The complement system is a set of serum proteins that works with both the innate and adaptive immune system to help rid the body of blood and tissue pathogens. There are three ways of activating the complement system; the classical pathway, lectin pathway, and alternative pathway. The classical pathway is a part of the adaptive immune system. It is activated when C1 recognizes the Fc that is bound to an antibody-antigen complex. This causes a catalytic cascade ending with a membrane attack complex (MAC). The lectin pathway is part of the innate immune system, and like the classical pathway, it too proceeds to activation of C4b2a. This pathway uses lectins as its receptor molecules. This pathway uses Mannose-binding lectin to bind to the mannose
The immune system is made up of a network of cells, tissues, and organs that work together to protect the body, and it defends the body from “foreign invaders.” Immunity can be divided in two three different defenses, and these are defined as first, second and third lines of defense. The first line of defense for the immune system is the primary defense against pathogens entering the body from the surface in order to prevent the start of disease and infection. Some examples of the first line of defense is the skin, protecting the external boundaries of the body, and the mucous membranes, protecting the internal boundaries of the body. Although the skin and mucous membranes work on the internal and external boundaries, they both release chemicals
1. In response to light, phytochrome undergoes a change in shape that leads to the activation of
...he viability of the microorganism nor the biological potency of the LPS. Deoxysugars are frequent components in O-chain structures but sugars that are more characteristic of the inner core region like heptose are seldom present. The most common substituents are O- and N- acetyl phosphate and phosphorylethanolamine groups. Amino acids in amide linkages, acetamidino groups as well as formyl groups and glyceric acid are often found as non stoichiometric substituents(Brade et al., 1999). The extended O-polysaccharide chains out from the bacterial outer membrane acts as a shield which enable the bacteria to get away from the lytic activity provided by the complement cascade. Many gram negative strains require O-polysaccharide as an essential component for the survival in host system as it prevents the attack from complement membrane attack complex (Joiner et al., 1984).
The bodies first line of defense includes the presence of physical and chemical barriers. These limit entry of microorganisms into the body. “These include: intact skin and epithelial surfaces that act as mechanical barriers, presence of normal micro flora on the skin that compete with pathogens for nutrients and inhibit pathogen growth through lactic acid production, normal flora of throat, colon, and vagina occupy receptors that prevents colonization by pathogens.” (Ogston-Tuck, 2014, p. 55). This also includes secretions which contain antibodies.
“Immune Response: MedlinePlus Medical Encyclopedia.” National Library of Medicine - National Institutes of Health. Web. 18 Dec. 2011. .
Pathophysiology of infection, inflammation response, and sepsis leading to septic shock (the cascade) is a major area of interest in the literature. Under normal circumstances, when a pathogen enters a human host and tissue damage occurs, the host initiates an inflammatory response to repair the tissue. The main types of pathogens include viruses, bacteria, and parasites (Porth & Matfin, 2009; Raghavan & Marik, 2006). Cellulitis is an example of an acute infection, which affects the skin and or subcutaneous tissue often in lower limbs. Cellulitis is caused by streptococcus pyogenes and staphylococcus aureus (multi-resistant bacteria) and is transmitted by direct contact, entering the body via broken skin such as ulcers and or following trauma. The presentation of cellulitis often includes pain (localised), erythema, fever and swelling. Infections such as cellulitis have a propensity to become systemic through distribution in the blood and lymph (Hadzovic-Cengic et al., 2012). The inflammation response to an infection involves the release of both pro and anti-inflammatory mediators. When excessive pro-inflammatory mediators such as cytokines are released they cause inflammation in a systemic manner that can cause sepsis or systemic inflammatory response syndrome (being the non-specific response to non-infectious cause) (Sagy, Al-Qaqaa, & Kim, 2013). Pro-inflammatory mediators also activate the complement system, which results in increased inflammation and upregulation of specific receptors that lead to cellular injury and apoptosis seen in severe sepsis and organ dysfunction (Ward, 2008). Organ dysfunction can occur in one or more organs such as the lungs, liver, kidneys and or heart and often results from a lack of...
1. EQ: How does the structure and function of my immune system keep me healthy?
The lymphatic system is very similar, and works with and directly at the side of the cardiovascular system. The lymphatic system has a network of vessels like the circulatory system which pump a plasma-like fluid called lymph around it’s own lymph vessels, and are found in most other tissues of the body, except the central nervous system.
“The lymphatic system is a vital and integral part of the cardiovascular system”. The lymphatic system contains many structures which consist of lymphatic vessels, lymph fluid, lymph cells, lymph nodes and other substances. (Hastie, 2012) The lymphatic system consists of a network of fine tubes or vessels which ramify throughout the body similar to blood vessels. Unlike the blood the fluid is moved by the muscles and limbs. The lymph vessels have fine walls, so water can pass easily through them. The main role of the lymphatic system is too drain off excess fluid from all parts of the body. This prevents the cells getting waterlogged. (Hayes, 2002). Other functions include returning the lymph back to the heart and immune surveillance within
M proteins: M proteins are found on the surface of the organism and protect it against phagocytosis. The M proteins prevent the attachment of complement proteins to the cell. Complement proteins which are attached to the bacterium “tag” it for destruction by phagocytic cells, such as neutrophils and macrophages, in a process called opsonisation. By inhibiting this process, the M protein allows the group A streptococcus to survive longer...
16. Describe two evolutionary consequences if the process of crossing over in meiosis ceased to occur. If crossing over in meiosis ceased to occur there would be less genetic variations and no diversity among a species. This would essentially mean that a species would not be able to adapt to an issue that could arise in the future, meaning that its species could potentially become extinct due to climate change or other arising events.
Seattle Education Project. (2013, November). STEP: The Immune System - An Overview, [Online]. Available: http://www.thebody.com/step/immune.html [11/12/14].
Bacteria exist everywhere in the environment and have continuous access to the body through the mouth, nose and pores of skin. Further more, many cells age and die daily and their remains must be removed, this is where the white blood cell plays its role.
Innate system critical main defense is the cellular component; there are several kinds of cells involved in the process. One of the crucial cells is the macrophage. ...
Lymphatic System Overview A well-functioning lymphatic system is essential to maintaining good health. The lymphatic system consists of a network of lymph vessels, lymph nodes, lymph ducts, and organs that can be likened to a drainage system in the body. Lymph Drainage Function The lymphatic system’s main task is transporting lymph consisting of.