Facts about Blood

What Is Blood?

Blood is one of the most important fluids in a human being's body. Blood transports oxygen and nutrition to the cells of the body and the removal of waste products from them. It further performs the function of maintaining homeostasis, protecting against diseases, and rendering service to the total organs of the body.

Knowing the composition of blood, functions, and related disorders is quite important in medical and biological studies. It helps diagnose and treat various health conditions, and hence the study is always ongoing for a healthcare professional.

Composition of Blood

The blood is composed of different constituents that play different functions. These are as follows:

Plasma

• Description: Liquid portion of blood

• Functions: Transfers nutrients, hormones, waste products

• Composition: 90% water, 10% proteins, electrolytes, nutrients

Red Blood Cells (Erythrocytes)

• Structure: Biconcave discs without nuclei

• Role: Transport of oxygen via haemoglobin

• Lifecycle: Formed in the bone marrow; living for approximately 120 days.

White Blood Cells (Leukocytes)

• Types: Neutrophils, lymphocytes, monocytes, eosinophils, basophils

• Role: Fight infections and other foreign invaders

• Disorders: Leukemia, Lymphoma

Platelets (Thrombocytes)

• Structure: Small pieces of cells

• Function: Blood coagulation to avoid loss of blood from the body.

Functions of Blood

Blood performs many vital functions in the human body:

Transport Functions

• Oxygen and carbon dioxide between the lungs and tissues.

• Nutrients from the digestive system to cells.

• Hormones and enzymes all over the body.

Regulatory Functions

• pH Balance for proper functioning of the body.

• Temperature of body

• Fluid balance

Protective Functions

• Immune protection through leucocytes

• Blood clotting by thrombocytes.

Interesting Facts About Blood (Top 10)

Some interesting facts about blood are listed below-

Fact 1 — Only Liquid Connective Tissue

The only liquid connective tissue that circulates throughout the body is blood. All essential elements, including proteins, glucose hormones, oxygen, minerals, electrolytes, and other waste products from metabolism, are also transported by it.

Fact 2 — Makes Up 7–8% of Body Weight

Approximately 7–8% of the body weight is made up of blood. The two primary components of blood are plasma and formed elements, or corpuscles, which include blood platelets, red blood cells, and white blood cells, or WBCs.

Fact 3 — Key Roles: Transport, Defence, Temperature/pH Control

Transportation, defence against external invasion, and control of body temperature and pH are among the main roles of blood.

Fact 4 — Not All Animals Have Red Blood

Humans have red blood, although the respiratory pigment, or haemoglobin, is primarily responsible for the varied blood hues of other species.

Fact 5 — Most of Blood is Plasma, Water, and Cells

Red blood cells, also known as erythrocytes, white blood cells, also known as leukocytes, blood platelets, also known as thrombocytes, and plasma, which is made up of protein, ions, and water, make up the majority of blood.

Fact 6 — WBCs Important for Reproduction

White blood cells, or leukocytes, are vital to the human reproductive system because they support a robust immune system and help the ovary's blood artery network grow.

Fact 7 — One Adult Has ~1.325 Gallons of Blood

About 1.325 gallons of blood make up an adult, healthy human body. Millions of red blood cells, thousands of white blood cells, and lakhs of blood platelets are all present in a single drop of blood.

Fact 8 — Blood Group is Inherited

Blood group is inherited genetically from our parents, just like other body traits like the eye, skin colour, and hair texture. The ABO blood type system refers to the four primary blood groups of humans: O, A, B, and AB.

Fact 9 — Blood Groups Depend on Antigens

The hereditary antigenic materials on the surface of red blood cells serve as the primary basis for differentiating these blood groups.

Fact 10 — ABO Blood Type Affects Health & Personality (Research)

Research indicates that the ABO blood type system influences a person's fertility, personality, stress levels, and other aspects of their life, as well as resulting in different nutritional needs.

Facts About Blood NEET MCQs (With Answers & Explanations)

This is an important topic and carries significant weightage in NEET exam. Types of questions asked from this topic are:

• Functions of blood

• Facts about blood

Practice Questions for NEET

Q1. Which instrument is used to determine the red cell count?

1. Haemocytometer

2. Haemoglobinometer

3. Electrocardiogram

4. Sphygmomanometer

Correct answer: 1) Haemocytometer

Explanation:

Red cell count measures the number of red blood cells in a given volume of blood. It is typically carried out using a device called a hemocytometer. A hemocytometer is a specialized microscope slide with a grid pattern etched onto its surface. By diluting a small volume of blood and placing it on the hemocytometer, the red blood cells can be counted under a microscope, allowing for the determination of the red cell count.

Explanation for incorrect options :

Option (2) The Haemoglobinometer is incorrect because it is a device used to measure the concentration of haemoglobin in the blood, not the red cell count.

Option (3) Electrocardiogram (ECG) is a diagnostic tool used to record the electrical activity of the heart, and it is not directly involved in determining red cell count.

Option (4) Sphygmomanometer is a device used to measure blood pressure, and it is not used for red cell count assessment.

Hence, the correct answer is option 1) Haemocytometer.

Q2. There is no DNA in:

1. Mature RBCs

2. Mature spermatozoan

3. Hair Root

4. An enucleated ovum

Correct answer: 1) Mature RBCs

Explanation:

As we learnt in

RBCs are formed in the red bone marrow in adults. RBCs lack nuclei in most mammals and are biconcave in shape.

- wherein

They have a red-coloured, iron-containing complex protein called haemoglobin, hence the colour and name of these cells. A healthy individual has 12-16 gms of haemoglobin in every 100 ml of blood.

Mature RBCs are devoid of nucleus and DNA is absent.

Hence, the correct answer is option 1) mature RBCs.

Q3. Assertion: Eosinophils play a role in the destruction of parasitic forms.

Reason: Eosinophils can bind to parasitic forms and induce their destruction by releasing lysosomal enzymes from their surface.

1. The assertion is true, and the reason is false.

2. The assertion is false, and the reason is true.

3. Both the assertion and reason are true and are correctly related.

4. The assertion is true, but the reason does not provide a valid explanation.

Correct answer: 3) Both the assertion and reason are true and are correctly related.

Explanation:

The assertion states that eosinophils contribute to the destruction of parasitic forms, which is true. Eosinophils are a type of white blood cell that plays a role in the immune response against parasitic infections.

The reason is that eosinophils can attach themselves to parasitic forms and initiate their destruction by releasing lysosomal enzymes from their surface. This is also true. Eosinophils have specific surface receptors that allow them to bind to parasites. Upon attachment, they release toxic granules containing enzymes, such as major basic proteins, eosinophil peroxidase, and eosinophil-derived neurotoxin, which can damage and kill the parasites.

Hence, the correct answer is option 3) Both the assertion and reason are true and are correctly related.

Also Read-

• MCQs on Composition of Blood

• Cardiac Cycle

• Facts about Blood

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