Question

Lungs are enclosed in (a) perichondrium (b) pericardium (c) pleural membrane (d) peritoneum.

Short answer

(c) pleural membrane.

Step-by-step solution

Identify the Correct Membrane for Lungs

The exercise requires knowledge of human anatomy, particularly the membranes surrounding the lungs. Among the options given, the answer is the membrane that specifically encloses the lungs within the thoracic cavity.

Eliminate Incorrect Options

Knowing that 'perichondrium' covers cartilage, 'pericardium' covers the heart, and 'peritoneum' lines the abdominal cavity, we can exclude these options as they do not pertain to the lungs.

Select the Correct Answer

With the elimination of the incorrect membranes, the remaining option that specifically encloses the lungs is the 'pleural membrane'. Therefore, option (c) is the correct answer.

Key concepts

Human Anatomy

Human anatomy is the scientific study of the structure of the human body. It is a foundational subject in medical and biological sciences that aims to provide a detailed understanding of the body's components, how they are organized, and the relationship between different structures. One key structure within human anatomy is the pleural membrane, which plays a vital role in the respiratory system.

This membrane is a double-layered serous membrane that surrounds the lungs and lines the thoracic cavity. It consists of two parts: the visceral pleura, which is attached to the surface of the lungs, and the parietal pleura, which lines the chest wall and diaphragm. The space between these two layers is called the pleural cavity, which contains a small amount of lubricating fluid to allow the lungs to move smoothly during respiration.

Thoracic Cavity

The thoracic cavity, also known as the chest cavity, is the upper part of the body's central compartment, the trunk. It is protected by the rib cage and is separated from the lower abdominal cavity by the diaphragm. This cavity is home to many vital organs, including the heart, lungs, esophagus, and major blood vessels.

The pleural membrane is an essential component within the thoracic cavity that helps to support the lungs and maintain the necessary negative pressure for lung expansion during inhalation.

Role of the Thoracic Cavity in Breathing

When we inhale, the diaphragm contracts and moves downward, enlarging the thoracic cavity's space and decreasing pressure, which allows air to enter the lungs. During exhalation, the diaphragm relaxes and moves upward, reducing the cavity's volume and pushing air out of the lungs. The pleural membrane's function is crucial in this process as it facilitates the smooth movement of the lungs against the thoracic wall.

Respiratory System

The respiratory system is composed of organs and structures that enable breathing or respiration, which includes the inhalation of oxygen and the exhalation of carbon dioxide. The main components of the respiratory system are the airways, the lungs, and the muscles of respiration, such as the diaphragm.

The lungs are the central organs of this system, with the pleural membrane playing a pivotal role in protecting them and aiding their function within the thoracic cavity. When the pleural membrane is functioning well, it allows the lungs to expand and contract without friction against the thoracic wall, hence fostering effective respiration. Disorders of the pleural membrane, such as pleural effusion or pleurisy, can significantly impact breathing and require medical attention.