reproduction in humans

Testes

Produce sperm & sex hormones-testosterone

Scrotum

Holds testes outside the body-lower temp, optimal temp essential for sperm to develop(enzyme catalyse reaction)

Sperm duct

After sperm released from testis, travel thru sperm duct

Prostate gland

Secretes fluid(semen) containing nutrients & enzymes which nourish & stimulate sperm to swim actively-mix with sperm

Urethra

Semen & urine pass out of body thru it

Penis

Deposit semen

 

Sperm travel

Testes→sperm duct→urethra→outside body

Sperm no

Large no released

Sperm life span

3 day

Ovary

Produce ova(egg) & hormones-oestrogen & progesterone

Oviduct

Fertilisation happens here

Ovary releases ova into oviduct

Movement of cilia helps move egg along oviduct

Uterus

Fetus develops here

Smooth muscle tissue in walls contract to push fetus out

Uterine lining:where embryo implanted

Cervix

Allow menstrual blood flow out of vagina

Vagina

Semen is deposited inside

Ova surrounded by outer membrane

Break thru by enzyme secreted by sperm

Ova number

1 released per month

Ova life span

1-2 day

1. Menstruation (0-5)

Loss of uterine lining & egg cell

2. Repair(6-10)

Oestrogen causes uterine lining to repair & thicken

High oestrogen concentration->ovulation

3. Fertile(10-15)

14 day: ovulation-ovary releases egg into oviduct

4. Maintenance(16-28)

Progesterone prevents ovulation & further dev of egg, causes uterine lining to thicken further-prepare for implantation & growth of embryo

Oestrogen production decrease

No fertilisation

1. Egg break down

2. Progesterone level decrease

3. On 28 day-without progesterone, uterine lining begin break down

Fertilisation occur

1. Fertilised egg become zygote which dev into embryo

2. Ovary secrete progesterone & oestrogen-maintainence & thickening of uterine lining for implantation of embryo

3. Embryo embed in uterine lining until placenta form

4. Ovary secrete progesterone & oestrogen until placenta take over

 

 

1. Implantation(embryo dev)

1. Cilia lining in inner surface of oviduct sweep zygote along oviduct

2. Zygote divides by mitosis form embryo

3. Embryo become embedded in uterine lining-implantation(occur 7 day after fertilisation)

2. Dev of placenta(embryo dev)

1. Villi grow from embryo into uterine lining-contain blood capillary

2. Villi & uterine lining make up placenta

3. Umbilical cord attaches embryo to placenta

Dev of amniotic sac(embryo dev)

1. Dev at same time as placenta

2. Encloses embryo in amniotic cavity, fluid in amniotic cavity-amniotic fluid

3.  Embryo dev->fetus

Placenta function

1. Allow O2 & dissolved food substances to diffuse

2. Allows metabolic waste/excretory product to diffuse

3. Allow protective antibody to diffuse

4. Produce oestrogen & progesterone-maintain uterine lining

Umbilical cord function

1. 2 umbilical artery transport deoxy blood & metabolic waste

2. 1 umbilical vein transport oxy blood & food

Amniotic fluid function

1. Supports & cushions fetus-shock absorber, protect fetus against physical injury

2. Allows fetus to move

3. Lubricates during birth

Fetal blood system separate from maternal blood system

1. Blood pressure of mother higher

2. Blood group diff

3. Potential harmful substances/pathogen