7 things to keep in mind while studying Body fluids and their circulation

In this topic, we will learn about the important topics which should not be neglected from NEET point of view. Of course, we’ll also be seeing into some previous year questions, which have been asked from this chapter. So let’s begin…

1. Blood

2. Blood groups

This topic is the most asked topics in NEET exams because applicative / understanding based questions can be asked from this topic. 

• Number of blood groups- (4) A, B, AB, O then there is Rh factor which makes A+, A-, B+, B-, AB+, AB-, O+, O-.
• Karl Landsteiner report first time ABO blood grouping in Human Beings. A, B and O blood groups were discovered by Landsteiner(1900) and AB blood group was found by de Castello and Steini (1902)
• Rhesus factor was also discovered by Landsteiner and Wiener in 1940 in a Rhesus monkey. A protein named rhesus antigen is present on the surface of RBC in many persons.
• Both Rh+ and Rh- individuals are phenotypically normal. The problem arises during blood transfusion and pregnancy.

PYQ- A certain road accident patient with unknown blood group needs an immediate blood transfusion. His one doctor friend at once offered his blood. What was the blood group of the donor?

     1. Blood group B                    2. Blood group AB          

     3. Blood group O                    4. Blood group A

PYQ- Person with blood group AB is considered as a universal recipient because he has

1. Both A and B antigens on RBC and no antibodies in the plasma
2. Both A and B antibodies in the plasma
3. No antigen on RBC and No antibody in plasma
4. Both A and B antigens in plasma but no antibodies

3. Coagulation of blood

Very simple questions are put up on this topic. If you understand the mechanism of blood clotting you can easily crack the questions. You just have to keep these points in your mind-

• When an injury is caused by a blood vessel bleeding starts which is stopped by a process called blood clotting and blood coagulation.
• At the sight of injury, platelets release platelet factor 3(= platelet thromboplastin) and the injured tissue also secretes Thromboplastin. These two factors combine with Ca²⁺. And form prothrombinase.
• Prothrombinase inactivates heparin and catalyzes prothrombin to produce active thrombin.
• Thrombin then, in turn, catalyzes Fibrinogen to produce
• The fibrin along with the cell corpuscles produces a clot.

PYQ- Which one of the plasma proteins is involved in coagulation of blood?

1. Albumin               2. Serum amylase             3. Globulin               4. Fibrinogen 

4. Structure of Human Heart

You just need to know the major parts of heart-

1. Names of the blood vessels and the types of blood they carry (oxygenated/ deoxygenated)
2. Name of valves
3. Name of different important nerves/nodes (SAN, AVN, Purkinje fibres, etc.)

Apart from that no other type of question can be asked from this topic. Truly, only one question has been asked on this topic so far. So there is a less chance of a question to pop up on this topic.

But please practice the diagram because if you are giving your boards this year it is very important for you to learn this diagram. 

PYQ- ‘Bundle of His’ is the part of which human organ?

1. Brain             2. Heart             3. Kidney             4. Pancreas

5. Electrocardiogram

This is an important topic because it is new for you and you need to understand the gist of this topic. So you have to study the following points-

• A normal electrogram (ECG) is composed of P wave, QRS wave (complex) and a T wave.
• The P wave is a small upward wave that represents electrical excitation or the atrial depolarization which leads to contraction of both atria.
• The QRS wave complex begins after a fraction of second of P wave. It represents ventricular depolarization (ventricular contraction).
• The T wave is dome-shaped which represents ventricular repolarization (ventricular contraction).

PYQ- The diagram given here is a standard ECG of a normal person. The P wave represents the-

1. Contraction in both the atria
2. Initiation of ventricular contraction
3. Beginning of systole
4. End of systole

6. Circulation of Blood

A diagrammatic question can be asked of this topic. So, you have to just understand the concept of Double circulation which includes Systemic circulation and Pulmonary circulation.

Systemic circulation:

The flow of oxygenated blood from the left ventricle to all parts of the body and deoxygenated blood from various body parts to the right atrium is called systemic circulation. All systemic arteries arise from the aorta. The bronchial arter­ies, which carry nutrients to the lungs, are also part of the systemic circulation.

After completing the circuit, all the veins of the systemic circulation bring deoxygenated blood into the superior vena cava, the inferior vena cava or the coronary sinus, which open into the right atrium.

Pulmonary Circulation:

The flow of deoxygenated blood from the right ventricle to the lungs and the return of oxygenated blood from the lungs to the left atrium is called the pulmonary circulation.

The pulmonary trunk arises from the right ventricle and then divides into the right pulmonary artery and left pulmonary artery which supplies deoxy­genated blood to the right and left lungs respectively. Exchange of gases takes place in the lungs. Two pulmonary veins from each lung transport the oxygenated blood to the left atrium.

7. Disorders of Circulatory System

Click on the link below to access the important lists: 

Important Chapters in Biology for NEET 2019 (Chapter-wise weightage)

 Best Preparation Tips for NEET Study

All the best!!

Team Gradeup