Human Life Cycle: Identification of the Secondary Sex Characteristics - Essay Example

Human Life Cycle Table of Contents Task 3 Task 2 6 Task 3 7 Task 4 10 Task 5 12 References 19 Appendices 22 Task Major Areas of Differences between Spermatogenesis & Oogenesis Spermatogenesis Oogenesis Spermatogenesis refers to the formation of spermatids from male testes Oogenesis refers to the formation of eggs in the female ovary A single spermatogonium happens to be divided into four sperms Only one ovum can be formed in the oogonium In the process of spermatogenesis, the matured sperms are released from the testes to a female body The complete process usually concludes inside the reproductive tract within the female body It is an incessant process that gets completed within 74days It is a discontinuing process that usually gets completed within a few days or within the span of a year (Witsuba & et. al., 2007; Aharonian, n.d.) Major Areas of Similarities between Spermatogenesis & Oogenesis Criteria Details Needs Both spermatogenesis and oogenesis are involved in the production of male and female gametes respectively Process Both follow a three staged process Mitosis Under both the processes mitosis creates or produces gonial cells Maturity During the maturity stage, both these processes have to undergo meiosis to fabricate haploid gametes (Witsuba & et. al., 2007; Aharonian, n.d.) Identification of the Secondary Sex Characteristics The three secondary sex characteristics that occur in males and females are development of facial hair in males, development of breasts in females and growth of pubic hairs in both males as well as females. The elaborations are as follows: Facial Hair The development of facial hairs in males is more common in the males irrespective of their locations and areas. During their puberty ages, the adolescence men develop hairs on their faces. This hair grows if it is unless shaved. To be noted in this context, even though observable, this development is not majorly present among women. To be specific, women do not usually develop facial hairs like their male counterparts on their faces as a sign of puberty at common instances (Bolin & Whelehan, 1999). Development of Breasts During pre-puberty stages, the development of female body takes place with the initial development of the breasts. It is a common phenomenon among female approaching their adolescence. In the stage of the pre-pubertal development, nipple enlargement occurs with the enlargement of the breasts and enlargement of the projected areola. With the maturity of the female, the breasts develop and the nipple appears to be the second mount. The development of breasts does not take place among males at such an apparent rate though. However, their chests expand as a sign of development at the time of their puberty (Bolin & Whelehan, 1999). Development of Pubic Hair In both females and males, the development of pubic hair is quite common. However, for females, the pubic hair grows sparsely along both sides of the labia, wherein with pigmentation, the hairs become coarse and curls as well as spreads to the medial of the thighs. For males, the pubic hair grows below the penis around the testes. The pubic hairs grow in the genital areas for both the sexes as a representation of the secondary sex characteristics (Bolin & Whelehan, 1999). Effects of Ageing in the Female Reproductive System The rate of women fertility is reduced during the late 20s and has a substantiate rate of decrease during the late 30s. Probabilities of pregnancy are high among women who are between the ages of 19-26 years than the women who are in their 30s. The female reproductive system is observed to age faster than any other organs. Even though the average age of menopause is 51 years for women, the reproductive system starts ageing at the age of 20s itself. Observably, there is a gradual as well as the drastic loss of fertility after the age of 35 years in females. Conversely, women maintain a regular ovulatory menstrual cycle even after 40s although the rate of fertility declines at an earlier age (American Society for Reproductive Medicine, n.d.). These changes are observed due to the deformity in the different organs related with the reproduction system. In subsequence, the changes in the shape of uterus and rate of ovulation followed by a steep decline in the rate of hormone secretion lowers the ability of women to bear children with their growing age. With age, the hormone flow also stops and the vaginal walls become drier and less elastic. This change in the reproductive organs obstructs the process of sexual intercourse at an initial level. The internal organs even losses its tenacity with ageing that creates a lack of ability among the aged women to become pregnant (Dunson & et. al., 2002). Task 2 Menstrual Cycle relates to a monthly phenomenon that prepares women body for a possible pregnancy. This cycle occurs on a monthly basis from the time of puberty and lasts till the age of menopause. Correspondingly, the menstrual