Lymphatic capillaries are larger than blood capillaries and provide for flow in just one direction. Lymph itself originates from blood plasma and returns to the blood after making its way through the lymphatic system.Know More
Lymphatic vessels comprise three layers. The outer layer, known as tunica adventitia, consists of connective tissue and collagen. The tunica media is the middle layer and consists mainly of smooth muscle. The innermost layer is the tunica intima and contains valves that prevent lymph from flowing backwards through the lymphatic system.
The walls of lymph capillaries are very thin. This allows fluid to enter the capillaries from the blood. From the capillaries, lymph moves into larger lymph vessels that transport it to the lymph nodes for filtering. Lymph nodes contain high numbers of white blood cells that destroy pathogens and foreign bodies in the lymph.
After leaving the lymph nodes, the clean lymph enters the lymphatic trunks that merge to form lymph ducts. Lymph ducts empty lymph back into the blood to start the process anew.
Unlike the lymphatic system, the circulatory system allows for movement of fluid in two directions. Fluid in the lymphatic system moves via skeletal muscle and changes in pressure. In the circulatory system, the heart pushes blood to the rest of the body through the arteries and draws it back through the veins.Learn more in Blood
Blood enters the heart through two major veins at the right atrium before going to the right ventricle and to the lungs. When blood returns from the lungs, it goes into the left atrium and the left ventricle before leaving the heart to go to the rest of the body through the aorta, according to Cleveland Clinic.Full Answer >
The blood in human body flows from the heart to the arteries which branch into arterioles and then smaller capillaries, which then merge to form venules that merge into larger veins that carry blood back to the heart. This process is called the circulatory system.Full Answer >
The flow of blood through the heart can be traced by injecting a dye into the arteries through a procedure known as an angiogram. Another procedure, cardiac catheterization, involves using a catheter to inject the dye. Magnetic resonance angiography or MRA, uses MRI technology.Full Answer >
The capillaries that contain a complete lining are called continuous capillaries. The lining itself is referred to as the endothelial lining. Variations in this lining determine the "leakiness" of the capillary.Full Answer >