Lymphatic Ducts Deliver Lymph to the Cardiovascular System Where These Wo Structures Meet

Learning Objectives

Aside the destruction of this incision, you testament be able-bodied to:

• Describe the structure and social function of the liquid body substance tissue paper (lymph fluid, vessels, ducts, and organs)
• Name the complex body part and function of the primary and secondary lymphatic organs
• Discuss the cells of the unaffected system, how they function, and their relationship with the lymphatic system

The immune organization is the interlocking solicitation of cells and organs that destroys surgery neutralizes pathogens that would otherwise cause disease or dying. The systema lymphaticum, for most people, is associated with the immune arrangement to such a stage that the two systems are virtually indistinguishable. The lymphatic scheme is the arrangement of vessels, cells, and organs that carries excess fluids to the bloodstream and filters pathogens from the descent. The swelling of lymph nodes during an infection and the ship of lymphocytes via the lymphatic vessels are but two examples of the many connections between these critical organ systems.

Functions of the Systema lymphaticum

A major function of the lymphatic system is to drain body fluids and return them to the bloodstream. Blood insistency causes leakage of fluid from the capillaries, resulting in the accumulation of fluid in the opening space—that is, spaces betwixt individual cells in the tissues. In humankind, 20 liters of plasma is released into the interstitial space of the tissues each day overdue to capillary filtration. One time this filtrate is out of the bloodstream and in the weave spaces, it is referred to as opening fluid. Of this, 17 liters is reabsorbed like a shot by the blood vessels. But what happens to the remaining three liters? This is where the lymphatic system comes into play. It drains the redundant fluid and empties information technology back into the bloodstream via a series of vessels, trunks, and ducts. Lymph is the term wont to describe interstitial fluid once it has entered the lymphatic system. When the lymphatic system of rules is damaged in some way, much American Samoa past existence blocked aside cancer cells or tattered aside trauma, protein-rich opening fluid accumulates (sometimes "backs raised" from the lymph vessels) in the tissue spaces. This inappropriate accretion of changeful referred to as lymphedema may pass to critical Greco-Roman deity consequences.

American Samoa the craniate immune organization evolved, the network of lymphatic vessels became expedient avenues for transporting the cells of the immune system. Additionally, the transport of dietary lipids and heavy-soluble vitamins captive in the gut uses this system.

Cells of the immune system of rules not only use lymphatic vessels to make their way from opening spaces back into the circulation, but they also use lymph nodes as Major theatrical production areas for the evolution of scholarly immune responses. A lymph node is one of the small, rounded organs situated throughout the lymphatic system.

Do Questions

Visit this web site for an overview of the systema lymphaticum. What are the three main components of the lymphatic system?

Show Respond

The three primary components are the lymph vessels, the lymph nodes, and the lymph.

Complex body part of the Lymphatic System

The lymphatic vessels begin as open-ended capillaries, which feed into larger and big lymphatic vessels, and in time empty into the bloodstream by a series of ducts. Along the way, the lymph travels through the lymph nodes, which are commonly found near the groin, armpits, neck, chest, and abdominal cavity. Humans have about 500–600 lymph nodes throughout the body.

Figure 1. Lymphatic vessels in the arms and legs convey lymph to the larger lymphatic vessels in the trunk.

A major distinction betwixt the lymphatic and cardiovascular systems in humans is that lymph is not actively wired by the heart, but is forced through the vessels away the movements of the body, the contraction of skeletal muscles during body movements, and breathing. Ace-way valves (semi-lunar valves) in lymphatic vessels dungeon the lymph moving toward the essence. Lymph flows from the lymphatic capillaries, through lymphatic vessels, and so is dumped into the cardiovascular system via the liquid body substance ducts located at the junction of the jugular and subclavian veins in the cervix.

Lymphatic Capillaries

Lymphatic capillaries, also titled the terminal lymphatics, are vessels where interstitial fluid enters the liquid body substance system to become lymph fluid. Placed in almost every tissue in the body, these vessels are interlaced among the arterioles and venules of the circulatory system in the soft connective tissues of the body. Exceptions are the systema nervosum centrale, bone essence, bones, teeth, and the cornea of the eye, which do not contain lymph vessels.

Figure 2. Humour capillaries are latticelike with the arterioles and venules of the circulatory system. Collagen fibers anchor a lymphatic capillary tube in the tissue (inset). Interstitial smooth slips through spaces between the overlapping epithelial tissue cells that compose the lymphatic capillary.

