Semen known as seminal fluid, is an organic fluid that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa, provide a medium through which they can move or "swim". Semen is produced and originates from the seminal vesicle, located in the pelvis; the process that results in the discharge of semen is called ejaculation. Semen is a form of genetic material. In animals, semen has been collected for cryoconservation. Cryoconservation of animal genetic resources is a practice that calls for the collection of genetic material in efforts for conservation of a particular breed. Depending on the species, spermatozoa can fertilize ova internally. In external fertilization, the spermatozoa fertilize the ova directly, outside of the female's sexual organs.
Female fish, for example, spawn ova into their aquatic environment, where they are fertilized by the semen of the male fish. During internal fertilization, fertilization occurs inside the female's sexual organs. Internal fertilization takes place after insemination of a female by a male through copulation. In most vertebrates, including amphibians, reptiles and monotreme mammals, copulation is achieved through the physical mating of the cloaca of the male and female. In marsupial and placental mammals, copulation occurs through the vagina. During the process of ejaculation, sperm passes through the ejaculatory ducts and mixes with fluids from the seminal vesicles, the prostate, the bulbourethral glands to form the semen; the seminal vesicles produce a yellowish viscous fluid rich in fructose and other substances that makes up about 70% of human semen. The prostatic secretion, influenced by dihydrotestosterone, is a whitish, thin fluid containing proteolytic enzymes, citric acid, acid phosphatase and lipids.
The bulbourethral glands secrete a clear secretion into the lumen of the urethra to lubricate it. Sertoli cells, which nurture and support developing spermatocytes, secrete a fluid into seminiferous tubules that helps transport sperm to the genital ducts; the ductuli efferentes possess cuboidal cells with microvilli and lysosomal granules that modify the ductal fluid by reabsorbing some fluid. Once the semen enters the ductus epididymis the principal cells, which contain pinocytotic vessels indicating fluid reabsorption, secrete glycerophosphocholine which most inhibits premature capacitation; the accessory genital ducts, the seminal vesicle, prostate glands, the bulbourethral glands, produce most of the seminal fluid. Seminal plasma of humans contains a complex range of inorganic constituents; the seminal plasma provides a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract. The normal environment of the vagina is a hostile one for sperm cells, as it is acidic and patrolled by immune cells.
The components in the seminal plasma attempt to compensate for this hostile environment. Basic amines such as putrescine, spermine and cadaverine are responsible for the smell and flavor of semen; these alkaline bases counteract and buffer the acidic environment of the vaginal canal, protect DNA inside the sperm from acidic denaturation. The components and contributions of semen are as follows: A 1992 World Health Organization report described normal human semen as having a volume of 2 ml or greater, pH of 7.2 to 8.0, sperm concentration of 20×106 spermatozoa/ml or more, sperm count of 40×106 spermatozoa per ejaculate or more, motility of 50% or more with forward progression of 25% or more with rapid progression within 60 minutes of ejaculation. A 2005 review of the literature found that the average reported physical and chemical properties of human semen were as follows: Semen is translucent with white, grey or yellowish tint. Blood in the semen can cause a pink or reddish colour, known as hematospermia, may indicate a medical problem which should be evaluated by a doctor if the symptom persists.
After ejaculation, the latter part of the ejaculated semen coagulates forming globules, while the earlier part of the ejaculate does not. After a period ranging from 15 – 30 minutes, prostate-specific antigen present in the semen causes the decoagulation of the seminal coagulum, it is postulated that the initial clotting helps keep the semen in the vagina, while liquefaction frees the sperm to make their journey to the ova. A 2005 review found that the average reported viscosity of human semen in the literature was 3–7 cP. Semen quality is a measure of the ability of semen to accomplish fertilization. Thus, it is a measure of fertility in a man, it is the sperm in the semen, the fertile component, therefore semen quality involves both sperm quantity and sperm quality. The volume of semen ejaculate varies but is about 1 teaspoonful or less. A review of 30 studies concluded that the average was around 3.4 milliliters, with some studies finding amounts as high as 5.0 ml or as low as 2.3 ml. In a study with Swedish and Danish men, a prolonged interval between ejaculations caused an increase of the sperm count in the semen but not an increase of its amount.
