Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
64 Cards in this Set
- Front
- Back
What is responsible for automatically adjusting the rate of Alveolar Ventilation almost exactly to the body's demands, and how is Arterial PCO2 and PO2 affected?
|
The Nervous system is responsible, thus Arterial PCO2 and PO2 are hardly modified even with moderate to intense exercise.
|
|
What is the Respiratory Center composed of and where is it located?
|
Composed of several groups of neurons:
1. Dorsal Respirator Group 2. Ventral Respiratory Group 3. Pneumotaxic Center Located bilaterally in the brain stem of the CNS - Medulla Oblongata and the Pons. |
|
Identify the part of the Respiratory Center: Responsible for inspiration or expiration depending on the nerves stimulated.
|
Ventral Respiratory Group
|
|
Identify the part of the Respiratory Center: Responsible for the rate and pattern of breathing.
|
Pneumotaxic Center
|
|
Identify the part of the Respiratory Center: Responsible for mainly inspiration.
|
Dorsal Respiratory Group
|
|
Identify the part of the Respiratory Center: Dorsally located in the Medulla Oblongata.
|
Dorsal Respiratory Group
|
|
Identify the part of the Respiratory Center: Dorsally located in the Pons.
|
Pneumotaxic Center
|
|
Identify the part of the Respiratory Center: Plays the most important role in controlling respiration.
|
Dorsal Respiratory Group
|
|
Where does the Dorsal Respiratory Group receive signals from?
|
Chemoreceptors
Baroreceptors Receptors in the Lungs |
|
What consists the Primary Inspiratory muscles?
|
Diaphragm
External Intercostals |
|
What type of signal is transmitted to the primary inspiratory muscles?
How does this function? |
Ramp Signal.
Starts from 0 and continues with a steady increase for about 2 seconds, then stops for 3 seconds and starts again thus causing a steady increase in the pulmonary volume during inspiration, instead of causing respiratory gasps. |
|
What is the duration of Expiration determined by?
|
The duration of Inspiration.
|
|
Identify the part of the Respiratory Center: Limits the duration of Inspiration and increases the respiratory rate. Strong signals reduce the time of inspiration while weak signals increase the time of inspiration.
|
Pneumotaxic Center
|
|
Identify the part of the Respiratory Center: Mostly involved in increased levels of Ventilation.
|
Ventral Respiratory Group
|
|
What is the ultimate goal of Respiration?
|
To maintain proper [H+], [O2], and [CO2] in the tissues, which is achieved by Respiratory activity.
|
|
Out of [H+], [O2], and [CO2], which ones directly stimulate the Respiratory center causing an increase of Inspiratory and Expiratory signals?
|
Increasing levels of [H+] and [CO2]
|
|
How does [O2] act to affect the Respiratory Center?
|
It does not have a direct effect but acts through the Peripheral Chemoreceptors located in the Carotid and Aortic Bodies.
|
|
What is the total pressure of a gas directly proportional to?
|
The concentration of the gas molecules.
|
|
What is the net diffusion of a gas in one direction directly proportional to?
|
The concentration gradient.
|
|
Which three gases are included in the case of Respiratory Physiology?
|
O2, CO2, N2
|
|
True or False: The rate of diffusion of each of the gases is directly proportional to the pressure cause by this gas alone, the partial pressure.
|
True
|
|
What is air comprised of?
What is the total pressure at sea level? |
79% N2 = 600 mmHg
21% O2 = 160 mmHg Total pressure at sea level: 760 mmHg |
|
Can gases that are already dissolved in H2O or Body Tissues exert pressure?
|
Yes because the dissolved molecules are moving randomly and have kinetic energy.
|
|
What two factors determine the pressure of a gas in a solution?
Which law encompasses this? |
Concentration
Solubility Coefficient Henry's Law |
|
The Solubility Coefficient is measured based on what constant factor?
|
Body Temperature
|
|
True or False: The Partial Pressure of each gas tends to force molecules of that gas into solution, first in the alveolar membrane and then in the blood of the alveolar capillaries.
|
True
|
|
True or False: The rate at which molecules escape from one medium to another is directly proportional to their partial pressure in the blood.
|
True
|
|
What is the term describing the gas pressure difference between two areas?
|
Pressure difference for diffusion
|
|
What are all the reasons for why Alveolar air hasn't got the same composition as Atmospheric air?
|
1. Alveolar air is only partially replaced (14%) with each breath.
2. O2 is going to the blood 3. CO2 is coming from the blood 4. Dry atmospheric air that enters the respiratory pathways is immediately humidified even before reaching the alveoli. |
|
Why is the slow replacement of Alveolar air important?
|
It prevents sudden changes in the gases in the blood, making the respiratory control mechanisms much more stable.
|
|
In reference to the Ventilation-Perfusion ratio normal values, list the # mmHg found for:
PO2 in: Air Alveoli Venous |
PO2 in:
Air = 159 mmHg Alveoli = 104 mmHg Venous = 40 mmHg |
|
In reference to the Ventilation-Perfusion ratio normal values, list the # mmHg found for:
PCO2 in: Air Alveoli Venous |
PCO2 in:
Air = 0.3 mmHg Alveoli = 40 mmHg Venous = 46 mmHg |
|
What does the Va/Q measure?
|
The ventilation-perfusion ratio
|
|
What does the Va and the Q stand for in the Va/Q ratio?
|
Va = Alveolar Ventilation
Q = Blood Flow |
|
If Va is 0 but Q (perfusion) is normal, what is the result of the Va/Q ratio?
