1. Anatomy & Physiology II Misericordia University
Respiratory System
Anatomy & Physiology II
Tony Serino, Ph.D.
Biology Department
Misericordia University

2. Respiration External Respiration Internal Respiration
The exchange of gas between the blood and external environment (usually includes ventilation)
Internal Respiration
The exchange of gas between the blood and the tissues
Cellular Respiration
Burning of fuel to produce energy within cells
Ventilation (Breathing)
Movement of air in and out of the lungs

3. Respiratory Organs Divided into:
Upper Respiratory Tract
Includes: nostrils (nares), nasal cavity, and nasopharynx
Lower Respiratory Tract
Includes: larynx, trachea, bronchi, and lungs
Conducting Air passages include: nares to terminal bronchioles
Move air to respiratory membrane
Condition the air
Moisten, Warm, Clean

4. Upper Respiratory Tract

5. Beginning of Lower Respiratory Tract

6. Larynx

7. Trachea

8. Mucous Membrane (pseudostratified columnar epithelium)

9. Bronchi Primary bronchi lead to to each lung (left and right)
Secondary (lobar) bronchi lead to each lung lobe (3 on right and 2 on left)

10. Bronchi Branches Tertiary Bronchi Primary Bronchi Secondary Bronchi
Tertiary (segmental) bronchi lead to each lung broncho-pulmonary segment
Bronchi continue to divide at least 20 more times.

11. Broncho-pulmonary Segments

12. Right Lung
Left Lung

13. Bronchioles Air passages less than 1 mm in diameter are bronchioles.
The terminal bronchioles are the last of the purely conducting air passages.

14. Alveoli highly specialized for Gas Exchange
Lots of Surface Area
Highly vascular
Thin walls

15. Alveolus

16. P = pressure to collapse
T = surface tension
r = radius
Role of surfactant is to decrease surface tension in alveoli.

17. Pressures affecting Breathing

19. Inspiration

20. Expiration

21. Pressure changes around lung

22. Only used during rapid breathing.

23. Lung Volumes

24. Normal Lung Volumes

25. Partial Pressure Favors Resp. Gas Movement

26. Time to Complete O2 Saturation in Pulmonary Capillaries

27. Oxygen Content of Blood
PO2 = 100 mmHg
Whole Blood
Plasma
Oxygen
Oxyhemoglobin
Total Volume of Oxygen = 0.3ml Plasma + 20 ml whole blood

28. Hemoglobin

29. Oxyhemoglobin Dissociation Curve

30. Hemoglobin Affinity for Oxygen: Effect of Temperature
Affinity decreases with increasing Temperature

31. Hemoglobin Affinity for Oxygen: Effect of pH
Affinity decreases with increasing acidity (i pH)

32. Gas Exchange in Lungs

33. Gas Exchange in Tissues

34. Neural Control of Breathing
Voluntary control located in cerebral cortex and acts through the corticospinal tract. Involuntary located in pons and medulla acting through the spinal cord in the roots of the phrenic nerve (C3-C5) and thoracic cord roots of the external (inspriation(I)) and internal (expiration(E)) intercostal nerves
PRG –pontine resp. group (formerly the apneustic and pneumotaxic centers) –play role in smoothing between insp. and exp., especially during sleep, vocalization and exercise. VRG and DRG – ventral and dorsal resp. group of the medulla. DRG primarily responsible for inspiration; VRG mixture of I and E neurons contains Pre-Botzinger complex which may be pacemaker cells for respiration

35. Neural control of Breathing
PRG
Red is inhibitory
Black is excitatory
DRG
VRG
Hering-Breuer Reflex
I neurons
E neurons
Ext. Intercostals & diaphragm
Int. Intercostals
Lung Stretch
Chemoreceptors

37. Medulla sensitive to H+ directly

39. Factors Effecting Respiratory Centers

40. CO2 Drive

41. COPD