human reproduction Flashcards
where is sperm produced
testes
where are the eggs produced
ovaries
structure of sperm
sac of enzymes to penetrate egg membrane
nucleus
mitochondria
flagellum
where is semen ejaculated through?
urethra of man
where does the semen reach
into vagina and swims towards oviducts
label
label
where is an egg released from
ovaries
where is the egg released to
an oviduct
what is ovulation?
process of an egg released into oviduct from ovary
explain what happens if egg is fertilized during intercourse.
zygote formed will begin to form embryo, which will implant uterus lining. the embryo will develop a placenta.
placenta function
allows embryo to obtain materials such as oxygen and nutrients from mothers blood.
gets rid of embryos waste substances.
anchors embryo in uterus
placenta secretes progesterone which prevents abortion, and other hormones.
barrier to pathogens
adaptions of placenta (5)
The placenta has numerous villi that increase surface area, maximizes the efficiency of diffusion, allowing greater exchange of substances.
The walls separating are very thin, minimizing diffusion distance. This enables fast and efficient transfer.
blood vessels are in close proximity, though they do not mix. efficient diffusion of substances between the two bloodstreams.
hormone production
oviducts/fallopian tube definition
connects ovary to uterus, where fertilization occurs
ovary function
gland, produces ova and hormones
whats baby held in inside uterus
embryo enclosed in a membrane called amnion, the amnion secretes amniotic fluid
how does amniotic fluid protect developing embryo
protects embryo against sudden movements and bumps
what is amniotic fluid made of
mothers plasma
stages of birth
- dilation of cervix
- delivery of baby (contractions)
- delivery after birth(placenta is pushed out together with membranes that surrounded the baby
puberty developments
gametes start to mature and be released
bodies adapt to allow reproduction
male sexual charecteristics
testes produces sperm
growth and development of sexual organs
growth of facial and body hair
increase in body mass
voice breaks
sex drive develops
hormone that control male sexual characteristics
testosterone
female sexual characteristics
sexual drive
growth of armpit and pubic hair
growth and development of sexual organs
menstrual cycle begins, ovulation also
breasts develop
hips widen
hormone that causes female development
oestrogen
oestrogen , gland produced and function
ovaries
formation and maintenance of uterus lining
inhibits (Follicle-stimulating hormone) production (FSH)
stimulates release of LH (helps control menstrual cycle)
progesterone, gland produced and function
ovaries
maintains uterus lining during pregnancy and later part of cycle
inhibits LH and FSH
ovulation day
14
period day
1-5
cycle duration
28
menstruation lining
loss of lining due to low progesterone and oestrogen
menstruation definition
cycle of shedding of uterus lining every 28 days
How does fertilisation occur once egg and sperm have met
Sperm and eggs meet in fallopian tube, head of sperm releases enzyme
Digests path through protective layer surrounding egg
Sperm moves along pathway through egg cell membrane
Immediately egg releases thick layer of material to prevent entry of further sperm (or too many chromosomes would be present)
moment of ovulation
egg grows inside follicle at day 14
follicle moves towards edge of ovary and the egg is released as follicle bursts open.
what happens with follicle if egg is fertillised
follicle forms corpus luteum. corpus luteum makes progesterone, completing development of uterus by thickening and maintaining it, ready for fertillised egg to sink into it and develop into an embryo.
what happens to corpus luteum if egg is not fetilised
corpus luteum breaks down and stops making progesterone.
what secretes progesterone later on in pregnancy instead of corpus luteum
placenta
