Gestation

Question 1

Define Copulation

Answer 1

is when an erect penis is inserted in the vaginal canal for ejaculation to occur.

Question 2

What is gestation?

Answer 2

time from fertilization to birth

Question 3

define fertilization? and give the process

Answer 3

fertilization is the fusing of a haploid sperm nucleus and haploid ovum nucleus to form a diploid zygote cell.

ovum sucked by fimbria into fallopian tube
sperm enters the vaginal canal and uses energy and propulsion to move to fallopian tubes- assisted by cilia. it then gathers around an egg and a head of sperm makes it through zona pellucid using acrosome enzymes. tail is discarded and nuclei fuse to form zygote. fertilization membrane to prevent further sperm form entering

Question 4

What occurs to blastocyst and define implantation?

Answer 4

up to two weeks. The diploid zygote cell undergoes mitosis to form a ball of cels called the morula which further divides into a blastocyst that has a trophoblast (external covering of cells and internal hollow fluid. the embryo develops from the cells into the cavity. the cilia move the blastocyst to endo metrium where implantation, the sinking of blastocyst into glandular vascular layer and attaches itsel, occurs.

Question 5

Explain the development of the embryo

Answer 5

up to 8 week. the embryo is the is the development of the blastocyst to form 3 layers: endoderm ectoderm and mesoderm from inner cell mass from which specialization of cells and differentiation occurs to form tissues and organs and a yolk sac therefore developing into a foetus.

Question 6

Label a developing foetus in womb (10)

Answer 6

amnion
amniotic cavity/ fluid
foetus
chorion
endometrium
myometrium
umbilical cord
placenta
cervix
mucous plug

Question 7

What is Chorion/ chorionic villi and its functions?

Answer 7

Chorionn surrounds and protects the amniotic sac.
It has outgrowths called chorionic villi which attach to the endometrium to form a placenta with a group of blood vessels. It has capalaries with high surface area to diffuse fetal products and oxygen from mum as it can’t mix.

Question 8

What is placenta supplied by and give functions?

Answer 8

placenta is supplied by the vessels of the mother and child through chorionic villi.
its function is to give oxygen and nutrients from mothers blood to foetus. to take waste products and urea/ co2 form baby and give to mother blood. prevents pathogens and supplies antibodies.
also controls production of progesterone after 3 months

Question 9

Explain the role of oestrogen and progesterone in maintaining pregnancy?

Answer 9

Oestrogen is to produce and control the production of progesterone. progesterone is needed to keep the endometrium lining thick to supply the foetus and to prevent ovulation from occurring as woman is already pregnant. prevent muscle contractions of myometrium until labour

Question 10

What is umbilical cord and describe what it contains for function?

Answer 10

from foetus abdomen to placenta.
has two arteries to take waste back to mother blood and one vein to take oxygen and nutrients from mothers blood

Question 11

Explain what the Amnion/cavity/fluid is and what its functions are?

Answer 11

amnion is sac that covers the foetus and secretes amniotic fluid to create amniotic cavity. and contains foetal cells and water

the fluid allows a medium for foetus to learn to swallow and breathe. it takes impacts to protect the foetus. it stores urine from the foetus and protects from dehydration and temperature change