Respiratory Physiology

What are the two phases of pulmonary ventilation?

Inspiration and expiration

How does Boyle's Law describe the relationship between pressure and volume of a gas?

At a constant temperature, the pressure of a gas varies inversely with its volume (P1V1=P2V2)

What happens to the thoracic cavity during inspiration?

Increases as the external intercostals and diaphragm contract.

What occurs during expiration in terms of thoracic volume and gas pressure?

The thoracic volume decreases as the inspiratory muscles relax, causing gas molecules within the lungs to be forced closer together, leading to an increase in intrapulmonary pressure higher than atmospheric pressure, resulting in the flow of gases out of the lungs.

What muscles are involved in inspiration during respiration?

External intercostals and the diaphragm

What happens to the thoracic cavity during inspiration?

The size of the thoracic cavity increases

What occurs to the diaphragm during inspiration?

It flattens out

What happens to the rib cage during inspiration?

It is lifted by the external intercostals

What occurs to the thoracic and intrapulmonary volumes during expiration?

They decrease

What are bronchial sounds?

Sounds produced by air rushing through the trachea and the bronchi

What are vesicular sounds?

Sounds that result from air filling the alveolar sacs

What is the typical volume of air moved during normal quiet breathing?

About 500 ml

How can respiratory volumes be measured?

With an apparatus called a spirometer

What is the respiratory volume that represents the amount of air moving into and out of the lungs during normal quiet breathing?

Tidal volume:About 500 ml of air.

What is the respiratory volume that indicates the amount of air that can be forcibly inspired beyond the tidal volume?

Inspiratory reserve volume (IRV).

Which respiratory volume refers to the amount of air that can be expelled from the lungs after a normal tidal volume expiration?

Expiratory reserve volume (ERV).

What is the respiratory volume that remains in the lungs even after the most strenuous expiration, helping to keep the alveoli open and prevent lung collapse

Residual volume (RV).

What is Inspiratory Capacity (IC)?

The total amount of air that can be expired after a normal tidal volume expiration, the sum of TV and IRV

What is Functional Residual Capacity (FRC)?

Represents the amount of air remaining in the lungs after a normal tidal volume and the combination of RV and ERV

What is Vital Capacity (VC)?

The total amount of exchangeable air, the sum of TV, IRV, and ERV

What is Total Lung Capacity (TLC)?

The sum of all lung volumes

What is the normal range for arterial blood pH?

7.4 ± 0.02

How does carbon dioxide affect blood pH?

It combines with water to form carbonic acid.

How are H+ ions neutralized in red blood cells?

They combine with hemoglobin.

What happens if the H+ concentration in the blood rises?

H+ combines with HCO3- to form carbonic acid.

What happens to the amount of carbonic acid in the blood with hypoventilation and hyperventilation?

It can greatly be altered

What are the characteristics of Respiratory Acidosis?

Elevated CO2, decreased bicarbonate, lowered pH

What are the characteristics of Respiratory Alkalosis?

Decreased CO2, increased bicarbonate, raised pH