Adrenal Glands
Identification and description of organs which make up the endocrine system
The human body comprises of organ systems which distinct but work together as a coordinated single unit (Marieb & Hoehn 1-35). This paper will single out the endocrine system because discussing the organ system in entirety is beyond the scope of this assignment. The adrenaline glands form part and parcel of the endocrine system, thus, the relevance of the topic. The endocrine glands comprise glands which secrete hormones which help to modulate on the functions of the cells and/or organs. Hormones are chemical substances which regulate cell activities (Axelrod et al 452-459). They act like messengers in that they relay information from one part of the body to another. The main glands of the endocrine system are the hypothalamus, thyroid and parathyroid glands, pineal body, reproductive organs; pituitary and most important to this paper the adrenal glands (Axelrod et al 452-459).
To understand how adrenaline glands function requires that one explore the other organs of the endocrine systems aforementioned from above. Let us begin with the pituitary gland. The process is offset a signal sent from the hypothalamus to the pituitary gland in form of “releasing hormone”, which in turn necessitates the production of stimulating hormone into the circulation system (Melmed et al 34), on reaching the target gland or organ, it stimulates it to produce the required hormone. A rise in the level of the target hormone in circulation leads to a decline in production of the releasing and stimulating hormones to slow release of hormones from the target organ, leading to stabilization in the balance of the hormones circulating in the blood.
As for the thyro...
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...nostic tool for Cushing's syndrome and adrenal insufficiency: improved screening by an automatic immunoassay." European Journal of Endocrinology 166.4 (2012): 613-618.
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While the respiratory and cardiovascular systems are most reliant on one another, all body systems require a functioning circulatory cycle in order to thrive. Blood circulation and consistent transfer of oxygen to cells is required to maintain cell and tissue life. Disturbances to this process will cause cells and tissues to die (Red Cross 48). This state of balance and functioning body systems is referred to as homeostasis, defined as a “condition of equilibrium in the body’s internal environment due to constant interaction of body’s many regulatory processes” (Tortura 8). Changes or disruptions to homeostasis are regulated by the Endocrine and Nervous systems of the body. The endocrine system is made up of glands placed throughout the body
The hypothalamus in the brain is above the pituitary gland. The hypothalamus releases corticotrophin (CHR) which is a chemical messenger. CHR stimulates the pituitary gland to release adrenal corticotrophin (ACTH). ACTH which is released into the blood then signals the adrenal gland. When the adrenal gland receives ACTH it is the chemical signal for cortisol production. In a normal system cortisol (an anti-inflammatory) production would st...
...the adrenal glands, attaches to the signal-binding site of a G-protein-linked receptor. When this happens, the G-protein, which has three subunits, is activated. One subunit, the α subunit, of the G-protein detaches, or dissociates, itself from the other two. This subunit carries a GDP molecule which is replaced by a GTP molecule. Then it attaches to a protein called adenylyl cyclase, which converts ATP into cAMP(Adenosine Monophosphate with a cyclic group). Cyclic AMP, the secondary messenger, is released by the adenylyl cyclase and binds to the regulatory portions of the protein kinase, releasing the catalytic portions. Then these catalytic portions are going to undergo the phosphorylation cascade. The newly activated protein kinases transfer their phosphate groups to a protein called phosphorylase which releases glucose from glycogen into the bloodstream.
Congenital Adrenal Hyperplasia (CAH) is an inherited condition that affects hormone production in the adrenal gland. The individual lacks enzymes to make cortisol, and hormones are instead are shifted away to make other hormones, specifically androgens. This results in the deficiency of cortisol and the abundance of testosterone.
When a receptor is activated and the stimulus is taken to the hypothalamus and then relayed out to the “limbic system and neocortical areas…impulses stimulate the neuroendocrine and autonomic nervous system,” which can cause an array of issues if not careful and if the stress signal is prolonged. (3)
Cortisol is in the class of hormones called glucocorticoids and affects almost every organ in the body. One of the most important functions of cortisol is to help regulate the body’s response to stress. Cortisol is also responsible for other necessary functions including: helping to maintain blood pressure and cardiovascular functions, helping to slow the immune system’s inflammatory response, helping to balance the effects of insulin in breaking down sugars for energy, helping to regulate the metabolism of proteins, carbohydrates, and fats, and helping to maintain proper arousal of sense of well being. The amount of cortisol is precisely balanced and regulated by the brain’s hypothalamus.
