420 likes | 939 Views
Respiratory Physiology. Quiet inspiration/expiration. Forced requires accessory muscles. Torque as an example of an amphiarthroidal joint. Respiratory Rates. One Respiratory Cycle. Resting Tidal Volume. Ventilation. Diffusion. Perfusion. Perfusion. Surfactant.
E N D
Respiratory Physiology Quiet inspiration/expiration Forced requires accessory muscles
Surfactant • Protects the alveolus • Promotes air flow • Facilitates effort-free respiration
Role of Surfactant • Lung Expansion=Overcoming resistance • Alveolar surface tension needs reduction • Surface Active Solution (Surfactant) solves the problem • Reduces the surface tension of alveoli • Keeps alveolar walls from collapsing • Keeps capillary fluid from invading lungs
Measurement of Respiration Lung volumes and capacities Pressure: force of expiration Rate of flow: movement of air in and out of the lungs
Respiratory Cycle quiet tidal respiration Breath Rates Adult: 12-18 per min Newborn: 40-70 per min
Volume The Amount of Air in the Lungs
Capacities Functional Use of Volumes
Pressures of the Respiratory System • Intraoral: pressure measured within the mouth P m • Subglottic: pressure below vocal cords P s • Alveolar or Pulmonic: pressure at level of alveoli P al • Intraplural: pressure between the pleurae P pl
Pressures Related to Atmospheric Pressure • P atm =760mm, or can be referred to as 0 • P atm = P m = P s = P al during open mouth quiet respiration • P pl is always negative
Relationships of Pressures, Flows, and Volumes Contraction of the diaphragm causes a drop in intraplural and alveolar pressure which results in an increase in airflow and lung volume
Relaxation Pressure Pressures generated by the passive forces of the respiratory system. Compression resulting from gravity, untorquing of the ribs, and elastic recoil of the alveoli
Relaxation Pressure 38% of VC
Position Requirements: What would change if you were lying down?