What is the primary function of ventilation in the respiratory system?
Click to see answer
Airflow in and out of the lungs.
Click to see question
What is the primary function of ventilation in the respiratory system?
Airflow in and out of the lungs.
What is the mathematical relationship expressed in Boyle's Law?
Pressure is inversely proportional to volume (P ∝ 1/V).
What is P_ip?
Intrapleural pressure; air pressure within the pleural cavity.
What is the volume of air ventilated through the lungs during quiet breathing called?
Tidal volume (V T).
What is the direction of the external intercostal muscle fibers?
Running downward and medially.
What are the external intercostal muscles responsible for?
They assist in inhalation by elevating the ribs.
How is transpulmonary pressure (P_TM) calculated?
P_TM = P_alv - P_ip.
What happens to alveolar pressure (P_alv) during inspiration?
P_alv decreases.
What is the direction of gas flow in relation to pressure?
Gases flow from high pressure to low pressure.
What happens if all air gets out of the lungs?
It implies lung collapse, which is difficult to inflate again.
What are the pressure changes in P_ip during expiration?
P_ip increases from 752 mmHg to 756 mmHg.
What is the formula for calculating vital capacity (VC)?
V T + IRV + ERV.
What distinguishes the innermost intercostal muscles from the internal intercostal muscles?
The innermost intercostal muscles are located deeper and assist in rib depression during forced expiration.
What occurs when bottle air pressure equals atmospheric pressure (P ATM) and balloon air pressure equals alveolar pressure (P alv)?
Transpulmonary pressure (P TM) is 0, causing the balloon (lung) to collapse.
What is the intrapleural pressure (P_ip) at the end of inspiration?
752 mmHg.
What is the transpulmonary pressure (P_TM) at the end of inspiration?
+8 mmHg.
Why is P_TM still positive at the end of inspiration?
To ensure the lung is not collapsed.
What is one function of the abdominal muscles?
To depress the rib cage.
What is internal respiration?
Gas diffusion between tissue cells and blood.
What is the relationship between bottle air pressure and transpulmonary pressure (P TM) when the balloon expands?
P TM is more positive.
Which muscles elevate the first two ribs?
Scalene muscles.
What is the intrapleural pressure (P_ip) at the end of expiration?
756 mmHg.
What is the extra volume of inspired air during forced inspiration called?
Inspiratory reserve volume (IRV).
What is the value of transpulmonary pressure (P_TM) at the end of inspiration?
+8 mmHg.
What are the three types of intercostal muscles involved in unforced breathing?
External intercostal, internal intercostal, and innermost intercostal muscles.
What happens to gas pressure if the concentration of gas molecules increases?
Gas pressure increases.
What is gas pressure in the context of respiration?
It refers to the force exerted by gas molecules in the lungs and atmosphere, influencing breathing mechanics.
What is the pressure difference (P_TM) at the end of inspiration?
More positive to facilitate inspiration.
What are the main abdominal muscles?
External oblique, internal oblique, rectus abdominis, and transversus abdominis.
What does P_alv represent?
Intra-pulmonary or intra-alveolar pressure; air pressure within all alveoli.
What does gas pressure represent?
The concentration of all gas molecules.
What happens to the balloon (lung) when intrapleural pressure decreases?
The balloon (lung) expands.
What does a positive P_TM indicate?
That P_alv is greater than P_ip, regardless of inspiration or expiration.
Which intercostal muscles are primarily involved in expiration?
Internal and innermost intercostal muscles.
What ribs does the Pectoralis major originate from?
1st to 6th ribs.
What is the partial pressure of N2 (PN2) in air at 760 mmHg?
PN2 = 79% × 760 mmHg = ~600 mmHg.
What is the effect of zero transpulmonary pressure (P TM)?
The balloon (lung) collapses.
What is the role of the Pectoralis major and minor in respiration?
They elevate the upper ribs.
What is the relationship between alveolar pressure (P_alv) and atmospheric pressure (P_ATM) at the end of inspiration?
P_alv = P_ATM - P_TM.
How are blood gases transported in the respiratory system?
Through the cardiovascular system between the lungs and tissues.
What is Dalton's law regarding gas mixtures?
The total pressure of a gas mixture is the sum of the partial pressures of individual gases.
What must happen to P_ip to enable lung volume decrease?
P_ip must increase.
