17- reproduction in humans Flashcards
testis
- found outside body
- make sperms
- make testosterone (sex hormone)
scrotum
- Sac supporting testis outside the body
- ensures sperm kept in temp lower than that of the body
sperm duct
A tube that carries sperms out of testes to urethra.
prostate gland
Makes the seminal fluid for sperms to swim in.
urethra
Carries both urine & sperms at different times out of the body.
ovaries
- make egg cells
- make female sex hormones
oviduct
- Carry the egg cell away from the ovaries to the uterus.
- Site of fertilization.
uterus
Has thick walls, made of muscle, can stretch when a
woman is pregnant. It is where the embryo develops.
cervix
The neck of uterus, supplies mucus to the vagina
vagina
part of the birth canal, it is muscular and stretchable
fertilization
The fusion of the nuclei of male gamete [sperm] & female gamete [egg cell].
adaptive features of egg cell
- cytoplasm with a store of energy (for zygote ltr)
- jelly like coating to stop sperms after fertilization
adaptive features of sperm cell
- has a tail for movement
- contains enzymes in acrosome to digest membrane of egg
- large number of mitochondria to supply energy
acrosome
head region of sperm cell
motility of gametes
sperm- moves (swim)
egg- doesnt move
size of gametes
egg larger than sperm
number of gametes released
sperm- millions at a time
egg- once a month
genetic material of gametes
male- XY
female- XX
structure of sperm
enzymes, tail and mitochondria
structure of egg
has nutrients in the cytoplasm
amniotic sac
contains amniotic fluid which protects the embryo and allows the fetus to movement during growing
zygote
the fertilized egg
umbilical cord
- its what connects the fetus’s blood to and from the placenta for exchange of nutrients and removal of waste products
function of placenta
- allow nutrients to diffuse from mother to fetus
- allow wastes to diffuse from fetus to mother
- prevents toxins and pathogens from passing to the fetus
components of umbilical cord
fetal blood vessels
arteries - carry waste - fetus to placenta
veins - carry nutrients - placenta to fetus
function of umbilical cord
helps placenta in nutrients and gas exchange
antenatal care
he care and advice given to expectant mothers along with checks on fetal growth and development
advice for expectant mothers (antenatal care)
- balanced diet with folic acid, calcium, iron
- exercise
- avoid tobacco drugs alcohol etc..
advantages of breastfeeding
- right amount of nutrients
- antibodies to prevent infection
- develop bond between mom and child
- free
disadvantages of breastfeeding
- can be painful
- damages beauty
- mother needs to be present
advantages of bottle feeding
- less painful
- others can feed the baby
- may contain supplements
disadvantages of bottle feeding
- more likely to develop illness (infection)
- expensive
cause of menstruation
- failure to fertilize egg
- breakdown of thickened lining of uterus
what controls the menstrual cycle
hormones released from the ovary and the pituitary gland in the brain.
peak of estrogen level
day 14 (just before the egg is released)
effect of high estrogen level
uterine wall to start thickening and the egg to mature
what causes the uterus lining to breakdown
a fall in progesterone levels
FSH
hormone produced in pituitary gland
- promotes ovulation
LH
hormone produced in pituitary gland
- Works with FSH to release eggs.
- Prompts ovary to release progesterone & estrogen.
estrogen
hormone produced in ovary
- Makes the lining to uterus wall before ovulation
pregesterone
- Secreted after ovulation to maintain the uterus lining
through out pregnancy. - Stops ovulation by inhibiting the release of FSH.
rhythm method
natural, least reliable method pf birth control
- limiting the sexual intercourse in times where fertilization is less likely.
- monitoring body temperature and quality of cervical mucus
Abstinence
natural method of birth control
- avoiding sexual intercourse completely
Contraceptive pills
chemical method of birth control
- they contain hormone that prevents ovulation.
(effective when taken regularly)
spermicides
chemical method of birth control
- put in the vagina before intercourse to kill sperms.
(effective when taken regularly)
Hormone injection
chemical method of birth control
- every 12 weeks to stop ovaries from ovulation.
(effective when taken regularly)
intrauterine device [IUD]
small, T-shaped birth control device, inserted into a woman’s uterus to prevent implantation.
reversible, (chemical method)
Contraceptive implant
is a small, thin, flexible, plastic tube, implanted under the skin of the arm.
-reliable & lasts for up to 3 years.
how does a contraceptive implant work
- releases progesterone like hormone to make the cervical mucus thick, so it is difficult for sperms to swim
- it stops ovulation & makes the uterus lining
too thin to support the fetus.
mechanical method of birth control (barrier)
work by preventing sperm from reaching the egg
- condom, male
- femidom and diaphragm, female
vasectomy
surgical method of birth control for males
- cutting sperm duct (effective, permanent)
female sterilisation
cutting (permanent) or tying (reversible) the oviduct
-effective
Artificial insemination
Introducing sperms into the female’s vagina or uterus using a technique, when the male is incapable of normal intercourse.
types of artificial insemination
by donor or by husband
In vitro fertilization [IVF]
- egg cell is taken from the woman & exposed to the sperms in lab.
- it is fertilized and returned to the uterus to continue the development.
social issues of IVF
- expensive
- can rise to multiple births
- some people dont approve of artificial ways
sexually transmitted infections (STI)
The infection that is transmitted via body fluids through sexual contact, like HIV
HIV
- Human Immunodeficiency Virus, which leads to AIDS
- found in semen and blood
ways HIV can be transmitted
- sexual intercourse
- needle sharing
- blood transfusions
- mother to baby through placenta or breastfeeding
ways to control STI
- spreading awareness
- Never sharing needles during injection.
- Avoid unsafe sex.
- Use a condom if one partner is having STI.
- Treat all blood products used in transfusions to destroy the virus.
