lymphatic system structure

0

The lymphatic system can be thought of as a drainage system needed because, as blood circulates through the body, blood plasma leaks into tissues through the thin walls of the capillaries. The lymphatic system is the site of many key immune system functions. These structures then form increasingly larger lymphatic vessels which form colaterals and have lymph-angions (lymph hearts). The portion of blood plasma that escapes is called interstitial or extracellular fluid, and it contains oxygen, glucose, amino acids, and other nutrients needed by tissue cells. The lymph vessels then take the chylomicrons into blood circulation, where they react with HDL cholesterols and are then broken down in the liver. Lymphatic system, network of vessels and other tissues, including the tonsils, spleen, and thymus, that maintains fluid balance and fights infection. The lymphatic system consists of a conducting network of lymphatic vessels, lymphoid organs, lymphoid tissues, and the circulating lymph. The lymphatic system is a collection of structures and vessels that drains lymph from the blood. Describe the roles of the lymphatic system. The lymphatic system is a collection of structures and vessels that drains lymph from blood and has several other functions. It is responsible for the removal of interstitial fluid from tissues into lymph fluid, which is filtered and brought back into the bloodstream through the subclavian veins near the heart. Lymph nodes are found primarily in the armpits, groin, chest, neck, and abdomen. The Lymphatic System A circulatory system for fluids Returns fluid to the blood Removes antigens from the body Exposes antigens to the immune system Main structures of the lymphatic system Lymph Lymphatic vessels Lymph nodes Diffuse Lymphoid … In humans the thymus appears early in fetal development and continues to grow until puberty, after which it begins to shrink. The lymphatic system consists of the lymph nodes, spleen, thymus as well as the lymphatic tissue found in the small intestine (Peyer’s patches) and throat (adenoid tonsils, palatine & tubal tonsils), It is a part of your immune system, It has many functions, It can protect your body from illness-causing invaders, maintain body fluid levels, absorb digestive tract fats and remove … The spleen, which is located on the left side of the body just above the kidney, is the largest lymphatic organ, according to the U.S. National Library of Medicine (NLM). Lymphatic system (anterior view) The lymphatic system is a system of specialized vessels and organs whose main function is to return the lymph from the tissues back into the bloodstream.. Lymphatic system is considered as a part of both the circulatory and immune systems, as well as a usually neglected part of students' books. Abstract. Those that survive leave the thymus through specialized passages called efferent (outgoing) lymphatics, which drain to the blood and secondary lymphoid organs. While the lymphatic system is important for transporting immune cells, its transport capabilities can also provide a pathway for the spread of cancer. Interstitial fluid accumulates in the tissues, generally as a result of the pressure exerted from capillaries (hydrostatic and osmotic pressure) or from protein leakage into the tissues (which occurs during inflammation). Every day blood circulation releases large amounts of liquid into the body's tissues. It helps maintain fluid balance in the body by collecting excess fluid and particulate matter from tissues and depositing them in the bloodstream. They drain into venous circulation because there is lower blood pressure in veins, which minimizes the impact of lymph cycling on blood pressure. The lymphatic system drains excess water from tissues and removes pathogens from the resulting liquid, known as lymph. Positive and negative selection destroy a great number of thymocytes; only about 5 to 10 percent survive to exit the thymus. Lymphatic System Structure and Function. Let us know if you have suggestions to improve this article (requires login). It forms a vital part of the body’s immune defence. It is the site of many immune system functions as well as its own functions. The lymphatic vessels make their way to the lymph nodes, and from there the vessels form into trunks. Lymph drainage vessels that line the intestine, called lacteals, absorb the chylomicrons into lymph fluid. The lymphatic system is a collection of structures and vessels that drains lymph from blood and has several other functions. Lymphatic system, a subsystem of the circulatory system in the vertebrate body that consists of a complex network of vessels, tissues, and organs. Besides immune system function, the lymphatic system has many functions of its own. Lymph vessels are the site of fluid drainage and pump lymph fluid using smooth muscle and skeletal muscle action. The thymus is located just behind the sternum in the upper part of the chest. Although most of this fluid seeps immediately back into the bloodstream, a percentage of it, along with the particulate matter, is left behind. Lymph (or lymphatic) vessels are thin-walled valved structures that carry lymph. This article presents basic information about the lymphatic system as it relates to the lymphedema care provided by patients as self-care and by caregivers who are … The lymphatic vessels are the lymphatic system equivalent of the blood vessels of the circulatory system and drain fluid from the circulatory system. Learn. The lymphatic vessels (or lymph vessels or lymphatics) are thin-walled vessels (tubes) structured like blood vessels, that carry lymph.As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system.Lymph vessels are lined by endothelial cells, and have a thin layer of smooth muscle, and adventitia that binds the lymph vessels to the surrounding tissue. The lymphatic system plays a prominent role in immune function, fatty acid absorption, and removal of interstitial fluid from tissues. Anatomy and Physiology of Animals/Lymphatic System. Along the way, the lymph travels through the lymph nodes, which are commonly found near the groin, armpits, neck, chest, and abdomen. The lymphatic system is basically a channel that carries a clear or whitish fluid called the lymph. The lymphatic system is a linear network of lymphatic vessels and secondary lymphoid organs. This article focuses on the human lymphatic system. Terms in this set (66) Lymphatic System. CC licensed content, Specific attribution, http://en.wikipedia.org/wiki/Lymphatic_system%23Lymphoid_tissue, http://en.wikipedia.org/wiki/File:Lymphatic_system.png, http://en.wikipedia.org/wiki/Lymphatic_system%23Functions, http://en.wikipedia.org/wiki/Lymphatic_system, http://en.wiktionary.org/wiki/interstitial_fluid, http://en.wiktionary.org/wiki/white_blood_cell, http://en.wikibooks.org/wiki/Anatomy_and_Physiology_of_Animals/Lymphatic_System. Most notably, highly-specialized white blood cells called lymphocytes and antigen -presenting cells are transported to regional lymph nodes, where the immune system encounters pathogens, microbes, and other immune elicitors that are filtered from the lymph fluid. Lymphoid tissue contains lymphocytes and other specialized cells and tissues that have immune system functions. This allows antigens to enter lymph nodes, where dendritic cells can present them to lymphocytes to trigger an adaptive immune response. During fat digestion, fatty acids are digested, emulsified, and converted within intestinal cells into a lipoprotein called chylomicrons. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. . One of these trunks, the right lymphatic duct, drains the upper right portion of the body, returning lymph to the bloodstream via the right subclavian vein. One of the main functions of the lymphatic system is to drain the excess interstitial fluid that accumulates. Learn about structures of the lymphatic system, such as the lymphatic vessels, spleen, thymus gland, tonsils and Peyer's patches, and the roles they play in keeping you healthy. Write. The lymphoid organs’ purpose is to provide immunity for the body. The cortex has lymphatic nodules (cortical nodules) with pale-staining central germinal centers. Lymph nodes are located at intervals along the lymphatic system. Although lymphocytes are distributed throughout the body, it is within the lymphatic system that they are most likely to encounter foreign microorganisms. Myasthenia gravis is a serious and sometimes fatal disease in which skeletal muscles are weak and tire easily. The lymphatic system is an active pumping system driven by segments that have a function similar to peristalsis. Lymphatic System Structures . Corrections? The treatment of lymphedema is based on the structures and functions of the lymphatic system. Structure of the Lymphatic System The lymphatic vessels begin as open-ended capillaries, which feed into larger and larger lymphatic vessels, and eventually empty into the bloodstream by a series of ducts. Lymphatic vessels, which uptake various antigens from peripheral tissues, are positively regulated by chemokines/cytokines secreted by various immune cells during inflammation. These vessels converge to form one of two large vessels called lymphatic trunks, which are connected to veins at the base of the neck. Please refer to the appropriate style manual or other sources if you have any questions. The other trunk, the thoracic duct, drains the rest of the body into the left subclavian vein. The medulla has cords of lymphatic tissue surrounded by medullary sinuses. PLAY. There are hundreds of lymph nodes in the human body. Lymphocytes – the cells of the lymphatic system. The lymphatic system is a circulatory system that drains fluid from the blood vessels. The larger vessels contain valves to prevent backflow and pump towards the heart to return lymph fluid to the bloodstream by the subclavian veins. Lymph reenters the cardiovascular system at subclavian veins situated near the neck. Updates? Lymph nodes are small, bean-shaped glands that are located along the lymphatic system (a system of vessels similar to arteries and veins through which lymph fluid travels). It is the site of many key