What occurs to the diaphragm during unforced expiration?
It relaxes and returns to a dome shape to shrink the pleural cavity.
How does the flow of gases relate to the flow of particles?
Just like particles flow from high to low concentration.
What must happen to intrapleural pressure (P_ip) for lung volume to increase?
P_ip must decrease more than P_alv.
What are the names of the openings in the diaphragm?
Caval hiatus, esophageal hiatus, aortic hiatus.
How do abdominal muscles affect the diaphragm?
They squeeze the abdominal cavity to raise the diaphragm back to its dome shape.
What does Boyle's Law describe?
The relationship between volume and pressure of a gas at constant temperature.
What is the extra volume of expired air during forced expiration called?
Expiratory reserve volume (ERV).
What is the function of the internal intercostal muscles?
They run downward but laterally.
What are respiratory muscles responsible for?
They facilitate the process of breathing by contracting and relaxing to change the volume of the thoracic cavity.
What is the transpulmonary pressure (P_TM) at the end of expiration?
P_TM = P_alv - P_ATM = 760 - 756 = +4 mmHg.
What is the alveolar pressure (P_alv) at the end of inspiration?
752 mmHg.
What is the partial pressure of O2 (PO2) in air at 760 mmHg?
PO2 = 21% × 760 mmHg = ~160 mmHg.
What is the function of the Sternocleidomastoid muscle during inspiration?
It elevates the sternum.
What is the total atmospheric pressure (P_ATM) given in the text?
760 mmHg.
What does external respiration involve?
Gas diffusion between the lungs and blood.
What is the function of the internal intercostal muscles?
They aid in forced exhalation by depressing the ribs.
What happens to pressure when volume increases according to Boyle's Law?
Pressure decreases.
What is the primary muscle involved in unforced inspiration?
Diaphragm.
What ribs does the Pectoralis minor originate from?
3rd to 5th ribs.
What happens to the diaphragm during unforced inspiration?
It contracts and flattens to expand the pleural cavity.
What does transpulmonary pressure (P TM) indicate?
It is the difference between intrapulmonary pressure and intrapleural pressure, crucial for lung inflation.
What is the relationship between P_alv and atmospheric pressure (P_atm) during inspiration?
P_alv < P_atm, causing air to be drawn into the lungs.
What are the approximate percentages of oxygen and nitrogen in the atmosphere?
21% O2 and 79% N2.
What happens to lung volume during expiration?
Lung volume decreases.
What is the relationship between P_alv and P_ATM at the end of expiration?
P_alv = P_ATM, which equals 760 mmHg.
What is the change in intrapleural pressure (P_ip) during inspiration?
From 756 mmHg to 752 mmHg.
How do you calculate the partial pressure of a gas?
Partial pressure (P) = [% of gas] × total pressure (P_ATM).
What is the relationship between P_alv and P_ATM at the end of inspiration?
P_alv = P_ATM.
What is the relationship between P_alv and P_atm during expiration?
P_alv > P_atm, causing air to be pushed out of the lungs.
What is the change in intrapleural pressure (P_ip) from 752 to 756 mmHg indicative of?
It indicates a change in lung mechanics during expiration.
What is the transpulmonary pressure (P_TM) during inspiration?
P_TM = +7 mmHg.
What is the change in intrapleural pressure (P_ip) during inspiration?
P_ip decreases from 756 mmHg to 752 mmHg.
What is the transpulmonary pressure (P_TM) at the end of expiration?
+4 mmHg.
What is the atmospheric pressure (P_ATM) used in the calculations?
760 mmHg.
What happens to pressure when volume decreases according to Boyle's Law?
Pressure increases.
Which intercostal muscles are primarily involved in inspiration?
External intercostal muscles.
How does Boyle's Law relate to lung function?
It explains how the lungs inflate and deflate.
What is the transpulmonary pressure (P_TM) during expiration?
+5.
What are the pressure changes in P_alv during expiration?
P_alv increases from 760 mmHg to 761 mmHg.
What does a positive transpulmonary pressure (P TM) indicate?
It indicates that the lung is expanding.
How many openings does the diaphragm have?
Three openings.
What are the percentages of O2 and N2 in air?
Air consists of 21% O2 and 79% N2.
What is the change in alveolar pressure (P_alv) during inspiration?
P_alv decreases from 760 mmHg to 759 mmHg.
