Respiratory system- Gas exchange in the body

phys and anatomy

Internal Respiration

The exchange of gases between the blood in the systemic capillaries and the cells or tissues of the body.

External Respiration

The exchange of gases between the alveoli in the lungs and the blood.

Partial Pressure

The concentration of a specific gas in a mixture of gases, expressed as a value.

Oxygen Saturation

The percentage of hemoglobin molecules in the blood that are bound to oxygen.

What is the average amount of oxygen consumed by the body per minute?

250 mL.

What percentage of oxygen from the air that reaches the alveoli is diffused into the blood?

Approximately 250 mL.

What does the oxygen dissociation curve indicate?

The relationship between the partial pressure of oxygen and the oxygen saturation of hemoglobin.

Haldane Effect

Describes how oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin, increasing carbon dioxide removal.

What is the role of chemoreceptors in respiration?

They respond to changes in blood gases and pH, adjusting the rate and depth of breathing.

How does temperature affect the hemoglobin-oxygen dissociation curve?

Increased temperature shifts the curve to the right, decreasing hemoglobin's affinity for oxygen.

Mechanoreceptors

Receptors located in the lungs that respond to the stretch during inspiration and help prevent over-inflation.

What is the primary function of the medulla oblongata in respiration?

It contains the dorsal respiratory group (DRG) and ventral respiratory group (VRG) responsible for the rhythm of breathing.

What does the reverse chloride shift during gas exchange in the lungs accomplish?

Allows bicarbonate ions to re-enter red blood cells, facilitating the release of carbon dioxide for exhalation.

Bicarbonate Ions Formation

Carbon dioxide reacts with water to form carbonic acid, which dissociates into bicarbonate ions and hydrogen ions.

What is the daily consumption of oxygen by an average adult body?

360,000 mL.

What does the term 'chloride shift' refer to?

The movement of bicarbonate ions out of red blood cells and chloride ions into red blood cells to maintain electrical neutrality.

What factors can shift the oxygen dissociation curve?

pH, temperature, and carbon dioxide levels.

How much carbon dioxide is transported in the blood as bicarbonate ions?

About 86-90%.

What effect does decreased pH have on the hemoglobin-oxygen dissociation curve?

It shifts the curve to the right, decreasing hemoglobin's affinity for oxygen.

What are the effects of acidosis on hemoglobin function?

Decreases hemoglobin's affinity for oxygen, facilitating unloading into tissues.

Arterial Blood

Oxygenated blood with a higher partial pressure of oxygen (~100 mm Hg), resulting in hemoglobin being about 98.5% saturated.

Venous Blood

Deoxygenated blood with a lower partial pressure of oxygen (~40 mm Hg), resulting in hemoglobin being about 75% saturated.

What is the primary function of the respiratory system?

To facilitate the exchange of oxygen and carbon dioxide between the body and the environment.

What are alveoli?

Tiny air sacs in the lungs where gas exchange occurs.

What is tidal volume?

The amount of air inhaled or exhaled during normal respiration.

What is vital capacity?

The maximum amount of air that can be exhaled after a maximum inhalation.

What is the significance of surfactant in the lungs?

Surfactant reduces surface tension in the alveoli, preventing collapse and maintaining stability.

What is the role of carbon dioxide in respiration?

Carbon dioxide is a waste product of metabolism that needs to be expelled from the body.

How does exercise affect oxygen consumption?

Oxygen consumption increases during exercise to meet the higher metabolic demands of the body.

What is the primary role of hemoglobin in respiration?

To transport oxygen from the lungs to body tissues and facilitate carbon dioxide transport back to the lungs.

What is respiratory rate?

The number of breaths taken per minute.

What is the effect of hyperventilation on blood gases?

It can lead to decreased carbon dioxide levels (hypocapnia) and increased blood pH (respiratory alkalosis).