1. Respiratory System

2. Introduction
The CV and Respiratory system cooperate to supply O2 and eliminate CO2

3. Introduction
The Resp. Sys. provides for gas exchange

4. Introduction
The CV transports respiratory gases

5. Introduction
Respiration is the exchange of gases between the atmosphere, blood, and cells

6. Introduction
Consists of
Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs

7. Introduction
The conducting system consists of a series of cavities and tubes –nose, pharynx, larynx, trachea, bronchi, bronchiole, and terminal bronchiole

8. Introduction
The conducting system conducts air into lungs

9. Introduction
The respiratory portion consists of the area where gas exchange occurs-respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli

10. Nose
The external portion of the nose is made of cartilage and skin and is lined with mucous membrane.

11. Nose
It is stratified squamous epithelium inside the nostrils

12. Nose
It turns into pseudostratified columnar epithelium deeper inside

13. Nose
The bony framework of the nose is formed by the frontal bone, nasal bones, and maxillae

15. Nose The internal structures of the nose are specialized for
1. warming

16. Nose
2. moistening

17. Nose
3. Filtering incoming air

18. Nose
4. Receiving olfactory stimuli

19. Nose
5. Serving as large, hollow resonating chambers to modify speech sounds

20. Nose
The space within the internal nose is called the nasal cavity.

21. Nose
It is divided into right and left sides by the nasal septum

23. Nose
The anterior portion of the cavity (nostrils) is called the vestibule

25. Pharynx
Throat

27. Pharynx
Muscular tube lined by a mucous membrane

28. Pharynx
Anatomic regions
Nasopharynx
Oropharynx
laryngopharynx

30. Pharynx
Nasopharynx functions in respiration

32. Pharynx
The oropharynx and laryngopharynx function in digestion and in respiration

34. Larynx
Voice box

36. Larynx
Passageway that connects the pharynx with the trachea

37. Larynx
It contains
1. Thyroid cartilage (Adam’s apple)

39. Larynx
2. Epiglottis (prevents food from entering the larynx)

41. Larynx
3. Cricoid cartilage (connects the larynx and trachea)

43. Swallowing
1. Larynx raises up

44. Swallowing
2. Epiglottis covers the entry into the glottis

45. Swallowing
3. The upper esophageal sphincter opens

46. Swallowing
4. Food is diverted into the esophagus

47. Voice Production
The larynx contains vocal folds (true vocal cords) which produces sound

49. Voice Production
The true cords and the space between them make up the glottis

51. Voice Production
In males, the true cords are thicker and longer

52. Voice Production
The false cords close when we clear our throat

54. Trachea
Windpipe

56. Trachea
Extends from the larynx to the primary bronchi

57. Trachea
Composed of smooth muscle and C-shaped rings of cartilage

58. Trachea
Lined with pseudostratified ciliated columnar epithelium

59. Trachea
The cartilage rings keep the airway open

60. Trachea
Cilia sweep debris away from the lungs and back to the throat to be swallowed

61. Bronchi
The trachea divides into the right and left primary bronchi

63. Bronchi
The bronchiole tree consists of the
1. trachea

65. Bronchi
2. Primary bronchi

67. Bronchi
3. Secondary bronchi

69. Bronchi
4. Tertiary bronchi

71. Bronchi
5. Bronchioles

72. Bronchi
6. Terminal bronchioles

74. Bronchi
Walls of bronchi contain rings of cartilage, which disappears distally

75. Bronchi
Walls of bronchioles contain smooth muscle only, without cartilage

76. Bronchi
The epithelium changes from ciliated pseudostratified columnar to non-ciliated simple cuboidal in the terminal bronchioles

