Respiratory Physiology Flashcards
Pulmonary Ventilation
Respiratory Cycle: Inspiration and Expiration
External Respiration
Occurs in the lungs where oxygen diffuses into the blood and CO2 diffuses into the alveolar air.
Internal Respiration
Occurs in the metabolizing tissues, where oxygen diffuses out of the blood and CO2 diffuses out of the cell.
Air movement
Moves from regions of high pressure to regions of low pressure.
During inspiration, the _______ contracts increasing the volume in the thoracic cavity.. This leads to a ______ in pressure in the lungs and air moves from the atmosphere into the lungs.
Ribs; Decrease
If the diaphragm relaxes then the abdominal pressure forces the diaphragm upward, and _______ pressure in the thoracic cavity beyond that of the atmospheric pressure causing air to move ______ of the lungs.
High; Out
TV
Tidal Volume Air exhaled after a normal inspiration (quiet breathing)
IRV
Inspiratory Reserve Volume Air in excess of tidal inspiration that can be inhaled with max effort. Normal: 3.3L
ERV
Expiratory Reserve Volume Air in excess of tidal expiration that can be exhaled with max effort. Normal: between 1.0 and 1.2 L
RV
Residual Volume Air remaining in the lungs after max expiration, keeps alveoli inflated. Normal: 1.1 - 1.2 L
VC
Vital Capacity Amount of air that can be exhaled with maximum effort after maximum inspiration. Influenced by the size of the thoracic cavity. VC = IRV + TV + ERV
IC
Inspiratory Capacity Max amount of air that can be inhaled after a normal (tidal) expiration.
FRC
Functional Residual Capacity Amount of air in lungs after a normal respiration (tidal)
TLC
Total Lung Capacity Max amount of air lungs can hold. Sum of all 4 lung volumes. TLC = TV + IRV + ERV + RV
Pneumothorax
Presence of air in pleural cavity. Allows lungs to recoil and collapse.
Atelectasis
Collapse of lung (or part of lung).
Spirometry
Common test used to assess how well your lungs work by measuring how much air you inhale, how much you exhale and how quickly you exhale. Used to diagnose asthma, Chronic Obstructive Pulmonary disease (COPD) and other conditions that affect breathing.
What can affect Respiratory Volumes and Capacities
Age Exercise Body Size Restrictive Disorders Obstructive Disorders
Obstructive Lung Disease
Not getting air out. Large over inflated lungs because air can’t get out. Asthma (airways spasm and close). Chronic bronchitis. Emphysema (lungs loose their elasticity).
Restrictive Lung Disease
No problem expiring air, there is just less air. Lungs can not expand (an intake problem - like having a belt across your chest) Fibrosis (tissue gets stiff) Muscular diseases (muscular dystrophy, ALS) Obesity
Hypercapnia
Too much CO2
Respiratory Acidosis
If CO2 accumulates in the bloodstream, the blood becomes acidic. pH < 7.35 - Caused by failure of pulmonary ventilation. - Corrected by hyperventilation, blows off excess CO2.
Hypocapnia
Too little CO2
Respiratory Alkalosis
Not enough CO2 in the bloodstream, and the blood becomes alkaline. pH > 7.45 - Caused by hyperventilation. - Corrected by hypoventilation. CO2 + H20 -> H2CO3 -> HCO3- + (H+) - increases H+, lowers pH to normal.
Forced Vital Capacity
AKA: Forced Expiratory Volume Maximum volume of gas expired/second during forced expiration. Exhaled from full inhalation as forcefully and rapidly as possible.
FEV1
Amount of air exhaled may be measured during first second of forced breath. Healthy adult: 75-85% in 1 sec.
Gas Exchange
CO2 + H2O H2CO3 HCO3- + (H+) H2CO3 (Carbonic Acid HC03- (Bicarbonate ion)
Buffer
Any mechanism that resists changes in pH by converting a strong acid or base into a weak one.
Chemical Buffer
A substance that binds H+ and removes it from solution as its concentration begins to rise, or releases H+ into solution as its concentration fails.
What is the importance of the carbonic acid/bicarbonate buffer system?
Keeps our bodies from becoming alkalotic or acidotic.
Hypoxia
Oxygen imbalances
Hypoxemic Hypoxia
Usually due to inadequate pulmonary gas exchange. - High altitudes - Drowning - Aspiration - Respiratory arrest - Degenerative lung disease - CO poisoning
Ischemic Hypoxia
Inadequate circulation
Anemic Hypoxia
Anemia
Histotoxic Hypoxia
Metabolic Poison (cyanide)
Cyanosis
Blueness of skin
Label the graph
- Inspiratory reserve volume
- Vital Capacity
- Inspiratory Capacity
- Tidal Volume
- Total Lung Capacity
- Functional Residual Capacity
- Expiratory Reserve Volume
- Residual Volume
Using phenol red, what color change was observed when blowing bubbles into the water?
- Pink to yellow (in acidic solutions)
- pH decreased
How successful was water in resisting pH changes when a strong acid (HCl) or a strong base (NaOH) was added?
Water didn’t resist change at all.
How does the carbonic acid buffer deal with excess acid or base?
By shifting the equation left or right accordingly. In acidic solutions, it binds more H+ to make it more basic, and in basic solutions it dissacociates H+.
