Introduction to Respiratory Physiology

<p>External respiration (D)</p> Signup and view all the answers

<p>Altitude levels (C)</p> Signup and view all the answers

<p>Exchange of gases between blood and tissue cells (B)</p> Signup and view all the answers

<p>It contracts and flattens (B)</p> Signup and view all the answers

<p>External intercostal muscles (C)</p> Signup and view all the answers

<p>The volume of the thoracic cavity decreases (A)</p> Signup and view all the answers

<p>Innervate the diaphragm (C)</p> Signup and view all the answers

<p>Lung pressure must be lower than atmospheric pressure for air to enter (D)</p> Signup and view all the answers

<p>Neck and shoulder muscles (B)</p> Signup and view all the answers

<p>They contract to help expand the rib cage (B)</p> Signup and view all the answers

<p>It produces a pressure difference of 1–3 mmHg. (A)</p> Signup and view all the answers

<p>External intercostal muscle (A)</p> Signup and view all the answers

<p>It is about 4 mmHg less than atmospheric pressure. (D)</p> Signup and view all the answers

<p>About 2–3 liters. (A)</p> Signup and view all the answers

<p>Involved in forced inspiration. (B)</p> Signup and view all the answers

<p>Scalene (D)</p> Signup and view all the answers

<p>The volume increases, lowering intrapleural pressure. (B)</p> Signup and view all the answers

<p>It increases both anteroposterior and lateral diameters. (B)</p> Signup and view all the answers

<p>The maximum volume of air that can be moved in and out of the lungs (C)</p> Signup and view all the answers

<p>The extra volume of air that can be inhaled during maximal inspiration (A)</p> Signup and view all the answers

<p>Residual volume (D)</p> Signup and view all the answers

<p>It indicates the volume of air left after normal expiration. (C)</p> Signup and view all the answers

<p>VC = Tidal volume + IRV + ERV (D)</p> Signup and view all the answers

<p>Intrapleural pressure and surface tension from moisture (C)</p> Signup and view all the answers

<p>Forced breathing during exercise (D)</p> Signup and view all the answers

<p>758 mmHg (D)</p> Signup and view all the answers

<p>Relaxation of the inspiratory muscles (B)</p> Signup and view all the answers

<p>Elastic fiber recoil and surface tension (A)</p> Signup and view all the answers

<p>It decreases in vertical, lateral, and anteroposterior dimensions (C)</p> Signup and view all the answers

<p>It is primarily a passive process (D)</p> Signup and view all the answers

<p>Increased lung volume which reduces pressure inside (A)</p> Signup and view all the answers

<p>An inwardly directed force that resists lung expansion (C)</p> Signup and view all the answers

<p>Lungs expand easily and require less effort for inflation (C)</p> Signup and view all the answers

<p>Airway resistance (A)</p> Signup and view all the answers

<p>Airway resistance increases as bronchioles diameter narrows (A)</p> Signup and view all the answers

<p>Presence of scar lung tissue (C)</p> Signup and view all the answers

<p>It accounts for two-thirds of the elastic recoil (D)</p> Signup and view all the answers

<p>Obstruction or collapse of airways (C)</p> Signup and view all the answers

<p>By the pressure difference divided by airway resistance (B)</p> Signup and view all the answers

<p>Because of easily stretched elastic fibers and reduced surface tension (B)</p> Signup and view all the answers

The respiratory system provides oxygen, eliminates carbon dioxide, regulates blood pH, produces speech sounds, and defends against microbes.

The process of inhaling and exhaling air.

Gas exchange between the lungs' alveoli and the capillaries.

Involves pressure and volume changes in the lungs during breathing.

Muscles that help inhale and exhale.

Air moves into the lungs when the air pressure inside the lungs is less than the air pressure in the atmosphere.

Air moves out of the lungs when the air pressure inside the lungs is greater than the air pressure in the atmosphere.

The diaphragm contracts and flattens.

The rib cage moves upwards & outwards.

The diaphragm relaxes.

The rib cage moves downwards and upwards.

The most important muscle of inhalation is the diaphragm, the dome-shaped skeletal muscle that forms the floor of the thoracic cavity.

Inhalation increases the vertical diameter of the thoracic cavity, primarily due to the diaphragm contracting and descending.

The diaphragm descends about 1 cm during quiet inhalation, creating a pressure difference of 1-3 mmHg. This allows for the inhalation of approximately 500 mL of air.

During strenuous breathing, the diaphragm descends 10 cm, generating a pressure difference of 100 mmHg. This enables inhalation of 2-3 liters of air.

Contraction of the external intercostal muscles elevates the ribs, increasing both the anteroposterior and lateral diameters of the chest cavity.

These muscles aid in forced inspiration during activities such as exercise, coughing, sneezing, and asthma.

Contraction of the scalene muscle enlarges the upper rib cage, increasing the thoracic cavity volume for inspiration.

Intrapleural pressure (pressure between the pleural layers) is always subatmospheric (lower than atmospheric pressure) during quiet inhalation.

As the diaphragm and external intercostals contract and the thoracic cavity expands, intrapleural pressure decreases due to the increased volume of the pleural cavity.

The pressure between the parietal and visceral pleurae, which is lower than atmospheric pressure due to surface tension. It's always negative, keeping the lungs inflated.

The pressure inside the alveoli drops below atmospheric pressure when the lungs expand, causing air to flow in.

Involves muscle contraction, such as the diaphragm and intercostals, to expand the chest cavity.

Doesn't require muscle contraction, instead relies on the elastic recoil of the lungs and chest wall.

Elastic recoil of chest wall and lungs, driven by stretched elastic fibers and surface tension of alveolar fluid.

The diaphragm relaxes, moving upwards and decreasing the volume of the thoracic cavity.

The ribs are depressed, helping to reduce the volume of the thoracic cavity.

Airflow and ease of breathing are affected by factors like airway resistance, lung compliance, and surface tension of the alveolar fluid.

The additional volume of air you can inhale after a normal breath, during a deep, maximal inspiration.

The extra volume of air you can exhale after a normal breath, during a forceful expiration.

The maximum volume of air you can move in and out of your lungs in one breath.

The amount of air that always remains in your lungs, even after a forceful exhalation. It cannot be directly measured.

The amount of air left in your lungs after a normal exhalation.

A force exerted by the thin layer of fluid lining the alveoli, pulling inwards due to the strong attraction between water molecules.

Surface tension must be overcome during inhalation to expand the lungs, and it also contributes to lung recoil during exhalation.

How easily the lungs and chest wall stretch during breathing.

Compliance is influenced by lung tissue elasticity and surface tension.

Conditions like scarring, fluid in the lungs, or surfactant deficiency make it harder to breathe.

The opposition to airflow through the airways, mainly due to the bronchioles.

Larger airway diameter leads to less resistance, while smaller diameter increases resistance.

These conditions increase airway resistance by narrowing or obstructing airways.

The amount of air breathed in and out during normal, quiet breathing.

Different measures of air volume in the lungs, including tidal volume, vital capacity, and residual volume.