Role of Hormones in Sexual Development and Behaviour - Essay Example

?Role of Hormones in Sexual Development and Behaviour Introduction Hormones are chemical components produced by endocrine glands to transport messages to the cells inside tissues in the body. Normally, sexual attributes are linked to the functioning of sex hormones prior to birth. In almost all animal genus nearly all features of reproduction is controlled by steroid hormones secreted by the gonads, or also referred to as the ‘sex glands’ (McAnulty & Burnette 2006). By producing the male hormone ‘androgen’ and the female hormone ‘estrogen’, these gonads influence sexual development and behaviour. The ‘ovaries’ are the female gonads while the ‘testes’ are the male gonads (Pfaff et al. 2002). These functions, according to Pfaff and colleagues (2002), involve the development of the phenotypes of females and males, sexual growth, and the formation of particular behaviours like the ability to engage in sexual intercourse, conditioned behaviours, and sex drive. Gender role and gender identity, and varied behaviours like habitual sexual patterns and the motivation towards control and dominance, are regarded as conditioned behaviours. These roles of steroid hormones are brought about by outcomes in the peripheral tissues and central nervous system (Becker 2002). Several impacts of steroid hormones on the brain produce long-term adjustments in the functional and anatomical area, whilst others need constant interaction with hormones. The degree of influence of gonadal hormones on the formation of conditioned behaviour in females and males is quite indecisive (Sanes, Reh, & Harris 2011). It is tough to work out correctly inhibited experiments to determine the influence of hormones in human behaviour, and almost all of the studies on the influence of hormones in sexual behaviour and growth have used subjects with anomalous conditions like postmenopausal symptoms or defects in sexual growth (Abramson & Pinkerton 1995). These studies, although flawed, reveal essential issues about the influences of biological, social, and psychological factors on sexual growth and behaviour. Role of Hormones in Sexual Development Remarkably, all of us naturally generate androgens and estrogens. Sex variations are associated with the amount of such hormones in the body. Prenatal formation of the anatomy of female or male, in reality, is mainly brought about by the lack or existence of ‘testosterone’— an androgen produced mostly by the testes (Abramson & Pinkerton 1995). Male and female embryos, within the initial six weeks of prenatal developments, appear genetically the same. Yet, there occurs a formation of the testes in the embryo and secrete testosterone, if there exists a Y chromosome (Etgen & Pfaff 2009). This drives the development of male components, such as the penis. The embryo, without the testosterone, will form female structures, such as organs for reproduction, irrespective of biological sex (Etgen & Pfaff 2009). Therefore, it may be assumed, that the main natural tendency is to develop a female. Prenatal development does not automatically complement biological sex. A biological male will not form male sex organs if not enough testosterone is produced. Although testosterone is secreted, a genetic insensitivity to testosterone may develop (Nyborg 1994). Yet again, the outcome is female growth. Likewise, in order for an XX embryo to form a female, androgens should be too little or lacking. Hence, for biological males and females, hormonal abnormalities prior to birth could develop an ‘intersexual’ being, or an individual who has indistinct sexual makeup (Persky 1987). For example, according to Abramson and Pinkerton (1995), the development of ‘androgenital syndrome’, in which estrogen is secreted in the body, but a biological defect forces the adrenal glands to produce high amount of androgen; thus, a female infant may develop sex organs that are masculinised. So the question is, is it possible to assign sex? In certain cases, it may be reasonable to change an individual’s sex. Surgical operation can reconstruct the outside appearance of the sex organs, hormone therapy can alter the body’s chemical equilibrium, and a planned attempt can be performed to change the sexual identity of an individual (Becker 2002). Nevertheless, professionals disagree about the appropriateness and effectiveness of these attempts. Role of Hormones in Sexual Behaviour The research on patterns of human behaviour is very complicated. The capacity to engage in sexual intercourse, or referred to as ‘potentia’, and natural sexual drive, also called ‘libido’, are affected by gonadal hormones (Kalat 2008). The most basic concern is whether sexual intercourse is doable in human beings without gonadal steroids. Mating ability of males is sustained for an uneven duration after ‘orchidectomy’— the removal of testicle/s through surgery—and afterwards followed by gradual defect, whilst ‘ovariectomy’ in females—removal of ovaries through surgery— brings about direct removal of female mating function (McAnulty & Burnette 2006). Males’ pre-pubertal castration consistently hampers the growth of usual male conduct, and “orchidectomy in the adult has sequelae similar to those in animals, i.e., castration of adult men causes a decline in sexual behaviour with only occasional castrated subjects capable of normal sexual activity after two years” (Abramson & Pinkerton 1995, 124). In addition, patients undergoing an androgen replacement treatment experience fast and safe renewal of male mating behaviour (Abramson & Pinkerton 1995). Hence, the role of hormones in sexual behaviour is identical in animals and human beings. Nevertheless, extraction of ovaries through normal menopause or by ovariectomy does not show any constant impact on sexual behaviour in females, contrary to the case of animals. The general explanation is that when sexual activities are patterned in females, libido becomes independent from endocrine (Pfaff et al. 2002). This explanation may be erroneous for extraction of ovarian secretions does not damage adrenal glands’ secretion of sex steroids. Adrenal androgen may have an immediate impact on females’ sexual urge, or andrenal androgen could provide adequate estrogen for preservation of libido without the ovaries (Etgen & Pfaff 2009). According to Sanes and colleagues (2011), it is also inconclusive whether hormones play a role in the beginning of natural libido at female puberty. A related dilemma of explanation is present as to precisely which hormones control sexual activities in males. It is rare for castrated males to maintain potentia and libido for length durations (Micevych 1995). Sexual drive and capacity would be maintained only in castrated males who are capable of secreting adequate hormones by peripheral tissues or adrenal glands (Micevych 1995). In simple terms, according to Abramson and Pinkerton (1995), an iota of estrogens or testosterone produced through this process may be sufficient to maintain potentia and libido in several castrated adult males. Conclusions Ovaries seem to play a major role in the sexual development and behaviour of females, as testes seem to be a major influence in the male potentia and libido. This fact, alongside the discovery that gonadal hormones may not be needed to sustain sex drive in females, indicates that the role of hormones in sexual development and behaviour are unique in human beings. References Abramson, P. & Pinkerton, S. (1995) Sexual Nature, Sexual Culture. Chicago: The University of Chicago Press. Becker, J. (2002) Behavioural Endocrinology. Massachusetts Institute of Technology. Etgen, A. & Pfaff, D. (2009) Molecular Mechanisms of Hormone Actions on Behaviour. UK: Academic Press. Kalat, J. (2008) Biological Psychology. Belmont, CA: Wadsworth. McAnulty, R. & Burnette, M. (2006) Sex and Sexuality. Westport, CT: Praeger Publishers. Micevych, P. (1995) Neurobiological Effects of Sex Steroid Hormones. UK: Cambridge University Press. Nyborg, H. (1994) Hormones, Sex, and Society: The Science of Physicology. Westport, CT: Praeger Publishers. Persky, H. (1987) Psychoendocrinology of Human Sexual Behaviour. New York: Praeger. Pfaff, D. et al (2002) Hormones, Brain, and Behaviour. UK: Academic Press. Sanes, D., Reh, T., & Harris, W. (2011) Development of the Nervous System. UK: Academic Press. Read More