and ovarian cycles have three phases as follows. Menstrual Phase The menstrual phase lasts from day 1 to day 5, as it begins from the first day of menses, and lasts until the last day of bleeding. This is the outflow of a thickened lining of the uterus. During this phase, there are series of changes in the internal organs and production of estrogens begins. This phase evidences the detachment of the endometrial lining from the wall of the uterus resulting in the flow of fluid and blood. This flow of blood lasts from 3-5 days each month in an adolescent female (Mtawali & et. al., 1997). Proliferative Phase Followed by the menstrual phase is the proliferative phase, i.e. the phase where the menstruation stops and preparation for the next ovulation begins. This phase evidences the release of the ovum prior to the next menses. The phase even has a production of mucus and the development of the uterine vessels with the ovum is released from the anterior pituitary glands. During this phase, there is a flow of FSH hormone from the pituitary gland, which helps the ovum to mature and excites the ovaries to release the oestrogen hormone. In order to ensure that no more than an egg is matured in the ovary, the oestrogen hormone blocks FSH flow during a menstrual cycle (Mtawali & et. al., 1997). Secretory Phase This phase is the final phase of the menstruation cycle that involves the chapter when the ovulation takes place, i.e. the ovary releases the matured eggs to the surface. The LH hormone assists in releasing a matured egg from the ovary. During this phase, the quantity of the flow of cervical mucus may stop. Just prior to the beginning of the next menstrual cycle, there is usually a thick cloudy flow of mucus. Shortly after the cloudy discharge, the menstrual cycle begins (Mtawali & et. al., 1997). Task 3 HCG And Maintaining Pregnancy Human Chorionic Gonadotropin (HCG) is a type of hormone that is released during the early days of pregnancy. This hormone is noted as a component of cells that nourishes the placenta during the early days of pregnancy. During the time of menstruation, different hormones are released with the secretion of HCG. HCG also protects the embryo during the initial days of the pregnancy wherein the level of HCG rises with the maturity of pregnancy and multiplies during the first 72 hours. It is noted that the level of the HCG increases during the initial six weeks of the embryonic development. This level keeps on increasing during the placental formation and acts as a protective shield across the embryo. During the initial phase of the pregnancy as well as embryonic development, HCG maintains the operations of the ovaries and the level of pregnancy during the initial days. However, a high level of HCG is even risky for the health of the mother as well as can cause Down’s syndrome. On the other hand, the lower level of HCG even may create a chance of pregnancy failures. This lower level flow of HCG hormones can lead to the situations of ectopic pregnancy in women. HCG hormones increase the flow of progesterone as well as oestrogen to prevent the flow of menses during pregnancy. During the phase when the placenta matures, HCG helps in maintaining a high level of hormones that prevents from any harm to the embryo (Gallego & et. al., 2010). HCG and Monitoring Pregnancy HCG is important for monitoring pregnancy. Organisations dealing with the different types of pregnancy related issues herewith need to be monitored. The larger production of HCG hormones also should be monitored during this phase. Both abnormal rise and fall in the HCG hormone are considered as bad signs of pregnancy and often indicate severe situations of miscarriage, ectopic pregnancy and failed pregnancy (Gallego & et. al., 2010). However, at the time of pregnancy, if there is an overflow of HCG, it may hint towards the development of multiple pregnancies. On the other hand, if the pregnant woman is having a lower level of HCG flow at the time of pregnancy, there are chances that the zygote has developed in a place other than the uterus. Continuous monitoring of the HCG must also be conducted among the pregnant women through blood test, so that the level of rise and fall in HCG could be speculated. This would prevent from any adverse situations and will even lead to a proper anticipation of the different projected risks identified during pregnancy (Gallego & et. al., 2010). This would even help in applying various protective measures that could prevent the pregnant women from having any adversity and have a healthy pregnancy. Monitoring of HCG hormones could even project towards the risks associated with pregnancy. Furthermore, this would even enhance the ability of healthcare service deliverers and the patient to take precautionary measures to mitigate the identified risks to the maximum (Gallego & et. al., 2010). The above graphs explain the different flow of hormones during the phases of pregnancy in women. The flow of HCG is also observed to be high during the initial weeks of