Human reproduction Flashcards
what is a gonad
an organ that produces sex cells
sexual reproduction
reproduction involving two parents
describe the role of the testies
act as both an endocrine gland and an excocrine gland
produces sperm cells by mitosis
produces testostrone
describe the role of the epididymis
matures and stores sperm cells
describe the role of the sperm duct
transports sperm cells from testes to urethra
describe the role of the seminal vesicle
prostate gland
cowpers gland
produces seminal fluid for sperm to swim
contains fructose for nourishment
describe the role of the urethra
carries sperm to outside the body
carries urine to outside the body
what is seman composed off
sperm and seminal fluid
describe the role of the penis
transfers sperm to the female body
name/describe the features of the sperm
head- acrosome ( Digest outer membrane of egg)
nucleus (Contains 23 chromosomes)
middle - collar (Contains many mitochondia which provides sperm with energy to swim long distances)
falgellum- tail- allowes sperm to swim up fallopian tubes
how long can sperm survive in the female reproductive system
0-7 days
How long can the egg survive in the female reproductive system
1-2 days
what is the role of meiosis in sperm and egg production
halves the chromosome number to produce haploid cells allow for gamate production
it introduces vairation
what is primary sexual charateristics
presence of make and female reproductice parts
what are secondary sex charateristics
charateristics that distinguish males and females apart from reproductive organs/ traits that appar during pubery.
Is nuclear inheirance maternal or paterinal
only the head of the sperm enters egg.
non nuclear inheirtance
inheirtance is when genes are passed to offspring ofter then the nucles
what are the males secondary sexual charateistics what is it controlled by
controlled by testosterone
deeping of voice
growth of facial + pubic + body hair
brodening of shoulders
name female secondary sexual charateristcs
breasts develop
controlled by oestrongen
widening of hips
growth of public hair
name the three male hormones , where they are produces and their function
testosterone-produced by testes- development of sex organs, development of secondary sexual charateristics
follicle stimulating hormone- pitutary gland- causes sperm development in testes
Luteinising horomone-pitutar gland- causes production of testosterone by testes
Infertility
the inability to achieve conception
name a cause of male infertility, treatment and prevention
low sperm count
caused by use of drugs, alcohol, cigarettes and anablic steriods
treated by a change in lifestyle, stop alcohol consumption and stop smoking cigrettes
prevented by a healthy lifestyle.
name a cause of female infertility
failure to ovulate- caused by an horomone imbalance
treatment is adminstration of an revelent horomone
what is IVF (in vitro fertilisation)
removing eggs from an ovary and fertilising them with sperm cells outside the body
the fertilised eggs develop into embryos and are placed back into the uterus to implant
what is the function of the ovaries
produces egg cell my meiosis
produces progesterone andd oestrogen (develops secondary sex charateristcs)
In vitro fertilisation why are several eggs removed?
to increase the chances of sucessful implantation
What is implantation
implantation is the embedding of zygote in lining of the endometrium
what is the function of the fallopian tube
carries egg cell from ovary
fertilisation occours here
what is the function of the endometrium
contains blood vessles which provide nutrients to embryo
implantation occours here
what is the function of the uterus
holds the foetues during pregnancy.
what is the function of the vagina
birth canal
alows entry of sperm during intercourse
what is the function of cervix
entry to uterus
name a menstral disorder, name the symptoms, cause, treatment
Fibroids
begnine uterine tumours
heavy and prolonged menstural bleeding
horomonal cause- abnornal response to oestrogen
what is ovulation
relese of an egg from the ovary
Describe the process that occours in ovulation
the potential diploid egg cell divides by meiosis to form the graffian follicle. the graffian follilcle releases the egg on day 14 and turnd in the to corpus luteum
how long is average menstural cycle
28 days
what is menstruation
when the lining of the uterus breaks down and is shed from the body
the fertile period
time during the menstural cycle where fertilisation can take place
describe the four horomones that control the menstural cycle
FSH (follicle stimulating hormomone)
produced by pitutary gland
stimulated the development of the graffian follicle
Oestrogen
produced by the graffian follicle (in the ovary)
causes endometrium to develop
inhinits FSH production
stimulated production LS production
LH (lutenising horomone)
produces by pitutary gland and causes ovulation
Progestrone
produced by the corpous luteum
maintains the endometrium
Inhibits FHS and LS production
feedback mechanism
when levels of one horomone control the prodiction of itself or another horomone
fertilisation
the fusion of the egg and sperm nuclei to form a diploid zygote, occours in the fallofian tube
insemination
the release of semen into the vagina at the cervix
simply describe the process leading up to fertilisation
insemination- the release of semen into the vagins at cervix
the egg releases chemicals (chemotaxis)
the acrosome digests outer egg membrane
this forms a zygote
an implantation membrane prevents other sperm from entering
After insemination describe the stages up until implantation
the zygote divides many times via mitosis to form a solid ball of cells called the morula
the morula divides by mitosis to form a fluid filled ball of cells called the blastocyst- the trophoblast forms the amion and the placenta
the inner cell mass forms the embryonic disc
the blastocyst embeds into the endometrium
what is the ammion and its function
a membrane that forms around the embryo and scretes amiontic fluid
what is the placenta made from
endometrium tissue and embryonic tissue
how is the placenta formed?
the embryo forms an outer layer called an chorion
the chorion develop into projection villi
what are the functions of the placenta
it allows for exchanges of nutrients, wastes, gasses, antibodies
produces progestrone
barrier proventing blood of mother and fortus from mixing
why is it crucial the blood of the mother does not mix with the baby
the blood groups of the mother and baby may not be compatable
the blood pressure maybe damage the foetus
what is the umbilical cord and describe its functions
connects the placenta with the embryo and contains blood vessles which may cause damage to the embryo
What is a germ layer
a group of embryonic cells that develop into different tissues and organs
name the three germ layers and the organ or system they form
ectoderm - skin, hair, nails
mesoderm- muscles ,skeleton
Endoderm- liver- pancreas- respiatory system
What is gestation
development of the embryo in the uterus until birth
how long is gestation in humans
40 wks
name key stages in the babys develops at X weeks
4-5 weeks- the heart forms, brain develops,limbs form
6 Weeks- eyes are visable, skeleton develops
12 weeks- Testes or ovaries form bone replaces catilage
End of 3rd month, nerves + nerves corrdinate
Describe the horomones involves in birth
placenta stops producing progesterone, the walls of uterus contract.
the pitutary gland released oxytocin and causes uterine contractions
name the stages of labour and breifly describe what occours
stage 1
-cervix dialates
-mucus plug falls out
-amnion breaks- amiontic fluid released
Stage 2
-uterine contractions push foetus through cervix and vagina
umbilical cord is tied and cut
Stage 3
-Contractions expell afterbirth (umbilical cord and placenta)
What is lactation
the secretion of milk drom the mammary glands
what is lactation caused by
prolactin
(secreted by the pitutary gland)
Advantages of breastfeeding
colostrum + breast milk contain antibodies.
Contain ideal balance of nutrients for baby
has little fat, making it easier for baby to digest
What is birth control
taking steps to reduce the number of children born
what is contraception
using methods to prevent fertilisation or pregnancy
name a form of mechanical contaception
condoms- a physical barrier
name a form of natural contraception
intercourse avoided during fertile perood
name a form of chemical contraception
contraceptive pill
name a form of surgival contraception
sterilisation or vacectomy
