When I was little, I would be working around the barn and I would see a bull go up to a cow that is urinating and stick his nose right in the urine. I would then think ‘what the heck are you doing, you know that’s not water, right?’. I could never figure out why the bull would do that. Well, now I do- he was smelling her pheromones. “Pheromones are air-borne chemical signals that are released during urination or in feces of animals (Rekwot).” Pheromones are secreted from cutaneous glands; from there they are then perceived by the olfactory system where they stimulate a behavioral or an endocrine response. In response to the signals being released, the reaction that happens in the animal’s body involves either the reaction of a specific behavior or a change in the endocrine or reproductive system. There are two types of pheromones- the Signaling and the Priming pheromones (Rekwot).
Signaling pheromones cause an immediate behavior response, invoking a stimulus or the transfer of information between animals. The area that signaling pheromones affects is the olfactory cue. Olfactory cues convey specific information and this result in specific and immediate behavioral response in the male. The Olfactory cue may also be produced in the urine or vaginal secretions of females (Rekwot). Males investigate the anogenital regions of females, this includes sniffing, licking, and nuzzling of that area, this will induce urination by the female. The male will then put his muzzle and mouth directly in the urine; this is related to the vomeronasal organ (VNO). The VNO neurons then respond to pheromones.It is thought that another function of the VNO is to stimulate and maintain sexual activity through the olfactory stimuli (Stowers 699-7032).
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...ows respond to pheromone stimulus from bulls in a dose-dependent manner.
“Cows that did not perceive the minimum daily dose or threshold of pheromone stimulation and relaxation cycles would not receive the appropriate biostimulatory signal and would not resume OA. (Taurck 13-18)
Many mammals use chemo signals to synchronize reproduction by altering the physiology and behavior. Once in reproductive ailment, odors produced and deposited by both males and females are used to find and select an individual for mating. The production, spreading and suitable responses to these cues are modulated by organizational and activational effects of gonadal sex steroids. Thereby intrinsically linking chemical communication to the broader reproductive context. Pheromones are becoming a very popular subject; however there is much lacking in the research and informational part of it.
The testes are the primary reproductive organs in the male; they are responsible for the production of sperm. The testes are responsible for the production of testosterone, and are almost nonexistent prior to puberty. Testosterone affects vary to the sound of your voice to hair baldness. The epididymis is a firm structure that consists of three parts, sperm that passes through the epididymis after they are formed. The male urethra is approximately 18-20 cm long. The urethra allows the passage of both urine and sperm. There are two main parts of the penis; the root and body. The three main parts of the root of the penis are, the midline bulb, and the left and right crura on either side of the bulb. While the body is formed by three cylindrical masses of erectile tissue, they are the corpus spongiosum in the midline, and the two-corpus cavernosa on either side. The urethra leaves the head of the penis at the end of the corpus spongiosum.
Scent is part of the five senses that are developed when an infant is still in the mother’s womb. It is processed by a part of the brain that correlates with memory, so at a young age an infant could differentiate who their mother is by scent. Odor is a sign and olfactory condition (Waskul & Vannini, 2008). As someone gets older they begin to develop scents they like and dislike. There are also scents that people find attractive and unattractive. When meeting another individual for the first time a human’s first instinct is to smell them without realizing it. For instance, have you ever sat by someone or hugged someone who smelled good or bad? If so, many people tend to associate the scent with attractiveness or unattractiveness depending on the level of smell. There have been many studies indicating that there is a strong correlation between odor and attractiveness. Although the scent is a universal and an undetectable smell it can influence the level of perceived attractiveness of another person.