pregnancy. This is fundamentally due to the support that hormone provides during the initial phases of pregnancy. HCG hormones provide the support for the embryo to develop during its initial days. The flow of HCG goes on increasing during the initial days of pregnancy as depicted in the graph and reaches its maximum during the second month of pregnancy. Once the embryo is attached to the uterus, the flow of HCG begins decreasing in a steep rate and gradually stabilises during the 6th month of pregnancy. Parallel to this, estrogens flows during the time of pregnancy. The estrogen flow gradually increases with the term of pregnancy and reaches its maxim during the third trimester of the course. The flow of estrogens herewith ensures a steady development of foetus and helps it to mature. The sudden increase in flow of estrogens also creates a situation of nausea in the initial days of pregnancy. Additional to the above, there is an increased flow of progesterone during the time of pregnancy. The flow of progesterone provides laxity to the different body parts and is involved with enlargement of the uterus. The stable flow of progesterone subsequently ensures that uterus develops from its initial size to a well-developed size to accommodate a full-grown baby. The flow of progesterone is also considered normal during the initial stages of pregnancy by gradually increasing during the later term of the course. Task 4 Different Contraception Methods Method of Contraception Mode of Action Evaluation Condoms This mode of contraception tool acts as a mechanical barrier when it is placed covering a penis (male condoms) or inside a vagina (female condoms) (Walsh & et. al., 2003) The use of condoms does not affect the health of users. Condoms are prepared from latex or polyurethane that does not create any side effect. However, the improper use of the contraceptive tool leads to breakage and does not effectively acts as a protection (Walsh & et. al., 2003) Pills There are several types of contraceptive pills available in the market. The pills are available for a pack of 21 days and 28 days. Oral contraception has been one of the most effective part of family planning (Mosher & et. al., 2004) Contraceptive pills are effective in birth controls and preventing from unplanned pregnancies. The use of the contraceptive pills must be consumed by consulting a doctor. There has been a record increase among women to use contraceptive pills to regularise their menstrual cycle. However, pills can lead to side effects among women wherein the use of contraceptive pills can only be effective with consultation from a doctor (Mosher & et. al., 2004) Coitus Interruptus The process of preventing pregnancy is by removing the penis during sexual intercourse before ejaculation. This prevents the ejaculation to take place within the vagina and lead to fertilisation (GPM, 2003) This is an unscientific method of preventing unwanted pregnancy. The process however imposes a high-risk level of being pregnant, as it is often noted that there is an improper control and the ejaculation takes place inside the vagina. There are also high chances that the sperms pass into the vagina even before ejaculation (GPM, 2003) Sterilisation This is a process preventing the sperms and ovum from meeting. The use of sterilisation is prevalent among both men and women. In women, it is done by cutting the fallopian tube that carries eggs from the ovum to the uterus. However, in men, it is done by cutting or tying the vas deference that carries the sperms from testicles to the penis (FPA, 2014) This effective process prevents from unwanted pregnancy. However, it is a permanent as well as an irreversible measure. Hence, if the individual undergoing such operations wants to get back his/her fertility will not be able to do so. Additionally, this can even affect the individual’s health and can lead to severe situations if it is not conducted properly (FPA, 2014) Intrauterine Device This is a type of device that is inserted into the womb, creating certain antibodies to prevent the sperm from fertilising the ovum. This device anticipates both the sperm and ovum as a antibodies and destroys them (GPM, 2003) There are certain adversities that are prevalent with the use of such modes of preventing contraception. If the device is placed in an improper position, may lead to pregnancy. Furthermore, it can hamper the life of the foetus as well as the mother (Moscho & Twickler, 2011) Diaphragm or cap with spermicide It is a silicon cap that is used to cover the cervix and prevents the sperms from entering the uterus. This type of caps usually comes with a spermicide and kills the sperm at the time of ejaculation (FPA, 2014) The silicon caps are effective in preventing pregnancy only if it is used in a proper manner. This method of contraception becomes ineffective if used for more than 3 hours or are damaged. Its is even observed that the caps that are used may lead to chemical reaction among the consumers (FPA, 2014) Task 5 Development of the