Reproductive System

• Sex cells contain structures which are referred to as chromosomes which contain genetic information responsible for the manifested traits of an offspring.
• Human sex cells contain only half the number of chromosomes of a regular body cell (somatic cell).
• As the contractions become stronger and in close succession, the amniotic sac usually breaks and releases its fluid.
• The contractions cause the opening of the uterus to widen so the baby can pass through the vagina and then out into the world, taking in his/her first gasp of air.
• Each sex cell carries around 23 chromosomes referred to as a haploid, while a body cell contains 46 chromosomes and is referred to as a diploid.
• Fertilization merges two sets of genetic information – one from the father (through the sperm) and one from the mother (through the egg) – to create an offspring that is genetically different from either parent.
• There should be genetic diversity, meaning the parents must not be related.
• The location of the testes in the scrotum allows for temperature regulation (37 ℃) optimal for sperm production.
• The testes are made up of clusters of compartments called seminiferous tubules.
• Sperm cells are produced in the linings of the seminiferous tubules – meiosis.
• Pregnancy is the period of rearing a child for nine months.
• As the contractions become stronger and in close succession, the amniotic sac usually breaks and releases its fluid.
• Eventually, the zygote becomes a small ball of cells (blastocyst) that attaches itself to the uterine wall in the process called implantation.
• Villi constitutes the placenta, with blood vessels and capillaries.
• Embryo is the developing child.
• During the third week of pregnancy, a thin membrane called amniotic sac begins to form around the embryo.
• Umbilical Cord forms and connects the placenta to the embryo.
• The zygote becomes a small ball of cells (blastocyst) that attaches itself to the uterine wall in the process called implantation.
• Fetus is when the embryo develops human-like features.
• In the 9th month of pregnancy, the fetus has usually rotated to a head-down position inside the uterus, signaling that the time for birth has arrived.
• By this time too, all the major organs are present to some extent.
• The amniotic sac becomes filled with a clear liquid called amniotic fluid, which helps cushion and protect the embryo.
• The birth process begins with the onset of labor, the muscular contractions of the uterus.
• Cell division (cleavage) takes place as the zygote travels down the oviduct toward the uterus, a journey that takes six to seven days after fertilization.
• The anterior pituitary gland regulates the function of the testes, secreting 2 hormones: Luteinizing Hormone (LH) which stimulates testosterone secretion and Follicle-Stimulating Hormone (FSH) which, along with testosterone, stimulates sperm production.
• Testosterone is responsible for the development of secondary male characteristics during puberty.
• Sperms start production at puberty, where males produce at least several hundred million sperm cells per day.
• Sperms travel through a series of tubes: epididymis, vas deferens, urethra.
• Menarche, the first discharge of blood which is typically around the ages of 11 to 14 signaling the onset of egg cell production.
• The head of a sperm cell contains the chromosomes and is covered by the acrosome.
• Semen normally contains 300 - 400 million sperm cells, or about 5 - 10 million in just one drop.
• Sperm production starts at puberty, where males produce at least several hundred million sperm cells per day.
• Sperms exit the penis through ejaculation, the forceful expulsion of sperm out of a male’s body.
• The testes are made up of clusters of compartments called seminiferous tubules.
• The urethra leads the sperm cell through the penis, the male organ that deposits the sperm in the female reproductive system during sexual intercourse or copulation.
• Estrogen is the chief hormone of females responsible for the development of secondary female characteristics.
• During puberty the increased production of hormones enables an immature egg cell to complete its cycle.
• Sperm cells are produced in the linings of the seminiferous tubules – meiosis.
• Sperms travel through a series of tubes: epididymis, vas deferens, urethra.
• Only a few sperm cells reach the egg cell because most of them die in the acidic environment of the female reproductive tract.