Does gas exchange exist? |
Va/Q = 0
No gas exchange exists. |
|
If Va is perfect but there is 0 Perfusion, what is the result of the Va/Q ratio?
Does gas exchange exist? |
Va/Q = Infinity
No gas exchange exists. |
|
If Va/Q = 0, does ventilation exist?
What are the values for PCO2 and PO2? What are these values identical to? |
No ventilation.
PCO2 = 45 mmHg PO2 = 40 mmHg Same as Venous blood. |
|
If Va/Q = Infinity, does perfusion exist?
What are the values for PCO2 and PO2? What are these values identical to? |
No perfusion.
PCO2 = 0 mmHg PO2 = 159 mmHg Same as Inspired air. |
|
True or False: All the blood going to the lungs goes through the Alveoli.
|
False.
Around 2% of the cardiac output will go to the bronchial vessels and also some of the blood going to the alveoli goes through alveoli with abnormal Va/Q ratio. |
|
What is the term for the nonoxygenated blood that goes directly to the bronchial vessels, skipping the alveoli?
How does this affect its Va/Q? |
Physiologic Shunt
Decreases the Va/Q to below normal. |
|
What could be the result with an abnormally high Va/Q ratio?
|
There is more O2 available than can be transported and the ventilation of these alveoli is said to be wasted.
|
|
What are the two types of "wasted" ventilations?
What are they collectively known as? |
Two types:
1. When the Va/Q is high, the alveoli are said to be wasted. 2. The ventilation of the anatomical dead space areas of the respiratory pathways is said to be wasted. Together they are known as Physiologic Dead Space. |
|
How much is O2 transport increased once it's bound to Hb?
|
30-100x
|
|
How much more O2 will a person require during exercise?
|
20x more O2
|
|
During exercise, when the CO2 remains in the blood capillaries, and the oxygenation suffers, what is the safety factor?
|
The O2 diffusion through the pulmonary membrane maintains the blood almost saturated with O2.
|
|
What happens when PO2 is high in the Alveoli?
|
It will bind with Hb
|
|
What happens when PO2 is low in tissues?
|
It will be released from Hb
|
|
What is the mmHg of PO2 in the Arteries?
|
95 mmHg
|
|
What is the usual O2 saturation of Arterial blood? (%)
|
97%
|
|
Shift of O2-Hb dissociation curve: Increasing acidity?
|
Right
|
|
What are all the factors that shift the O2-Hb dissociation curve to the right?
|
Increasing [CO2]
Increasing blood Increasing Temperature Exercise Decreasing pH (increasing acidity) Abnormal Hemoglobin Acute Acidosis |
|
What are all the factors that shift the O2-Hb dissociation curve to the left?
|
Increasing pH (basicity)
Decreased [CO2] Acute Alkalosis Decreasing temperature Carboxyhemoglobin Abnormal Hemoglobin |
|
Explain the concept of Extracorporeal Gas Exchange.
|
Once O2 diffuses from the Alveoli it is transported by the blood with Hb.
(Opposite for CO2) |
|
True or False: WIth exercise, more capillaries open up to diffuse.
|
True.
|
|
How fast/slow is blood oxygenated if the Va/Q ratio is high?
|
Almost immediately.
|
|
What is the cause for the blood PO2 being 95 mmHg as it leaves the ventricle?
|
Due to the Pulmonary Shunt
|
|
How much Hb/dl is found in a normal person's blood?
|
15 Hb/dl
|
|
How many # ml of O2 can each gram of Hb bind to, maximally?
|
1.34ml of O2
|
|
Hb in 100ml of blood can combine with a total of almost exactly #ml of O2? How is this expressed when Hb is 100% saturated?
Why? |
20ml of O2
Expressed as 20 volumes per cent. Due to Hb not being pure. |
|
True or False: The O2-Hb dissociation curve can be expressed in terms of volume per cent of O2.
|
True
|
|
What is the total amount of O2 that will be bound with Hb in normal Arterial Blood?
|
O2-Hb = 19.4 ml/dl of blood
(showing a 97% O2-Hb saturation) |
|
After the O2-Hb 19.4 ml/dl of Arterial blood passes through the capillaries, how low does this value drop to?
|
14.4 ml/dl of capillary blood
(showing a 75% O2-Hb saturation) |
|
Under normal conditions, #ml of O2 is transported to the tissues by each 100ml of blood.
|
5ml of O2
|
|
True or False: Hb will maintain a constant PO2 in the tissues despite changes in the PO2 in the Alveoli.
|
True
|