Lymphatic capillaries are formed past a unrivaled electric cell-thick level of endothelial cells and represent the acceptant ending of the system, allowing interstitial graceful to flow into them via overlapping cells. When interstitial pressure is degraded, the endothelial flaps or so prevent "backflowing." As interstitial pressure increases, the spaces between the cells open up, allowing the smooth to enter. Entry of fluid into lymphatic capillaries is as wel enabled by the collagen filaments that anchor the capillaries to surrounding structures. Equally opening pressure increases, the filaments pull on the endothelial cell flaps, opening up them even further to set aside easy entry of changeable.

In the small intestine, liquid body substance capillaries called lacteals are critical for the transport of dietary lipids and lipid-soluble vitamins to the bloodstream. In the small bowel, dietary triglycerides combine with other lipids and proteins, and enter the lacteals to form a milky fluid called chyle. The chyle then travels through the lymphatic system, eventually ingress the liver and then the bloodstream.

Larger Lymphatic Vessels, Trunks, and Ducts

The lymphatic capillaries empty into big lymphatic vessels, which are similar to veins in terms of their three-tunic bodily structure and the presence of valves. These unidirectional valves are settled fairly close to one another, and each one causes a bulge in the liquid body substance vessel, giving the vessels a beaded appearance.

The superficial and deep lymphatics eventually merge to form large humour vessels called liquid body substance trunks. On the right sidelong of the body, the right sides of the header, pectus, and right upper limb drain lymph fluid into the right subclavian mineral vein via the right lymphatic duct. On the leftist side of the body, the remaining portions of the body drainpipe into the bigger thoracic duct, which drains into the left subclavian vein. The body part duct itself begins just beneath the diaphragm in the cistern chyli, a sac-like chamber that receives lymph from the let down abdomen, pelvis, and lower limbs by way of the left and right lumbar trunks and the intestinal trunk.

Figure 3. The thoracic duct drains a much larger fate of the body than does the right lymphatic channel.

The overall drain system of the body is asymmetrical. The opportune lymphatic epithelial duct receives lymph from only the upper right side of the body. The lymph from the rest of the body enters the bloodstream finished the body part canal via all the remaining humor trunks. In general, humour vessels of the subcutaneous tissues of the skin, that is, the dilettanteish lymphatics, follow the same routes as veins, whereas the deep lymphatic vessels of the viscera generally follow the paths of arteries.

The Organization of Condition Function

The immune system is a collection of barriers, cells, and soluble proteins that interact and communicate with each other in extraordinarily complex slipway. The progressive model of immune procedure is organized into three phases based on the timing of their effects. The three temporal phases consist of the followers:

• Barrier defenses so much as the skin and mucous membranes, which act instantaneously to prevent pathogenic invasion into the consistence tissues
• The rapid but nonspecific innate immune response, which consists of a variety of differentiated cells and alcohol-soluble factors
• The slower just more specific and effective adaptive immune response, which involves many cell types and soluble factors, merely is primarily controlled by egg white blood cells (leukocytes) called lymphocytes, which help control status responses

The cells of the blood, including all those involved in the immune response, arise in the marrow via various differentiation pathways from haematogenic stem cells. In contrast with embryonic radica cells, biological process stem cells are present throughout adulthood and allow for the continuous distinction of blood cells to replace those lost to geezerhoo or affair. These cells can be multilane into three classes based on social function:

• Phagocytic cells, which ingest pathogens to destroy them
• Lymphocytes, which specifically coordinate the activities of adaptive immunity
• Cells containing protoplasm granules, which help arbitrate immune responses against parasites and intracellular pathogens such as viruses

Fig 4. All the cells of the status response A well as of the origin arise past differentiation from hemopoietic stem cells. Platelets are cell fragments involved in the clotting of rakehell.

Lymphocytes

A stated above, lymphocytes are the primary cells of adaptive status responses (encounter Table 1 for to a greater extent details). The ii basic types of lymphocytes, B cells and T cells, are identical morphologically with a banging central core group enclosed by a thin layer of cytoplasm. They are distinguished from each otherwise by their rise up protein markers as well as by the molecules they secrete. While B cells suppurate in red marrow and T cells mature in the thymus, they both initially develop from bone up marrow. T cells migrate from grind away marrow to the thymus where they promote mature. B cells and T cells are found in many parts of the body, circulating in the bloodstream and lymph, and residing in secondary lymphoid variety meat, including the spleen and lymph nodes, which will be represented later therein section. The soma contains approximately 10¹² lymphocytes.

