using a named examples explain the differences between a specific body defence mechanism and a non- specific body defence mechanism

Specific body defence mechanism are resistance that are directed against only one specific invader while,

Non specific defence mechanism protects against any of an enormous range of possible dangers.

Explanation:

NON SPECIFIC DEFENCE MECHANISM are the first lines of general defence, they prevent entry and minimise further passage of microbes and other foreign material into the body. There are five main non specific defence mechanisms, these include:

--> defence at body surface

--> phagocytosis

--> natural antimicrobial substances

--> inflammatory response

--> immunological surveillance

Using PHAGOCYTOSIS as a named example of non specific defence mechanism. This involves phagocytes such as the macrophages and neutrophils which are able to trap any invading microbes either by engulfing them or by extending long pseudopodia towards them which grasp them and reel them in. These cells are NON SELECTIVE in their targets.

SPECIFIC BODY DEFENCE MECHANISM directs its actions against a specific invader. In addition immunological memory develops which confers long term immunity to specific infections. The immunity could be cell mediated or antibody mediated immunity.

Using CELL MEDIATED IMMUNITY as an example, Cytotoxic T-cells directly inactivate any cells carrying antigens. This means they are SELECTIVE in their targets. They attach themselves to the target cell and release powerful toxins, which are very effective because the two cells are so close together. This leads to destruction of abnormal body cells such as infected cells and cancer cells.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.