Tag: hormones

Hormones are powerful. It takes only a tiny amount to cause big changes in cells or even whole body. Hormones are chemicals produced by special cells in glands and other organs of the body; most hormones are produced by cells in the endocrine glands. These hormones, which are produced in very small amounts, are released into the bloodstream and travel to the target organ or tissue where they exert their effect. That is why too much or too little of a certain hormone can be serious. Not all the hormones are easily diffusible. Among the diffusible lipid-soluble molecules are steroid hormones. Hormones are nonantigenic that is no antibody formation occurs against hormones.

Hormones are special chemical messengers in the body that are created in the endocrine glands like Thyroid gland produces thyroxine and calcitonin. 

Hormone is a chemical messenger produced in the body that controls and regulates the activity of certain cells or organs. Hormones are secreted from the endocrine glands in the body. The glands are ductless, so hormones are secreted directly into the bloodstream. 

Vitamin D is a hormone produced by the kidneys that help to control the concentration of calcium in the blood and is vital for the development of strong bones. Thyroxine, also called as 3,5,3,5-tetraiodothyronine, or $T _ 4$, is one of the two major hormones secreted by the thyroid gland. Epinephrine, more commonly known as adrenaline, is a hormone secreted by the medulla of the adrenal glands.

The hormone is a regulatory substance produced in an organism and transported in tissue fluids, such as blood or sap to stimulate specific cells or tissues into action. Usually, it is a class of signaling molecules, produced by glands in multicellular organisms, that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.

Rickets is defective mineralization or calcification of bones before epiphyseal closure in immature mammals due to deficiency or impaired metabolism of vitamin D, phosphorus or calcium, leading to fractures and deformity. 

The local hormones are known as kinins, which are released to overcome changes in body tissues. Kinins help in vasodilation and increase blood supply to the affected part, causing a mild local pain. Thus, they act as the first aid of the body. The sensation of pain at the time of stinging by a poisonous insect, burning or internal injury is due to kinins. So, they are called, first aid hormones.

Pheromones are the chemicals or compounds which have peculiar odour. These are secreted and released by the organisms with the help of glands present on the skin surface at various locations. These pheromones have odour which help in attracting the other member of the same species. The pheromone initiates a neuronal response and there is change in the physiolodical behaviour of the organism. There are various forms of pheromones like alarm pheromeones, food trail phereomeones and sex phereomones.

The chemical substances that are secreted by cells/tissues or glands are categorised as biological substances. It includes digestive juices, hormones and other secretions. Gastrin, thyroxin and oxytocin are the hormones secreted by stomach, thyroid gland and posterior pituitary respectively. These are biochemical substances. Creatinine is a breakdown product of creatine phosphate and does not fall under the biological category of chemical substances. Thus, the correct answer is D.