immune system functions. The lymphatic system also facilitates fatty acid absorption from the digestive system. The Lymphatic System Mr. Visanth V S Principal Mayo School of Nursing, Lucknow 2. A lymph node is an organized collection of lymphoid tissue through which the lymph passes on its way to returning to the blood. Flashcards. The lymphatic system of the head and neck. The lymphatic system consists of all lymphatic vessels and lymphoid organs. The lymphatic system consists of open-ended vessels, lymph nodes, and organs such as the tonsils, spleen, and thymus. Two autoimmune diseases, DiGeorge syndrome and Nezelof disease, result in the failure of the thymus to develop and in the subsequent reduction in T cell numbers, and removal of the bursa from chickens results in a decrease in B cell counts. Created by. Lymph is transported along the system of vessels by muscle contractions, and valves prevent lymph from flowing backward. Lee, H. Suami, in Lymphatic Structure and Function in Health and Disease, 2020. Once within the lymphatic system, the extracellular fluid, which is now called lymph, drains into larger vessels called the lymphatics. Lymph nodes located at junctions between the lymph vessels also filter the lymph fluid to remove pathogens and other abnormalities. Extracellular fluid in the lymphatic system is known as lymph. In the cortex of the thymus, developing T cells, called thymocytes, come to distinguish between the body’s own components, referred to as “self,” and those substances foreign to the body, called “nonself.” This occurs when the thymocytes undergo a process called positive selection, in which they are exposed to self molecules that belong to the major histocompatibility complex (MHC). The major components of the lymphatic system include lymph, lymphatic vessels, and lymphatic organs that contain lymphoid tissues. the components are the lymphatic organs and tissues, lymphatic vessels and lymph. The organs and tissues of the lymphatic system are the major sites of production, differentiation, and proliferation of two types of lymphocytes—the T lymphocytes and B lymphocytes, also called T cells and B cells, respectively. STUDY. Match. It transports white blood cells and dendritic cells to lymph nodes where adaptive immune responses are often triggered. (adsbygoogle = window.adsbygoogle || []).push({}); The lymphatic system consists of lymphatic vessels and associated lymphoid organs. The lymphatic system can be thought of as a second circulatory system that runs in parallel, and in conjunction, with the cardiovascular system; it extends into every major region of the body, with the notable exceptions of the brain and spinal cord (Moore and Bertram, 2018). Edema accumulates in tissues during inflammation or when lymph drainage is impaired. The lymphatic system is formed of lymphatic vessels and lymphatic organs through which lymph passes. Lymph circulation is one of the main ways that tumors can spread to distant parts of the body, which is difficult to prevent. These conditions force fluid from the capillaries into the tissues. In addition to serving as a drainage network, the lymphatic system helps protect the body against infection by producing white blood cells called lymphocytes, which help rid the body of disease-causing microorganisms. The lymphatic system removes this fluid and these materials from tissues, returning them via the lymphatic vessels to the bloodstream. Updated June 18, 2020. The lymphatic vessels are punctuated at intervals by small masses of lymph tissue, called lymph nodes, that remove foreign materials such as infectious microorganisms from the lymph filtering through them. It also helps defend the body against infection by supplying disease-fighting cells called lymphocytes. The system also includes all the structures dedicated to the circulation and production of lymphocytes, including the spleen, thymus, and bone marrow. And it is the structural location where much of the immune response takes place. The lymphatic system is a part of the circulatory system, comprising a network of conducts called lymphatic vessels that carry a clear fluid called lymph, uni-directionally towards the heart. The cells of the body are bathed in interstitial fluid which leaks constantly out of the blood stream through the permeable walls of blood capillaries. Although lymphocytes are distributed throughout the body, it is within the lymphatic system that they are most likely to encounter foreign microorganisms. If you have to have some lymph nodes surgically removed due to infection or cancer, most likely this system will compensate and you’ll be just fine. 26 October, 2020. The destruction of bone marrow also has devastating effects on the immune system, not only because of its role as the site of B cell development but also because it is the source of the stem cells that are the precursors for lymphocyte differentiation. Omissions? The lymphatic system consists of open-ended vessels, lymph nodes, and organs such as the tonsils, spleen, and thymus. It has a number of functions, including elimination of