Respiratory PhysiologyRespiratory Physiology

Quiet inspiration/expiration

Forced requires accessory

muscles

Torque as an Torque as an example of an example of an

amphiarthroidal amphiarthroidal jointjoint

Respiratory Respiratory RatesRates

One Respiratory CycleOne Respiratory Cycle

Resting Resting Tidal Tidal

VolumeVolume

VentilationVentilation

Diffusion

PerfusionPerfusion

PerfusionPerfusion

SurfactantSurfactant

•Protects the alveolus

•Promotes air flow

•Facilitates effort-free respiration

Role of SurfactantRole 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 RespirationMeasurement of Respiration

Lung volumes and capacities

Pressure: force of expiration

Rate of flow: movement of air in and out of the lungs

Respiratory Cycle Respiratory Cycle quiet tidal respirationquiet tidal respiration

Breath Rates Adult: 12-18 per min Newborn: 40-70 per min

Volume Volume The Amount of Air in the The Amount of Air in the

LungsLungs

Capacities Capacities Functional Use of VolumesFunctional Use of Volumes

Volumes and CapacitiesVolumes and Capacities

Respiratory Respiratory VolumesVolumes

Respiratory PressuresRespiratory Pressures

Volumes and PressuresVolumes and Pressures

Pressures of the Respiratory Pressures of the Respiratory SystemSystem

Intraoral: pressure Intraoral: pressure measured within the measured within the mouth P mmouth P m

Subglottic: pressure Subglottic: pressure below vocal cords P below vocal cords P ss

Alveolar or Alveolar or Pulmonic:Pulmonic:

pressure at level of pressure at level of alveoli P alalveoli P al

Intraplural: pressure Intraplural: pressure between the pleurae between the pleurae P pl P pl

Pressures Related to Pressures Related to Atmospheric PressureAtmospheric 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 Relationships of Pressures, of Pressures,

Flows, and Flows, and VolumesVolumes

Contraction of the diaphragm causes a drop in intraplural and alveolar pressure which results in an increase in airflow and lung volume

Relaxation PressureRelaxation 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 PressureRelaxation Pressure

38% of VC

Muscular Muscular Activity, Activity, Aveolar Aveolar

Pressure Pressure and and

Lung Lung VolumeVolume

Loudness and Syllable Stress Requirements

Position Requirements: What would change if you were lying down?

Volume Volume RequirementsRequirements