Genetics and Reproduction - Case Study Example

Genetics and Reproduction Genetic and Reproduction Introduction The human reproductive system is ified as the male and the female reproductive system. The male and female reproductive system consist of distinct organs that perform a particular reproductive function. Factors affecting the development of these structures can result into sterility. Male Reproductive System The male reproductive system consists of several structures that work in synergy to ensure an efficient reproductive life of the male. Externally, the male reproductive system consists of the scrotum that holds the testes. The testes are reproductive organs within which spermatogenesis occurs. Seminiferous tubules are tubules in the testes where actual spermatogenesis occurs from the primordial gonadal cell. The produced sperms in the seminiferous tubules are stored temporarily in the epididymis where they are as well concentrated. The sperm from the epididymis is transported to urethra via the vas deferens. Along the transit from the epididymis to the urethra, sperms receive secretions from the prostate gland and the secretory duct. During ejaculation, sperm flows out through the urethra (McLafferty, Johnstone, Hendry, & Farley, 2014 p.39). Female Reproductive System The female reproduction system is constituted of ovaries, oviduct, womb, cervix and vagina. The ovary is the production site of the female eggs through the process of ovulation. Ovulation is a monthly process that recurs throughout the reproductive age of females. Ovaries produce luteinizing hormone after conception. The fallopian tube is a fairly long tube that provides fertilization site between the mature female eggs and the sperm. In certain instances, implantation occurs in the fallopian tube resulting in an ectopic pregnancy (McLafferty et al. 2014, p. 40). The uterus is the structure that provides implantation site for the fertilized eggs after fertilization. Both the myometrium and the endometrium uterine walls have dense blood supply that enables for the adequate supply of nutrients and the oxygen to the developing neonate. The cervix receives the sperm into the uterus. It’s a common site for cancer infection. The vagina is the sperm receptive structure during coitus and while the vulva holds the sperm. Menstrual Cycle Menstrual cycle refers to changes taking place in the female body before, during and after ovulation takes place. The menstrual cycle takes an estimate of 28 days and the first day of the cycle is the day that the menstrual flow takes place. The end of the cycle is the day before the next menstrual flow. The menstrual cycle consist of three distinct phases. The phases are marked by days in 28-day menstrual cycle (McLafferty et al., 2014 p. 42). Phase 1 Menstrual cycle. Phase 1 menstrual cycle proceeds from the first day to the last day of bleeding usually lasting for a maximum of seven days. Bleeding results due to the absence of fertilization of the mature egg. During this phase, the levels of progesterone and estrogen decrease to a very low levels which consequently results in the vasoconstriction of the endometrium blood vessels. The vasoconstriction of the blood vessels results to low blood supply to the endometrium hence the death of the endometrium cells. The death of endometrial cells causes the sloughing off of the endometrial wall by two-thirds its initial thickness and flows out in menses. The ovarian cycle is experiencing follicular phase during the phase one menstrual cycle proceeds. Phase 2- Proliferative Phase The phase starts at the end of menses to the time of ovulation. There is remarkable thickening of the endometrium lining in readiness to the implantation of the fertilized egg. During the secretory phase, secretory glands experience increase in size and produce more mucus in the endometrium. The uterine blood vessels also increase in size. The secretory phase ends with ovulation that is stimulated by an acute surge of the luteinizing hormones secreted by the anterior pituitary gland (McLafferty et al., 2014 p.43) Phase 3- Secretory Phase The last phase of the menstrual cycle last from ovulation to the time of the next menses. There is an increase in mucus secretion by the endometrial gland in readiness for the implantation process. The corpus luteum produces estrogen. The cells of the ovary mainly produce progesterone. Endometrium further thickens up to the start of the menstrual flow. The ovarian phase proceeds concurrently with the menstrual cycle. It starts with the follicular phase that takes an estimate of 14 days followed by the ovulatory and the luteal phase (McLafferty et al., 2014 p. 41). Case study In the case of Sam and Carina, the blood test is necessary to determine the concentration of various hormones and