC+ RV=TLC

20. Exchange of gases

21. Partial pressure pressure gas exerts
Found by multiplying air pressure by % of gas in atmosphere
N (78%), O (21%), other (1%)
Oxygen PO mmHg x 21% = 160 mmHg

22. Diffusion
Gases will diffuse independently until its partial pressure is equalized
gases dissolved in plasma only effect partial pressure ( not attached to hemoglobin)

23. External respiration alveoli & blood stream
Always a higher partial pressure O2 in alveoli that plasma
CO2 higher partial pressure in plasma than alveoli
O2 & CO2 moves across the pressure gradient easily
98% binds to hemoglobin ( oxyhemoglobin) 2% in plasma
High PO2
High PCO2

24. Internal respiration exchange between capillaries and body
Partial pressure of O2 is greater in capillaries than interstitial fluid or cells and the opposite for CO2
CO2 in the blood stream moves as bicarbonate (HCO3), CO2 & a small amount on RBCs

25. buffering in blood stream In lungs reverse order
CO2 +H20 >>>>>>>>> H2CO3 ->>> HCO H
Carbonic anhydrase carbonic acid bicarbonate
In lungs reverse order
HCO3 + H >>>>>>> H2CO3 ->>>>>>>> CO2 +H20
Bicarbonate carbonic acid Carbonic anhydrase
Removal of H ion prevents pH from changing( buffers)
If excess H ion are created by increased activity your body changes breathing rate to increase removal rate

26. Control of Breathing

27. Respiratory center medulla oblongata & pons
Medullary rhythmicity center: Rhythm of breathing
Pneumotaxic area: regulate breathing rate
Apneustic area: inhibit expiration, work in compliment to Pneumotaxic

28. Factors affecting breathing
Chemical changes in blood
Chemosensitive areas of medulla monitor CO2, O2& H-
Chemoreceptors found in aorta & corotid
Degree of stretch of lungs
Stretch receptors found in bronchiole walls
Protect from over inflation
Mental state
Involuntary: Stress, fear, or pain
Voluntary control: holding breath

29. Disease
Normal lung
Smokers lung
Heavy smoker lung