Test: Respiration In Humans - Class 10 MCQ

Residual Volume is important because it prevents the lungs from collapsing. The lungs always contain a residual volume of air so that during breathing cycle there is sufficient time for oxygen to be absorbed and for the carbon dioxide to be released.

The primary function of the lung is gas exchange. The alveoli allow this gas exchange to occur. Each alveoli has a network of capillaries that carry oxygen-poor red blood cells. The capillaries bring the red blood cells very close to the air space in the alveoli. The air in the alveoli is oxygen rich. Oxygen moves from the alveolar space into the red blood cell by diffusion. This can happen very quickly because the surface are of the alveoli is large and the membranes separating the lungs from the red blood cells are very thin. The rate of oxygen diffusion is dependent on surface area, so gas exchange occurs more quickly with larger surface areas

Exhalation is the act of exhaling air taken in and is passive. The diaphragm relaxes, moving upwards into the chest cavity. During exhalation, the diaphragm moves up and ribs move downward and inward, decreasing the space in  the chest cavity, this increases the air pressure inside the lungs and forces the air out of the lungs.

Carbon Monoxide Poisoning: While carbon dioxide can readily associate and dissociate from hemoglobin, other molecules, such as carbon monoxide (CO), cannot. Carbon monoxide has a greater affinity for hemoglobin than does oxygen. Therefore, when carbon monoxide is present, it binds to hemoglobin preferentially over oxygen. As a result, oxygen cannot bind to hemoglobin, so very little oxygen is transported throughout the body. Carbon monoxide is a colorless, odorless gas which is difficult to detect.

 

The air passing through the nostrils in humans is filtered by:
The correct answer is option D: Mucus and fine hairs in the nostrils.
Explanation:
The air we breathe in through our nostrils undergoes a process of filtration to remove any impurities or particles present in the air. This filtration process is essential to protect our respiratory system from potential harm. Here's a detailed explanation of how the air is filtered:
1. Mucus: The inner lining of our nostrils contains mucus-secreting cells. Mucus is a sticky substance that helps to trap dust, pollen, bacteria, and other particles present in the air.
2. Fine Hairs (Cilia): Inside the nostrils, there are tiny hair-like structures called cilia. The cilia move in coordinated waves, transporting the mucus along with the trapped particles towards the throat. This process is known as the mucociliary escalator.
3. Nostril Surface: The innermost surface of the nostrils also plays a role in filtering the air. The surface is lined with small blood vessels and specialized cells that can detect and capture certain harmful substances present in the air.
Overall, the combination of mucus, fine hairs, and the innermost surface of the nostrils effectively filters the air we breathe, ensuring that the particles and impurities are removed before the air reaches our lungs.
Note: It is important to maintain proper hygiene, such as regular nose cleaning, to support the natural filtration process and prevent the build-up of excess mucus or blockage of the nostrils.

Gas exchange takes place in the millions of Alveoli in the lungs and the capillaries that envelop them. Inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

The pharynx is the body cavity that connects the nasal and oral cavities with the larynx and esophagus. It is commonly referred to as the throat. For the digestive system, its muscular walls function in the process of swallowing, and it serves as a pathway for the movement of food from the mouth to the esophagus.

Answer:
The correct answer is B: Rings of cartilage.
Explanation:
The air passage in the respiratory system of humans does not collapse due to the presence of rings of cartilage. These cartilage rings provide structural support and prevent the collapse of the airway during respiration. Here is a detailed explanation:
- Rings of ligament: Ligaments are fibrous connective tissues that connect bones to other bones, providing stability to joints. However, ligaments do not provide the necessary support to prevent the collapse of the air passage.
- Rings of cartilage: Cartilage is a flexible connective tissue that is more rigid than ligament but less rigid than bone. It is present in various parts of the body, including the respiratory system. The rings of cartilage in the trachea and bronchi provide structural support and prevent the collapse of the airway.
- Rings of muscular tissue: Muscular tissue is responsible for the contraction and relaxation of various body parts. While there are muscles involved in the respiratory system, such as the diaphragm and intercostal muscles, they do not form rings in the air passage to prevent collapse.
- Rings of tendons: Tendons are fibrous tissues that connect muscles to bones. They are responsible for transmitting the force generated by muscles to produce movement. However, tendons do not play a role in preventing the collapse of the air passage.
In summary, the rings of cartilage in the respiratory system of humans are responsible for providing structural support and preventing the collapse of the airway.

 

The gaseous exchange take place at alveoli. Alveoli are present on the end of the each bronchioles of the responsible site of gaseous exchange. when oxygen reaches at the alveoli, the air sacs of alveoli fulfilled with the oxygen. The capillaries that present on the wall of the alveoli traps oxygen by the help of haemoglobin. Haemoglobin present only in RBCs involves in gaseous exchange .from hete haemoglobin combines with oxygen and makes carboxyhaemoglobin.The blood runs in body tissue and provide the oxygen for every cells

Pleural membrane. A thin layer of tissue that lines the pleural cavity, the space that surrounds the lungs and lies underneath the chest wall.

Oesophagus is a part of human digestive system. Therefore, it is not a part of human respiratory system. 

The trachea, colloquially called the windpipe, is a cartilaginous tube that connects the pharynx and larynx to the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi.

Oxygen is transported from alveoli to tissues in the form of oxy haemoglobin that is an association of O2 with Hb.

In times of intense energy needs, such as during a sprint, muscles switch to anaerobic respiration because it's a much quicker way to produce energy. Lactic acid.

During the process of inhalation, ribs move upwards and the diaphragm becomes flattened. During the process of exhalation, ribs move downwards and the diaphragm becomes dome shaped. Air pressure inside the lungs increases, so, air from the lungs is automatically expelled.