chemical whose fluctuation in the level might cause fertility problems to the partners. Among the chemicals tested includes prolactin and thyroid hormones that tend to decrease fertility at higher concentrations. Other chemicals such follicle-stimulating hormones and luteinizing hormones assessment are also important in the assessment of the fertility in the couple. The physical examination also provides essential information on the couple fertility. For instance, small testicular size in men suggests the likelihood of impotence. In females, the pelvic examination is essential in the determination of fertility of the couples. The couple had to fill a detailed form on their health, diet, and lifestyle. These records show unhealthy practices such as smoking and alcoholism that can reduce the couple fertility and results to sterility. Other effects of lifestyle such as stress can also affect the fertility of couples (Kamel, 2010 p. 5). Fertilization and Implantation Fertilization refers to the fusion of the female egg to the male sperm. It leads to the formation of the fertilized egg that subsequently develops into zygote through embryo to fetus ready for birth. The acrosome reaction precedes the fertilization process. The sperm locates near the egg since its lifespan after the acrosome reaction is only up to 20 minutes. The sperm locates next to the outer layer of the zona pellucida, the outer layer of the female egg. The zona pellucida consist of three glycoproteins, that is, ZP1, ZP2, and ZP3. The ZP 3 binds to the apical part of the sperm that has not undergone the acrosome reaction. The sperm after the fusion enters the sub-zonal space that is located next to olema. The fusion leads to the stoppage of tail movement. The oocyte fertilization is now complete leading to the formation of the zygote. The process of fertilization comes to an end with the formation of a zygote. Implantation The embryo undergoes series of mitotic division to form a mass of cells referred to as the blastocyst. The blastocyst grow for a duration of between 4-10 days form the embryo. The embryo generates a luteotropic signal that results in a surge in the production of the human chorionic gonadotropin (hCG). HCG mimics the action of the luteinizing hormone. The actual implantation of the embryo occurs after seven days. There is subsequent digestion of the zona pellucida by the blastocyst that hatches from it into a separate entity. The size of the attachment structures is dependent upon the different species. In humans, the attachment is small, but as the embryo grows, it invades the endometrium wall that eventually envelops it. The embryo induces erosion of maternal material, in particular, the endometrial wall, and the blood vessels. The erosion process creates a pool of blood from which the placenta projects. Case study 2 Naomi is a thirty-six year old woman she has had two miscarriages and is trying to get pregnant again. The recurrent miscarriages of Naomi might be as a result of the fall in the level of luteinizing hormone after implantation. Luteinizing hormone is responsible for the sustenance of pregnancy before the surge of human chorionic gonadotrophin hormones. The process of implantation is hindered which results in the premature release of the uterine content hence miscarriages. Pregnancy and Birth Pregnancy in human’s proceeds via three trimesters spanning a total of approximately forty weeks in total. Different development takes place in each trimester that results to an eventually fully grown fetus at birth. The pregnancy starts at the time of conception and ends at birth. In most women, it takes nine months. The three different trimesters entails the following developmental processes. First Trimester At four weeks of the first trimester, facial features begin to develop. Other structural features such as the spinal cord and the heart also start developing. At the end of the first trimester, the fetus resembles a tiny human being. The heart is fully developed and starts pumping blood to the rest of the body. Both the digestive system and sexual organs are developed by the end of the first trimester. Second Trimester By the 20th week of the second trimester, the fetus experiences faster growth rate. Feet bone grows to its maximum as well as other structures in the body. Placenta supplies all the nutrient and oxygen requirement of the fetus. Third Trimester By the 29th week of the third trimester, the brain of the fetus is fully nerve. Nerve fibers are covered by a sheath, and there is an increase in impulse conduction in the fetus. The placenta becomes more selective on what to transport across while the lung also shows substantial growth in its structure. By fetus is ready for birth at the 40th week of the pregnancy. Birth The birth process consists of