CHP 17 - MECHANICS OF VENTILATION

respiratory system function

1. exchange of gases - between atmosphere and blood

2. homeostatic regulation of body pH

3. protection - from inhaled pathogens and irritating substances

4. vocalization

total pulmonary ventilation number

6 L/min

total alveolar ventilation number

4.2 L/min

maximal voluntary ventilation number

125-20 breaths/min

respiration rate number

12-20 breaths/min

what is eupnea

normal quiet breathing

define hyperpnea

increased respiratory rate and/or volume in response to increased metabolism (exercise)

define hyperventilation

increased respiratory rate and/or volume without increased metabolism (emotional hyperventilation)

define hypoventilation

decreased alveolar ventilation (shallow breathing; asthma)

define tachypnea

rapid breathing; panting

define dyspnea

difficulty breathing (various pathogens or hard exercise)

define apnea

breath holding

functions of airways

1. warming air to body temp

2. humidifying air (adding water)

3. filtering out foreign invaders

2 divisions of respiratory system

1. upper respiratory system

2. lower respiratory system

3 lobes of right lung

1. superior lobe

2. middle lobe

3. inferior lobe

2 divisions of left lung

1. superior lobe

2. inferior lobe

function of pleural fluid

• encloses the lungs

• lowers friction between membranes

• holds lungs tight against thoracic wall

what is boyles law

• describes inverse relationship of pressure and volume

• P1V1 = P2V2

define ventilation

movement of air

define respiration

gas exchange during ventilation

what is a respiratory cycle

1 inspiration followed by an expiration

4 lung volumes

1. tidal volume (VT)

2. inspiratory reserve volume (IRV)

3. expiratory reserve volume (ERV)

4. residual volume (RV)

define tidal volume

volume that moves during a respiration cycle

define inspiratory reserve volume (IRV)

additional volume above tidal volume

define expiratory reserve volume (ERV)

forcefully exhaled after the end of a normal expiration

define residual volume

volume of air in the respiratory system after maximal exhalation

equation for vital capacity

VT + IRV + ERV

equation for total lung capacity

VC + RV

equation for inspiration capacity

VT + IRV

equation for functional residual capacity

RV + ERV

boyle’s law

P1V1=P2V2

2 types of alveoli cells and function

1. type 1 alveolar cells - gas exchange

2. type 2 alveolar cells - produce surfactant

features of surfactant

• reduces surface tension

• improves lung compliance

• stabilizes alveoli

• aids in gas exchange

total pulmonary ventilation equation

VE= VT x Bf

VE = tidal volume x breathing frequency

define hypoventilation

• occurs when breathing is too shallow

• alveolar ventilation decreases

• build up of CO2

define hyperventilation

• occurs when breathing to fast

• alveolar ventilation increases

• too much CO2 being removed

what is anatomic dead space

air that enters the respiratory system and doesn’t reach alveoli (trachea and bronchi)