Block 3 Resp Flashcards
The volume of air inhaled or exhaled with each normal breath
Tidal Volume (TV)
the volume of air that can be inhaled at the end of a normal tidal inspiration
Inspiratory Reserve volume (IRV)
the volume of air within the lungs that can be exhaled after the end of a tidal exhalation
Expiratory reserve volume (ERV)
the air remaining in the lungs after a maximal expiration (cannot be measured on spirometry and cannot be expelled)
Resdiual volume (RV)
The total volume of air remaining in the lungs at the end of a tidal exhalation
Functional Residual Capacity (FRC)- cannot be measured by spirometry
the volume of air in the lungs at the end of a maximal inspiration
Total Lung Capacity (TLC) - cannot be measured by spirometry
the volume of air exhaled from maximal inspiration to maximal exhalation; maximum expiration, when done with force this volume is termed…
Vital capacity (VC) Force Vital capacity (FVC)
the volume of air exhaled in the first second of a FVC test
forced expiratory volume in 1 second (FEV1)
Obstructive Disorder
Expiratory flow rate is decreased, decrease FEV1 & FVC
FEV1/FVC ratio is low
Restrictive disorder
Lung inflation is decreased resulting in decreased FEV1 & FVC
FEV1/ FVC ratio is normal or increased
The Max amount of O2 that can be bound to hemoglobin
Oxygen Carrying Capacity
Ratio of quantity of O2 actually bound to the quantity of O2 that can be potentially bound. 98%
Oxygen saturation
Amount of O2 actually bound to hemoglobin + dissolved O2
Oxygen Content
Anemia
defined as a decreased the RBC mass
Once O2 is bound to Hb it becomes easier for the next O2 to bind
Cooperative Binding
Blood arriving at the lungs with O2 sat of 75%
Association (loading)
Blood arrives at tissue where O2 is needed
Dissociation (unloading)- steep curve
High affinity of O2
low P50
Low affinity of O2
High P50
What diseases have a rightward shift?
Chronic hypoxia, altitude, COPD, anemia (2, 3 BPG increase)
What makes the curve shift leftward?
Carbon monoxide
Carboxyhemoglobin
CO+Hb
How is carbon dioxide transported?
- Bicarbonate
- Dissolved CO2
- Carbonate
- Carbonic acid
- Carbamino compound
What enzyme accelerates carbon dioxide transport?
Carbonic anhydrase
Haldane Effect
Higher PO2: down and to the right
-Allows blood to load more CO2 in the tissues and unload more CO2 in the lungs
Chloride Shift
Exchange of chloride for bicarbonate in RBCs
Respiratory Acidosis
- lower pH
- decrease alveolar vent
- hypoventilation
- increase PAO2
Cilia lining the airways beat the mucus covering them away from alveoli and toward the pharynx
Mucociliary escalator
What type of cells secrete surfactant?
Type 2 alveolus (pneumocytes), increases compliance, reduces surface tension
IRDS
Infant respiratory distress syndrome, low levels of surfactant in underdeveloped lungs –> ventilation failure
- use of accessory muscles of respiration
- cyanosis
- hypoxia
- tachy
- poor gas exchange
Mechanism for fall in pulmonary vascular resistance
Recruitment
Widening of capillary segments due to high compliance
Distension
Hypoventilation
Decrease alveolar ventilation, increased PaCO2
Hyperventilation
Increased alveolar ventilation, decreased PaCO2
Hypercapnia
Increased CO2 in blood
Eupnea
Normal breathing
Hypopnea
Decreased ventilation in response to lowered CO2 production
Hyperpnea
Increased ventilation in response to increased metabolic CO2 production
Tachypnea
increased frequency of breathing. Ventilation may or may not change depending on tidal volume
Dyspnea
SOB
Apnea
temporary cessation of breathing
Inspiratory Center
DRG
Intense inspiration
Expiration
VRG
Depth and duration of inspiration
Pneumotaxic center (upper pons)