B Cells

B cells are unaffected cells that function primarily aside producing antibodies. An antibody is whatever of the group of proteins that binds specifically to pathogen-related molecules titled antigens. An antigen is a chemical structure happening the surface of a pathogen that binds to T surgery B lymphocyte antigen receptors. Once activated by dressing to antigen, B cells differentiate into cells that release a soluble take form of their surface antibodies. These activated B cells are better-known as plasma cells.

T Cells

The T electric cell, but then, does not release antibody only performs a variety of functions in the adaptive immune reaction. Different T cell types have got the power to either secrete solvable factors that communicate with other cells of the adaptive exempt response or destroy cells infected with intracellular pathogens. The roles of T and B lymphocytes in the adaptive immune response will follow discussed further in this chapter.

Plasma Cells

Another eccentric of lymph cell of grandness is the plasm cell. A plasma cell is a B cell that has differentiated in response to antigen binding, and has thereby gained the ability to secrete soluble antibodies. These cells differ in morphology from standard B and T cells in that they contain a large come of cytoplasm packed with the protein-synthesizing machinery known as emarginate endoplasmic reticulum.

Natural Killer Cells

A fourth important lymph cell is the natural killer cell, a participant in the innate immune response. A instinctive killer prison cell (NK) is a circulating origin cellular phone that contains toxin (cell-putting to death) granules in its extensive cytoplasm. It shares this chemical mechanism with the cytotoxic T cells of the adaptive immune reception. NK cells are among the body's first lines of defense against viruses and certain types of cancer.

Table 1. Lymphocytes
Type of lymphocyte	Of import social occasion
B lymphocyte	Generates different antibodies
T cell	Secretes chemical messengers
Plasma cell	Secretes antibodies
NK cell	Destroys virally infected cells

Apply Question

Call in this website to learn about the many different mobile phone types in the immune system and their very specialized jobs. What is the role of the dendritic cell in an HIV infection?

Show Answer

The dendritic cell transports the virus to a lymph node.

Primary Lymphoid Variety meat and Lymphocyte Development

Intellect the distinction and development of B and T cells is critical to the reason of the adaptive unsusceptible response. It is through this process that the body (ideally) learns to destroy only when pathogens and leaves the personify's own cells relatively intact. The primary lymphoid organs are the bone marrow, short temper, and thymus gland. The lymphoid organs are where lymphocytes mature, proliferate, and are designated, which enables them to attack pathogens without harming the cells of the body.

Marrow

Figure 5. Red off-white marrow fills the head of the femur, and a spot of yellow marrow is visible in the center. The white reference bar is 1 cm.

In the conceptus, blood cells are made in the yolk sac. As development return, this function is taken over aside the spleen, lymph nodes, and liver. Later, the bone marrow takes over most hematopoietic functions, although the last stages of the differentiation of some cells may happen in different variety meat. The coloured bone marrow is a loose collection of cells where hematopoiesis occurs, and the yellow marrow is a site of energy store, which consists largely of abdominous cells. The B cell undergoes nearly all of its growth in the red marrow, whereas the prepubertal T electric cell, known as a thymocyte, leaves the mug up nub and matures largely in the thymus gland.

Thymus

The thymus secretor is a bilobate electric organ found in the space between the sternum and the aorta of the heart. Connective tissue holds the lobes nearly together merely also separates them and forms a capsule.

Fiugre 6. The thymus lies above the heart. The trabeculae and lobules, including the darkly staining pallium and the lighter staining medulla of each lobule, are clearly visible in the light micrograph of the Thymus of a newborn. Lumen × 100. (Micrograph provided past the Regents of the University of Michigan Medical School © 2012)

Though the University of Michigan WebScope to explore the tissue sample in greater item.

The connective tissue capsule further divides the thymus into lobules via extensions called trabeculae. The external region of the organ is known As the cortex and contains large numbers racket of thymocytes with some epithelial cells, macrophages, and dendritic cells (two types of phagocytic cells that are derived from monocytes). The cerebral cortex is densely packed so it stains much intensely than the rest of the thymus. The medulla, where thymocytes migrate in front leaving the thymus, contains a less dense collection of thymocytes, epithelial cells, and dendritic cells.

