1. Chap 18 The Respiratory System
Memmler’s A&P
Chap 18
The Respiratory System

2. The Respiratory System p387
Nasal cavities
Pharynx
Larynx
epiglottis
Trachea
Bronchi
Lungs
Alveoli
Pleura
Visceral pleura
Parietal pleura

3. Respiration p386
Process by which oxygen is obtained from the environment and delivered to the cells. Carbon dioxide is transported to the outside in a reverse pathway.

4. Phases of respiration p386
Pulmonary ventilation
External gas exchange
Internal gas exchange

5. Pulmonary ventilation p391 inhalation/exhalation active/passive

6. Gas exchange p393
External gas exchange
Internal gas exchange

7. Transport of Oxygen (O2) p394
98.5% of O2: carried in the blood bound to hemoglobin
Oxygenated blood is 97% saturated with O2
Deoxygenated blood is usually about 70% saturated with O2
To enter cells, O2 separates from hemoglobin
Carbon monoxide (CO) binds with hemoglobin at the same molecular sites as O2. It binds more tightly and displaces O2. This is why CO is toxic.

8. Transport of carbon dioxide (CO2) p394
CO2 is produced continuously in the tissues as a byproduct of cellular metabolism.
10% of CO2 is dissolved in plasma
15% of CO2 is combined with the protein portion of hemoglobin
75% of CO2 is transported in solution in plasma

9. CO2 p395 CO2 is involved in pH level of blood.
When CO2 goes into solution, hydrogen ions (H+) are produced.
Therefore, the blood becomes more acidic as the amount of CO2 increases to yield more H+ ions. The exhalation of CO2 shifts the blood’s pH more toward the alkaline (basic) range.

10. Regulation of respiration p395
Nervous control in medulla and pons
Chemical control
Central chemoreceptors: medulla oblongata
Monitor CO2 levels: hypercapnia triggers respiration
Primary chemical control: respiration is increased to blow off excess carbon dioxide gas

11. Regulation of respiration cont
Peripheral chemoreceptors: located in carotid arteries and aorta
Monitor O2 levels: hypoxic drive to breathe
O2 levels must fall considerably below normal before this triggers breathing

12. Abnormal ventilation p396
Hyperventilation: increase in amount of air entering alveoli
Results in increased O2 levels, decreased CO2 levels
Hypocapnia
Increase blood pH (alkalosis)
CNS excitation: dizziness, tingling, muscle twitches, ultimately paralysis

13. Abnormal ventilation p396
Hypoventilation: decrease in amount of air entering alveoli
Results in decreased O2 levels, increased CO2 levels
Hypercapnia
Decrease in blood pH (acidosis)
CNS depression: mental confusion, ultimately coma

14. Breathing patterns p396
Normal breathing rates: breaths per minute for adults
Altered breathing terms:
-pnea refers to breathing
Tachypnea
Apnea
Dyspnea
Orthopnea
Kussmaul respiration
Cheyene-Stokes respiration

15. Disorders of Respiratory system p396
Infection
Sinusitis, pharyngitis, laryngitis, bronchitis
Deviated septum
Epistaxis

16. Diseases of respiratory system p398
Pneumonia
Tuberculosis
Hay fever
Asthma
Chronic obstructive pulmonary disease (COPD)

17. COPD p399 Includes chronic bronchitis, asthma, emphysema
Obstruction to normal air flow, reduced exchange of gases, air trapping, over inflation of alveoli.
COPD patients have a hypoxic drive to breathe.

18. Sudden infant death syndrome p400
SIDS: crib death: unexplained death of seemingly healthy infant under age of 1 year.

19. Respiratory distress syndrome p400
Actelectasis: incomplete expansion of lungs

20. Lung cancer p400 Most common cause of cancer death in men and women
Most important cause: cigarette smoking

21. Disorders involving the pleura p401
Pleurisy: pleuritis: inflammation of pleura
Pneumothorax: accumulation of air in pleural space
Hemothorax: accumulation of blood in pleural space

22. Age and the respiratory tract p401
Tissues in respiratory tract lose elasticity and become more rigid.
Rigidity in chest wall, combined with arthritis and loss of strength in breathing muscles, results in overall decrease in breathing capacity.
Increased susceptibility to infection from decreased phagocytosis.
Gradual reduced capacity for exercise.

23. Respiratory treatments p402
Oxygen therapy
Suction apparatus
Artificial respiration
Bronchoscopy
Thoracentesis
Tracheostomy tube

24. Bronchoscopy p402

25. Thoracentesis

26. Tracheostomy tube p402