Foetus First Trimester The development of the foetus takes place following a series of steps during the tenure of pregnancy. The foetal development starts from the women’s egg being fertilised by the sperm. The foetal development takes place following a series of developments during the different trimesters. During the first trimester, the development begins with the fertilisation of the egg by the sperm. At the immediate point of fertilisation the zygote is divided into 2 cells and continues to multiply its cell division. After the formation of around 13-32 cells, the cluster of cells moves from the fallopian tube to the uterus. This cluster of cells is called blastocyst and increases in size gradually. In the following eight days of the conception, the cluster of the cell is attached to the wall of the uterus and starts growing at a rapid rate. Notably, the implantation of the embryo takes place during the first 2 weeks of fertilisation. After the fourth week, the distinct blood vessels forms within an embryo that further develops into a tubular shape and starts beating at the end of the fifth week (IDAHO, n.d.). The cells of embryo keeps on multiplying in the later days and the spine of the embryo starts developing, but in the form of a cartilage at this stage of the embryonic development. The embryo continues to develop in a fluid filled sack that prevents the embryo from getting destroyed. In the sixth week, the four-chambered heart develops and the fingers and the toes start to develop within the foetus. With the development of the brain and the nervous system, the reflexive activity starts to develop. The cell division also continues to form the different body parts of the embryo. Following the eighth week, the foetus starts developing the key body parts that are essential. However, these body parts are not completely placed in their final positions, as they will look after complete development. It is in this stage that the nervous system develops and the responses become more prominent. Conversely, the skeletal system is still developing and the different body parts, like the limbs and eyes, become prominent and identifiable at this stage (IDAHO, n.d.). After the 10th week, the major body parts, such as the hands and feet, become prominent and the nails are identifiable. The foetal heartbeat is even identifiable at this stage of the embryonic development. The body muscle continues to develop and the foetus makes some random movements at this stage. However, this movement are usually not felt by the expecting mother, as they are too slight (IDAHO, n.d.). Post twelve weeks of birth, the major body parts develop and it can be identified if the foetus is a boy or a girl. However, the head continues to be the most prominent part of the body. The limbs are exactly in proportion to the rest of the body parts. The foetus develops its eyelids and 20 buds are observed in places of teeth. During this stage, blood begins to form in the bone marrows and the joint as well as muscles supports body movement. In the 12th week, a foetus can sleep and wake (IDAHO, n.d.). Second Trimester The second trimester starts at the 14th week of conceiving. The legs of the foetus are well developed but the head of the foetus is large in comparison to the other body parts. The skin appears on the body and a layer of the hair follicle is visible at this stage (IDAHO, n.d.). Post 14th week of the embryonic development, the ears become visible and there is a synchronised development of the different body parts. The hairs as well as the nails begin to grow but the skin is still transparent. The foetus starts kicking in a feeble manner for the mother to feel. The different movements, such as grasping, sleeping as well as the opening of the mouth also begin at this stage (IDAHO, n.d.). After the 18 weeks, fine hairs start developing across the body of the foetus and the different body parts, such as the respiratory system. At this stage, all the major body parts are fully developed followed by simple growth and a greasy material covers the skin to protect it (IDAHO, n.d.). For the following four weeks, the foetus undergoes a rapid development and the skeletal system evolves. During the next four weeks, the skeletal system starts hardening followed by identifiable heartbeats and movement of the foetus. During this phase, the foetus even evidences rapid brain development followed by the substantial weight gaining. The foetus even develops its sense organs and can feel its mother’s movements and sounds (IDAHO, n.d.). Third Trimester This stage is observed after the 24 weeks of the embryonic development. The foetus continues with its normal development and the different body parts begin developing. With the stabilisation of the internal organs takes place. The reflexes become stronger and the foetus can even react to the external stimuli. Post 28 weeks, a foetus can breathe and the body temperature is well controlled by the brain. After the 30th week of the embryonic development, the growth of the