Lymph vs Blood
Blood is circulated through the body by blood vessels and lymph is transported by lymphatic vessels.
Lymphatic system is a system of vessels, cells and organs. Vessels originate blindly, and the structure is similar to a vein with valves. The vessels transport fluid called lymph that is similar in composition to extra cellular fluid. Lymphatic system also consists of a number of organs and cells that are collectively referred to as white blood cells.
Lymph is a protein containing fluid transported by lymphatic vessels. Lymphatic vessels transport the lymph at a low pressure. Structurally and functionally they are similar to a vein. Lymphatic vessels eventually join with the veinous system. Primary lymphoid organs are the organs involved in the development of cells of the lymphatic system. Secondary lymphoid organs are the organs involved in housing cells of the lymphatic system and immune response.
Cells of the lymphatic system include granulocytes and agranulocytes. Granulocytes are the Neutrophils, eosinophils, basophils and mast cells. Agranulocytes are the monocytes, T and B lymphocytes, macrophages and natural killer cells. In the body, lymph nodes are found in the places where pathogens can enter the body. Lymphatic system maintains the blood volume in the cardio vascular system by returning the lost fluid from the capillaries. It transports fats and fat soluble material from the digestive system. It defends the body from various pathogens and parasites.
Blood plasma is a straw colored liquid. It consists of water and dissolved solutes like minerals, metabolites, hormones, plasma proteins and nutrients. Plasma proteins constitute 7-9% of plasma. Albumin is synthesized in the liver. It accounts for 60% of plasma proteins. It provides the colloid osmotic pressure needed to draw water from the interstitial fluid to capillaries. It maintains blood pressure and transport bilirubin and fatty acids.
Globulins account for 36% of plasma proteins. Alpha globulin transport lipid and fat soluble vitamins. Beta globulins transport lipids and fat soluble vitamins. Gamma globulins are antibodies that function in immunity. Alpha and beta globulins are synthesized in the liver whereas gamma globulin is synthesized by B-lymphocytes. Fibrinogen consists 4% of plasma proteins. It is an important clotting factor. It is converted into fibrin during the clotting process. These are synthesized by the liver.
Erythrocytes are flattened biconcave discs. They lack nuclei and mitochondria. The cytoplasm is packed with hemoglobin molecules. Leukocytes contain nuclei and mitochondria. They are able to squeeze through capillary walls by amoeboid fashion. They are named after staining properties, shape of the nucleus and the nature of the cytoplasm. Granulocytes are the Neutrophils, eosinophils and basophils. Agranulocytes are the monocytes and lymphocytes. Platelets are the smallest of the formed elements. They are fragments of megakaryocytes. They lack nuclei. They are important in blood clotting.
What is the difference between Blood and Lymph?
• Blood is red colored due to the presence of red blood cells and lymph is colorless due to the absence of red blood cells.
• Blood plasma contains red blood cells, white blood cells and platelets, and the lymph plasma contains white blood cells.