Elizabeth Svoboda, the author of “Scents and Sensibility” develops her claim that true happiness in love is based on scent by supporting her opinions with a scientific experiment and its results as well as identifiable and relatable facts. In the cleverly-named article, Svoboda describes the highlights of a study in which women were asked to identify the “attractiveness” of a multitude of T-shirts worn by several different men. After outlining the basis of the study, Svoboda states the profound results, including how “far more than often would predict, the women preferred the smell of T-shirts worn by men who were immunologically dissimilar to them” and that “the smell of their favorite T-shirts also [suggested] that MHC (major histocompatibility
As you can see, it is important to research sexual selection across various species’. Similar mechanisms of selection are present in all animals. By learning how these mechanisms act in one species, it is possible to gain insight into the behavior of all animals, including human beings.
Lontra candensis, river otters, use their pheromones in a behavior commonly referred to as scent marking. River otters are semi-aquatic, carnivorous mammals that live mainly in inland waterways, ponds, and lakes. They are most well-known for their playful antics, and they can be observed playing in their natural habitats throughout North America.1 Scent marking is a behavior that has been observed in several different animal species, particularly mammals, but for otters it is very strange. Otters are semi-aquatic, and aquatic animals usually do not partake in this behavior. There are many different hypotheses as to why otters demonstrate this behavior.
The activation of men’s sexual organs would be androgen hormones. Androgens are a major contributor in male’s sexual hormones. Testosterone is the most commonly known active and abundant androgen hormone. Androsterone is an inactive androgen that is made by the metabolism of testosterone and is developed in the male testes. Androgens have the ability to influence several different actions and desires within men. Usually, androgens are known as the masculine hormones although they are also found in women as well. Although not an androgen, many studies observe cortisol along with androgens because cortisol is a response to stress, also known as the "get-up-and-go" hormone. It gives men bravery to overcome challenges to reach their goals. It appears that men pride themselves in having high levels of androgens because it makes a man, a “macho man.” But what happens to androgen levels when these masculine men are exposed to situations in which they are expected to act graciously? What happens to these levels when they are preforming a task that is thought of as un-masculine? For instance, do androgen hormones levels rise or fall when men are in a relationship or become fathers? It is hypothesized that androgen levels would be lower in men who are in a committed relationship and/or in men who are fathers. Perhaps this is caused by the stress obtained or lack thereof from being in a relationship or from being a father. In this paper, we will discuss the effects of stress on men and their androgen levels, determine how being in a committed relationship can effect androgen levels, determine whether or not sexual orientation is a factor in these effects, and lastly we will be looking at how being a father or desiring to be a father can effe...
Pheromones are natural scents, which play an important role in sexual communication. Animals and humans release masses of biological chemicals in tears, saliva and perspiration. These aromas convey signals relating to mood, status, drive and health to the subconscious awareness of the female. The dominant male will exude more of these biological attractants than his submissive counterpart, consequently he inevitably attracts more females and enjoys more conquests. This philosophy holds well in the animal world, pheromones are consciously detected over considerable distances and serve at times in place of spoken communication. They help animals mark territory, recognize mates, and signal sexual interest. For example, female dogs in heat leave their pheromone and can attract male dogs over a mile away (5).
Fly Drosophila in a great model organism that is used to show courtship behavior when a gene is mislocated and improperly expressed. This results in male courtship behavior between male-male and male Drosophila not being able to receive chemicals signals from the brain to repel sensory signals.
Oestrogen receptors in the brain are believed to cause gender-appropriate behaviour. Oestrogen, a hormone found in the female genital tissue, acts as a ligand and, by activating the oestrogen receptors found on the surfaces of brain cells, causes notable changes in behaviour. Professors at Yale University have studied the effects of oestrogen and found the hormone increases neural connectivity in the brain resulting in a more accurate memory. Turnham et al (2002) supports this as upon investigation...
