Skip to main content

Thyroid Hormones

THYROID HORMONES
The thyroid gland secretes 3 3 hormones-thyro-xine (T4), triiodothyronine (T,) and calcitonin.
The former two are produced by thyroid follicles,have similar biological activity and the term
'thyroid hormone' is restricted to these only. Calcitonin produced by interfollicular "C cells is chemically and biologically entirely different. It is considered along with parathormone with which it regulates calcium metabolism.
          The physiological significance of thyroid gland was
recognized only after Graves and Basedow (1835, 1840)
associated the clinical features of the Graves' disease'
with swelling of thyroid gland and Gull (1874) correlated
myxoedema with its atrophy. Kendall (1915) obtained
erystalline thyroxine and postulated its chemical formula
which was confirmed in 1926. Thyroxine was the first
hormone to be synthesized in the laboratory. Since T
could not account for all the biological activity of thy-
roid extract, search was made and more potent T, was
discovered in 1952.
Labels:

Comments

Post a Comment

Popular posts from this blog

Diabetes

  What is Diabetes ?  Diabetes refers to a group of conditions characterized by a high level of blood glucose, commonly referred to as blood sugar. Too much sugar in the blood can cause serious, sometimes life-threatening health problems.There are two types of chronic diabetic conditions: type 1 diabetes and type 2 diabetes. Pregnant women may acquire a transient form of the disease called “gestational diabetes”which usually resolves after the birth of baby. Pre-diabetes is when the blood sugar level is at the borderline: higher than normal, but lower than in diabetics. Prediabetes mayor may not progress to diabetes. During food digestion, carbohydrates - or carb - break down into glucose which is carried by the bloodstream to various organs of the body. Insulin is a hormone produced by beta cells of the pancreas and is necessary for glucose intake by target cells. In healthy people, beta cells of the pancreas produce insulin; insulin binds to its receptor on target cells and ...
Post a Comment
Read more

Vaccine Work Mechanism

How Vaccines work ?                                                                               Vaccines prepare the immune system, getting it ready to fight disease-causing organisms, called pathogens. To understand how vaccines work, we must first learn how our immune system responds to invading pathogens. When a new pathogen enters the body, it meets with the body’s first-line defense, the innate division of the immune system. The innate response is immediate, but non-specific,meaning it destroys all foreign invaders without discrimination. Fever is one of the signs that the body is fighting the disease at this stage. If this fails to contain the infection, the adaptive immune system comes into play. The adaptive response is more effective, but it may take many days to activate, during...
Post a Comment
Read more

Adrenergic Drugs

Mechanisms of action & Classification  Adrenergic drugs are medications that stimulate or inhibit adrenergic receptors. Adrenergic receptors mediate the action of noradrenaline, also known as norepinephrine; and adrenaline, also known as epinephrine. Adrenergic neurotransmission is responsible for the body’s sympathetic response - the “fight or flight” state - which dilates pupils, increases heart rate and respiratory rate, diverts blood flow to the muscles, inhibits activities that are not essential in emergency, and releases stored energy. Adrenergic receptors are also active in the central nervous system, in processes such as memory and alertness. There are several types of adrenergic receptors,all of which are G-protein coupled, but they differ in several aspects:- They couple with different G-proteins, leading to different downstream signalings, and hence different cellular responses. - They differ in sensitivity to different drugs. - While several receptors may coexist i...
Post a Comment
Read more