Human Reproduction Flashcards
Draw a labelled diagram of the male reproductive system
Bladder
Seminal vesicles
Sperm ducts
Prostate gland
Urethra
Penis
Scrotum
Testis
Epididymis
Coppers gland
Function of the scrotum
Contains the testis and holds them outside the body
Why are testis located outside the body?
Sperm production requires a lower temperature of 25°C
What are the 2 functions of the testes
Sperm production
Testosterone production
What produces sperm?
Seminiferous tubules
What is the function of the epididymis
To mature and store sperm
Where is sperm matured
Epididymis
Function of sperm duct
Carry sperm to the urethra
Function of the urethra
Carries sperm and urine out of the body
What are the 3 glands in the male reproductive system
Seminal vesicle
Prostate gland
Cowpers gland
What are the components of semen
Sperm + seminal fluid
What do the 3 glands produce?
Seminal fluid
What is the function of seminal fluid
To provide a medium for sperm to swim
Draw and label a sperm
Head:
Nucleus
Acrosome
Middle:
Collar
Tail:
Flagellum
Function of the acrosome
Contains digestive enzymes that break down the membrane of the egg
Are sperm haploid or diploid discuss
Haploid- they are formed by meiosis in the testes
Which part of the sperm contain mitochondria
Middle- collar
How long can sperm survive in the female body
0-7 days
How many chromosomes are found in sperm
23
Name the form of cell division that results in the production of sperm
Meiosis
Does a zygote contain mitochondria from both gametes?
No, zygote only contains mitochondria from the egg as only the head of the sperm enters the egg and a sperms mitochondria are in its collar (middle)
Function of the sperms flagella
allows it to move
What are androgens
Male hormones
what are gonads
sexual glands that undergo meiosis ie testis and ovaries
gamete
haploid cell capable of fusion
how many chromosomes does a sperm have
23
which part of the sperm enters the egg?
head only
what does FSH stand for
follicle stimulating hormone
function of FSH
causes diploid cells in testes to divide by meiosis producing sperm ie stimulates sperm production
where is FSH made
pituitary gland
what does LH stand for
lutenising hormone
function of LH
testosterone production
where is LH made
pituitary gland
function of testosterone
responsible for the development of primary and secondary sexual characteristics
what are primary sexual characteristics
the presence of male and female reproductive parts
secondary sexual characteristics
features that distinguish males from females, apart from sex organs themselves
male secondary sexual characteristics
- growth of pubic, facial and body hair
- voice breaking
- a growth spurt at puberty
- increased muscular development and bone development
draw a large labelled diagram of the female reproductive system
fallopian tube
ovary
funnels
uterus
endometrium
cervix
vagina
vulva
function of the ovary
produce egg and female hormones
where does fertilization occur
fallopian tube
what is the function of the funnels
catch the egg after it is released from the ovary
how is the egg moved along the fallopian tube
peristalisis
what is the outer wall of the uterus made of
involuntary muscle
function of endometrium
nourishes fertilized egg
function of cervix
separates uterus from the vagina
uterus function
site of implantation, holds developing embryo, forms placenta
what is the vagina
elastic muscular tube that allows entry of sperm
what is the function of mucous in the vagina
to protect against the entry of pathoagens
name the 2 female hormones
oestrogen and progesterone
female secondary characteristics
maturing and enlargement of breasts
widening of pelvis to allow for birth
growth of pubic and underarm hair
a growth spurt
what do ovaries produce
eggs
oestrogen
progesterone
when does a female recieve its eggs
a female foetus has all its potential eggs at birth
are potential eggs haploid or diploid
diploid
by what form of cell division do haploid eggs form
meiosis
how many haploid eggs are produced each month
20
how many eggs are released from the ovary?
usually only 1
ovulation
release of an egg from an ovary
what is the first structure that surrounds an egg
graafian follicle
what hormone does the graafian follicle produce
oestrogen
what does the graafian follicle change to at ovulation
corpus luteum
which hormone does the corpus luteum secrete
progesterone
how long is the average menstrual cycle
28 days
list the 4 hormones involved in the menstrual cycle
FSH
LH
oestrogen
progesterone
what is the purpose of the menstrual cycle
to prepare the body for pregnancy
describe the events of days 1-5 of the menstrual cycle
endometrium breaks down and menstruation occurs
FH stimulates the production of an egg
egg is surrounded by the graafian follicle
describe the events of days 6-14 of the menstrual cycle
graafian follicle releases oestrogen
oestrogen causes the lining of the uterus to build up and prevents the production of another egg
describe the events of days 14 of the menstrual cycle
graafian follicle releases the egg
LH is responsible for ovulation
describe the events of days 14-28 of the menstrual cycle
graafian follicle developes into the corpus luteum
corpus luteum releases progesterone which maintains the lining of the uterus and prevents more eggs from developing
fertile period
time when fertilization is most likely to occur
which days are referred to as the fertile period
12-16
what causes menstruation
drop in progesterone levels
where is FSH produced
pituitary gland
when is FSH active in the menstrual cycle
days 1-5
function of FSH in females
stimulates egg production and causes oestrogen to be produced
where is oestrogen produced
in the ovary and graafian follicle
when is oestrogen active in the menstrual cycle
days 6-14
what is the function of oestrogen
causes the lining of the uterus to build up
where is LH produced
pituitary gland
function of Lh in females
causes ovulation
when is LH present in the menstrual cycle
day 14
where is progesterone produced
corpus luteum
when is progesterone active in the menstrual cycle
