Respiratory System Physiology Quiz

The movement of air through airways and alveoli, driven by pressure differences.

Oxygen and carbon dioxide diffusion between alveoli and bloodstream, requiring good blood flow and hemoglobin.

Oxygen and carbon dioxide movement in blood and fluids to and from body tissues, reliant on cardiovascular system and hemoglobin.

Volume of air moved with each breath.

Number of breaths per minute.

Increased breathing rate and depth beyond metabolic needs leading to excess CO2 removal.

Increased breathing rate, but not necessarily depth.

Increased breathing rate and depth matching metabolic needs (e.g., exercise).

A cessation of air movement through the airways and alveoli, which can be temporary or permanent.

A temporary stoppage of breathing during sleep lasting for many seconds, often recurring.

A complete and irreversible cessation of breathing due to medical issues like stroke or trauma.

The sensation of difficulty breathing.

Difficulty breathing caused by underlying medical conditions like cardiovascular or pulmonary disease.

The physical processes involved in air movement into and out of the lungs.

The primary muscle for inspiration at rest, contracting and flattening to increase lung volume.

Muscles that assist with breathing during exercise or increased respiratory demand.

A condition where vocal cords involuntarily close during physical activity, causing a high-pitched breathing sound (stridor).

A treatment approach for EILO that aims to improve the voluntary control of vocal cord muscles.

Muscle activity involved in breathing requires energy (ATP). This energy demand is increased during exercise.

Increased breathing rate and depth during exercise require greater effort from respiratory muscles.

Prolonged, intense muscle activity can lead to limitations in exercise tolerance, increased resting energy expenditure, and decreased respiratory muscle function.

The medulla oblongata in the brainstem houses the respiratory center, responsible for regulating breathing patterns.

The medulla's respiratory center includes the dorsal respiratory group (DRG), ventral respiratory group (VRG), and pontine respiratory group (PRG).

The DRG sets the basic rhythm of breathing, the VRG controls accessory muscle activation, and the PRG fine-tunes breathing patterns.

The primary control center for inspiration, responsible for generating the normal rhythm of breathing. It's active during quiet breathing and also during heavy ventilation, working with the diaphragm and external intercostals to increase air intake.

This group is primarily inactive during normal breathing but becomes crucial during intense ventilation. It assists in inspiration, especially when your body requires more oxygen (e.g., during exercise). It activates accessory muscles like neck and shoulder muscles for deeper breaths.

This center within the pons gradually increases inspiration by stimulating the dorsal respiratory group, leading to a smooth and gradual increase in breath depth. It's responsible for the ‘respiratory ramp’ which gradually increases inspiration.

Located in the pons, this center plays a critical role in regulating the rate and depth of breathing by sending signals to the dorsal respiratory group. It essentially tells the body 'stop inhaling.' It also receives input from the lungs about their expansion.

During the initial phase of the Valsalva maneuver, increased intrathoracic pressure compresses the vena cava, squeezing blood into the right atrium, leading to a temporary increase in venous return. This activates the Bainbridge reflex causing an increase in heart rate.

The Valsalva maneuver also increases pressure on the coronary arteries, temporarily decreasing blood supply to the heart muscle. While this is usually not a problem for healthy individuals, it can be problematic for those with pre-existing coronary artery issues, potentially causing problems with muscle contraction.

The increased pressure on the aorta during the Valsalva maneuver creates a greater resistance for the left ventricle to pump blood against, increasing its workload (afterload).

This reflex, activated by increased pressure in the right atrium, results in increased heart rate. This helps the heart pump out the extra blood that's been pushed into the right atrium due to increased venous return.

When the heart has to pump against increased resistance (afterload) and also pumps out more blood per beat (increased stroke volume), it has to work harder.

Coronary arteries supply blood to the heart muscle. If they are blocked, the heart muscle might not get enough blood, especially when it's working harder due to increased afterload and stroke volume.

A damaged or weakened heart muscle may not be able to pump strongly enough to overcome increased afterload, even with increased stroke volume.

A forced exhalation against a closed airway increases pressure in the chest cavity, squeezing blood from the vena cava. This leads to decreased venous return to the heart momentarily.

Continued holding of breath maintains the increased chest pressure, making it hard for blood to get back to the heart, leading to decreased cardiac output. This phase is problematic for individuals with heart issues.

After releasing the breath-holding, the chest pressure returns to normal, allowing blood to flow back to the heart again.

Individuals with heart conditions should avoid performing Valsalva maneuvers, as the low cardiac output and reduced blood flow to the heart can cause fainting (syncope) or further heart damage.

The Valsalva maneuver can worsen blood flow to the heart, especially in individuals with narrowed coronary arteries (atherosclerosis).

Phase 3 sees a decrease in intrathoracic pressure on coronary arteries, allowing for increased blood flow. This could potentially dislodge a plaque or clot, increasing the risk of a heart attack.

