Respiration and Ventilation Quiz

Exercise Physiology

Respiratory System

• The VD/VT ratio increases due to an increase in dead space ventilation
• At around 50% of maximum work rate, oxygen levels in muscle decrease
• Exercise-induced arterial hypoxemia (EIAH) is primarily caused by a diffusion limitation

Altitude and Pressure

• At altitude, pressure is lower compared to sea level

CO2 Levels and Exercise

• Higher intensity exercise decreases arterial CO2 levels

Gas Exchange

• The A-a (alveolar to arterial) PO2 difference increases during incremental exercise
• Venous blood saturation decreases as workload increases
• Atmospheric pressure at sea level is 760 mmHg

Exercise-Induced Arterial Hypoxemia (EIAH)

• Mild EIAH is defined as a decrease in arterial oxygen saturation (SaO2) of 3-5%

Oxygen Transport

• Oxygen (O2) mm Hg decreases from gradients to travel from atmosphere to mitochondria
• Hyperpnea is defined as an increase in ventilation that exceeds metabolic demand

Ventilation and Dead Space

• Anatomical dead space is approximately 150 mL per 10 kg of body weight
• The triphasic response refers to the three phases of ventilation during exercise
• VD/VT ratio is a measure of dead space ventilation

Minute Ventilation and Blood Gas Exchange

• Minute ventilation (VE) is calculated as tidal volume (VT) x breathing frequency (f)
• Ventilatory drift refers to the gradual increase in ventilation during prolonged exercise
• Physiological dead space is attributed to the ventilatory response
• The primary factor influencing minute ventilation (VE) is arterial PCO2

Gas Exchange and Transport

• The primary gas exchange site in the lungs is the alveoli
• It is not advisable to take a big breath every time because it can lead to respiratory acidosis

Bronchodilation and Chemoreceptors

• Bronchodilation primarily functions to increase airflow
• Peripheral chemoreceptors primarily function to sense changes in oxygen levels

Oxyhemoglobin Dissociation Curve

• The primary factor influencing the oxyhemoglobin dissociation curve is pH
• Increasing temperature shifts the oxyhemoglobin dissociation curve to the right
• The primary source of H+ that affects the body's acid-base balance is metabolic production
• The Haldane effect primarily functions to facilitate CO2 transport
• The bicarbonate buffering system primarily involves the buffering of excess H+ ions

Exercise and Acid-Base Balance

• The primary cause of hyperpnea during heavy exercise is to compensate for metabolic acidosis
• Hyperventilation primarily functions to compensate for metabolic acidosis
• Alveolar ventilation is calculated as (tidal volume - dead space volume) x breathing frequency
• Peripheral chemoreceptors function to sense changes in oxygen levels

Blood pH and Acid-Base Balance

• Normal blood pH at rest is approximately 7.4
• The oxyhemoglobin dissociation curve shifts to the right in response to increases in pH, temperature, and 2,3-DPG
• Hyperpnea refers to an increase in ventilation that exceeds metabolic demand
• The bicarbonate buffering system primarily involves the buffering of excess H+ ions