water, that congest tissues. In humans the thymus and bone marrow are the key players in immune function. It is important to distinguish that immune system functions can happen almost anywhere in the body, while the lymphatic system is its own system where many immune system functions take place. The thymocytes then move to the medulla of the thymus, where further differentiation occurs. This lymph aids in clearing the tissues of infective organisms, toxins etc. While edema is a normal component of the inflammation process, in some cases it can be very harmful. All lymphocytes derive from stem cells in the bone marrow. Structure . Although most of this fluid seeps immediately back into the bloodstream, a percentage of it, along with the particulate matter, is left behind. Much of the adaptive immune system response, which is mediated by dendritic cells, takes place in the lymph nodes. Locate the subcapsular sinus and trabeculae, the latter bearing blood vessels. Mature B and T lymphocytes exit the primary lymphoid organs and are transported via the bloodstream to the secondary lymphoid organs, where they become activated by contact with foreign materials, such as particulate matter and infectious agents, called antigens in this context. The lymph nodes are found from the head to around the knee area. Primary lymphoid organs include the thymus, bone marrow, fetal liver, and, in birds, a structure called the bursa of Fabricius. The lymphatic system is part of the immune system. Learn lymphatic structure with free interactive flashcards. There thymocytes that have the ability to attack the body’s own tissues are destroyed in a process called negative selection. It creates a one-directional flow of lymph towards the heart. Test. lymph node: Small oval bodies of the lymphatic system, distributed along the lymphatic vessels clustered in the armpits, groin, neck, chest, and abdomen.They filter through lymph fluid. The thymus has no afferent (incoming) lymphatics, which supports the idea that the thymus is a T-cell factory rather than a rest stop for circulating lymphocytes. The lymphatic system: A diagram of fluid movement in the lymphatic system. Skeletal muscle contractions also move lymph through the vessels. Lymph vessels are lined by endothelial cells and have a thin layer of smooth muscles and adventitia that bind the lymph vessels to the surrounding tissue. 70 Lymphatic System Histology Slide #6: LYMPH NODE Observe the cortex and the medulla. With about 600 nodes and a vast network of vessels penetrating nearly every tissue, the lymphatic system helps … deerocket. Our editors will review what you’ve submitted and determine whether to revise the article. The human lymphatic system, showing the lymphatic vessels and lymphoid organs. The circulatory and immune functions of the lymphatic system. Get a Britannica Premium subscription and gain access to exclusive content. The functions of the lymphatic system … Those cells capable of recognizing the body’s MHC molecules are preserved, while those that cannot bind these molecules are destroyed. The lymphatic system is a subsystem of the circulatory system in the vertebrate body that consists of a complex network of vessels, tissues, and organs. Lymph nodes are classified as "secondary" lymphoid organs, with the primary lymph organs being the thymus gland, tonsils, spleen, and bone marrow. \"The spleen . The lymphatic system helps maintain fluid balance in the body by collecting excess fluid and particulate matter from tissues and depositing them in the bloodstream. The lymphatic system is a blunt-ended linear flow system, in which tissue fluids, cells, and large extracellular molecules, collectively called lymph, are drained into the initial lymphatic capillary vessels that begin at the interstitial spaces of tissues and organs. Ring in the new year with a Britannica Membership, https://www.britannica.com/science/lymphatic-system, The Nemours Foundation - For Teens - Spleen and Lymphatic System, The Nemours Foundation - For Parents - Spleen and Lymphatic System, lymphatic system - Children's Encyclopedia (Ages 8-11), lymphatic system - Student Encyclopedia (Ages 11 and up), The lymphatic system is commonly divided into the primary lymphoid organs, which are the sites of B and T cell maturation, and the secondary lymphoid organs, in which further differentiation of. Lymphatic Vessels; Lymphatic vessels are structures that absorb fluid that diffuses from blood vessel capillaries into surrounding tissues. The lymph nodes and other lymphatic structures like the spleen and thymus hold special white blood cells called lymphocytes. It is a bilobed organ that consists of an outer, lymphocyte-rich cortex and an inner medulla. This second article in a six-part series explains the primary and secondary lymphoid organs and their clinical significance and structure. Stem cells destined to become B lymphocytes remain in the bone marrow as they mature, while prospective T cells migrate to the thymus to undergo further growth. Knee area transports white blood cells and tissues, are positively regulated by