Introduction
Chemical Coordination and integration are on the whole completed via way of means of the endocrine glands, which secrete numerous hormones that adjust specific frame functions. In the animal kingdom, vertebrates have greater complicated and superior endocrine structures as compared to invertebrates. Plants do now no longer own those glands, however, they do secrete plant hormones that manage numerous functions. To maintain homeostasis, the functions of the organs/organ systems in our body must this coordination and integration of all organ activities is ensured by the neural system and the endocrine system (neuroendocrine system). The neural system provides rapid point-to-point coordination between organs. This reaction is rapid but short-lived. For example, the nerve impulse causes the skeletal muscle to respond in milliseconds. Since not all cells in the body are innervated by neurons, cell functions are continuously coordinated and integrated by the endocrine system through hormones. The response of the target tissue to the effects of the hormone takes seconds or minutes or even more.
Endocrine Glands and Hormones
The study of the endocrine glands and hormones is called endocrinology. The name hormone was coined by H. Starling. Hormones are also known as “chemical messengers”. The first hormone discovered is secretin. Endocrine glands are called ductless glands because they lack ducts are defined as chemicals that are not nutrients. They act as intercellular messengers and are produced in small amounts. Hormones are short-lived and are broken down in the tissues and excreted in the bile and urine.
Human Endocrine Gland
The endocrine system consists of endocrine glands and diffuse hormone-producing tissues/cells located in various parts of the body. The endocrine system consists of organized endocrine organs such as the pituitary, pineal, thyroid, adrenal, pancreas, parathyroid, thymus, and gonads. Some other organs, for example; the liver, heart, kidneys, gastrointestinal tract also produce hormones.
The Hypothalamus
The hypothalamus is positioned under the thalamus, constituting the ground of the diencephalon It connects the neural and endocrine device as it’s miles carefully tied to the pituitary gland. Hypothalamus is the basal part of the diencephalon. It incorporates numerous corporations of neurosecretory cells referred to as nuclei. They produce forms of hormones namely 1) The liberating hormones and 2) the inhibiting hormones. The liberating hormones stimulate the secretion of pituitary hormones.
For example, The synthesis and launch of boom hormone from the pituitary are inspired through the liberating hormone (GHRH / somatocrinin), secreted through the hypothalamus. The inhibiting hormones inhibit the secretion of pituitary hormones. For example, somatostatin/GHIH from the hypothalamus inhibits the discharge of boom hormone (somatotropin) from the pituitary.
These hormones are secreted through the hypothalamic neurons by skipping thru the axons and launched into the hyperphysical portal device thru which they attain the anterior pituitary (adenohypophysis). The posterior pituitary (neurohypophysis) is beneath the direct neural law of the hypothalamus. Adenohypophysis is beneath the hormonal law of the hypothalamus.
The Pituitary Gland
It is a pea-sized (1.3 cm) gland located in the Sella Turkic of the sphenoid bone. It is connected to the hypothalamus through the infundibulum. Anatomically, it is divided into an adenohypophysis and an adenohypophysis consists of the pars distal is (anterior lobe of the pituitary gland) and the pars intermedia. The adenohypophysis develops as an outgrowth of the ectoderm (Rathke’s pouch) from the roof of the oral cavity (stomodaeum).
The anterior pituitary gland (pars distal is) secretes six protein hormones, while the pars intermedia secretes a protein hormone called melanocyte-stimulating hormone (MSH). In humans, the pars intermedia is almost fused with the pars distal is. The neurohypophysis (pars nervosa), also called the posterior pituitary gland, develops as an ectodermal outgrowth of the hypothalamus (floor of the diencephalon). It stores and releases two hormones called oxytocin and vasopressin, which are actually synthesized by the hypothalamus and transported atonally to the neurohypophysis.
Thyroid Gland
It is endodermal in origin. This is relatively vascular and the biggest endocrine gland positioned on both facet of the trachea with inside the neck region. It includes lobes linked with a skinny flap of connective tissue referred to as isthmus. Each lobe includes follicles and stromal tissue. The follicular cells secrete amine.
These hormones boom basal metabolic rate (BMR), assist RBC formation, controls the metabolism of carbohydrates, proteins, and fats, continues water and electrolyte balance, influences boom and they may be important for metamorphosis in amphibians parafollicular cells of thyroid gland secrete a protein hormone referred to as thyrocalcitonin (TCT) or calcitonin.
Mechanism Of Hormone Action
Hormones only act on specific target cells by binding to specific proteins called hormone receptors that are only found on target cells. Some hormones (e.g. growth hormone and thyroxine) affect many different types of cells because all of these cells have receptors for these hormones. they may not be specific to a particular hormone. But the receptors are specific because each receptor is specific to only one hormone. There are two types of hormone receptors. Membrane-bound receptors Intracellular receptors.
Conclusion
There are special chemicals that act like hormones and provide chemical coordination, integration, and regulation in the human body. These hormones regulate the metabolism, growth, and development of our organs, endocrine glands, or certain cells. Adrenals, pancreas, parathyroid, thymus, and gonads (testes and ovaries). In addition, some other organs, e.g. gastrointestinal tract The kidneys, heart, etc. also produce hormones. The pituitary gland is divided into three main parts called the pars distalis, pars intermedia, and parsnervosa. Pars distalis produce six trophic hormones. pars intermedia secreta only one hormone, while the pars nervosa (neurohypophysis) secretes two hormones.
The growth and development of somatic tissue is regulated through Pituitary hormones. In addition the activities carried by the peripheral endocrine glands are also carried through these hormones. The hormonal factor that is important to maintain the rhythm of the body throughout the day, known as melatonin is released by the pineal gland (e.g. sleep-wake cycle, body temperature, etc). In order to regulate the basal metabolic rate, the thyroidal hormones play an important role for the purpose of, the development, and maturation of the central nervous system. Erythropoiesis, metabolism of carbohydrates, proteins, and fats, menstrual cycle.
Namely, thyrocalcitonin,another thyroid hormone regulates the level of calcium in our blood by lowering it. The secretion of parathyroid hormone (PTH) is done through parathyroid glands, which is responsible for the increment of Ca2+ levels in blood resulting in calcium homeostasis. The secretion of thymosins is through thymus, which plays an important role in the differentiation of T lymphocytes, resulting in immunity of cell-mediated. In order to provide humoral immunity,the production of antibodies is increased by the thymosinalso.