Tag: immunity related disorders and problems

Histamine is an organic nitrogenous compound involved in the inflammatory response and has a central role as a mediator of itching. Histamine causes vasodilation of peripheral blood vessels due to which there is increased blood flow to the site of inflammation. It mediates the inflammatory reaction by the release of other chemical mediators of inflammation and causes redness, swelling etc at the site of inflammation.

In localized infection, redness and heat are due to increased blood flow at body core temperature to the inflamed site, swelling is caused by accumulation of fluid, pain is due to the release of chemicals such as prostaglandin and histamine that stimulate nerve endings.Histamine are mono-amine produced from mast cells and basophils these are stored in preformed granules, and is released to a number of stimuli these lead to arterial dilation and increased venous permeability. Prostaglandins are eicosaniod produced from mast cells they leads to vasodilation, fever and pain. Hence, localized inflammatory response at the sight of infection producing redness, swelling, pain and heat is due to prostaglandin and histamine.

Histamine is an organic nitrogenous compound involved in the inflammatory response and has a central role as a mediator of itching. Histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine is stored in cytoplasmic granules along with other amines and rapidly released upon triggering with a variety of stimuli. It causes the contraction of smooth muscle, dilation of blood vessels etc..

A mast cell is a type of white blood cell that contains many granules rich in histamine and heparin. Mast cells play an important protective role in inflammatory and allergic reactions. When mast cells are activated, they release mediators or compounds that induce inflammation from storage granules into the local site and promotes the inflammatory response. In allergic reactions, mast cells remain inactive until an allergen binds to IgE already coated upon the cell.

• Asthma is a common long-term inflammatory disease of the airways of the lungs.
• Symptoms include reversible airflow obstruction and easily triggered bronchospasms. 
• Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. 
• Asthma can be caused by Environmental factors including allergens, air pollution, and other environmental chemicals.
•  Hence, Asthma is caused by an allergy.
• So, the correct answer is 'Asthma'.

• Shock is a life-threatening situation due to poor tissue perfusion with impaired cellular metabolism, manifested inturns by serious physiological abnormalities.
  
• Anaphylactic shock is also called as Type I immunogenic reaction.
• Anaphylactic shock is characterized High permeability of capillaries causing loss of fluid from the blood.
  
• Anaphylaxis symptoms usually occur within minutes of exposure to an allergen. 
  
• The most common anaphylactic reactions are to foods, insect stings, medications and latex.
  
• So, the correct answer is 'High permeability of capillaries causing loss of fluid from the blood'

Allergies, also known as allergic diseases are caused by hypersensitivity of the immune system to typically harmless substances in the environment. The mechanism involves immunoglobulin E antibodies (IgE) binds to an allergen and then to a receptor on mast cells or basophils where it triggers the release of inflammatory chemicals such as histamine. The release of histamine develops symptoms such as red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling.