Problem 79 - Objective Biology for NEET

Question

The blood coming out of lungs is richer than that one entering into lungs in (a) \(\mathrm{CO}_{2}\) (b) \(\mathrm{O}_{2}\) (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

(b) \(\mathrm{O}_{2}\)

Step 1: Understanding the Respiratory Process

In the respiratory process, oxygen (\(\mathrm{O}_{2}\)) is inhaled and carbon dioxide (\(\mathrm{CO}_{2}\)) is exhaled. The main responsibility of the respiratory system is to take oxygen from the air we breathe and transfer it to our bloodstream, while at the same time removing carbon dioxide from the blood to the air.

Step 2: Deductive Analysis

Once the oxygen is taken into the bloodstream, it will be taken to all parts of the body, which means that the blood leaving the lungs will have a higher concentration of oxygen than the blood entering the lungs. Similarly, the carbon dioxide will be removed from the blood in the lungs, meaning that the blood coming into the lungs has a higher concentration of \(\mathrm{CO}_{2}\) whereas the blood leaving the lungs will have less \(\mathrm{CO}_{2}\).

Key Concepts

Oxygen Transport

Oxygen transport is a vital function of the body's respiratory system. The process begins when you inhale air into your lungs. Inside the lungs, oxygen molecules diffuse into the alveoli, which are tiny air sacs.
These alveoli have thin walls that allow oxygen to pass into the neighboring blood capillaries. Once inside the capillaries, oxygen binds to hemoglobin, a protein found in red blood cells. Hemoglobin is crucial because it can carry oxygen efficiently, ensuring sufficient oxygen reaches all body tissues.
Oxygen-rich blood then travels from the lungs to the heart, which pumps it throughout the body. The cells of your body use this oxygen to produce energy, and in return, they generate carbon dioxide as a waste product. This is where the cycle continues, as deoxygenated blood carrying carbon dioxide returns to the lungs.

Carbon Dioxide Exchange

The exchange of carbon dioxide is equally important as oxygen transport in the respiratory process. After your body uses the oxygen from your blood, carbon dioxide is produced as a byproduct.
This carbon dioxide needs to be expelled from the body to maintain a healthy internal environment. The blood, now carrying the carbon dioxide, returns to the lungs.
In the lungs, carbon dioxide moves from the blood in the capillaries into the alveoli. This movement is driven by concentration gradients, as the concentration of carbon dioxide is higher in the blood than in the alveoli. Once in the alveoli, carbon dioxide is expelled from the body when you exhale. This exchange ensures that blood returning to the heart and then to the rest of the body has less carbon dioxide.

Blood Circulation

Blood circulation is essential for transporting oxygen to tissues and removing carbon dioxide from the body. The heart is at the center of this process, efficiently pumping blood through the circulatory system.
The system consists of arteries, veins, and capillaries. Arteries carry oxygen-rich blood away from the heart to various tissues. Veins bring deoxygenated blood back to the heart and eventually to the lungs.

• Arteries: Transport oxygenated blood from the left side of the heart to tissues.
• Veins: Return deoxygenated blood from tissues to the right side of the heart.
• Capillaries: Connect arteries and veins, enabling the exchange of oxygen and carbon dioxide.

The lungs play a pivotal role. They reoxygenate the blood while the heart circulates it. This synchronized function of the lungs and heart ensures tissues receive the oxygen they need and can remove carbon dioxide efficiently. Blood circulation and gas exchange are interdependent processes that keep our bodies functioning smoothly.