Aging and the Immune System

By the class 2050, 25 percent of the population of the United States will constitute 60 years aged or older. The CDC estimates that 80 percent of those 60 years and older have one or more chronic disease associated with deficiencies of the immune systems. This loss of status use with age is called immunosenescence. To treat this growing population, medical professionals must bettor understand the aging treat. One starring cause of related to immune deficiencies is thymic involution, the shrinkage of the genus Thymus gland that begins at birth, at a rate of virtually three percent tissue loss per yr, and continues until 35–45 old age of age, when the rate declines to about one percent red ink per year for the rest of one's life. At that tempo, the sum loss of thymic epithelial tissue and thymocytes would occur at about 120 years of years. Thus, this maturat is a theoretical limit to a healthy anthropomorphic lifespan.

Thymic involution has been observed all told vertebrate species that have a thymus gland. Animal studies have shown that transplanted thymic grafts between interbred strains of mice involuted accordant to the age of the donor and not of the recipient, implying the process is genetically programmed. In that respect is evidence that the thymic microenvironment, so vital to the development of naïve T cells, loses thymic epithelial cells according to the decreasing expression of the FOXN1 gene with years.

It is also notable that thymic involution can follow edited past hormone levels. Sex hormones such as estrogen and testosterone enhance involution, and the hormonal changes in pregnant women cause a improvised thymic involution that reverses itself, when the size of the thymus and its endocrine levels return to normal, usually afterward suckling ceases. What does all this tell us? Force out we reverse immunosenescence, or at least slow it mastered? The potential is there for using thymic transplants from younger donors to keep thymic output of naïve T cells high. Gene therapies that fair game gene facial expression are also seen as succeeding possibilities. The more we get a line through immunosenescence research, the more opportunities there will constitute to develop therapies, even though these therapies wish likely take decades to germinate. The ultimate goal is for everyone to live and be healthy yearner, but there may be limits to immortality imposed by our genes and hormones.

Secondary Lymphoid Variety meat and their Roles in Active Immune Responses

Lymphocytes develop and mature in the primary humour organs, but they ride immune responses from the junior-grade lymphoid variety meat. A naïve lymphocyte is 1 that has left hand the primary reed organ and entered a secondary lymphoid organ. Naïve lymphocytes are fully structural immunologically, but have yet to showdown an antigen to respond to. In addition to circulating in the blood and lymph, lymphocytes concentrate in minor lymphoid organs, which include the lymph nodes, spleen, and lymphoid nodules. All of these tissues have many features in common, including the shadowing:

• The comportment of lymphoid follicles, the sites of the establishment of lymphocytes, with specific B cell-rich and T cubicle-rich areas
• An internal structure of reticular fibers with associated fixed macrophages
• Germinal centers, which are the sites of speedily dividing B lymphocytes and plasma cells, with the exception of the irascibility
• Specialized spot-capillary vessels notable atomic number 3 commanding epithelial tissue venules; the cells lining these venules are thicker and more columnar than normal epithelial tissue cells, which allow cells from the blood line to directly enter these tissues

Lymph Nodes

Lymph nodes function to move out detritus and pathogens from the lymph, and are thus sometimes referred to as the "filters of the lymph". Any bacterium that infect the interstitial fluid are obsessed past the lymphatic capillaries and transported to a regional lymph client. Dendritic cells and macrophages within this reed organ internalize and kill many of the pathogens that transit, thereby removing them from the body. The node is also the site of adaptive immune responses mediated aside T cells, B cells, and accessory cells of the adaptive status system. Same the thymus, the bean-shaped lymph nodes are encircled by a tough capsule of connective weave and are separate into compartments by trabeculae, the extensions of the capsule. In increase to the structure provided by the capsule and trabeculae, the structural support of the lymph node is provided by a serial of reticular fibers arranged down by fibroblasts.

Anatomy 7. Lymph nodes are masses of lymphoid tissue located on the larger lymph vessels. The micrograph of the lymph nodes shows a germinal center, which consists of rapidly disjunctive B cells surrounded by a layer of T cells and another accessory cells. Lumen × 128. (Micrograph provided by the Regents of the University of Michigan Medical School © 2012)

The major routes into the lymph lymph node are via receptive lymphatic vessels. Cells and lymph fluid that leave the lymph gland may do so by another set of vessels illustrious as the motor lymphatic vessels. Lymph enters the lymph lymph node via the subcapsular sinus, which is engaged aside dendritic cells, macrophages, and reticular fibers. Within the cortex of the lymph node are lymphoid follicles, which consist of germinal centers of rapidly dividing B cells surrounded by a stratum of T cells and other accessory cells. Equally the lymph continues to flow through the node, information technology enters the medulla, which consists of neural structure cords of B cells and plasma cells, and the animal tissue sinuses where the lymph collects earlier leaving the node via the corticofugal lymphatic vessels.

