Bio 169 L01 Study Guide Lymphatics and Immune system Lymphat

Bio 169 L01 Study Guide, Lymphatics and Immune system Lymphatic system: What is lymph and why does it need a whole system of vessels to deal with it? Know the function of the lymphatic system, and how the lymph vessel and organs are arranged in the body. Be able to compare and contrast lymph vessels to blood vessels -knowing some similarities and some differences. Where are lymph capillaries found? Where are they NOT found? What makes the lymph capillaries be open or closed?

Solution

1). Lymph is the transparent or yellowish fluid which is found within the lymphatic vessels and collected from tissues in all parts of the body and returned to the blood through the lymphatic system. The lymphatic system is comprised of a network of lymphatic vcapillaries that pick up any leaked fluid from the tissues and return it to blood. The lymphatic vessels are connected to lymph nodes and organs containing lymphoid tissues, which play a very important role in fighting infections.

2). The function of these lymphatic vessels is to carry unfiltered lymph to the lymph node and to carry filtered lymph from the node back into circulation. The lymph nodes serve as check points for the immune system as it carries immune cells that carry out screening of the lymph for bacteria, cancer cells and other harmful agents. The lymphatic system plays a key role in transport of lymph, which contains lymphocytes that fight infection. The lymphoid tissue found in the organs and the lymph nodes also play a vital role in fighting infections and removing toxins. It also acts as a one-way drainage system transporting fluid from body tissues into the blood circulation. It is also important in the absorption of fats and fat-soluble vitamins from the digestive system and transport of these elements to the venous circulation.

The lymphatic system is a network of lymphatic vessels which drain lymph from all over the body and lymph nodes that run throughout the body. The lymphatic vessels which are larger tubes, formed by the joining of lymphatic capillaries, function like blood capillaries in the circulatory system. They branch through all parts of the body carrying yellowish liquid lymph. The lymph nodes, are bean shaped structures that are present in your under arms, in each groin and in the neck. Lymphatic system also includes organs such as spleen, thymus, tonsils andd adenoids. The spleen is under your ribs on the left side of your body. While, the thymus is a small gland under your breast bone.The tonsils are two glands in the back of your throat and the adenoids are glands at the back of the nose, where it meets the back of the throat.

The lympatic system and circulatory system are closely connected, and share some similarities. One similarity being, both these systems work in a similar manner i.e. they both transport liquid substance (lymph and blood respectively) that move through their networks of vessels and ducts to various parts of the body. Lymph and blood not only carry nutrients but also remove excess waste and hence both these systems can be considered circulatory. Both these systems may also be responsible for the spread of cancer cells, since they are so prevalent all across the body.

The difference between the two is that the lymphatic system lacks blood cells and 2 types of vessels (veins and arteries). Also, the fluids of the circulatory system move through the heart, arteries, capillaries, veins and lungs, but lymph just flows through lymphatic vessels.

3). Lymphatic capillaries are tiny thin walled vessels, which are closed at one end. They are located in the spaces between cells throughout the body, except in the central nervous system and non-vascular tissues.The lymphatic capillaries open when the pressure in the interstitial liquid is higher than in the lymph, which aids in the entry of interstitial fluid into the lymphatic capillary. However, when the pressure inside the lymphatic capillary is higher, the minivalve cells adhere closely, and lymph cannot flow back into interstitial fluid.