Blood

Lymph

1. Blood is a red-colored fluid that contains RBCs. 

1. Lymph is a colorless fluid that lacks RBCs. 

2. It contains plasma, RBCs, WBCs, and platelets. It also contains proteins. 

2. It contains plasma and a lesser number of WBCs and platelets. It lacks proteins.

3. Blood transports nutrients and oxygen from one organ to another. 

3. Lymph plays a role in the defensive system of the body. It is a part of the immune system.

The open system of circulation 

The closed system of circulation 

1. In this system, blood is pumped by the heart, through large vessels, into body cavities called sinuses. 

1. In this system, blood is pumped by the heart, through a closed network of vessels. 

2. The body tissues are in direct contact with blood. 

2. The body tissues are not in direct contact with blood. 

3. Blood flows at low pressure. Hence, it is a slower and less efficient system of circulation. 

3. Blood flows at high pressure. Hence, it is a faster and more efficient system of circulation.

4. The flow of blood is not regulated through the tissues and organs. 

4. The flow of blood can be regulated by valves. 

5. This system is present in arthropods and mollusks. 

5. This system is present in annelids, echinoderms, and vertebrates. 

Systole 

Diastole 

1. It is the contraction of the heart chambers to drive blood into the aorta and the pulmonary artery. 

1. It is the relaxation of the heart chambers between two contractions. During diastole, the chambers are filled with blood.

2. Systole decreases the volume of the heart chambers and forces the blood out of them.

2. Diastole brings the heart chambers back into their original sizes to receive more blood.

P-wave 

T-wave

1. In an electrocardiogram (ECG), the P-wave indicates the activation of the SA node. 

1. In an electrocardiogram (ECG), the T-wave represents ventricular relaxation. 

2. During this phase, the impulse of contraction is generated by the SA node, causing atrial depolarization. 

2. During this phase, the ventricles relax and return to their normal state

3. It is of atrial origin. 

3. It is of ventricular origin.