Investigation Of Reproduction And Development In Animals :: essays research papers fc

Investigation of Reproduction and Development in AnimalsCycles, Conception and ContraceptionFertility is the precondition of being fertile. The aim of contraception is toinhibit fertility in individuals, hence, slowing population growth. The systemby which all female contraception must contain the menstrual cycle.What is the menstrual cycle? and what hormones are involved in controlling it?After puberty, the female divulges an musket ball each month. Other changes take placeon a cyclic basis including the uterus lining and hormone levels. These changesare called the menstrual cycle. Follicle stimulating hormone (FSH) from thepituitary gland stimulates the growth of follicles in the ovary. Folliclesproduce oestrogen that stimulates the pituitary to produce leutinising hormone(LH). As LH increases the size of the follicle increases until an egg isreleased. The corpus luteum formed in the follicle secretes progesterone thatprepares the lining of the uterus for pregnancy. If fertil ization does not occurthe lining of the uterus is discharged from the body in the process calledmenstruation.What is the birth control oral contraceptive?The combined oral contraceptive tabloid (the pill) is a reversable, hormonalmethod of birth control. The pill consists of a mixture of two synthetichormones similar to oestrogen and progesterone, the womans natural hormoneswhich amaze the menstrual cycle. The pill is on of the most popular methodsof birth control.How does it work?The pill basically prevents ovulation, therefore, the ovaries cant release amature egg. Without an egg for the sperm to fertilize , a woman cannot getpregnant . The hormones also increase cervical mucus, making it difficult forsperm to pass into the uterus.How effective is the pill?If used correctly, the pill is highly effective. It has a less than one percentfailure rate. However, because many people misuse it, the actual failure rate is much like three percent. The pill does not provide protection aga inst sexuallytransmitted diseases.How are pills used?One pill must be swallowed at the same time every day. It is not any singlepill, but the day-to-day process of taking the pill which provides protectionagainst pregnancy.What is infertility?Infertility in humans and other species(animals) is the inability to concieve orcarry a pregnancy to a live birth. The causes of infertility can be identifiedin slightly cases. The majority of cases relate to female factors (50%), 40% relateto male factors and 10% aree unknown. Infertility sometimes may serve as acombination of some(prenominal) male and female factors.If the cause of infertility is known, treatment of some kind may be available.In other cases a problem may vanish on its own and fertility is restored.