Some dietary supplements have been marketed with claims to increase seminal volume. Like other supplements, including so-called herbal viagra, these are not approved or regulated by the Food and Drug Administration
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. The various types of sugar are derived from different sources. Simple sugars are called monosaccharides and include glucose and galactose. "Table sugar" or "granulated sugar" refers to a disaccharide of glucose and fructose. In the body, sucrose is hydrolysed into glucose. Sugars are found in the tissues of most plants, but sucrose is concentrated in sugarcane and sugar beet, making them ideal for efficient commercial extraction to make refined sugar. Sugarcane originated in tropical Indian subcontinent and Southeast Asia, is known of from before 6,000 BP, sugar beet was first described in writing by Olivier de Serres and originated in southwestern and Southeast Europe along the Atlantic coasts and the Mediterranean Sea, in North Africa, Macaronesia, to Western Asia. In 2016, the combined world production of those two crops was about two billion tonnes. Other disaccharides include lactose. Longer chains of sugar molecules are called polysaccharides.
Some other chemical substances, such as glycerol and sugar alcohols, may have a sweet taste, but are not classified as sugar. Sucrose is used in prepared foods, is sometimes added to commercially available beverages, may be used by people as a sweetener for foods and beverages; the average person consumes about 24 kilograms of sugar each year, or 33.1 kilograms in developed countries, equivalent to over 260 food calories per day. As sugar consumption grew in the latter part of the 20th century, researchers began to examine whether a diet high in sugar refined sugar, was damaging to human health. Excessive consumption of sugar has been implicated in the onset of obesity, cardiovascular disease and tooth decay. Numerous studies have tried to clarify those implications, but with varying results because of the difficulty of finding populations for use as controls that consume little or no sugar. In 2015, the World Health Organization recommended that adults and children reduce their intake of free sugars to less than 10%, encouraged a reduction to below 5%, of their total energy intake.
The etymology reflects the spread of the commodity. From Sanskrit शर्करा, meaning "ground or candied sugar," "grit, gravel", came Persian shakar, whence Arabic سكر, whence Medieval Latin succarum, whence 12th-century French sucre, whence the English word sugar. Italian zucchero, Spanish azúcar, Portuguese açúcar came directly from Arabic, the Spanish and Portuguese words retaining the Arabic definite article; the earliest Greek word attested is σάκχαρις. The English word jaggery, a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin: Portuguese jágara from the Malayalam ചക്കരാ, itself from the Sanskrit शर्करा. Sugar has been produced in the Indian subcontinent since ancient times and its cultivation spread from there into modern-day Afghanistan through the Khyber Pass, it was not plentiful or cheap in early times, in most parts of the world, honey was more used for sweetening. People chewed raw sugarcane to extract its sweetness. Sugarcane was a native of Southeast Asia.
Different species seem to have originated from different locations with Saccharum barberi originating in India and S. edule and S. officinarum coming from New Guinea. One of the earliest historical references to sugarcane is in Chinese manuscripts dating to 8th century BCE, which state that the use of sugarcane originated in India. In the tradition of Indian medicine, the sugarcane is known by the name Ikṣu and the sugarcane juice is known as Phāṇita, its varieties and characterics are defined in nighaṇṭus such as the Bhāvaprakāśa. Sugar remained unimportant until the Indians discovered methods of turning sugarcane juice into granulated crystals that were easier to store and to transport. Crystallized sugar was discovered by the time of the Imperial Guptas, around the 5th century CE. In the local Indian language, these crystals were called khanda, the source of the word candy. Indian sailors, who carried clarified butter and sugar as supplies, introduced knowledge of sugar along the various trade routes they travelled.
Traveling Buddhist monks took sugar crystallization methods to China. During the reign of Harsha in North India, Indian envoys in Tang China taught methods of cultivating sugarcane after Emperor Taizong of Tang made known his interest in sugar. China established its first sugarcane plantations in the seventh century. Chinese documents confirm at least two missions to India, initiated in 647 CE, to obtain technology for sugar refining. In the Indian subcontinent, the Middle East and China, sugar became a staple of cooking and desserts. Nearchus, admiral of Alexander of Macedonia, knew of sugar during the year 325 B. C. because of his participation in the campaign of India led by Alexander. The Greek physician Pedanius Dioscorides in the 1st century CE described sugar in his medical treatise De Materia Medica, Pliny the Elder, a 1st-century CE Roman, described sugar in his Natural History: "Sugar is made in Arabia as well, but Indian sugar is better, it is a kind of honey found in cane, white as gum, it crunches between the teeth.
