READ THE POSTS BELOW AND RESEARCH ON THE TOPIC TO ADD MORE TO THE DISCUSSION. MUST INCLUDE REFERENCES.
Post 1: Compare and contrast: Antibodies; the structure, types, and actions
“Antibodies (Abs) are proteins in the gamma globulin class that play a variety of roles in defense” (Saladin, 2018 p. 823). Antibodies are produced by B- Cells (plasma) use a detection and response method to tag and find antigens (5miniteschool, 2013). Antibodies then bind themselves to the antigen for the T- Cells to engulf and get rid of (5minuteschool, 2013). These Y shaped antibody monomers are made up of four chains, two heavy chains and two light chains (Saladin, 2018). All antibodies have a constant (C ) region that decides what its mechanism is and a variable (V) region that forms the antigen- binding site where it attaches to the antigen’s epitopes (Saladin, 2018).
There are five classes of antibodies, named by the structure in their C region: alpha, delta, epsilon, gamma, and mu.
Alpha (IgA): Two Ig subunits formed together. It prevents pathogens from sticking to epithelial cells and can also stimulate inflammation (Boskey, 2018).
Delta (IgD): Bonded to B- Cells and signals those cells to activate. It is very important in early immune protection (Boskey, 2018 & Saladin, 2018).
Epsilon (IgE): This is in charge of allergy responses and release histamine, causing an allergy attack (Boskey, 2018). This is a transmembrane protein of basophils and mast cells (Saladin, 2018)!
Gamma (IgG): 80% of plasmas circulating antibodies (Saladin, 2018). It is made up of only 1 Ig and is the only one that can cross the placenta during pregnancy, helping the baby fight off an infection (Boskey, 2018). This is the antibody built by immunization and can also neutralize certain toxins (Boskey, 2018). This is also very powerful in breastfeeding mothers as it is found in colostrum the first few days after birth (Saladin, 2018).
Mu (IgM): 10% of circulating antibodies. This is the first one produced after a pathogen has entered the body (Boskey, 2018). It sticks very strongly to its target and it functions as part of the antigen receptors (Boskey, 2018 & Saladin, 2018).
A human body can produce ten billion, if not one trillion different antibodies and it why we are so capable of living in a world with so many antigens in our world (Saladin, 2018).
Post 2: The major type of cells of the lymphatic system and state their functions.
The lymphatic system is a network of vessels, tissues, and organs that aid in getting rid of excessive fluids, toxins, waste, and other unwanted materials from the body (Shier, Butler, & Lewis, 2003, P. 367). The lymphatic system transport lymph- a “clear, colorless fluid, like blood plasma but low in protein” (Saladin, 2018, P. 803), throughout the body. The human body has lymph nodes that are located deep within the body and surrounds organs such as the spleen, and heart. The lymphatic system aid in fluid balance, immunity, and lipid absorption. Did you know the spleen is the largest lymphatic organ?
The major types of cells of the lymphatic system are:
1. Natural Killer (NK) cells: are “large lymphocytes that attack and destroy bacteria, tissues, and host cells “(Saladin, 2018, P. 805), that is produced within the red bone marrow. Natural Killers are a part of the innate immune system that defend the host from virus infected cells and tumors. NK cells can distinguish between non-infectious cells and infectious cells. “Upon recognition of an enemy cell, NK cell binds to it and release proteins called perforins” (Saladin, 2018, P. 817). This chemical substance kills the target cells and its plasma membrane which creates the cell to lyse.
2. T Lymphocytes (T- cells) and B Lymphocytes (B- cell): T-cells are produced in the red bone marrow and mature within the thymus by the hemopoietic stem cells. (Saladin, 2018, P. 805, 825). T-cells are involved in cell-mediated immunity and does not secrete antibody within the body. T cells secretes chemical messengers within the body. B-cells lymphocytes are mature within the bone marrow and is responsible for humoral immunity. “B- cells fight bacteria and viruses by making Y-shaped proteins called antibodies, which are specific to each pathogen and are able to lock onto the surface of an invading cell and mark it for destruction by other immune cells within the body” (Tan, “What’s the Difference? B-cells and T-cells, CTCA, 2007). T-cells and B-cells recognized specific antigens within the body, in which they become tailored to eliminate and inhibit non-pathogens or pathogen infected cells once they have received an antigen. B cells function primarily by providing antibodies to the body.
3. Macrophages: Macrophages are monocytes that are produced by stem cells in our bone marrow. They clean the body of microscopic debris and invaders that leave the blood and enter tissues. Monocytes leave through the bloodstream, and when they do, they mature into macrophages. They are large, phagocytic cells with no longer life spans than neutrophils. They can ingest more and larger phagocytic particles than neutrophils (Seeley, 2011, P. 792). A macrophage uses a process called phagocytosis to destroy and get rid of unwanted particles. “They phagocytize tissue debris, dead neutrophils, bacteria, and other foreign matter” (Saladin, 2018, P. 807).
4. Dendritic cells: Dendritic cells are the most antigen presenting cells (APCs) that alert the immune system to pathogens that have breached the body surfaces (Saladin, 2018, P. 807). Dendritic cells can activate other immune cells such as: macrophages, neutrophils, T-cells and B-cells.
5. Reticular cells: Reticular cells produced the fibrous stoma located in lymphoid organs. They produce and maintain the thin networks of fibers that are a framework of the lymphoid organs. (Britannica, Lymphoid tissue 2016