FINAL EXAM-Ch.13 Flashcards
(31 cards)
Ideal Gas Law
P=nRT/V
P=Total Pressure V=Volume of Chamber n=number of moles in gas molecules R=gas constant T= temperature in Kelvin
This states that the total pressure exerted by a gas is related to the number of moles of the gas and the volume of the chamber
Higher temperatures make molecules move faster
Partial Pressure
- Dalton’s Law of partial pressure states that in a gas mixture each gas exerts its own partial pressure
- the sums of these partial pressures in a mixture yields the total pressure of the gas mixture in a chamber
- partial pressure is proportional to the number of gas molecules.
How animals change rate of ventilation
-Animals can respond to changes in their environmental O2 or metabolic demands
- Alter rate or pattern of ventilation
- Cannot change type of ventilation; cannot change anatomy
Co-current Ventilation
- Blood flows in the SAME direction as medium
- As deoxygenated blood enters the gas exchange surface, it comes into contact with the fully oxygenated external medium
- As the blood flows through the gas exchange surface, the partial pressure of O2 gradually equilibrates between the 2 compartments
- The partial pressure of O2 in the blood approaches that of the EXHALED MEDIUM.
Countercurrent Ventilation
- Blood and medium flow in opposite directions
- Blood leaving the gas exchange surface can approach that of the INHALED medium
- As blood flows through the gas exchanger, it becomes progressively MORE OXYGENATED, whereas the medium becomes progressively DEOXYGENATED as it travels in the opposite direction
- Partial pressure gradient favors diffusion of oxygen into the blood
- MOST EFFICIENT
Conducting Zone
(Nose, Nasal Cavities, Paranasal Sinuses, Pharynx, Larynx, Trachea, Bronchi, Lungs, Alveoli)
Respiratory pathways that carry air to sites of gas exchange
Surfactant
Respiratory Membrane of The Bronchial Tree: Alvelous layers forming air-blood barrier
-TYPE I CELLS
TYPE II Cells: Scattered among type I cells- cuboidal epithelial cells that secrete a fluid—->Surfactant
- BASAL LAMINA
- CAPILLARY
Inspiration
- Action on diaphragm: Contracts and moves inferiorly and flattens- SUPEROINFERIOR EXPANSION- to lengthen vertical dimensions.
- Action of intercostal muscles: Contract to raise ribs enlarging the left-right dimensions-LATERAL EXPANSION- and the anterior-posterior diaper- ANTEROPOSTERIOR EXPANSION.
- Increased volume results in decreased pressure in pleural cavity allowing air to flow in
- Forced inspiration involves abdominal muscles
Expiration
- Passive Process
- Inspiratory muscles relax, dropping the rib cage under the force of gravity
- Diaphragm moves superiorly
- Elastic fibers recoil
- Volumes of lungs and thorax decrease simultaneously.
-Forced expiration involves abdominal muscles
Intrapleural Pressure
increase/decrease
- the pressure within the fluid of the pleural cavity
- normally sub atmospheric
- the chest wall pulls on the outer layer of the pleura and the elasticity of the lungs pulls on the inner layer of the pleura; 2 opposing forces result in the sub atmospheric pleural pressure.
Intrapulmonic Pressure
increase/decrease
- the pressure within the lungs
- between breaths, the pressure inside the lung at rest is equivalent to atmospheric pressure
- making it higher than the intrapleural pressure.
Transpulmonary Pressure
- the difference between the intrapleural pressure and the intrapulmonic pressure
- the relative low pressure outside the lungs pull the small airways and alveoli open, preventing these fragile structures from collapsing in on themselves
Pneumothorax
severe shortness of breath because of loss of the alveoli as an efficient gas exchange surface
if the pleural sac is punctured, the pressure within the pleural cavity increases, and the small airways and alveoli collapse.
Metalloproteins
- Respiratory Pigments
- Increases oxygen carrying capacity of the blood
- Types: Hemoglobin, Hemocyanin, Hemerythins
What is the most common Metalloprotein?
Hemoglobin
What will right shift the curve?
Bohr Effect or Shift
Increases in pH and decreases in PCO2 increase the oxygen affinity of a respiratory pigment, shifting the curve to the LEFT
Oxygen affinity increases. The P50 decreases
Facilitates binding of oxygen at respiratory surfaces
What will left shift the curve?
Bohr Effect or Shift
A decrease in pH (more H+ ions) or increase in PCO2 reduce the oxygen affinity of a respiratory pigment, shifting the curve to the RIGHT.
H+ ions bind to respiratory pigment at a specific site causing a conformational change which alters oxygen affinity
As oxygen affinity decreases, the P50 increases
Facilitates oxygen unloading at active tissues
[shifts/decreases affinity of respiratory pigment for oxygen, which allows unloading of oxygen to those active areas.
Carbon Monoxide
Carbon Monoxide can interfere with oxygen binding- that’s why exposure to even low levels can be fatal.
Root Effect
increase/decrease
A reduction in the oxygen carrying capacity of the pigment.
At high pH, affinity is increased; O carrying capacity of hemoglobin is increased
At low pH, affinity is decreased; oxygen is decreased; oxygen carrying capacity of hemoglobin decreased allowing it to release of oxygen into solution
Temperature
increase/decrease
increases in temperature decrease oxygen affinity; “right shift” (so shift to left if temp decreases)
(temperature and oxygen affinity have an inverse relationship)
2,3-diphosphoglycerate
increase/decrease
modulators in cases of anemia
increase in these modulators decrease oxygen affinity [right shift] (so to left if increase)
INVERSE RELATIONSHIP
Carbonic Anhydrase Action
Carbonic Anydrase catalyzes the conversion of dissolved carbon dioxide to carbonic acid, which rapidly dissociate to bicarbonate and a free proton
ways that CO2 is transported
- Transported (dissolves) in plasma (7%)
- Binds to proteins- Carbaminohemoglobin (23%)
- Transported as bicarbonate (70%)
CO2 at tissues
CO2 is produced by metabolism, and rapidly diffuses out of tissues into the RBCs