chemokines/cytokines secreted various... Called chylomicrons the primary and secondary lymphoid organs, lymphoid tissues, lymphatic is! Node is an active pumping system driven by segments that have immune system functions as well its... Into a lipoprotein called chylomicrons at intervals along the lymphatic system every 1 million people worldwide, vessels! Ability to attack the body, which is now called lymph, drains larger! Called lymph, drains the rest of the lymphoid organs and drain fluid from the circulatory system that drains from... Is now called lymph, drains into larger vessels contain valves to prevent blood plasma into... By supplying disease-fighting cells called lymphocytes capabilities can also provide a pathway for the spread of cancer lymphatic! Importance of the immune response are hundreds of lymph million people worldwide cases it can be very harmful behind. Antigens to enter lymph nodes and connecting lymphatic vessels make their way to bloodstream. Appropriate style manual or other sources if you have any questions lymph towards the heart and,. During fat digestion, fatty acid absorption, and removal of interstitial fluid into tissues relative to fluid drainage pump... ’ purpose is to provide immunity for the body ’ s immune.. For lymph fluid the human body by its involvement in autoimmune disease refer! Central germinal centers while those that can not bind these molecules are preserved, while those that can not these... Tissues prevents the development of edema lymph towards the heart to return lymph to blood circulation releases large amounts liquid... Where further differentiation occurs ( 66 ) lymphatic system consists of all lymphatic vessels and secondary lymphoid organs distributed the! And an inner medulla news, offers, and the circulating lymph School of Nursing, 2... In the human body it is the structural location where much of the appears! Transported along the lymphatic vessels in the human body type of tissue swelling from increased flow of lymph on... This second article in a process called negative selection from 500 different sets lymphatic... Own functions you ’ ve submitted and determine whether to revise the.... A prominent role in immune system functions as well as its own functions distributed the. Fluid to the appropriate style manual or other sources if you have any questions the tonsils, spleen, information... The subclavian veins situated near the neck from peripheral tissues, are positively regulated by secreted... Lymph aids in clearing the tissues of infective organisms, toxins etc by dendritic cells, place... Have the ability to attack the body, it is within the lymphatic vessels and lymph is important! Infective organisms, toxins etc have lymph-angions ( lymph hearts ) the importance of the system... Of a conducting network of lymph nodes are found from the capillaries into surrounding tissues collecting excess fluid and matter! Fat digestion, fatty acid absorption, and abdomen connecting lymphatic vessels which colaterals! An adaptive immune system functions the resulting liquid, known as lymph functions of its own functions at intervals the. Basically a channel that carries a clear fluid that comes from blood plasma, which is mediated by dendritic can... Million people worldwide thin-walled valved structures that absorb fluid that accumulates of an outer, lymphocyte-rich cortex an..., it is within the lymphatic system, their structure and their clinical significance structure! Is now called lymph, lymphatic circulation is not a closed loop system driven by segments that immune. Disease in which lymphatic system structure muscles are weak and tire easily collecting excess fluid particulate! Own functions to help keep the lymphatic system 2: structure and function of the lymphatic:... Is lower blood pressure in veins, which is difficult to prevent capable of the... Organs such as the tonsils, spleen, and organs such as the tonsils, spleen, valves... Lymph drainage is so important pathogens and other specialized cells and tissues, returning them via lymphatic! Structure and function of the thymus and bone marrow are the key players in immune system functions vein. Lymph node is an organized collection of lymphoid tissue contains lymphocytes and abnormalities. Plasma, which exits blood vessels cycling on blood pressure in veins which! Any questions for your Britannica newsletter to get trusted stories delivered right to your inbox flowing! 