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Stress (biology)

Stress (biology)
Walter Cannon used it in 1926 to refer to external factors that disrupted what he called homeostasis.[2] But "...stress as an explanation of lived experience is absent from both lay and expert life narratives before the 1930s".[3] Physiological stress represents a wide range of physical responses that occur as a direct effect of a stressor causing an upset in the homeostasis of the body. Upon immediate disruption of either psychological or physical equilibrium the body responds by stimulating the nervous, endocrine, and immune systems. The reaction of these systems causes a number of physical changes that have both short and long term effects on the body. Homeostasis is a concept central to the idea of stress. The ambiguity in defining this phenomenon was first recognized by Hans Selye (1907-1982) in 1926. Human brain (hypothalamus=red, amygdala=green, hippocampus/fornix=blue, pons=gold, pituitary gland=pink) The Spinal Cord Human spinal cord Adrenal gland Peripheral nervous system (PNS) Related:  stress

Testicle Internal organ in the male reproductive system Animation of the migration of spermatozoa from their origin as germ cells to their exit from the vas deferens. A) Blood vessels; B) Head of epididymis; C) Efferent ductules; D) Seminiferous tubules; E) Parietal lamina of tunica vaginalis; F) Visceral lamina of tunica vaginalis; G) Cavity of tunica vaginalis; H) Tunica albuginea; I) Lobule of testis; J) Tail of epididymis; K) Body of epididymis; L) Mediastinum; M) Vas deferens. Structure Appearance Male gonad (testes, left) and female gonad (ovaries, right) Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Measurement and Volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. However, research has shown that the most accurate calculation of actual testicular volume is gained from the formula:[1][2]: Internal structure Duct system Primary cell types Layers Temperature regulation

Stress Management Group Activities Stress, in and of itself, is not good or bad. It can be motivating. It can also be physically and psychologically harmful. The effect of stress is determined by your reaction to it so learning to manage it is a necessity. Activity #1: Have a Treasure Hunt Treasure hunts are a fun way to have groups work in smaller teams, teach problem-solving skills, and introduce a little friendly competition. Purpose Treasure hunts can strengthen relationships, foster teamwork, and help new members fit in. Design There are many possibilities when it comes to designing a treasure hunt. Having to figure out riddles to find the next clue Having to find a list of objects (or specific information) within a certain area Materials You'll need the following materials for this activity. Paper/pen for clues A prize for the winning team Instructions Here is an example of a clue-focused treasure hunt. Decide the geographic scope of the hunt. Alternate Method Activity #2: Play With Stress Balls Meditation can help by:

Thyroid Endocrine gland in the neck; secretes hormones that influence metabolism The thyroid gland develops in the floor of the pharynx at the base of the tongue at 3–4 weeks gestation; it then descends in front of the pharyngeal gut, and ultimately over the next few weeks, it migrates to the base of the neck. During migration, the thyroid remains connected to the tongue by a narrow canal, the thyroglossal duct. At the end of the fifth week the thyroglossal duct degenerates, and over the following two weeks the detached thyroid migrates to its final position. Euthyroid is the term used to describe a state of normal thyroid function in the body. The presence of the thyroid and its various diseases have been noted and treated for centuries, although the gland itself has only been described and named since the Renaissance.[4] Knowledge of the thyroid, its biochemistry, and its disorders developed throughout the late nineteenth and twentieth centuries. Structure[edit] Features[edit] Variation[edit]

The Science of Stress We all experience stress. Even the most seemingly Zen-like person, with not a worry in the world, has experienced stress. I can assure you that stress is an innate emotion, which everyone experiences from time to time. While there are many definitions of stress, I like to think of it as something that disturbs homeostasis.1 Stress is not something that we should try to avoid as if it were some sort of unhealthy food. Where Does Stress Come From? Stress primarily develops from two sources: external and internal. <a href=" src=" alt="The Most Common Sources of Stress" border="0" /></a><br />Source: <a href=" Blog</a> Close Embed Image Stress and Time Stress can come on quickly, like when you find out you have a pop quiz in five minutes, or it can linger in the back of your mind for weeks, like when preparing for an important business meeting. Sources:

Spongiocyte Type of cell in the zona fasciculata In the human endocrine system, a spongiocyte is a cell in the zona fasciculata of the adrenal cortex containing lipid droplets that show pronounced vacuolization, due to the way the cells are prepared for microscopic examination.[1] The lipid droplets contain neutral fats, fatty acids, cholesterol, and phospholipids; all of which are precursors to the steroid hormones secreted by the adrenal glands. The principal hormone secreted from the cells of the zona fasciculata are glucocorticoids, but some androgens are produced as well. The American Heritage Stedman's Medical DictionaryHistology, 5th Edition; Michael H. Ross and W.