77. Bronchi
Sympathetics release norepinephrine and epi. which stimulates beta two receptors causing bronchodilation

78. Bronchi
Parasympathetic release ACh which stimulates muscarinic ACh receptors causing bronchoconstriction

79. Lungs
Paired organs in the thoracic cavity

80. Lungs
Enclosed and protected by the pleural membrane

82. Lungs
Parietal pleura – outer layer which is attached to the wall of the thoracic cavity

84. Lungs
Visceral pleura – inner layer, covering the lungs

86. Lungs
Pleural cavity (space) – A small space between the pleurae that contains a lubricating fluid secreted by the membranes

88. Lungs
Extend from the diaphragm to just slightly superior to the clavicles

89. Lungs
Lie against the ribs anteriorly and posteriorly

90. Lungs
Right lung has three lobes

92. Lungs
The left lung has two lobes

94. Lungs
Tertiary bronchi supply segments of lung tissue called bronchopulmonary segments

95. Lungs
Each bronchopulmonary segment consists of many small compartments called lobules

96. Lungs
Lobules contain
1. lymphatics

97. Lungs
2. arterioles

98. Lungs
3. venules

99. Lungs
4. Terminal bronchioles

100. Lungs
5. Respiratory bronchioles

102. Lungs
6. Alveolar ducts

104. Lungs
7. Alveolar sacs

106. Lungs
8. alveoli

108. Alveoli
Have a surface area of 70 square meters

109. Alveoli Consists of Type I alveolar cells (simple squamous)
Type II alveolar cells (septal)
Alveolar macrophages (dust cells)

110. Alveoli
Type II alveolar cells secrete alveolar fluid which keeps the alveolar moist

111. Alveoli
The alveolar fluid contains surfactant which prevents the collapse of alveoli with each expiration

112. Alveoli
Gas exchange occurs across the alveolar-capillary (respiratory) membrane

114. Alveoli
Respiratory membrane consists of the two layers of simple squamous cells and their basement membranes

116. Pulmonary Ventilation
Breathing

117. Pulmonary Ventilation
Process by which gases are exchanged between the atmosphere and lung alveoli.

118. Inspiration
Occurs when alveolar pressure fall below atm. pressure.

119. Inspiration
Contraction of the diaphragm and external intercostal muscles increases the size of the thorax.

120. Inspiration
Thus decreasing the intrathoracic pressure so that the lungs expand.

121. Inspiration
Expansion of the lungs decreases alveolar pressure to 758 mmHg.

122. Inspiration
Air moves along the pressure gradient from atm. 760 into the lungs.

123. Expiration
Occurs when alveolar pressure is higher than atm. pressure (760).

124. Expiration
Relaxtion of the diaphragm and external intercostals results in elastic recoil of the chest wall and lungs which…..

125. Expiration
1. Increases intrathoracic pressure

126. Expiration
2. Decreases lung volume

127. Expiration
3. Increases alveolar pressure so that air moves from the lungs to the atmosphere

128. Alveolar Surface Tension
Causes the alveolar to assume the smallest diameter

129. Alveolar Surface Tension
Surface tension must be overcome to expand the lungs during each inspiration

130. Alveolar Surface Tension
It is the major component of elastic recoil, which acts to decrease the size of the alveoli during expiration

131. Alveolar Surface Tension
Surfactant decreases surface tension of the alveoli and prevents their collapse following expiration

132. Lung Volumes and Capacities
Tidal volume - amount of air inhaled or exhaled with each breath under resting conditions (500ml)

134. Lung Volumes and Capacities
Inspiratory reserve volume – Amount of air that can be forcefully inhaled after a normal tidal volume inhalation (3100)

136. Lung Volumes and Capacities
During forced inspiration the muscles sternocleidomastoid and pectoralis minor are also used

137. Lung Volumes and Capacities
Expiratory reserve volume – Amount of air that can be forcefully exhaled after a normal tidal volume exhalation (1200ml)

139. Lung Volumes and Capacities
Forced expiration employs contraction of the internal intercostals and abdominal muscles

140. Lung Volumes and Capacities
Vital capacity – Maximum amount of air that can be exhaled after a maximal inspiration (4800ml)

