Monocytes become what type of cell in the tissue

The daughters are the myeloid and lymphoid progenitor cells, which cannot self renew but differentiate into various myeloid leukocytes and lymphocytes respectively. Two different leukocyte lineages and two non-leukocyte lineages arise from the progeny of HSCs. Following this split in differentiation, the subtypes undergo eventual differentiation into terminally-differentiated leukocytes, which typically do not divide independently.

Hematopoiesis in Humans : This diagram shows hematopoiesis as it occurs in humans. In developing embryos, blood formation occurs in aggregates of blood cells in the yolk sac called blood islands. However, most of blood supply comes from the mother through the placenta. As development progresses, blood formation occurs primarily in the spleen, liver, and lymph nodes.

When bone marrow develops, it eventually assumes the task of forming most of the blood cells for the entire organism. However, maturation, activation, and some proliferation of lymphoid cells occurs in lymphoid organs spleen, thymus, and lymph nodes. In children, haematopoiesis occurs in the marrow of the long bones such as the femur and tibia. In adults, it occurs mainly in the pelvis, cranium, vertebrae, and sternum.

In some cases, the liver, thymus, and spleen may resume their haematopoietic function if necessary. This is called extramedullary haematopoiesis. It may cause these organs to hypertrophy and increase in size substantially. During fetal development, the liver functions as the main haematopoetic organ since bones and marrow develop later. Therefore, the liver is enlarged during development relative to its mature proportions. Privacy Policy. Skip to main content.

Cardiovascular System: Blood. Search for:. White Blood Cells. Types of WBCs The different types of white blood cells leukocytes include neutrophils, basophils, eosinophils, lymphocytes, monocytes, and macrophages. Learning Objectives Distinguish between the two major types of leukocytes white blood cells : granulocytes and agranulocytes. Key Takeaways Key Points The two main types of leukocytes are granulocytes and mononuclear leukocytes agranulocytes.

Leukocytes arise from hemopoietic stem cells in the bone marrow. Leukocytes are involved in pathogen recognition, phagocytosis ingestion of particles , pathogen destruction, inflammation mediation, and antigen presentation.

Granulocytes include neutrophils, basophils, eosinophils, and mast cells. Their granules contain enzymes that damage or digest pathogens and release inflammatory mediators into the bloodstream.

Mononuclear leukocytes include lymphocytes, monocytes, macrophages, and dendritic cells. This group is involved in both innate and adaptive immune system function. Key Terms endocytosed : Engulfed during the process by which the plasma membrane of a cell folds inwards to ingest material.

Macrophages stay in the tissues. They ingest bacteria, foreign cells, and damaged and dead cells. The process of a cell ingesting a microorganism, another cell, or cell fragments is called phagocytosis, and cells that ingest are called phagocytes. Macrophages secrete substances that attract other white blood cells to the site of the infection. They also help T cells recognize invaders and thus also participate in acquired immunity.

Neutrophils, the most common type of white blood cell in the bloodstream, are among the first immune cells to defend against infection. They are phagocytes, which ingest bacteria and other foreign cells.

Neutrophils contain granules that release enzymes to help kill and digest these cells. Neutrophils circulate in the bloodstream and must be signaled to leave the bloodstream and enter tissues.

The signal often comes from the bacteria themselves, from complement proteins, or from damaged tissue, all of which produce substances that attract neutrophils to a trouble spot.

The process of using substances to attract cells to a particular site is called chemotaxis. Neutrophils also release substances that produce fibers in the surrounding tissue.

These fibers may trap bacteria, thus keeping them from spreading and making them easier to destroy. Eosinophils can ingest bacteria, but they also target foreign cells that are too large to ingest. Eosinophils contain granules that release enzymes and other toxic substances when foreign cells are encountered. Eosinophils circulate in the bloodstream. However, they are less active against bacteria than are neutrophils and macrophages.

One of their main functions is to attach to and thus help immobilize and kill parasites. Eosinophils may help destroy cancer cells. They also produce substances involved in inflammation and allergic reactions Overview of Allergic Reactions Allergic reactions hypersensitivity reactions are inappropriate responses of the immune system to a normally harmless substance.

Usually, allergies make people sneeze; the eyes water and itch People with allergies, parasitic infections, or asthma often have more eosinophils in the bloodstream than people without these disorders. Basophils do not ingest foreign cells. They contain granules filled with histamine, a substance involved in allergic reactions. When basophils encounter allergens antigens that cause allergic reactions , they release histamine.

Histamine increases blood flow to damaged tissues, resulting in swelling and inflammation Molecules The immune system is designed to defend the body against foreign or dangerous invaders.

Natural killer cells recognize and attach to infected cells or cancer cells, then release enzymes and other substances that damage the outer membranes of these cells. Natural killer cells are important in the initial defense against viral infections. I would predict that they would. I think that this has been shown in fact. You might take a look at that work. Hi Anne lodge, pls I difference between recruited Macrophages and resident Macrophages..

I also want to know their distinct functions in the heart. Hi Rita, I can tell you that tissue resident macrophages arise from cells in the yolk sac, early in development. The recruited macrophages originate in the bone marrow. As for the functions of the two, I am not certain that they function differently.

They may only traffic differently since the tissue resident macrophages arrive in the tissues during fetal development and recruited macrophages move about the body through the lymphatic system. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Post comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. Forgot your password? Lost your password? Please enter your email address.

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