Question

Gas exchange that occurs at the level of the tissues is called a. external respiration b. interpulmonary respiration c. internal respiration d. pulmonary ventilation

Short answer

Answer: c. Internal respiration

Step-by-step solution

a. External respiration

External respiration refers to the exchange of gases between the atmosphere and the blood in the lungs.

b. Interpulmonary respiration

Interpulmonary respiration is not a commonly used term, and it seems to be a distractor in this exercise. We will discard this option.

c. Internal respiration

Internal respiration is the exchange of gases between the blood in the capillaries and the body's tissues.

d. Pulmonary ventilation

Pulmonary ventilation is the process of moving air in and out of the lungs, allowing fresh oxygen to enter and carbon dioxide to exit. #Step 2: Identify the correct term# Now, we need to choose the option that refers to gas exchange at the level of the tissues.

Choose the correct option

From the definitions, we can see that the term 'Internal respiration' is related to gas exchange at the tissue level, so the correct answer is: c. Internal respiration

Key concepts

Gas Exchange

Gas exchange is a crucial process in the human respiratory system that allows the body to take in oxygen for cellular metabolism and expel carbon dioxide, a byproduct of that metabolism. It occurs in two primary locations: external respiration in the lungs and internal respiration in body tissues.

This process is facilitated by diffusion, where gases naturally move from an area of higher concentration to one of lower concentration:

• In external respiration, oxygen from the air in the lungs diffuses into the blood, while carbon dioxide diffuses out of the blood to be expelled. This takes place in the alveoli of the lungs, which have thin walls and a rich blood supply to maximize efficiency.
• Internal respiration occurs at the systemic capillaries, where oxygen diffuses from the blood into body tissues and carbon dioxide diffuses from the tissues back into the blood.

The efficient functioning of gas exchange is vital to ensure that cells receive the oxygen they need for energy production and that carbon dioxide does not accumulate to harmful levels in the body.

Internal Respiration

Internal respiration is the process by which oxygen is transferred from the blood to body tissues and cells, while carbon dioxide is transferred from those tissues and cells back into the blood. This exchange is critical for maintaining cellular function and overall homeostasis.

During internal respiration:

• Oxygen-rich blood travels from the lungs, through arteries, to the capillaries that surround tissues.
• Oxygen diffuses out of the blood, moving into the cells where it is needed for the production of ATP, the energy currency of the cell.
• Carbon dioxide, produced as a waste product of metabolism, diffuses from the cells into the blood. It is then transported back to the lungs for removal from the body.

Understanding internal respiration clarifies its crucial role in the body's ability to sustain life, as it directly impacts energy production and waste elimination.

Pulmonary Ventilation

Pulmonary ventilation, commonly referred to as "breathing," is the process of moving air in and out of the lungs. This process is essential for sustaining gas exchange within the lungs, where oxygen is picked up by the blood, and carbon dioxide is released for exhalation.

The mechanics of pulmonary ventilation depend on changes in pressure and volume in the thoracic cavity, accomplished through:

• Inhalation (or inspiration), where the diaphragm contracts and the rib cage expands, increasing the volume of the chest cavity and decreasing its pressure to draw air in.
• Exhalation (or expiration), where the diaphragm relaxes and the rib cage contracts, decreasing the volume of the chest cavity and increasing its pressure to push air out.

This rhythmic process is driven by the nervous system and can be influenced by physical activity, emotional state, and altitude, among other factors. Pulmonary ventilation is foundational to the entire respiratory process, enabling the sustained delivery and removal of respiratory gases.