Physiology and Its Functions - Essay Example

"Physiology and Its Functions" is an interesting example of a paper on the cardiovascular system.
T cells – are antibodies that exist within the bloodstream which actively work to seek out and destroy foreign pathogens.  These cells are also unique in the fact that they have what is known as a type of “memory” of specific pathogens they have encountered before.  In this way, these cells help the immune system to retain immunity to diseases it has come in contact with or been immunized against, etc.  However, HIV specifically targets these T cells so that they no longer have the ability to target the virus and simply allow it to exist within the body.  These T cells can be further classified into Memory T cells, Helper T cells, Cytotoxic T cells, and Regulatory T cells; all of which have unique functions to protect and secure the human body against infection (Bollinger et al 2010). 

Acquired Immunity Deficiency Syndrome (AIDS)- refers to the advanced stages of the HIV in which the body is unable to adequately defend itself against the threat of disease posed by other illnesses as well as tumors and other such deviations to the body’s normally regulated immune system.  Accordingly, the person that is infected with AIDS does not die of the virus itself but as a result of the weakened state that the virus leaves the immune system of its host.  Once the virus enters the body, it replicates itself extremely rapidly to account for thousands of virus cells in a single milliliter of blood.  The virus then sets to work attacking T cells so that their numbers are drastically reduced to the point that the body is no longer able to ward off infection.  Once this has been accomplished, the body is more and more likely to develop any number of other diseases. 

Antibodies – also known as an immunoglobulin is a Y shaped protein that is produced by B cells that act as the primary agents of the body’s immune system by seeking out and destroying pathogens that the Y shaped arms of the antibody comes in contact with.  These antibodies are initially secreted by white blood cells known as plasma cells.  Once the plasma cell is alerted to the fact that a foreign body is within the area, the antibodies are released and set to work targeting and killing the pathogen. 

Passive immunity – refers to the type of immunity that is passed along without the individual having to be directly exposed to the given pathogen.  In this way, a mother can pass along passive immunity through breast milk to the infant.  Additionally, a person can become passively immune to several illnesses via a shot or passive exposure to a given disease. 

Pathogens – refer to any of several different micro-organisms that cause infectious diseases.  These can include fungi, bacteria, viruses, and prions.  Although the understanding of the term is usually negative, several pathogens can be helpful to humans – such as the ones that live on the skin and work in a symbiotic way to keep the body healthy.  Pathogens can invade the host organism through a variety of ways but the most common way is via an opening in the body; whether this is through the skin, the eyes, the mouth, nostrils, ears, anus, or genital region.