It comes in lumps the size of a hazelnut. Sugar is used only for medical purposes." Crusaders brought sugar back to Europe after their campaigns in the Hol
The pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs or the skeleton embedded in it. The pelvic region of the trunk includes the bony pelvis, the pelvic cavity, the pelvic floor, below the pelvic cavity, the perineum, below the pelvic floor; the pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs, they are attached to the sacrum posteriorly, connected to each other anteriorly, joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and consists of the reproductive organs and the rectum, while the pelvic floor at the base of the cavity assists in supporting the organs of the abdomen. In mammals, the bony pelvis has a gap in the middle larger in females than in males, their young pass through this gap.
The pelvic region of the trunk is the lower part of the trunk, between the thighs. It includes several structures: the bony pelvis, the pelvic cavity, the pelvic floor, the perineum; the bony pelvis is the part of the skeleton embedded in the pelvic region of the trunk. It is subdivided into the pelvic spine; the pelvic girdle is composed of the appendicular hip bones oriented in a ring, connects the pelvic region of the spine to the lower limbs. The pelvic spine consists of the coccyx; the pelvic cavity defined as a small part of the space enclosed by the bony pelvis, delimited by the pelvic brim above and the pelvic floor below. Each hip bone consists of 3 sections, ilium and pubis. During childhood, these sections are separate bones, joined by the triradiate cartilage. During puberty, they fuse together to form a single bone; the pelvic cavity is a body cavity, bounded by the bones of the pelvis and which contains reproductive organs and the rectum. A distinction is made between the lesser or true pelvis inferior to the terminal line, the greater or false pelvis above it.
The pelvic inlet or superior pelvic aperture, which leads into the lesser pelvis, is bordered by the promontory, the arcuate line of ilium, the iliopubic eminence, the pecten of the pubis, the upper part of the pubic symphysis. The pelvic outlet or inferior pelvic aperture is the region between the subpubic angle or pubic arch, the ischial tuberosities and the coccyx. Ligaments: obturator membrane, inguinal ligament Alternatively, the pelvis is divided into three planes: the inlet and outlet; the pelvic floor has two inherently conflicting functions: One is to close the pelvic and abdominal cavities and bear the load of the visceral organs. To achieve both these tasks, the pelvic floor is composed of several overlapping sheets of muscles and connective tissues; the pelvic diaphragm is composed of the coccygeus muscle. These arise between the symphysis and the ischial spine and converge on the coccyx and the anococcygeal ligament which spans between the tip of the coccyx and the anal hiatus; this leaves a slit for the urogenital openings.
Because of the width of the genital aperture, wider in females, a second closing mechanism is required. The urogenital diaphragm consists of the deep transverse perineal which arises from the inferior ischial and pubic rami and extends to the urogential hiatus; the urogenital diaphragm is reinforced posteriorly by the superficial transverse perineal. The external anal and urethral sphincters close the urethra; the former is surrounded by the bulbospongiosus which narrows the vaginal introitus in females and surrounds the corpus spongiosum in males. Ischiocavernosus clitoridis. Modern humans are to a large extent characterized by large brains; because the pelvis is vital to both locomotion and childbirth, natural selection has been confronted by two conflicting demands: a wide birth canal and locomotion efficiency, a conflict referred to as the "obstetrical dilemma". The female pelvis, or gynecoid pelvis, has evolved to its maximum width for childbirth—a wider pelvis would make women unable to walk.
