Endocrinology

Endocrinology is a branch of biology which deals with that of endocrine system. "Endo" means within and "krinein" mean separate. The name explains that there is a separate control system for the body, apart from nervous system.

Endocrine system consists of a group of ductless glands in the human body which controls and the co-ordinates the body functions and maintains a homeostasis{keeping the body in a good and balanced condition}.

Ductless glands: These ductless glands are called endocrine glands. These are ductless because they do not have a duct that carry their secretions to a specific part as that of pancreas, liver, salivary glands etc.(exocrine glands)

Secretions of the endocrine system is called as harmones . Harmones are chemical substances which are transported to target organs through blood.

Endocrine glands are located at different regions of the body but still form an organs system. the metabolic use of glucose depends on the nutritional situation existing at any time. Before breakfast after a 10 h fast (termed the post-absorptive state), the metabolic situation is fairly stable. Depending on prior nutritional state, the glucose stores (glycogen) in the liver may have been partly used and glucose production comes from a combination of hepatic gluconeogenesis and glycogenolysis. Glucose production and utilization are approximately equal at about 12 mol/kg body weight/min. After breakfast, the blood glucose concentration rises. The magnitude of the increase depends not only on the type of carbohydrate ingested (i.e. its glycemic index) but also on the rates of digestion and absorption. The portal vein glucose concentration rises from, say, 4 mmol/l to around 10 mmol/l and the liver takes up some of this glucose. A smaller fraction is taken up by muscle. Thus, in the anabolic phase of glucose metabolism, that fraction of glucose not directly utilized by cells is stored in the liver or muscle in the form of glycogen. In the catabolic phase (i.e. post-absorptive state), glucose is first obtained from glycogen stores (glycogenolysis) and then by gluconeogenesis. Insulin has anabolic actions on glucose metabolism, glucagon has catabolic actions .

Various endocrine glands in our body includes:

• Pituitary gland
• Adrenal gland
• Thyroid gland
• Parathyroid gland
• Gonads
• Pancreatic islets
• Thymus gland
• Pineal gland

However it has been proved through biochemical studies and electron microscopy that endocrine and nervous system function in intricately connected ways.