Question

The given diagram shows respiratory system of man.Which of the following correctly shows the functions of the parts labelled W, X, Y and Z?

• A. W - Facilitates movement of air by expansion and contraction, X - Traps dust and helps to filter inhaled air, Y - Prevents the wind pipe from collapsing, Z - Help in exchange of gases.
• B. W - Helps in gaseous exchange, X - Traps dust and helps to filter inhaled air, Y - Serves as a common passage for air and food, Z - Protect the lungs from damage.
• C. W - Prevents the wind pipe from collapsing, X - Serves as a common passage for air and food, Y - Helps in upward and downward movement of ribcage, Z - Trap dust and help to filter inhaled air.
• D. W - Facilitates movement of air by expansion and contraction, X - Helps in gaseous exchange, Y - Serves as a common passage for food and air, Z - Protect the lungs from damage.

Answer 1

Answer: (A)

Diaphragm is the muscle that separates the thoracic cavity from the abdomen. The diaphragm is the main muscle of respiration. Contraction of the diaphragm muscle expands the lungs during inspiration when breathing air in. The function of the nasal cavity is to warm, moisturize, and filter air entering the body before it reaches the lungs. Hairs and mucus lining the nasal cavity help to trap dust, mold, pollen and other environmental contaminants before they can reach the inner portions of the body. The trachea, or windpipe, is a 5-inch long tube made of C-shaped hyaline cartilage rings lined with pseudostratified ciliated columnar epithelium. The trachea connects the larynx to the bronchi and allows air to pass through the neck and into the thorax. The rings of cartilage making up the trachea allow it to remain open to air at all times. Gas exchange of oxygen and carbon dioxide takes place in the alveoli. Oxygen from the inhaled air diffuses through the walls of the alveoli and adjacent capillaries into the red blood cells. The oxygen is then carried by the blood to the body tissues.