reproduction in human Flashcards
purpose of fallopian tube
carries an ovum to the uterus, the site of fertilisation
what is ovary
contains follicles in which ova are produced
purpose of urethra
carries urine from the bladder
where the baby develops
uterus
purpose of vagina
receives the male penis during sexual intercourse
purpose of penis
transfer sperm
purpose of the prostate gland
add fluid and nutrients to sperm to from semen
purpose of scrotum
hold the testes outside the body, to keep them cooler than body temperature
purpose of the sperm duct
the muscular tube that links the testis to the urethra to allow the passage of semen
purpose of the urethra in the male
passes semen containing sperm, also carries the urine from the bladder
feature of egg cell
jelly coat- and cell surface membrane to protect ovum also a barrier to entry of other sperm after fertilisation
cytoplasm to store the energy for fertilisation
a nucleus containing gene information
larger than sperm
feature of sperm cell
a nucleus containing gene information
acrosome containing enzymes to dissolve jelly coat
mitochondria to release energy to swim
flagellum that producing swimming movement
process of fertilisation in human
egg travel slowly towards the uterus with the help of muscle in the wall of the oviduct.
sperm get deposits at the top of the vagina and swim up through the uterus, into the oviduct
one sperm enters the egg. the nucleus of the sperm with the nucleus of the egg. as successful sperm enters the egg, no other sperm can go in.
process of implantation after fertilisation
when the sperm nuclues and the egg nuclues have fused together, they form a zygote. zygote moves slowly down the oviduct, and as it moves it divides by mitosis and become an embryo.
embryo sink into a spongy lining of the uterus, which is called implantation.
what is a placenta
an organ where substances are exchanged between the mother’s blood and the embryo’s blood by diffusion
how long it takes for the embryo to develop into a fetus
11 weeks
how is the placenta joined to the fetus
by umbilical cord
the feature of the umbilical cord
it is made out of two arteries and a vein
the arteries take blood from the fetus into the placenta and the vein returns the blood from the fetus
purpose of amniotic fluid
protect the fetus from mechanical shock and also change the temperature
feature of placental villi
large surface area for exchange of materials
what is happening at the umbilical cord
oxygen and food materials in the mother’s blood diffuse across the placenta into the fetus’s blood.
carbon dioxide and waste material diffuse the other way and are carried away in the mother’s blood
stages of development of an embryo
6 weeks- all the organs have began to grow
8 weeks- most organs are now present, some movement occurs
10weeks- all organs are now developed and more movement occurs
how the birth happens
the strong muscle in the wall of the uterus starts to contract, which is painful. the contraction of the muscle slowly stretches the opening of the cervix. the amniotic sac breaks. the placenta falls away from the wall of the uterus.
why is there no pain when the umbilical cord is cut
there are no nerves
