Conception To Birth Flashcards
What happens during copulation or sexual intercourse?
The man places his erect penis inside the women’s vagina. He releases semen, containing sperm cells into the vagina as he ejaculates. The sperm cells swim into the uterus and into the Fallopian tubes. If an ovum or egg is present, fertilization will take place.
What is fertilization?
It is the fusion of a male sperm with a female’s ovum. Only one sperm cell will penetrate the egg’s outer covering. Once inside the egg, the sperm travels through the cytoplasm and fuses with the egg nucleus forming a zygote. This is the moment of fertilization or conception.
What does the zygote form and why?
A special membrane around it to prevent any other sperm from entering.
True or false
It is impossible for more than one sperm to enter an egg
True
What is implantation?
When the zygote starts dividing immediately while moving through the oviduct and into the uterus. This mass of cells sinks into the thick spongy lining of the uterus wall
What happens after implantation?
A hormone released stops the ovaries releasing any more eggs and cause further thickening of the uterus wall.
What is the gestation period?
It is the time in which the foetus develops inside the mother’s uterus until it is born. It is 9 months long (40 weeks)
The uterus expands from a volume of _____ to a volume of _____.
5cm3
700cm3
When does the embryo take human shape?
8 weeks and is now a foetus
Where does the foetus develop?
The foetus develops in an amniotic sac filled with a watery substance called amniotic fluid, which protects the foetus from injuries and acts as a shock absorber. It also keeps it warm and prevents it from drying out.
What is the placenta?
It is an organ attached to the uterus by tiny finger-like structures. It acts a barrier to prevent any infections from getting to the foetus.
What is the placenta made of?
Lots of blood vessels and supplies the foetus with nutrients to keep it alive and growing. The placenta also removes waste from the uterus.
What is the umbilical cord?
A long work like tube which connects the removes waste from the foetus. It is the foetus’s lifeline and without it, it would not survive.
What are 2 functions of the umbilical cord?
- transporting nutrients and oxygen from the mother’s blood to the blood of the foetus
- responsible for removing carbon dioxide and waste products from the foetus and transporting them out through the blood of mother.
Which week does birth take place?
38th to 40th week in pregnancy