foetus is the sole development that takes place. The skin becomes thicker and the connections between the brain and the other body parts continue to strengthen. Post 34 weeks, the foetus develops continuously and develops into a full-grown baby. The body parts start becoming round and lump forms. The hairs that were prominent in the body parts slowly disappear except those on the head. After 38 weeks, the foetus is considered to be fully developed and can survive after birth (IDAHO, n.d.). Role of the Placenta Placenta plays a key role in the development of the foetus. It acts as a mediator for transporting the key nutrients to the foetus for it to survive. Additionally, this also carries the different metabolic wastes from the foetus. Placenta plays an effective role to fuel the growth of the foetus and acts as a link between the mother and foetus. The foetus even develops a bridge between the mother and foetus to carry nutrients and carry the metabolic wastes away from the foetus. Placenta is one of the most important parts of the women body that ensures the protection of the foetus. The oxygen supply and other nutrients that are supplied to the foetus take place through the placenta. Furthermore, placenta even protects the foetus from certain infections while it is still in the womb (Jansson & Powell, 2007). The placenta protects the baby from communicating different viruses and even protects the stem cells. By developing an immunological barrier between the mother and the foetus, the placenta ensures that certain diseases do not pass from the mother to the baby. It is worth mentioning in this context that the foetal growth can only be ensured with the nutrient supply that takes place through the placenta. However, it has been noted that the malfunctioning of the nutrient supply to the foetus may lead to the development of certain backlogs that can affect the foetus even during its growth stage. The improper functioning can even lead to certain stagnation of foetal growth that may further develop into a permanent deformity for the lifetime. The health condition of the mother even has a major role to play. Even though the placenta develops an immune barrier between the mother and foetus, if the mother is too weak, the placenta may not prevent the baby from getting affected by certain diseases. Hence, placenta plays a huge role in developing the foetus and even protecting it within the womb (Jansson & Powell, 2007). Changes in Neonatal Stage and Its Importance Post delivery, the newborn starts adapting to the external environment. This adaptation takes place as an outcome of the different changes that the baby faces in the external environment post delivery. Hence, the independent functioning of the liver, lungs and circulation is compulsory for the baby to survive. At this stage, the lungs develop at the different stages of the foetal development preparing to shift to air breathing. There was a dramatic reduction in the pulmonary arterial pressure due to the increased level of oxygen tension in the blood. There was also a steep change in the flow of the blood from the right ventricle to the lungs to support the gaseous interchange (Gao & Raj, 2010). During the prenatal stage, the liver of the foetus functions through the nutrients it receives from the umbilical cords and thus, is immature. The maturity of the liver takes place at the different stages and even continues until the postnatal period. The development of the liver is therefore necessary, depending on the proper functioning of the body, developing a proper balance in the flow of the ducts (Grijalva & Vakili, 2013). These changes are necessary for the newborn baby to survive independently outside the womb. This development helps the baby to develop its independent immunity and enhance the quality of life. Hence, these features need to be well developed to ensure a better growth and ascertain that the baby is able to cope up with the external environment and sustain thereafter to lead a healthy life. Until the birth, the foetus lives with the support of the mother. It is even observed that the baby sustains on the different supportive styles in the mother’s body. When the child is born, it needs to rapidly adapt to the changed situations and hence, these changes are predominant for the baby to survive (Grijalva & Vakili,, 2013). These alterations in the body parts are most important to ensure that the newborn is able to cope up with the changed environment. The biological system also develops in an independent way and enhances the ability of the baby to cope up with the changed needs of the survival. At birth, there is an onset of breathing and an unsupportive metabolism develops creating a huge need for the different body parts to develop. Hence, the development of a proper cardiovascular system as well as an immune system ensures a steady growth of the newborn with an effective development of the sustainable domain (Gao & Raj, 2010). The ductus arteriosus is a blood vessel that connects the pulmonary