Gas Exchanges Flashcards
what type of movement is diffusion?
passive movement, that moves down the concentration gradient
Rate of gas movement between the alveolus and blood is determined by:
- Physical property of the gas
- Surface area available for diffusion
- Driving partial pressure gradient between the alveolus and the capillary
what are factors influencing ventilation/breathing?
- air resistance
- alveolar surface tension surfactant
- Lung compliance
are the chemical bonds between O2 and hemoglobin stable or unstable?
unstable
About _____ of the O2 remains bound to hemoglobin in the venous
75%
Oxygen capacity
maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood
Oxygen content
amount of oxygen is in the blood
Oxygen saturation
percentage of all the available heme binding sites saturated with oxygen
each hemoglobin molecule can bind to how many O2 molecules?
4
Cyanosis
- the hemoglobin is depleted of oxygen, and its color change from a bright red to a bluish red
- Can result from deficient oxygen uptake in the lungs or reduced blood flow to the peripheral tissues
factors affecting oxygen dissociation
- blood temperature:
Increased blood temperature reduces hemoglobin affinity for O2 - Blood pH
Lowering of blood pH (acidic)
Caused by presence of H+ ions from lactic acid or carbonic acid reduces affinity of Hb for O2 - Carbon dioxide concentration
Higher CO2 concentration in tissue less the affinity of Hb for O2
CO2 transported to the lungs in 3 forms:
- CO2 dissolved in plasma
- Part of the compound with hemoglobin
- Part of the bicarbonate ion (mostly)
how does HCO3- make exchange?
Cl- shift
factors affecting breathing?
- Partial pressure of oxygen
- Partial pressure of CO2
- Degree of stretch of lung tissue
- Emotional state
- Level of physical activity
what receptors are involved in breathing?
mechanoreceptor and central/peripheral chemoreceptors
Respiratory areas include:
- Respiratory center of the medulla
- Respiratory group of the pons
Chemoreceptors
- Sensitive to Pco2, pH, or Po2 of the blood or cerebrospinal fluid
- Increased Pco2 = increased breathing
Baroreceptors
In the aortic or carotid sinuses sensitive to changes in blood pressures
Stretch receptors
Respond to changes in volume of the lungs
Carotid bodies
- innervated by the cranial nerve IX (glossopharyngeal)
- Respond primarily to Pco2 and secondary to pH or Pco2
Aortic bodies
- innervated by the vagus nerve (cranial nerve X)
- Have chemoreceptors similar to carotid bodies
local control of O2 delivery is made by?
- arterioles
- Local arterioles will dilate, to due relaxation of vasomotor tone
Carbon dioxide is converted into carbonic acid in the cytoplasm or red blood cells by the enzyme_____.
Hemoglobin
Carbonic anhydrase
Oxyhemoglobin
Carbon monoxide
Carbonic anhydrase
The majority of carbon dioxide is transported in the blood is _______.
Attached to the hemoglobin
Bound to oxygen
Dissolved in the plasma
Carbon monoxide in the red blood cells
Bicarbonate ions in the red blood cells
Bicarbonate ions in the red blood cells
The expansion of the lung and initiation of air in part the result for:
Muscles of the lungs relax, allowing the lungs to get larger
Decreased pressure of the intrapleural fluid
Contraction of the muscles of the diaphragm
A and B are correct
Contraction of the muscles of the diaphragm
Which of the following statements are true?
Increased Pco2 drives increased breathing
A decrease in pH increases respiratory rate
In high altitude, breathing and heart rate increases
Most of the CO2 diffuses unto the RBC
All the above
all the above
Respiratory areas are located in ______.
Pons
Medulla
Both a and b
Carotid and aortic bodies
both A and B
During the Mount Kaala hike trail which is the tallest peak, and sits 4,010 feet above sea level, will your blood pH be more acidic?
True
False
false
