WEEK 12 Respiratory System - MRAD 2235

These flashcards cover essential concepts related to the respiratory system, including pulmonary ventilation, gas exchange, and muscle functions during breathing.

What is the process of gas exchange within the body that supplies tissues with oxygen and disposes of carbon dioxide called?

Respiration.

What are the two main components of pulmonary ventilation?

Inspiration and expiration.

In which type of respiration does gas exchange occur between pulmonary blood and the alveoli?

External respiration.

What is the role of the diaphragm during inhalation?

It contracts, pulling the central tendon inferiorly, increasing the thoracic cavity's vertical dimensions.

How does intrapulmonary pressure change during inspiration?

It decreases.

What effect does a decrease in thoracic cavity volume have on intrapulmonary pressure during expiration?

It increases intrapulmonary pressure.

What law describes the relationship between gas pressure and volume?

Boyle's Law.

What is the formula representing Boyle's Law?

P = 1/V.

What percentage of total inspiratory volume does the diaphragm contribute?

60 - 75%.

What are the three types of intercostal muscles and their function during breathing?

External intercostals elevate ribs during inhalation; Internal intercostals and Innermost intercostals depress ribs during exhalation.

What pressure must inside the alveoli drop below for air to flow into the lungs?

Atmospheric pressure.

What is atmospheric pressure at sea level?

760 mmHg.

How does the contraction of external intercostal muscles affect the thoracic cavity during inhalation?

It increases the anterior, posterior, and lateral dimensions of the thoracic cavity.

What happens to intrapleural pressure (PIP) during inhalation?

It becomes more negative.

What is the importance of intrapleural pressure during respiration?

It allows the parietal and visceral pleura to adhere, preventing lung collapse.

What is the primary driving force for gas diffusion during external respiration?

Partial pressure gradient.

What is Dalton’s law of partial pressures?

The total pressure exerted by a mixture of gases equals the sum of the partial pressures of each individual gas.

What are the main gases and their percentage in atmospheric air?

Nitrogen (78.6%), Oxygen (20.9%), Argon (0.093%), Carbon Dioxide (0.04%).

According to Henry's Law, what factors influence the quantity of a gas that will dissolve in a liquid?

Partial pressure of the gas above the liquid and the solubility of the gas in the liquid.

What is the primary gas that diffuses from the alveoli into the blood?

Oxygen (O2).

How does the solubility of carbon dioxide compare to that of oxygen and nitrogen in blood?

CO2 is very soluble, O2 is less soluble, and N2 has very low solubility.

What is the role of surfactant in the lungs?

It reduces surface tension within the alveoli.

What occurs when gas pressure decreases in relation to dissolved gases?

Dissolved gases leave the solution.

During forced breathing, which accessory muscles assist in inhalation?

Sternocleidomastoid, Pectoralis Minor, Scalene Muscles.

What is the difference between quiet breathing and forced breathing?

Quiet breathing involves active inhalation and passive exhalation; forced breathing engages accessory muscles for both inhalation and exhalation.

How does alveolar air composition change compared to atmospheric air?

Alveolar air has less O2, more CO2, and more water vapor.

What factors, aside from partial pressure, affect gas exchange efficiency?

Surface area, diffusion barrier permeability, diffusion distance.

What effect does the elastic recoil of the lungs have on expiration?

It decreases the intrapulmonary volume.

What does the contraction of the diaphragm do to the thoracic cavity during inhalation?

It increases the vertical dimensions of the thoracic cavity.

What occurs to the intrapulmonary pressure when the thoracic cavity expands?

It decreases.

What causes the inward pull on the rib cage during expiration?

Recoil of elastic lung tissue and surface tension.

What is the relationship between partial pressures of gases in a mixture?

The partial pressure of each gas is directly proportional to its percentage in the mixture.

What muscular action occurs during passive expiration?

Relaxation of inspiratory muscles and elastic recoil of lungs.

What happens to intrapleural pressure during the respiratory cycle?

It changes, remaining subatmospheric.

What is the primary driving force for oxygen diffusion into cells during internal respiration?

Low partial pressure of oxygen in the tissue interstitial fluid.