The hormonal mechanisms that influence the male reproductive functions involve the endocrine tissues, the hypothalamus, anterior pituitary and the reproductive organ that is also considered and endocrine tissue, the testis. In the hypothalamus specific neurosecretory glands secrete GnRH, or gonadotropin releasing hormone. GnRH is carried by the blood to the anterior pituitary gland where it binds to receptors on gonadotrophic cells. The GnRH stimulates the gonadotrophic cells to increase the secretion of two gonadotrophic hormones, Luteinizing hormone (LH), Follicle - stimulating hormone (FSH). These to hormones are transported in the blood from the anterior pituitary gland to the testis. In the testes LH bind to leydig cells which in turn stimulates the secretion of testosterone. With the assistance of FSH and testosterone, stertoli cells are able to produce ABP, Androgen-bind protein maintains high levels of testosterone. ABP binds to testosterone and maintains high levels of that hormone near spermatogenic cells. This with FSH help in the maturation of spermatozoa. In addition to all this, testosterone is converted into DHT, dihydrotestosterone, this hormone may also contribute to the formation of sperm cells. The two androgens testosterone and DHT, help to develop males sexual characteristics and The process described above can be seen in figure
Testosterone production in men occurs in the testes; removal of the testes consequently eradicates some social behaviours often characterised as male (Haigh, Cates, Glover & Rawlings, 1984). Awareness for the function of the testes, influenced Chinese scholars to prescribe ingestion of dog testes to increase male fertility and enhance courtship behaviours (Breedlove, Rosenzweig & Watson, 2007). The behavioural qualities of the testes was confirmed by Arnold Berthold (1849), by castrating juvenile roosters it was observed that there was a failure to develop 'normal' reproductive behaviour. Testosterone can be labelled as having an activational effect promoting several specific behaviours (Berthold, 1849).
Evolution, typically, favors vision over olfactory sensation, which implies that a creature will develop keener vision, while olfaction remains the same or even degenerates. With an emphasis put on visionary evolution, it is obvious that, for the most part, animals are not going to evolve in a way that allows them to detect other organisms through pheromone; because of this, it would be beneficial for an organism to stand out with chemosignals because it will allow them to mate without getting caught by predators (Jacobs, 2009). A prime example of this is the whitetail deer. Almost any hunter would attest that covering one’s self in doe urine will attract bucks; this is because, although the doe itself does not possess a fur that would attract mates, she is tan, similar to her surroundings, her urine is filled with pheromones, and this is what truly attracts a father for her young. It would; however, be inappropriate to say that animals never adapt a sense of smell adequate to detect pheromones of another species because it is true, but it occurs far less often than an animal being detected because of its appearance (Blum, 1977). Remaining inconspicuous to predators is beneficial not only to the individual, but also to the species because, without being killed, an animal has more opportunity to pass on its genes and thus
The male reproductive system works to create sperm and then release it into the female during sexual intercourse. The organs in the system are the testes, the epididymides, hanging in a skin bag called the scrotum, the sperm ducts, the prostate gland, and the penis containing the urethra. The testes are also known as sperm glands. They make tiny sperm cells called spermatozoa. They also produce hormones especially testosterone (this activates the production of sperm cells). Epididymides are tightly coiled tubes on each side of the testes. They help sperm become mature. The sperm ducts carry fresh sperm towards the outside. The ducts join with the urethra inside of the prostate. The urethra carries the sperm through the penis to the outside. This pathway is also known as the male reproductive tract.
For example, the smell of a steak on the grill triggers a small dopamine release in the brain of someone who likes steak. The smell becomes a source of pleasure.
The human male reproductive system organs are located outside of the body around the pelvic region of a male (wikipedia, 2010). The testes produce sperm that would fertilize the female’s egg. Males have several secondary genitalia’s the penis, sperm ducts, epididymis, vas deferens and the urethra. The urethra is used for two purposes to urine and to ejaculate semen. Males also have accessory glands such as the prostate gland, seminal vesicles, and bulbourethral glands. The prostate gland contributes fluid for ejaculation. Prostate fluids helps to nourish the sperm (Web Md, 2009). The seminal vesicle makes up most of the volume of a man's ejaculatory fluid and provide the sperm with nutrients that give the sperm energy(Web Md, 2009). Bulbourethral glands produce a clear, slippery fluid that empties directly into the urethra. This fluid serves to lubricate the urethra ...