three phases. The early phase of the labor involves the dilation of cervix up to about 4cm in diameter. The active phase follows where the cervix dilates from 4-7cm. The final stage is the transitional stage where there is longer contraction with a very minimal rest period. The cervical dilation proceeds to maximal length, and there are more urge and pressure to push by the mother. The process finally ends with the passage of the baby out through the birth canal hence birth. Case study Concerning the Shola pregnancy, various accounts can be attributed to the morning sickness during the first trimester. The most likely causes of morning sickness are high levels of estrogen, HCG levels and increased stomach sensitivity among other factors. Morning sickness can affect the baby in that it may lead to low birth weight and poor health of the baby. In the second instance where the mother comes into contact with the German measles, there is a likelihood of transfer of the virus to the neonate resulting in stillbirth. The breech position refers to the wrong positioning of the fetus in the uterus in a position and hinders natural birth. Stages of Human Growth and Development from Babyhood to Adulthood. Humans experience four fundamental types of growth and development from babyhood to adulthood. These includes emotional, physical, social and emotional growth. Principally, there are six stages through with a normal individual grows through. The initial stage of development is the infancy, followed by early childhood, late childhood through adolescence eventually to the early and late adulthood (Franklin-Hall, 2013, p. 241). During infancy, the neonate’s exhibit physical development by walking and grasping. There marked mental development since the infant start responding to the cold and hunger stimuli among other stimuli. The infancy stage also entails social and emotional development. In the childhood stage, there is marked mental, social, emotional and physical development. During the adolescence stage, individuals experience mental and physical maturity. The growth rates are at the peak resulting in a drastic increase in height and size (Blakemore, Burnett & Dahl, 2010, p. 2). Development proceeds through early, middle and late adulthood where full maturity occurs and finally usher in the old age. In the adulthood, full muscle and motor development occurs. Individual becomes more aggressive and active in life. The vigor recedes with old age and finally death (Franklin-Hall, 2013 p. 242). Case study Kyle’s growth retardation can result from various physiological, nutritional, disease and lifestyle factors. Taking food deficient in protein results to inadequate amino acids in the body hence growth retardation. The low level of growth hormones in the body can also result in the growth and development retardation since it is that hormone responsible for stimulating growth and development in the body. Process of Aging and its Effect on the Human Body Aging results from the accumulation of the wide variety of dangerous changes both in the cells and the tissues and worsen with age. The aging process potentiates an individual ultimately to death. Aging also results from the accumulation of the reactive free radicals in the body and hence destruction of the body cells and tissues. Aging results in physical and immunological weakness of the body. It leads to inactivity of the body and eventually death of individual (Tosato, Zamboni, Ferrini, & Cesari, 2007, p.1). Case study William is sixty-five years old and who has just retired from his job. To maintain his health, William need to have renal, cardiovascular and nervous system regularly check due to the prone nature of such system to the aging process. Aging predisposes individuals to higher risks of congestive heart failure. There is receding renal function hence the accumulation of toxic excretes in the plasma. In the nervous system, there is a higher risk of developing stroke in the old people than the young (Tosato et al., 2007, p.10). Bibliography Blakemore, S. J., Burnett, S., & Dahl, R. E. (2010). The role of puberty in the developing adolescent brain. Human brain mapping, 31(6), 926-933. Franklin-Hall, A 2013, On Becoming an Adult: Autonomy and the Moral Relevance of Lifes Stages, Philosophical Quarterly, 63, 251, pp. 223-247. Kamel, R. M. (2010). Management of the infertile couple: an evidence-based protocol. Reproductive Biology and Endocrinology, 8(1), 21. McLafferty, E., Johnstone, C., Hendry, C, & Farley, A., 2014, Male and female reproductive systems and associated conditions, Nursing Standard, 28, 36, pp. 37-44, Tosato, M., Zamboni, V., Ferrini, A., & Cesari, M. (2007). The aging process and potential interventions to extend life expectancy. Clinical interventions in aging, 2(3), 401. Read More