Intrathoracic pressure returns to normal, allowing the accumulated blood from Phase 3 to enter the right atrium. This increases right atrial pressure, triggering the Bainbridge reflex, and causes a surge of blood to the right ventricle.

As blood from the right atrium enters the right ventricle in Phase 4, ventricular contractility increases due to increased blood volume. This leads to a rapid rise in cardiac output and systolic blood pressure, potentially dislodging clots or rupturing aneurysms.

The increased ventricular contractility during Phase 4 of the Valsalva maneuver leads to a higher demand for oxygen by the heart muscle, which is met by the increased blood supply to the coronary arteries.

The larynx and carina of the trachea are sensitive to mechanical and chemical stimuli that will trigger a cough.

Afferent nerve impulses travel from the vagus nerve to the medulla, initiating a cough response.

The cough reflex involves rapid inspiration followed by forceful abdominal and intercostal muscle contraction, while the epiglottis closes and vocal cords shut tightly.

Cartilage decreases as you move down the airways, with the trachea having the most and bronchioles having none.

The bronchioles have the greatest resistance to airflow because they have smooth muscle that can constrict, and lack cartilage for support.

Airway resistance decreases during inspiration because lung inflation pulls the airways open.

Airway resistance increases during expiration because lung deflation compresses the airways.

Bronchoconstriction is caused by the parasympathetic nervous system, particularly by acetylcholine.

Bronchodilation is caused by the sympathetic nervous system, particularly by neuroepinephrine and epinephrine.

Inflammation increases airway resistance by causing swelling in the airway walls and thickening of the airway lining, narrowing the passage.

Blockages inside the airway lumen, such as mucus, tumors, or foreign objects, restrict airflow and increase resistance.

Medications that widen the airways by activating β-adrenergic receptors, making breathing easier.

Anti-inflammatory medications delivered directly to the lungs to reduce swelling and inflammation.

The lungs become stiffer, requiring more effort to inflate and making breathing difficult.

The pressure exerted by a specific gas in a mixture, directly related to the amount of that gas dissolved in a liquid.

Partial pressure of oxygen, usually referring to the oxygen we breathe in.

Fraction of oxygen in the air, which remains relatively constant regardless of altitude.

Fraction of oxygen in the air we breathe in, potentially controlled for clinical purposes.

A higher rate of energy expenditure due to increased effort needed for breathing, especially in conditions like decreased lung compliance.

Gases move from areas of high partial pressure to areas of low partial pressure. This means oxygen moves from the alveoli into the blood, and carbon dioxide moves from the blood into the alveoli.

Factors affecting gas exchange include: concentration gradients, surface area, and membrane permeability.

A smaller difference in partial pressure between the alveoli and blood makes gas exchange less efficient. This can occur at high altitudes or with lung diseases.

A smaller surface area for gas exchange reduces the efficiency of the process. This can occur with fluid buildup, blockages, or damage to the alveoli.

Any factor that impedes the movement of gases across the alveoli-blood barrier will limit gas exchange.

Oxygen is carried in the blood primarily bound to hemoglobin (97%) and a smaller amount dissolved in plasma (3%).

Most carbon dioxide is transported in the blood as bicarbonate (70%), while a smaller amount binds to hemoglobin (95%) and a very small amount dissolves in plasma.

Pulse oximetry only measures hemoglobin saturation, not total hemoglobin amount. It cannot differentiate between oxygen and other molecules bound to hemoglobin, and can be affected by skin pigmentation.

Increased levels of carbon dioxide in the blood (hypercapnia) stimulate increased ventilation, leading to faster and deeper breathing.

Carbon monoxide binds to hemoglobin, preventing oxygen binding. Despite high hemoglobin saturation, pulse oximetry will not detect oxygen deficiency.

High melanin levels in skin can interfere with pulse oximetry readings, causing them to appear higher than actual saturation.

At low hemoglobin saturation, melanin's interference becomes more significant, potentially masking true severity.

Blood gas levels, particularly carbon dioxide (CO2), play a critical role in regulating breathing. High CO2 levels stimulate increased ventilation.

This occurs due to conditions like fluid buildup in alveoli, fluid in the interstitial space, or scar tissue formation, ultimately making gas exchange less efficient.

This refers to the optimal balance between air flow (ventilation) and blood flow (perfusion) in the lungs, ensuring efficient gas exchange.

During exercise, pulmonary blood flow significantly increases (more than 4x) due to more open capillaries and distended capillaries, resulting in lower vascular resistance.

Air that enters the respiratory system but does not participate in gas exchange. This air is removed first during exhalation, making it harder to expel gases from the alveoli.

Areas in the respiratory system where gas exchange cannot occur. This includes the nose, trachea, bronchi.

Alveoli where there is insufficient perfusion to allow for efficient gas exchange.

A blood clot in a pulmonary vessel restricts blood flow, leading to inadequate perfusion and inefficient gas exchange. This causes an increase in resistance for the right side of the heart.

The movement of oxygen and carbon dioxide throughout the body, via the blood, to and from tissues.