Sexual Reproduction and Embryo Development Flashcards
What is the process of sexual reproduction in humans?
when a male becomes sexually excited blood rushes to the penis, become erect and is placed in the female vagina. Semen composed of sperm and other secretions from the seminal vesicles and prostate gland is ejaculated into the top of the vagina.
What is ejaculation?
The process of releasing semen from the penis.
Where does the sperm go?
It swims through the cervix and unterus into the oviducts
What happens when an egg is present in the oviducts?
The sperm will fertilize the egg and they fuse to form a zygote while will develop into a baby.
Why can only 1 sperm fertilize an egg?
The fertilization membrane lifts from the egg surface enclosing the sperm making sure that no more can enter
What is fertilization?
When the nucleus of the sperm fuses with the nucleus of the ovum
What happens if no fertilization takes place?
Mentruation takes place.
Which part of the sperm enters the egg?
The head
What is the fertilized ovum called?
A zygote
When does the egg become a embryo?
When it reaches the uterus
What is implantation?
When the embryo is embedded in the thick lining o the uterus wall.
Where does fertilization take place?
In the fallopian tube.
What happens inside the uterus?
As the embryo develops it gets surrounded by a membrane call the amniotic sac which contains a liquid called amniotic fluid.
What does the amniotic sac do?
It serves as a cushon against knocks and bumps as the mother moves around her daily routine
When is the embryo called a foetus?
From about 12 weeks until the baby is born
How does the foetus survive in the uterus.
A tough strand called the umbilical cord is attactched to the adomen of the foetus at one end and the placenta at the other end. It surves as a lifeline between the baby and the mother. The placenta provides a large surface are for exchange of food, oxygen etc
What does the placenta consists of?
It consists of blood vessels with spaces in between. The mothers blood runs through the spaces while the baby’s blood run through the vessels. The mothers blood flows through the placena carrying food oxygen which is then passed into the baby’s blood through the thin blood vessels. Carbon dioxide and waste materials pass from the baby’s blood to the mother’s .
What does the artery in the umbilical cord do?
Carries deoygented blood with waste products from the foetus to the placenta.
What does the vein in the umbilical cord do?
Carried oxygenated blood with food and oxygen from the placenta to the foetus
What is another word for pregancy?
gestation period
What is pregancy?
The time between conception and birth
How does the baby position itself when its ready for birth?
Head downward above the cervix
What happens to the cervix during birth?
A ring of muscles around the neck of the womb dilates and at the same time the uterus begins to undergo a series of contractions which are gentle at first but become more powerful and frequent. This is called labour.
What is the breaks of the water?
When the amniotic sac bursts and the amniotic fluid flows out the vagina.
What is the birthing process also known as?
Delivery
What happens after birth?
The umbilical cord is cut and the placenta falls out.
What is a zygote?
A fertilized ovum
What is an embryo?
A zygote which has been divided into 100 cells
