Lymph nodes are the sites where white blood cells circulate in the lymphatic system patrolling all the vessels and the ducts


Lymph nodes are the sites where white blood cells circulate in the lymphatic system patrolling all the vessels and the ducts, they are in lymph fluid searching for invaders and pathogens (Kent, 2000). When this happens, you can feel the immune response by it swelling (Kent, 2000). White blood cells also search for damaged cells or host cells (Kent, 2000). They should destroy these hosts cells as it could be compromised by a virus or our own cells that have gone rogue (Kent, 2000). In mitosis to ensure this doesn’t happen check points are in place to prevent our own cells going rogue (Kent 2000)

The tonsils make a ring around the lymphatic tissue surrounding the entrance to the pharynx, they are swellings of the mucosa (Spellman, 2007). The cilia within them collect and remove pathogens entering the pharynx where it be food or inhaled (Spellman, 2007).

Adenoids are located at the back of the nasal cavity, they protect the lungs from pathogens getting into the body through the nose in the same way (Spellman, 2007).

The thymus secrets the hormones Thymopoietin and Thymosin resulting in T lymphocytes being able to work against specific pathogens in the immune system (Spellman, 2007). Differentiation of T cells happen in the thymus (Spellman, 2007).

Cervical lymph nodes when a pathogen is detected it becomes swollen inflamed (Spellman, 2007).

Right lymph duct drains lymph from the upper right of the body (Spellman, 2007).
Thoracic duct drains lymph from everywhere else (Spellman, 2007).

The spleen filters out toxins and filters your red blood cells (Kent, 2000). Red blood cells can live up to 100-120 days, after this you don’t want them in your blood stream they are not as effective as transported oxygen around your body or carbon dioxide (Kent, 2000). The spleens job is to filter out red blood cells that have exceeded 120 days (kent 2000). If your spleen gets damaged or removed due to an injury your body can still function, but your filtration system won’t be as efficient (Kent, 2000). If the spleen ruptures, because it holds a residual volume of blood, your more at risk of rapid intensive bleeding (kent 2000).

Peyers patches are big isolated clusters of lymphoid follicles located in the small intestine (Spellman, 2007).They prevent pathogens from penetrating the intestinal wall and produce memory lymphocytes to be able to have long term immunity (Spellman, 2007).

Appendix release some mucus into the large intestine (Encyclopedia Britannica, 2018). Leukocytes are introduced to antigens within the gastrointestinal tract by the appendix (Encyclopedia Britannica, 2018).

Inguinal lymph nodes filter lymph from the legs before the lymph heads toward the thoracic duct (Spellman, 2007).

In the bone marrow B cells mature and are tested, any that bind to with self-proteins in the bone marrow undergo apoptosis, deactivated then killed (Spellman, 2007).
Lymphocytes originate from stem cells within the bone marrow. It constantly renews red blood cells (Spellman, 2007).

Popliteal lymph nodes filter and balance the blood supply to the lower part of body
(Spellman, 2007).

Part B (assessment criterion 3.2)

Q2 What are the different types of Leukocytes and how does their structure and function differ?

Leukocytes are white blood cells that are present in the non-specific immune system (Brooker, 2008). They patrol our lymphatic system and the blood, there method of transport is they are carried around by our circulatory system (Brooker, 2008).

Neutrophils are the majority of leukocytes in the body (Brooker, 2008). They go around in the blood searching for their primary target (Brooker, 2008). At the point when the body sends out a chemical substance showing that a microorganism is endeavouring to enter, the neutrophils are the initial ones to touch base at the site (Brooker, 2008). By engrossing them they kill the invaders (Brooker, 2008). The discharge present in infections is comprised of these neutrophils that in this process have died (Brooker, 2008).

Basophils can have a big impact once activated but only account for a small number of leukocytes in the body (Brooker, 2008). They are in charge of the hypersensitive responses that reason a few people to have asthma attacks, struggle to breath, swelling, and hives (Brooker, 2008). Despite the fact that these indications are not nice, it is the body’s reaction to particular trespassers (Brooker, 2008). Basophils recognize these intruders in the body and make antibodies that assist in destruction of their foreign substances (Brooker, 2008). They additionally call different leukocytes to come help in the battle (Brooker, 2008).

Eosinophils trap trespassers, disturbing foreign bodies, and taking part in the hypersensitive responses (Brooker, 2008). In comparison to other leukocytes they don’t need to know what the specific invader is before they kill (Brooker, 2008). Any intruder that has the potential to cause harm, the eosinophils distinguish them and attack them (Brooker, 2008).

Monocytes are phagocytes that circulate the blood then develop into macrophages in the tissue (Brooker, 2008).

Lymphocytes mount immune response by direct cell attack or via antibodies (Brooker, 2008). T lymphocytes (T cells) work in the immune response by working directly against infected cells (Brooker, 2008). B lymphocytes (B cells) give rise to plasma cells these make antibodies known as immunoglobulins that are released into the blood (Brooker, 2008).

Macrophages surround and engulf pathogens and dead cells they also alert other immune system cells of a problem (Brooker, 2008).

Mast cells release chemical alarms that alert other immune cells to invaders (Brooker, 2008). They are accountable for the majority of allergic and inflammatory response (Brooker, 2008).

Natural killer cells do not directly attack pathogens alternatively they attacked cells that have become infected, enforcing them to undergo apoptosis (Brooker, 2008).

Q3 How do macrophages activate helper T cells?

The innate responses will decide the type of effector cell a helper T cell will develop into (Alberts et al., 2018).

Infected cells fibrocytes by antigens. These foreign body antigens combine with MHC II and this will form the MHC II antigen complex (Alberts et al., 2018). Once it has been formed it will be expressed on the surface of the cell (Alberts et al., 2018). The MHC II antigens complex is going to be recognised by the T cell receptors on the T helper cells, this is the first signa (Alberts et al., 2018).

The second signal is the costimulatory signal its occurs when by the interaction of B7 and CD28 take place (Alberts et al., 2018). When both these signals have interacted, it will lead to activation of cytotoxic T cells and helper T cells (Alberts et al., 2018). Helper T cells are now able to produce cytokines, whereas the cytotoxic T cells recognise and kill the infected cell (Alberts et al., 2018).