The Complement System: A Decisive System in Body Defence. This article will discuss the complement system's role in the body's defense mechanisms, including its site of origin and mechanism of action. Keywords: cellular immunity| humoral| Mannose-binding lectin (MBL)| Histamine|Body defense system|WBC| Classical Pathway| Lectin Pathway| Properdin or Alternative P athway Introduction The complement system is crucial in the body's defense against invading pathogens and tumor cells. The complement system is a system of plasma enzymes. The liver synthesizes enzymes of the complement system. It comprises over 30 enzymes circulating in the blood and is responsible for cell killing by humoral and cellular immunity. These enzymes are inactive and become active when stimulated by an antigen-antibody complex or other pathways. When in active form, they work in a sequence of cascade reactions to remove pathogens, kill pathogens, initiate and promote inflammation, an...
Endocrine|Thyroid gland Thyroid gland|isthumus|thyos|size| Thyroxine |calcitonin| thyroglobulin |thyrocyte| pyramidal lobe' | Lalouette's lobe' | Berry's ligament.| transthyretin |thyroxin binding globulin|. parathyroid hormone |C cells| hormone receptors TR-α 1 and α 2 , TR-β 1 and β2| The thyroid gland is a butterfly-like organ, an endocrine gland, present superficially in the neck. It consists of two lobes right lobe and the left lobe. In the lower two-thirds, the lobes are connected by a thin band of tissue known as the Isthmus. Shape : It is a butterfly-like endocrine organ. In the 1600s, Thomas Wharton named this gland due to its shape resembling an ancient Greek shield or 'thyos.' Size : The weight of the gland is 25 grams. Each lobe is 5 cm long,3 cm wide, and 2 cm thick. The Isthmus is 1.25 cm in height and breadth. The thyroid gland is more prominent in women than men and increases during pregnancy...