Spleen

Additionally to the lymph nodes, the irascibility is a major secondary bodily fluid organ. It is about 12 cm (5 in) long and is attached to the lateral border of the stomach via the gastrosplenic ligament. The irascibility is a fragile organ without a strong capsule, and is caliginous coloured imputable its extensive vascularization. The spleen is sometimes called the "filter of the blood" because of its extensive vascularisation and the bearing of macrophages and nerve fiber cells that remove microbes and other materials from the bloodline, including dying ruddy blood cells. The spleen as wel functions as the localisation of immune responses to blood-borne pathogens.

Figure 8. (a) The spleen is attached to the digest. (b) A micrograph of short temper tissue shows the germinal meat. The marginal zone is the area between the red flesh and white flesh, which sequesters particulate antigens from the circulation and presents these antigens to lymphocytes in the white pulp. Mut × 660. (Micrograph provided by the Regents of the University of Michigan School of medicine © 2012)

The spleen is also divided aside trabeculae of connective tissue, and within each splenic nodule is an area of scarlet pulp, consisting of mostly red blood cells, and white mush, which resembles the lymphoid follicles of the lymph nodes. Upon incoming the spleen, the arteria lienalis splits into individual arterioles (surrounded past white pulp) and eventually into sinusoids. Blood from the capillaries subsequently collects in the venous sinuses and leaves via the vena lienalis. The Red pulp consists of reticular fibers with fixed macrophages attached, free macrophages, and every last of the other cells typical of the blood, including some lymphocytes. The unintegrated pulp surrounds a central arteriole and consists of germinal centers of dividing B cells surrounded by T cells and accessary cells, including macrophages and dendritic cells. Olibanum, the Marxist pulp primarily functions as a filtration system of the blood, using cells of the comparatively nonspecific immune reaction, and white pulp is where adaptive T and B cell responses are affixed.

Lymphoid Nodules

The other lymphoid tissues, the lymphoid nodules, take up a simpler architecture than the spleen and lymph nodes in that they consist of a dense cluster of lymphocytes without a encompassing fibrous capsule. These nodules are located in the respiratory and digestive tracts, areas habitually open to environmental pathogens.

Tonsils are lymphoid nodules located on the inner surface of the pharynx and are grave in developing immunity to viva voce pathogens. The tonsil placed at the back of the throat, the Luschka's tonsil, is sometimes referred to as the adenoid when swollen. Much swelling is an indication of an active immune reaction to contagion. Histologically, tonsils do not contain a complete space capsule, and the epithelial layer invaginates deeply into the interior of the tonsil to form tonsillar crypts. These structures, which accumulate every last sorts of materials taken into the body through feeding and snorting, in reality "promote" pathogens to penetrate rich into the tonsillar tissues where they are acted upon by numerous lymphoid follicles and eliminated. This seems to be the major role of tonsils—to assistant children's bodies recognize, destroy, and develop granting immunity to common environmental pathogens so that they volition be protected in their later lives. Tonsils are often removed in those children who have recurring throat infections, especially those involving the palatine tonsils on either side of the throat, whose swelling May interfere with their eupnoeic and/or swallowing.

Figure 9. (a) The pharyngeal consonant tonsil is located on the roof of the posterior superior wall of the nasopharynx. The palatine tonsils lay on each side of the pharynx. (b) A micrograph shows the palatine tonsil tissue. LM × 40. (Micrograph provided by the Regents of the University of Michigan Medical Schooltime © 2012)

Mucosa-associated liquid body substance tissue (MALT) consists of an totality of lymphoid follicles directly associated with the mucous membrane epithelia. MALT makes up dome-shaped structures found underlying the mucous membrane of the gastrointestinal tract, breast tissue, lungs, and eyes. Peyer's patches, a type of MALT in the bantam gut, are especially important for immune responses against ingested substances. Peyer's patches turn back specialized endothelial cells called M (or microfold) cells that try bodily from the intestinal lumen and rapture it to nearby follicles so that adaptive immune responses to potential pathogens can be affixed.

See 10. LM × 40. (Micrograph provided by the Regents of the University of Michigan Medical School © 2012)

Bronchus-associated lymphoid tissue (BALT) consists of lymphoid cyst structures with an overlying epithelial layer found on the bifurcations of the bronchi, and between bronchi and arteries. They also have the typically less-unionized structure of early lymphoid nodules. These tissues, in gain to the tonsils, are effective against inhaled pathogens.

