Chapter 22: The Respiratory System

What is the primary function of the respiratory system?

The respiratory system is responsible for ventilation of the lungs and gas exchange within the lungs.

What are the principal organs of the respiratory system?

The principal organs include the nose, pharynx, larynx, trachea, bronchi, and lungs.

What is the site of gas exchange in the lungs?

The alveoli are the site of gas exchange between the air and the blood.

What is a respiratory cycle?

One complete breath consisting of inspiration and expiration.

What are the principal muscles involved in respiration?

The diaphragm and the intercostal muscles.

How does contraction of respiratory muscles affect air inflow?

Contraction enlarges the thoracic cavity and decreases pressure inside, leading to inflow of air.

What regulates resistance to airflow in the respiratory system?

Resistance to airflow is regulated by the diameter of the bronchioles and pulmonary compliance.

What stimulates bronchodilation?

Epinephrine and sympathetic nerves (norepinephrine) stimulate bronchodilation to increase airflow.

What is pulmonary compliance?

Pulmonary compliance refers to the ease with which the lungs expand.

What role does pulmonary surfactant play in respiratory function?

Pulmonary surfactant disrupts hydrogen bonds in water, reducing surface tension and aiding alveoli expansion.

What may lack of pulmonary surfactant in premature infants lead to?

It can lead to difficulty breathing, known as infant respiratory distress syndrome.

How does oxygen move from the alveolus into the blood?

Oxygen must dissolve in the thin film of water covering the epithelium of the alveolus and then pass across the wall into the blood.

How is oxygen primarily transported in the blood?

About 98.5% of oxygen is bound to hemoglobin, with the rest dissolved in the blood plasma.

What is the utilization coefficient?

The percentage of oxygen released from hemoglobin at the systemic capillaries.

What is the majority way carbon dioxide is transported in the blood?

About 90% of carbon dioxide reacts with water to form carbonic acid, which dissociates into bicarbonate and hydrogen ions.

What is the chloride shift?

The process where bicarbonate is pumped out of the RBC in exchange for a chloride ion.

What pH range indicates acidosis?

A blood pH lower than 7.35 is called acidosis.

What is a method to correct acidosis?

Hyperventilation drives off carbon dioxide, shifting the carbonic acid reaction to the left.

What is a method to correct alkalosis?

Hypoventilating allows for accumulation of carbon dioxide, shifting the carbonic acid reaction to the right.