In contrast, human male pelvises are not constrained by the need to give birth and therefore are more optimized for bipedal locomotion. The principal differences between male and female true and false pelvis include: The female pelvis is larger and broader than the male pelvis, taller and more compact; the female inlet is oval in shape, while the male sacral promontory projects further. The sides of the male pelvis converge from the inlet to the outlet, whereas the sides of the female pelvis are wider apart; the angle between
Arousal is the physiological and psychological state of being awoken or of sense organs stimulated to a point of perception. It involves activation of the ascending reticular activating system in the brain, which mediates wakefulness, the autonomic nervous system, the endocrine system, leading to increased heart rate and blood pressure and a condition of sensory alertness and readiness to respond. Arousal is mediated by several different neural systems. Wakefulness is regulated by the ARAS, composed of projections from five major neurotransmitter systems that originate in the brainstem and form connections extending throughout the cortex. Activation of these neurons produces an increase in cortical activity and subsequently alertness. Arousal is important in regulating consciousness, attention and information processing, it is crucial for motivating certain behaviours, such as mobility, the pursuit of nutrition, the fight-or-flight response and sexual activity. It is important in emotion and has been included in theories such as the James-Lange theory of emotion.
According to Hans Eysenck, differences in baseline arousal level lead people to be extraverts or introverts. The Yerkes-Dodson law states that an optimal level of arousal for performance exists, too little or too much arousal can adversely affect task performance. One interpretation of the Yerkes-Dodson Law is the Easterbrook cue-utilisation hypothesis. Easterbrook states. Wakefulness is regulated by the ascending reticular activating system, composed of five major neurotransmitter systems – the acetylcholine, dopamine and serotonin systems – that originate in the brainstem and form connections which extend throughout the cerebral cortex; when stimulated, these systems alertness. The noradrenergic system is a bundle of axons that originate in the locus coeruleus and ascends up into the neocortex, limbic system, basal forebrain. Most of the neurons are projected to the posterior cortex, important with sensory information, alertness; the activation of the locus coeruleus and release of norepinephrine causes wakefulness and increases vigilance.
The neurons that project into the basal forebrain impact cholinergic neurons that results in a flood of acetylcholine into the cerebral cortex. The acetylcholinergic system has its neurons located in the basal forebrain. Stimulation of these neurons result in cortical activity, shown from EEG records, alertness. All of the other four neurotransmitters play a role in activating the acetylcholine neurons. Another arousal system, the dopaminergic system, releases dopamine produced by the substantia nigra; the neurons arise in the ventral tegmental area in the midbrain, projects to the nucleus accumbens, the striatum forebrain, limbic system, prefrontal cortex. The limbic system is important for control of mood, the nucleus accumbens signal excitement and arousal; the path terminating in the prefrontal cortex is important in regulating motor movements reward oriented movements. The serotonergic system has all of its serotonergic neurons originating in the raphe nuclei; this system projects to the prefrontal cortex.
Stimulation of these axons and release of serotonin causes cortical arousal and impacts locomotion and mood. The neurons of the histaminergic system are in the tuberomammillary nucleus of the hypothalamus; these neurons send pathways to the cerebral cortex and the basal forebrain, where they stimulate the release of acetylcholine into the cerebral cortex. All of these systems show similar redundancy; the pathways described are ascending pathways, but there arousal pathways that descend. One example is the ventrolateral preoptic area, which release GABA reuptake inhibitors, which interrupt wakefulness and arousal. Neurotransmitters of the arousal system, such as acetylcholine and norepinephrine, work to inhibit the ventrolateral preoptic area. Arousal is important in regulating consciousness and information processing, it is crucial for motivating certain behaviors, such as mobility, the pursuit of nutrition, the fight-or-flight response and sexual activity. Arousal is an essential element in many influential theories of emotion, such as the James-Lange theory of emotion or the Circumplex Model.
According to Hans Eysenck, differences in baseline arousal level lead people to be either extraverts or introverts. Research suggests that extroverts and introverts have different arousability, their baseline arousal level is the same. The Yerkes–Dodson law states that there is a relationship between arousal and task performance arguing that there is an optimal level of arousal for performance, too little or too much arousal can adversely affect task performance. One interpretation of the Yerkes–Dodson law is the Easterbrook cue-utilisation theory, it predicted that high levels of arousal will lead to attention narrowing, during which the range of cues from the stimulus and the environment decreases. According to this hypothesis, attention will be focused on the arousing details of the stimulus, so that information central to the source of the emotional arousal will be encoded while peripheral details will not. In positive psychology, arousal is described as a respon
Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into blood during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847; the name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, odorless, crystalline solid, is the most water-soluble of all the sugars. Fructose is found in honey and vine fruits, flowers and most root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, maize. Crystalline fructose is the monosaccharide, ground, of high purity. High-fructose corn syrup is a mixture of fructose as monosaccharides. Sucrose is a compound with one molecule of glucose covalently linked to one molecule of fructose. All forms of fructose, including fruits and juices, are added to foods and drinks for palatability and taste enhancement, for browning of some foods, such as baked goods.