Chapter Reassessmen

The lymphatic system is a series of vessels, ducts, and trunks that remove interstitial fluid from the tissues and return IT the roue. The lymphatics are as wel used to transport fare lipids and cells of the immune system. Cells of the immune system all come from the hematopoietic system of the marrow. Primary lymphoid organs, the bony marrow and thymus secretor, are the locations where lymphocytes of the adaptive immune scheme proliferate and mature. Junior lymphoid variety meat are site in which fully grown lymphocytes congregate to mount condition responses. Many immune system cells use the lymphatic and circulatory systems for rapture passim the body to search for and past protect against pathogens.

Self Check-out procedure

Answer the question(s) below to see how intimately you understand the topics covered in the previous section.

Critical Thinking Motion

Report the flow of lymph from its origins in interstitial changeful to its emptying into the blood vessel bloodstream.

Show Answer

The lymph enters through lymphatic capillaries, so into larger lymphatic vessels. The lymph can only survive in ane direction due to valves in the vessels. The larger lymphatics merge to form trunks that enter into the blood via lymphatic ducts.

Glossary

adaptive immune response:relatively slow but identical specific and effective immune reception dominated aside lymphocytes

sensory nerve lymphatic vessels:lead into a lymph node

antibody:antigen-particularized protein secreted by plasma cells; immunoglobulin

antigen:molecule recognized by the receptors of B and T lymphocytes

roadblock defenses:antipathogen defenses deriving from a barrier that physically prevents pathogens from entering the body to make an infection

B cells:lymphocytes that act by differentiating into an antibody-secreting plasm electric cell

bone kernel:tissue found inside bones; the website of all blood line cell specialization and maturation of B lymphocytes

bronchus-connected lymphoid tissue (BALT):lymphoid nodule associated with the airway

chyle:lipid-rich lymph inside the lymphatic capillaries of the small intestine

cisterna chyli:bag-like vessel that forms the beginning of the thoracic duct

efferent lymphatic vessels:lead out of a lymph node

germinal centers:clusters of apace proliferating B cells found in inessential bodily fluid tissues

high endothelial venules:vessels containing unique endothelial cells specialized to allow migration of lymphocytes from the profligate to the lymph node

immune system:series of barriers, cells, and soluble mediators that combine to response to infections of the body with pathogenic organisms

innate immune reply:fast but comparatively nonspecific immunologic response

lymph:mobile controlled within the lymphatic system

lymph node:one of the noggin-shaped organs found associated with the humour vessels

lymphatic capillaries:smallest of the lymphatic vessels and the origin of lymph flow

lymphatic system:mesh of lymphatic vessels, lymph nodes, and ducts that carries lymph from the tissues and backward to the bloodstream.

liquid body substance short pants:hulky lymphatics that due lymph from smaller lymphatic vessels and empties into the blood via lymphatic ducts

lymphocytes:white blood cells characterized aside a large nucleus and small rim of cytoplasm

lymphoid nodules:unencapsulated patches of lymphoid tissue found throughout the body

mucosa-associated lymphoid tissue (MALT):body fluid tubercle joint with the mucosa

naïve lymphocyte:mature B or T cell that has not yet encountered antigen for the first time

natural killer cell (NK):cytotoxic lymphocyte of born immune response

plasma cell:differentiated B cell that is actively secreting antibody

main lymphoid organ:site where lymphocytes mature and proliferate; red marrow and thymus

right bodily fluid duct:drains lymph fluid from the upper right side of body into the suitable vena subclavia

secondary lymphoid organs:sites where lymphocytes mount adaptive immune responses; examples include lymph nodes and spleen

spleen:secondhand lymphoid harmonium that filters pathogens from the blood (white pulp magazine) and removes degenerating or scorched blood cells (red pulp)

T electric cell:lymphocyte that acts by secreting molecules that regulate the immune system or by causing the destruction of established cells, viruses, and cancer cells

pectoral duct:large duct that drains lymph from the lour limbs, left thorax, left upper limb, and the left side of the head

thymocyte:childly T cell found in the genus Thymus

thymus:primary lymphoid pipe organ; where T lymphocytes proliferate and mature

tonsils:lymphoid nodules associated with the nasopharynx

Lymphatic Ducts Deliver Lymph to the Cardiovascular System Where These Wo Structures Meet

Source: https://courses.lumenlearning.com/ap2/chapter/anatomy-of-the-lymphatic-and-immune-systems/