Diabetes mellitus is disorder of carbohydrate metabolism in which sugars in the body are not oxidised to produce energy due to lack of the pancreatic hormone insulin. The accumulation of sugar leads to its appearance in the blood (hyperglycaemia), then in the urine (glycosuria); symptoms include thirst, loss of weight, and the excessive production of urine. The use of fats as an alternative source of energy leads to disturbances of the acid-base balance, the accumulation of ketones in the bloodstream (ketosis), and eventually to diabetic coma.
So, the correct answer is (A): underproduction of insulin
The chemical coordination and integration of all physiological functions in the animal body are jointly synchronized by the neural and endocrine systems. The control and coordination of body functions are executed by the endocrine glands. They are ductless glands that secrete severel hormones to control and coordinate body functions.
The human body has several endocrine glands located in different parts. They cover the pituitary gland, thymus, thyroid gland, pineal gland, parathyroid, pancreas (dual gland), adrenal gland, and gonads (testes and ovaries). The liver, kidney, heart, and gastrointestinal tract also produce hormones in small traces to harmonize the functioning of these organs.
The Hypothalamus comprises groups of secretory cells called nuclei which secrets various hormones. These hormones released by the hypothalamus are important in regulating the synthesis and secretion of pituitary hormones.