About 240,000 tonnes of crystalline fructose are produced annually. Excessive consumption of fructose may contribute to insulin resistance, elevated LDL cholesterol and triglycerides, leading to metabolic syndrome, type 2 diabetes and cardiovascular disease; the European Food Safety Authority stated that fructose is preferable over sucrose and glucose in sugar-sweetened foods and beverages because of its lower effect on postprandial blood sugar levels, noted that "high intakes of fructose may lead to metabolic complications such as dyslipidaemia, insulin resistance, increased visceral adiposity". Further, the UK’s Scientific Advisory Committee on Nutrition in 2015 disputed the claims of fructose causing metabolic disorders, stating that "there is insufficient evidence to demonstrate that fructose intake leads to adverse health outcomes independent of any effects related to its presence as a component of total and free sugars." The word "fructose" was coined in 1857 from the Latin for fructus and the generic chemical suffix for sugars, -ose.
It is called fruit sugar and levulose. Fructose is a 6-carbon polyhydroxyketone. Crystalline fructose adopts a cyclic six-membered structure owing to the stability of its hemiketal and internal hydrogen-bonding; this form is formally called D-fructopyranose. In water solution, fructose exists as an equilibrium mixture of 70% fructopyranose and about 22% fructofuranose, as well as small amounts of three other forms, including the acyclic structure. Fructose may be anaerobically fermented by yeast or bacteria. Yeast enzymes convert sugar to carbon dioxide; the carbon dioxide released during fermentation will remain dissolved in water, where it will reach equilibrium with carbonic acid, unless the fermentation chamber is left open to the air. The dissolved carbon dioxide and carbonic acid produce the carbonation in bottled fermented beverages. Fructose undergoes non-enzymatic browning, with amino acids; because fructose exists to a greater extent in the open-chain form than does glucose, the initial stages of the Maillard reaction occur more than with glucose.
Therefore, fructose has potential to contribute to changes in food palatability, as well as other nutritional effects, such as excessive browning and tenderness reduction during cake preparation, formation of mutagenic compounds. Fructose dehydrates to give hydroxymethylfurfural; this process, in the future, may become part of a low-cost, carbon-neutral system to produce replacements for petrol and diesel from plants. The primary reason that fructose is used commercially in foods and beverages, besides its low cost, is its high relative sweetness, it is the sweetest of all occurring carbohydrates. The relative sweetness of fructose has been reported in the range of 1.2–1.8 times that of sucrose. However, it is the 6-membered ring form of fructose, sweeter. Warming fructose leads to formation of the 5-membered ring form. Therefore, the relative sweetness decreases with increasing temperature; however it has been observed that the absolute sweetness of fructose is identical at 5 °C as 50 °C and thus the relative sweetness to sucrose is not due to anomeric distribution but a decrease in the absolute sweetness of sucrose at lower temperatures.
The sweetness of fructose is perceived earlier than that of sucrose or glucose, the taste sensation reaches a peak and diminishes more than that of sucrose. Fructose can enhance other flavors in the system. Fructose exhibits a sweetness synergy effect; the relative sweetness of fructose blended with sucrose, aspartame, or saccharin is perceived to be greater than the sweetness calculated from individual components. Fructose has higher water solubility than other sugars, as well as other sugar alcohols. Fructose is, difficult to crystallize from an aqueous solution. Sugar mixes containing fructose, such as candies, are softer than those containing other sugars because of the greater solubility of fructose. Fructose is quicker to absorb moisture and slower to release it to the environment than sucrose, glucose, or other nutritive sweeteners. Fructose is an excellent humectant and retains moisture for a long period of time at low relative humidity. Therefore, fructose can contribute a more palatable texture, longer shelf life to the food products in which it is used.
Fructose has a greater effect on freezing point depression than disaccharides or oligosaccharides, which may prot