An analogy that fits very well with the study of the endocrine system is that of a message in a bottle. We can think of the body as a river, and a specific hormone may be a bottle containing a message. The organs or glands mentioned above would manufacture the “bottles'; (hormones) that would be released into the river (blood stream). If there were no receptor sites for the hormones in the body, then they would continue to flow along the river and probably not make their destination. However, there are systems of receptor sites that enable specific hormones to bind in specific places. Structure also plays a major role in determining which hormones are able to bind to which receptors.
Cushing syndrome was named after Harvey Cushing in 1912. “Harvey Cushing first described the symptom complex of obesity, diabetes, hirsutism, and adrenal hyperplasia. He gave a vivid description of his first patient who was 23 years old and presented with the “most extraordinary appearance”” (“Osler’s phenomenon”: misdiagnosing Cushing’s syndrome; Postgraduate Medical Journal; October 2003). Although, Sir William Osier was the first to describe the symptoms of Cushing’s, but diagnosed his patient with myxoedema by mistake. Unfortunately many people were misdiagnosed, therefore, leading to mortality. In 1933, Cushing performed his first neurosurgery on his patient, which did not gain acceptance until much later. “Adrenal surgery was for many years the treatment of hypercorticism but prior to the availability of glucocorticosteroids substitution an extremely perilous undertaking” (Cushing’s syndrome: Historical Aspects, Lindholm J., October 2000).
The thyroid gland is found in the front of the neck and produces two main hormones. The hormones are called thuroxine (T4) and Triiodothyronine (T3). Together these hormones regulate the body’s metabolism by increasing energy use in cells, regulate growth and development, help to maintain body temperature and aid in oxygen consumption. These two hormones are regulated by hormones produced by the hypothalamus and pituitary gland. The hypothalamus senses changes in body’s metabolic rate and releases a hormone known as thyropin-releasing hormone (TRH). This hormone then flows through connecting vessels to the pituitary gland which signals it to release another hormone. This hormone is known as thyroid-stimulating hormone (TSH). TSH then makes its way to the bloodstream until it reaches the thyroid where it is then signaled to activate T3 and T4 production [1]. This mechanism is controlled by a negative feedback loop meaning that when there is a sufficient amount of thyroid hormones in the blood stream, this will signal back to stop production of thyroid stimulating hormones. Complications occur when the thyroid hormones keep increasing even though there is already a sufficient amount of T3 and T4 in the blood stream. This process of over expression of thryroid hormones is known as hyperthyroidism. Hyperthyroidism is a general term that includes any disease that has a consequence of an overabundance of thyroid hormones. Hyperthyroidism is a general term but there are many variant diseases that are in the hyperthyroidism category. These diseases include diffuse toxic goiter, Basedow’s disease, thyrotoxicosis, Parry’s and Graves’ disease.
Norepinephrine is the neurotransmitter released by sympathetic nerves (e.g., those innervating the heart and blood vessels) and, within the brain, those of the locus coe...
Approximately 20 million Americans are currently suffering from thyroid disease. This common, yet subtle disease can be have an immense impact on one’s health and lifestyle. I chose to research thyroid disease because I have had blood tests done in speculation of this disease because of the similar symptoms I was experiencing. Although I do not have thyroid disease, I am curious about how it affects the body and why this disease often goes undiagnosed. This system involving the thyroid is crucial in regulating the body’s hormones and keeping them.
The lighter, inner region is called the medulla. Each ... ... middle of paper ... ... pituitary to release antidiuretic hormone (ADH). The release of ADH into the bloodstream brings about the following: § ADH make the distil convoluted tubule and the collecting duct more permeable to water.
EDTA Titrations [homepage on the internet]. No date. [cited 2014 Mar 24]. Available from: http://bionmr.unl.edu/courses/chem221/lectures/chapter-12.ppt.
There are three major glands in the endocrine system, which are the thyroid gland, adrenal glands, the ovary and testes, and the pituitary gland. A section of the brain above the pituitary gland called the hypothalamus controls the endocrine system and communicates with...