NEET Biology Body Fluids and Circulation

SYNOPSIS

• Blood is a fluid connective tissue made of plasma and cellular elements. 
  
  
  

  Plasma	Cellular elements
  Water Proteins Minerals Clotting factors	RBCs	WBCs		Platelets
  		Granulocytes	Agranulocytes
  		Eosinophils basophils Neutrophils	Lymphocytes Monocytes

• According to the ABO blood group system, there are four blood groups—A, B, AB and O. O type of blood is called a universal donor, and AB type of blood is called a universal recipient.
  
  
• Lymph is a tissue fluid which supplies oxygen and nutrients and also has a role in the defence mechanism
  
  
• Hearts in Vertebrates
  
  

  Fish	Amphibians & Reptiles	Birds
  Two-chambered heart	Three-chambered heart	Four-chambered heart
  One atrium, one ventricle	Two atria, one ventricle	Two atria, two ventricles

• Cardiac Cycle

• During each cardiac cycle, approximately 70 ml of blood is pumped out of each ventricle which is called the stroke volume.
  
  
• ECG or electrocardiogram is the graphical representation of the electrical activity of the heart during a cardiac cycle.
  
  
• The instrument used to obtain ECG is called an electrocardiograph.
  
  
• Double circulation means blood passes through the heart twice.

• Pulmonary circulation
• Systemic circulation  
  
  

• The hepatic portal system connects the digestive tract and the liver. The hepatic portal vein carries blood from the small intestine to the liver before it is sent into the systemic circulation.
  
  
• The coronary system of blood vessels takes care of the circulation of blood to the cardiac wall of the heart.