reproductive system junior cert science

reproduction

when a living organism produces another organism of the same type

asexual reproduction

1 parent

offspring is genetically identical to the parent

eg bacteria

sexual reproduction

2 parents

genetically different to parent

involves fusion of sex cells called gametes at fertilisation to produce a zygote

eg humans

sexual reproduction in human

sperm with 23 chromosomes and egg with 23 chromosomes fuse at fertilisation to produce zygote with 46 chromosomes

sperm duct

carries sperm and seminal fluid

seminal gland

produce seminal fluid

testicle

produce sperm and male sex hormone

penis

transfers sperm into vagina during sexual intercourse

scrotum

holds testes and keeps them at 25 degrees the ideal temperature for sperm production

male sex hormone

testosterone

female sex hormone

eostrogen and progesterone

fallopian tube

carry eggs to uterus fertilisation often occurs here

ovary

produce eggs and female sex hormones

uterus

where a fertilised egg grows and develops into a baby

cervix

entry to the uterus

vagina

holds penis during sexual intercourse is the birth canal

menstrual cycle

a monthly preparation for the possibility of pregnancy usually lasts 28 days

days 1-5

your period lining of uterus sheds

days 6-12

new egg matures and lining of the uterus begins to thicken

days 13-15

egg released usually on day 14 but can vary this is called ovulation

days 16-28

egg travels to uterus if fertilised embryo implants if its not fertilised it dissolves

fertile period

time a woman is most likely to become pregnant if she has sexual intercourse

when fertile period occurs

3-4 days before and after ovulation occurs (day 9-16 ) sperm can survive a week in a female body

contraception

the deliberate use of artificial methods to prevent pregnancy

methods of contraception

abstinence

condom

pill

abstinence

not having sexual intercourse during ovulation

condom

barrier that covers the penis preventing sperm from entering the vagina

contraceptive pill

hormones taken by the female to prevent ovulation from occuring

before birth

amniotic sac bursts known as water breaking

uterus contracts

cervix begins to dilate/widen

during birth

cervix is fully dilated

baby is pushed out by the mothers muscular contractions

umbilical cord is clamped then cut to prevent blood loss from the baby

after birth

uterus contracts again

the placenta and umbilical cord are pushed out of the body

placenta

muscular bag that surrounds developing embryo

it allows food, oxygen and waste eg co2 to pass from the mothers blood to the babys blood

benefits of breastfeeding

babies that are breastfed tend to get fewer infections in early life as antibodies against infection are given to the baby

lactation

the production and secretion of milk from the mammary glands

stages of sexual reproduction

sexual intercourse

fertilisation

implantation

pregnancy

birth