day 14-28
what is the function of progesterone
maintains the lining of the uterus
name a menstrual disorder
fibroids
what are fibroids
benign tumours in the uterus lining
what causes fibroids
abnormal response to the contraceptive pill
what is the prevention of fibroids
none
treatment of fibroids
surgery
symptoms of fibroids
heavy and prolonged menstruation
pain
miscarriage or infertility
sexual arousal
penis becomes erect
vagina become lubricated elongated and wider
copulation
penis is inserted into the vagina
heart rate and breathing rate increase
orgasm
pelvis muscles contract heart and breathing rate increase
semen is released from the penis (ejaculation)
sphincter muscles in males closes
contraction of vagina and uterus helps sperm swim towards fallopian tube
insemination
release of sperm into the female
what chemical does an egg release to attract sperm
chemotaxis
fertilisation
the union of sperm and egg nuclei to form a diploid zygote
function of the acrosome
releases enzymes to digest the egg membrane
infertility
inability to produce offspring
what is male infertility
low sperm count or mobility
what causes male infertility
smoking
correction of male infertililty
stop smoking
what is female infertility
failure to ovulate
cause of female infertility
FSH or LH not produced
correction of female infertility
hormone supplements
what type of division does a zygote divide by
mitosis
implantation
the embedding of the fertilised egg into the lining of the uterus
when does implantation occur
6-9 days after fertilisation
what membrane is formed at implantation
amnion
what is the function of the amnion
secretes amniotic fluid which acts as a shock absorber
when does the placenta form
after implantation
what tissues/materials ect make up the placenta?
uterine and embryonic tissue
what is the outer membrane the EMBRYO forms after implantation
the chorion.
what are the functions of the placenta
exchange of materials between mother and embryo
produces progesterone
prevents the embryo and mothers blood from mixing
what are some examples of materials passed in the placenta
oxygen, food, antibodies, drugs enter the embryo
co2 salts and urea enter the mother
why is it important that the mother and babys blood types do not mix
the 2 blood groups may not be compatible
the blood pressure of the mother may cause damage to the embryo
minimises the chance of infection passing from mother to foetus
in vitro fertilisation
involves removing eggs from an ovary and fertilising them outside the body
how does IVF work?
fertility drugs are given to the female to stimulate the ovaries to produce more than 1 egg
these eggs are surgically removed and fertilised.
if embryos form, they are placed back into the uterus to implant naturally
why is twins or triplets ect common with ivf
more than one embryo is placed into the uterus to increase the likelyhood of pregnancy
what is a major problem with IVF
its very expensive
why do people freeze their eggs?
egg count and quality reduces overtime so many women choose to freeze eggs to preserve the quality
what does the zygote develope into
morula
what is the morula
a solid ball of cells that are undifferenciated
what forms from the morula
blastocyst
what is a blastocyst
a ball of cells with a fluid filled cavity
what is the outer layer of the blastocyst called
trophoblast
what forms from the trophoblast
the embryo
germ layers
basic layers of cells in the blastocyst from which adult tissue and organs will form
what are the 3 germ layers
ectoderm
mesoderm
endoderm
function of the ectoderm
forms skin, hair, nails, nervous system
function of the mesoderm
forms muscles and skeletal system
function of the endoderm
forms inner lining of digestive system and the respiratory system
how many layers does the mesoderm have
2
what is the space between the 2 layers of the mesoderm
coelom
function of the coelom
produces more complex organs
embryo development week 4
heart is formed and starts to beat, brain and umbilical cord start to form
embryo development week 5
internal organs formed, limbs formed
embryo development week 6
eyes visible, nose and ears forming
embryo development week 8
tail shortened, bone starts replacing cartilage. now called the foetus
from what week can sex be determined in
pregnancy
12 weeks onwards
gestation
the length of time spent in the uterus from fertilisation to birth
usually 38 weeks
what structure produces oestrogen and progesterone during pregnancy
placenta- it acts as an endocrine gland
the drop of what hormone begins labour
progesterone
which hormone causes contractions
oxytocin
stage one of birth
contractions push the head of the foetus towards the cervix
the amnion bursts and amniotic fluid is released
stage 2 of birth
head of the baby is forced out through the vagina
stage 3 of birth
the afterbirth is expelled from the vagina
why are babies born headfirst
its easier, safer and less painful
lactation
is the production of milk by the mothers breasts. it is stimulated by breastfeeding
prolactin
hormone produced by the pituitary of the mother after birth which stimulates milk production
colostrum
thick yellow fluid produced by the breasts for the first few days after birth before the milk. high in protein, minerals and antibodies
benefits of breastfeeding
ideal nutrients
antibodies fight infection
safe as it is sterile
improves recovery in the mother
reduces risk of breast cancer
birth control
involves taking steps to reduce the number of children born
contraception
involves using methods to prevent fertilisation or pregnancy
what are the 4 types of contraception
natural
mechanical
chemical
surgical
natural contraception
not having sexual intercourse during the fertile period
monitoring body temperature- raises slightly after ovulation
mechanical contraception
physical barrier to stop egg and sperm meeting eachother
male condom
female diaphragm
chemical contraception
chemicals that kill sperm ie spermicides or hormones to prevent egg formation ie the pill
surgical contraception
vasectomy or tying tubes