artery to the proximal descending aorta. The prime role of this artery is that it pumps the blood from the right ventricle into the fluid filled lungs that are in a non-functional stage before birth. Post birth this circulation stops and this artery converts into a ligamentum aretriosum (Amin & et. al., 2014). The ‘ductus venosus’ is involved with passing a certain proportion of the blood from the umbilical vein into inferior vena cava. This process also allows the oxygenated blood to flow into the foetus’ liver, which was in a non-functional state until birth (Schmidt & et. al., 2014). Foramen ovale is one of the two cardiac push that the foetus faces during its birth. Under this push, the blood is forced from the right atrium of the foetus to the left atrium (Amin & et. al., 2014). References Aharonian, G., No Date. Methods for Female Mammalian Spermatogenesis and Male Mammalian Oogenesis Using Synthetic Nanobiology. Field of the Invention, pp. 1-36. American Society for Reproductive Medicine, No Date. Prevention Of Infertility Source Document. The Impact of Age on Female Fertility, pp. 1-8. Amin, Z. & et. al., 2014. Patent Foramen Ovale. Springer. Bolin, A. & Whelehan, P., 1999. Perspectives on Human Sexuality. SUNY Press. Dunson, D. B. & et. al., 2002. Changes With Age In The Level And Duration Of Fertility In The Menstrual Cycle. Human Reproduction Vol. 17, Iss. 5, pp. 1399-1403. FPA, 2014. Your Guide to Male and Female Sterilisation. Department of Health, pp. 1-11. FPA, 2014. Your Guide to Diaphragms and Caps. Department of Health, pp. 1-11. Gallego, M. J. & et. al., 2010. The Pregnancy Hormones Human Chorionic Gonadotropin And Progesterone Induce Human Embryonic Stem Cell Proliferation And Differentiation Into Neuroectodermal Rosettes. Stem Cell Research & Therapy, pp. 1-13. Gao, Y. & Raj, J. U., 2010. Regulation of the Pulmonary Circulation in the Fetus and Newborn. Physiological Reviews, Vol. 90, No. 4, pp. 1291-1335. GPM, 2003. Contraception at a Glance. Information from Patentex Oval, pp. 1-11. Jansson, T. & Powell, T. L., 2007. Role of the Placenta in Foetal Programming: Underlying Mechanisms and Potential Interventional Approaches. Clinical Science, Vol. 113, pp. 1-13. Mosher, W. D. & et. al., 2004. Use of Contraception and Use of Family Planning Services in the United States: 1982–2002. U.S. Department Of Health And Human Services, pp. 1-46. Moscho, E. & Twickler, D. M., 2011. Intrauterine Devices in Early Pregnancy: Findings on Ultrasound and Clinical Outcomes. American Journal of Obstetrics & Gynaecology, pp. 1-6. Mtawali, G., 1997. The Menstrual Cycle and Its Relation to Contraceptive Methods. A Reference for Reproductive Health Trainers, pp. 1-90. Schmidt, K. G. & et. al., 2014. Assessment of Flow Events at the Ductus VenosusInferior Vena Cava Junction and at the Foramen Ovale in Fetal Sheep by Use of Multimodal Ultrasound. Articles. [Online] Available at: http://circ.ahajournals.org/content/93/4/826.full [Accessed 19th December 2014]. Witsuba, J. & et. al., 2007. Mammalian Spermatogenesis. Functional Development of Embryology, Vol. 1, No. 2, pp. 99-117. Walsh, T. L. & et. al., 2003. Evaluation of the Efficacy of a Nonlatex Condom: Results from a Randomized, Controlled Clinical Trial. Perspective on Sexual and Reproductive Health, Vol. 35, No. 2, pp. 79-86. Appendices Assessment Criteria The learner has achieved this outcome because s/he can: Page Number/s on which you feel you have achieved the assessment criteria For a Pass: 1.1 Compare spermatogenesis and oogenesis 3-4 1.2 Describe the events of the menstrual cycle and relate these to the roles of FSH, LH, oestrogen and progesterone 6-7 1.3 Explain the role of HCG in maintaining pregnancy and pregnancy testing 8-9 1.4 Use knowledge of reproduction to explain the various methods of contraception 11-13 2.1 Distinguish the main features of embryonic and foetal development 13-19 2.2 Relate the structure of the placenta to its role in exchange of materials between mother and the embryo 19-20 3.1 Interpret the data relating to the hormonal changes during pregnancy and birth 10-11 3.2 Explain the importance of the changes to the foetal circulation lungs and liver which needs to occur at birth 18-19 4.1 Describe the secondary sexual characteristics of males and females 4-5 4.2 Explain the effect of aging on the body system 5-6 Your Comments on this Assignment The assessment has been done following all the guidelines that are specified under the different marking criteria A detailed knowledge has been provided on the different reproductive systems that are prevalent and provides a detailed knowledge on the flow of the different hormones A detailed overview has been provided for the development of different criteria that would enhance the credibility of the study and develop a better understanding of the research The assessment requirements has been duly met with regard to the different hormonal flows has been effectively meet drawing out the development of the different stages of the hormonal flow Read More