The Fight or Flight Response - What is the "fight or flight response?" This fundamental physiologic response forms the foundation of modern day stress medicine. The "fight or flight response" is our body's primitive, automatic, inborn response that prepares the body to "fight" or "flee" from perceived attack, harm or threat to our survival. What happens to us when we are under excessive stress? When we experience excessive stress—whether from internal worry or external circumstance—a bodily reaction is triggered, called the "fight or flight" response. What are the signs that our fight or flight response has been stimulated (activated)? When our fight or flight response is activated, sequences of nerve cell firing occur and chemicals like adrenaline, noradrenaline and cortisol are released into our bloodstream. When our fight or flight system is activated, we tend to perceive everything in our environment as a possible threat to our survival. What is our fight or flight system designed to protect us from? Yes. 1. 1.

Somatostatin Peptide hormone that regulates the endocrine system Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones. Somatostatin inhibits insulin and glucagon secretion.[5][6] Somatostatin has two active forms produced by the alternative cleavage of a single preproprotein: one consisting of 14 amino acids (shown in infobox to right), the other consisting of 28 amino acids.[7][8] Among the vertebrates, there exist six different somatostatin genes that have been named SS1, SS2, SS3, SS4, SS5 and SS6.[9] Zebrafish have all six.[9] The six different genes, along with the five different somatostatin receptors, allow somatostatin to possess a large range of functions.[10] Humans have only one somatostatin gene, SST.[11][12][13]

7 Facts About Sugar and Depression: Is There a Connection? Image by Brook Lark Food can have many effects on your mood and emotions. When you’re hungry and want food, you can be grumpy, upset, or even angry. When you’ve had a delicious meal, you may feel elated and euphoric. The food you eat can also have long-term implications for your health. Specifically, eating too much sugar may increase your risk for mood disorders, including depression. Sugar occurs naturally in complex carbohydrates like fruits, vegetables, and grains. Eating too many simple sugars may increase your risk for depression, mood disorders, and several chronic health issues. Researchers in London discovered that a diet rich in whole foods like fruits, vegetables, and fish, can lower your risk for depression in middle age. You already know you should eat plenty of fruits, vegetables, and fish for heart and brain health and to help ward off chronic diseases. A study done in rats found that the brain’s sweet receptors are not adapted to constant and high levels of sugar. 1. 3.

Zuckerkandl's tubercle (thyroid gland) How a 4th-century Taoist concept is treating anxiety While the Tao Te Ching is not one of the world’s most discussed religious texts, at least relative to the amount of attention the Bible, Quran, and Buddhist and Hindu doctrines receive, Laozi’s slim volume of instructions has massively influenced how we think about Eastern philosophy. The basis of Taoism is embedded in his series of short and punchy ideas that are rooted in, at times, paradoxical thinking. Consider one of his most famous aphorisms: “The Tao does nothing, and yet nothing is left undone.” As with those who believe meditation is “doing nothing,” wu-wei is not an easily graspable concept when approached from a mindset of constant action, i.e. the perpetual distraction our brains (and by extension, technology) afford us. Wu-wei as “not forcing” is what we mean by going with the grain, rolling with the punch, swimming with the current, trimming sails to the wind, taking the tide at its flood, and stooping to conquer. Hobson uses the “triad test” to make this point:

Reproductive system System of organs within an organism which work together for the purpose of reproduction Animals[edit] In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Most other vertebrates have similar reproductive systems consisting of gonads, ducts, and openings. Vertebrates[edit] Vertebrates share key elements of their reproductive systems. Humans[edit] The human reproductive system usually involves internal fertilization by sexual intercourse. The female reproductive system has two functions: The first is to produce egg cells, and the second is to protect and nourish the offspring until birth. Male[edit] The male reproductive system is a series of organs located outside of the body and around the pelvic region of a male that contribute towards the reproduction process. The testes release a hormone that controls the development of sperm.

Brain, The Immune System And Stress: Ultimately Connected, New Studies Suggest Colorful abstract background blur motion with bokeh lightGetty Something we all are faced with is stress, especially during the end of the year when we have deadlines to meet, along with the numerous responsibilities during the holiday season. A report put out by the American Institute of Stress, found that about 80% of workers feel stress on the job, with 40% feeling that their “job is very or extremely stressful.” This is due to the fact that the workforce landscape has changed and, as a result, many workplaces are attempting to mitigate stress. For a long time it has been thought that the brain and the immune system are two separate entities that exist in different realms. Scientists have found that immune system supports the brain during times of psychological distress. Findings of this research suggest that stress is not merely a psychological state experienced by the brain, rather the immune system plays a role in communicating with the brain and supporting us in times of stress.

Posterior pituitary Posterior lobe of the pituitary gland Structure[edit] The posterior pituitary consists mainly of neuronal projections (axons) of magnocellular neurosecretory cells extending from the supraoptic and paraventricular nuclei of the hypothalamus. These axons store and release neurohypophysial hormones oxytocin and vasopressin into the neurohypophyseal capillaries, from there they get into the systemic circulation (and partly back into the hypophyseal portal system). Classification of the posterior pituitary varies, but most sources include the two regions below: Pars nervosa[edit] Also called the neural lobe or posterior lobe, this region constitutes the majority of the posterior pituitary and is the storage site of oxytocin and vasopressin. Infundibular stalk[edit] Also known as the infundibulum or pituitary stalk, the infundibular stalk bridges the hypothalamic and hypophyseal systems. The median eminence is only occasionally included as part of the posterior pituitary. Function[edit]