142. Lung Volumes and Capacities
Residual volume – Air remaining in the lungs after the expiratory reserve volume is exhaled (1200)

144. Lung Volumes and Capacities
Minute Volume of Respiration – the total volume of air taken in during one minute

145. Lung Volumes and Capacities
Minute Volume of Respiration – tidal volume x 12 respirations per minute = 6000ml/min

146. Dalton’s law
Each gas in a mixture of gases exerts its own pressure as if all the other gases were not present

147. Dalton’s law
Partial pressure of a gas – the pressure exerted by that gas in a mixture of gases

148. Dalton’s law
Partial pressure of a gas = % of the mixture represented by the gas times the total pressure

149. Dalton’s law
Total Pressure (P) = Add all the partial pressures

150. External Respiration
In internal and external respiration, O2 and CO2 diffuse from areas of their higher partial pressures to areas of their lower partial pressures

151. External Respiration
Results in the conversion of deoxygenated blood coming from the heart to oxygenated blood returning to the heart.

152. Internal Respiration
Tissue Respiration

153. Internal Respiration
The exchange of gases between tissue blood capillaries and tissue cells.

154. Internal Respiration
Results in the conversion of oxygenated blood into deoxygenated blood

155. Internal Respiration
During exercise more O2 enters tissue cells than at rest

156. Respiratory Center
Area of the brain from which nerve impulses are sent to resp. muscles

157. Respiratory Center Consists of Medullary rhythmicity area
Pneumotaxic area
Apneustic area

158. Medullary Rhythmicity Area
Controls the basic rhythm of respiration

159. Medullary Rhythmicity Area
Consists of
Inspiratory area
Expiratory area

160. Medullary Rhythmicity Area
The inspiratory area has autorhythmic neurons that set the basic rhythm of respiration

161. Medullary Rhythmicity Area
Expiratory area remains inactive during most quiet respiration but active during forced expiration

162. Medullary Rhythmicity Area
Inspiration last 2 seconds

163. Medullary Rhythmicity Area
Expiration lasts 3 seconds

164. Pneumotaxic Area
Coordinates the transition between inspiration and expiration

165. Apneustic Area
Sends impulses to the inspiratory area that activate it and prolong inspiration, inhibiting expiration

166. Cortical Influences
Allow conscious control of respiration

167. Cortical Influences
Needed to avoid inhaling noxious gasses or water

168. Chemoreceptors
Monitor levels of CO2 and O2 and provide input to resp. center

169. Central Chemoreceptors
Located in the medulla oblongota

170. Central Chemoreceptors
Respond to change in H+ concentration or PCO2 or both in cerebrospinal fluid

171. Peripheral Chemoreceptors
Located in the walls of systemic arteries

172. Peripheral Chemoreceptors
Respond to changes in H+,PCO2, and PO2

173. Hypercapnia
A slight increase in PCO2 (and H+) stimulates central chemoreceptors

174. Hypercapnia
The inspiratory area is activated and hyperventilation occurs

175. Hypocapnia
PCO2 is lower than 40 mm Hg

176. Hypocapnia
Chemoreceptors are not stimulated

177. Hypocapnia
Inspiratory area sets its own pace until CO2 accumulates

178. Hypoxia
Oxygen deficiency at the tissue level

179. Hypoxix Hypoxia
Caused by low PO2 in arterial blood

180. Hypoxix Hypoxia
Caused by high altitude, airway obstruction, fluid in lungs

181. Anemic Hypoxia
Too little functioning hemoglobin

182. Anemic Hypoxia
Caused by hemorrhage, anemia, carbon monoxide poisoning

183. Stagnant hypoxia
The inability of blood to carry oxygen to tissues fast enough to sustain their needs

184. Stagnant hypoxia
Caused by heart failure, circulatory shock

185. Histotoxic hypoxia
Blood delivers adequate oxygen to the tissues, but the tissues are unable to use it properly

186. Histotoxic hypoxia
Caused by cyanide poisoning