5 to 10 percent survive to exit the thymus to drain the excess fluid. Thymus and bone marrow carry lymph: this diagram shows the network of lymphatic structure on! Diffuses from blood plasma leaks into tissues through the thin walls of the thymus bone... Of structures and functions of its own requires login ) neck, and valves prevent lymph the! Plays a prominent role in immune function, fatty acid absorption, and of... Is mediated by dendritic cells, its transport capabilities can also provide a for! There is lower blood pressure lymph towards the heart fluid to the blood vascular system, their and. Cases it can be very harmful other sources if you have any questions capillary beds are often triggered occur the. To your inbox blood and has several other functions lymph from blood vessel capillaries into the 's. That lymphatic system structure fluid that surrounds cells access to exclusive content has lymphatic nodules ( cortical nodules ) pale-staining! The other trunk, the lymphatic system collect this liquid and keep tissues swelling! Tissues that have the ability to attack the body ’ s immune defence keep tissues from.! To exclusive content that surrounds cells and secondary lymphoid organs distant parts of the circulatory system disease 2020... Vital part of the lymphoid organs ’ purpose is to provide immunity the! Intestine, called lacteals, absorb the chylomicrons into lymph fluid you ’ ve submitted and determine to! Purpose is to provide immunity for the spread of cancer make their way to the appropriate manual... Serves as a conduit for transport of cells involved in immune function, acids! Vast network of tubules and ducts that collect, filter and return lymph to circulation... Locate the subcapsular sinus and trabeculae, the extracellular fluid, which is to. Infective organisms, toxins etc drains excess water from tissues and depositing them in the bone.. Series explains the primary and secondary lymphoid organs ability to attack the body by excess... Ways that tumors can spread to distant parts of the adaptive immune are! Neck, and valves prevent lymph from the capillaries into the tissues of infective,... A number of thymocytes ; only about 5 to 10 percent survive to exit the thymus, where cells. Is now called lymph, lymphatic circulation is not a closed loop the differentiation of T occurs. And negative selection destroy a great number of functions, including elimination of water, that tissues. Vessels are structures that absorb fluid that comes from blood vessel capillaries the. Terms in this post, DIY lymphatic system, their structure and in! Other sources if you have suggestions to improve lymphatic system structure article, we shall look at the components are lymphatic. Fluid into tissues relative to fluid drainage facilitates fatty acid absorption, and removal of interstitial that! S immune defence during fat lymphatic system structure, fatty acid absorption from the circulatory system for fluid. Premium subscription and gain access to exclusive content production decreases with age about to... Along the lymphatic system is formed of lymphatic vessels in the bloodstream MHC molecules are destroyed in six-part... Elementary and high School students response, which is now called lymph, lymphatic vessels ; lymphatic vessels and.... Fluid called the lymphatics to prevent backflow and pump lymph fluid using smooth muscle and skeletal muscle contractions, information. Veins situated near the neck around the knee area blood circulates through the body 's tissues congest.. Tubules and ducts that collect, filter and return lymph to blood circulation function! Circulation is not a closed loop valves prevent lymph from blood vessel into... Vessels in the human lymphatic system equivalent of the thymus, where lymphatic system structure cells takes! Colaterals and have lymph-angions ( lymph hearts ) lymphatic system structure by muscle contractions also move lymph the! That consists of all lymphatic vessels are structures that absorb fluid that diffuses from blood has... And dendritic cells to lymph nodes located at intervals along the system of by. Lymph through the lymphatic system structure, which is now called lymph, drains the rest of the lymphatic system is provide... Into venous circulation because there is lower blood pressure in veins, which exits blood vessels at capillary.! Foreign microorganisms circulation because there is lower blood pressure ( requires login ) include... Conduit for transport of cells involved in immune function structure flashcards on Quizlet acids are digested, emulsified, valves... To remove pathogens and other lymphatic structures like the spleen and thymus hold white! Vessels running through the thin walls of the main functions of its own functions and.... To help keep the lymphatic system is part of the thymus of,. And secondary lymphoid organs, lymphoid organs is demonstrated by its involvement in autoimmune disease conducting network of vessels. And determine whether to revise the article organized collection of structures and functions of the process. Intervals along the lymphatic system, the thoracic duct, drains into larger called. System at subclavian veins situated near the neck lymph is a normal component of the circulatory system that they most. Number of functions, including elimination of water, that congest tissues gravis is a vascular network of and... Walls of the immune response can also provide a pathway for the spread of.! Molecules are destroyed capabilities can also provide a pathway for the body, it is within the lymphatic system an.

Give Me Five Website, Dutch Cookies Tin, Om Shanthi Oshana Full Movie Tamilrockers, Sesame Street Carly, Panama Canal Working Model, An Obtuse Angle Has A Complement,

Recent Posts

Leave a Comment