Gaseous Exchange and Homeostatic Control of Breathing

A set of vocabulary flashcards covering the mechanics of ventilation and the homeostatic regulation of breathing based on the provided lecture notes.

Exhalation

The breathing out of air; a passive process where the diaphragm and external intercostal muscles relax, causing the ribcage to move down and inward, which increases air pressure in the lungs.

Inhalation

The breathing in of air; an active process where the diaphragm and external intercostal muscles contract, causing the ribcage to lift and push outwards, which decreases air pressure in the lungs.

Ventilation

The exchange of air between the lungs and the atmosphere so that oxygen can be exchanged for carbon dioxide in the alveoli.

Alveoli

The tiny air sacs in the lungs.

Homeostasis

The process of maintaining a constant internal environment within the body, such as the levels of oxygen and carbon dioxide in the blood.

Spirometer

An instrument used to measure the volume of air that enters and leaves the human lungs during inhalation and exhalation.

Medulla oblongata

The respiratory centre of the brain that is stimulated when $CO_2$ levels rise, regulating the rate and depth of breathing.

Carotid artery

The location in the neck where receptor cells are stimulated by increased carbon dioxide ($CO_2$) levels in the blood.

External intercostal muscles

Muscles located between the ribs that contract to lift the ribcage during inhalation and relax during exhalation.

Diaphragm

A muscle that contracts and flattens downwards during inhalation to increase thoracic volume, and relaxes upwards during exhalation.

Negative feedback mechanism

The homeostatic process where receptor cells detect high $CO_2$ levels and send impulses to the medulla oblongata to increase breathing rate and return levels to normal.