Problem 10 - Objective Biology for NEET

Question

Number of erythrocyte in \(\mathrm{mm}^{3}\) of blood are (a) \(4.5\) to 5 million (b) 5 to \(5.5\) million (c) \(5.5\) to \(6.5\) million (d) 3 million

Step-by-Step Solution

Answer

Both options (a) and (b) represent healthy erythrocyte counts per \(\mathrm{mm}^{3}\) of blood.

Step 1: Understand the Question

First, it's important to be clear on what the question is asking. It's asking about the number of erythrocytes (red blood cells) in 1 \(\mathrm{mm}^{3}\) or 1 cubic millimetre of blood, a standard measurement for blood cells.

Step 2: Refer the Factual Knowledge

In a healthy adult human, the number of erythrocytes in each cubic millimetre (mm^3) of blood is typically between 4.5 and 5.5 million.

Step 3: Match the Knowledge with the Choices

Upon checking the options, the ranges given in options (a) 4.5 to 5 million and (b) 5 to 5.5 million both fall within the general healthy range for erythrocytes in 1 mm^3 of blood.

Key Concepts

Red Blood Cells

Red blood cells, also known as erythrocytes, are the most common type of blood cell and the principal means of delivering oxygen from the lungs to all parts of the body through the blood circulatory system. These cells are shaped like tiny, flexible biconcave discs, which increases their surface area for oxygen absorption.

Hemoglobin, a protein inside red blood cells, binds to oxygen molecules and carries them to the body's tissues and organs. Red blood cells are produced in the bone marrow and have a lifespan of about 120 days. After their life cycle, they are removed from the bloodstream by the spleen.

It is essential that the body maintains an appropriate number of red blood cells. Too few can lead to a condition called anemia, while too many, a condition known as polycythemia, can cause blood thickening and various health complications.

Blood Cell Count

The blood cell count is a common test often carried out during a complete blood count (CBC) to evaluate an individual's overall health and detect a wide range of disorders, including anemia, infection, and leukemia. A blood cell count includes the number of red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes) in a certain volume of blood. The test typically uses a sample measured in cubic millimeters (mm^3) and is performed using automated machines in a laboratory.

For red blood cells, the normal count in adults typically ranges between 4.5 and 5.5 million cells per mm^3 of blood, which can vary depending on various factors such as age, sex, altitude at which one lives, and individual health. Understanding the normal range is crucial for interpreting the test results and identifying potential health issues.

Hematology

Hematology is the branch of medicine concerned with the study, diagnosis, treatment, and prevention of diseases related to the blood. Hematologists focus on understanding how blood components like red and white blood cells and platelets are produced and function, and how they can be affected by diseases.

Diseases within the realm of hematology include blood clots, anemia, hemophilia, blood cancers like leukemia, lymphomas, and myeloma. Tests such as the complete blood count (CBC) are essential tools in hematology, providing detailed information about the numbers and quality of different blood cells, allowing hematologists to assess the status of a patient's blood health and guide diagnosis and treatment. Routine hematology tests are fundamental for monitoring health, managing diseases, and guiding treatment protocols.