The three stages of prenatal development is always followed by birth, a process all of its own. The germinal stage starts with fertilization, when the sperm unites with an egg in a fallopian tube. When the egg is fertilized it is called a zygote, its first journey is down the fallopian tube towards the uterus. It is a long trip that can take up to a week, all the while on this journey the zygote is dividing and growing. Once the zygote has divided multiple times the zygote changes into a blastocyst.
Fertilisation is when the genetic material in the sperm joins with the genetic material in the ovum to start a new life. Pregnancy (the gestation period) begins when a sperm penetrates an egg cell. One to one and a half days later the single egg cell starts to divide. After two or three days there are enough divided cells to make the fertilised egg the size of a pin head. The collection of cells then travel to the lining of the uterus where it then embeds its self and now becomes an embryo, which is attached to the wall of the uterus by a placenta.
The fertilisation of the egg means that both genetic material from the egg and sperm joins together to give the beginning of a new life. The second stage is pregnancy. This occurs when the egg has been fertilised from conception it will start to divide in roughly one to one and a half days. Give it two or three days the cell will have divided to make the size of the cell miniscule. These cells then travel to the lining of the uterus where it then becomes embedded.
Dealing with Polycystic Ovary Syndrome Polycystic Ovary Syndrome, better known as PCOS, affects many women today. According to the Nursing Resource Center, “PCOS is a disorder in which women do not experience normal release of eggs from the ovaries, they have an abnormal production of male hormones, and their body is resistant to the effects of the hormone insulin. The disorder results in infertility, abnormal masculinization, and increased risk of developing heart disease and certain cancers (Traub1). This disease has become a big problem for women today, but fortunately there are a few options that women can use as a solution to this problem. There are many women who are not aware of this disease, and even women who are affected by it,
Ectopic Pregnancy Monica Rocha Med 220 Anatomy and Physiology II Professor Bradford This paper submitted is in fulfillment to the research of ectopic pregnancy. Outline I. Ectopic Pregnancy Research A. Introduction B. Definition of Ectopic Pregnancy C. Causes of Ectopic Pregnancy D. Risks and Treatment E. Conclusion Thesis Statement Every pregnancy holds a risk that something will go wrong. An ectopic pregnancy is just one of the tragedies.
al. 1999). The eggs of Sepia apama are larger than average aquatic eggs and are lemon shaped. The eggs consist of having a jelly-like outer layer, the chorion membrane, perivitelline fluid, and vitelline membrane that encloses the yolk and embryo (E. Cronin and R. Seymour 2000). The female Sepia apama can store sperm for several different males prior to fertilization, which is why males watch the female closely to ensure she doesn’t mate with another male.
Gamete production is the responsibility of the ovaries, whereas protection and nourishment of the growing embryo and fetus before birth are functions of the uterus. The two uterine tubes, one from each ovary, provide pathways for the female gametes (eggs) to get from the ovaries to the uterus. The portion of the reproductive tract called the vagina is between the narrow uterine cervix and the outside of the body. In female humans there is a second opening where the urethra from the urinary bladder connects to the outside of the body. The urethral opening is normally separate from, and in front of, the vagina.
Chris & Christina’s Journey (Tale of the Sperm and the Egg) Rutasha Brabham June 20, 2011 Psy 265 Introduction: The sperm and the egg are two variables that are necessary for life to begin. We all are familiar with how the sperm must connect with the egg in order for reproduction to occur. In this essay I will explain the role of the sperm and the egg in detail. Today we will be exploring the adventures of Chris (the sperm) and Christina (the egg). ------------------------------------------------------------------------------------------------------------------------------------------ Today in Chris and Corey’s life they will be experiencing fertilization, something they have been waiting for their whole entire life.
Millions of sperm are ejaculated by a man. Just one sperm is needed to fertilise the egg. Fertilisation means that genetic material in the egg joins with the genetic material in the sperm to create a baby. Only half of all fertilised eggs develop to become babies. Many eggs are lost without a woman knowing that fertilisation ever happened.
The time frame that a fetus is in the womb is the most crucial stage for development. During pregnancy there are numerous threatening biological agents that should be avoided in order to lower the risks of birth defects and disorders. The fetus is most susceptible to damage from substances that the mother consumes or is exposed to. First time mothers are often not aware or well informed to know the serious effects of what they consume and their environmental exposure. Teratogens generate adverse effects to the fetus from the moment the egg implants onto the uterus wall.