Sexual reproduction in humans

testis and Scrotum

Create sperm

Protect testis

Sperm duct and eppidleymis

Transport sperm out of tesis to urethra

Store sperm temporary and develop ability to move

Seminal vesicle

Urethra

Secrete seminal fluid give sperm nutrients

Urethra take out semen and urine out of body

Ovary and oviduct uterus

Produce egg cell and sex hormone

Transport egg to uterus (baby grow

Uterus develop into embryo during pregnancy

Structure of sperm

Tail for movement

Acrosome tip (has enzyme to dissolve jelly coat of ovum)

Head has nucleus contain genetic material as chromosome

Neck (has mitochondria to provide energy for movement of sperm

Structure of ovum

Cytoplasm:contains nutrients for embryo

Cell membrane:jelly coat to protect cell change when being fertilised

Nuclues hold genetic material

How is fertilisation occurred

Penis inject to vagina and eject sperm

Follicle in ovary bust to release ovum move along oviduct

Sperm swim through vagina cervix and uterus up to oviduct sperm meet ovum in oviduct penetrate it by enzymes to digest jelly coat of ovum and to prevent entry of other sperm

Nucleus of sperm fuse with ovum nucleus called zygote

Divide by mitocic cell division

Move down oviduct to uterus to implant and develop to embryo

What is menstrual cycle for

And when is ovum released

Prepare body for potential pregnancy

Released at 28 days remaining follicle cell become yellow body after ovulation(release of ovum)

Day 1-5 of menstrual cycle

If fertilisation don’t take place:Uterine lining break down and yellow body is appeared in day 28

If fertilisation menstruation won’t take place

Day 5/-14 of menstrual cycle

Uterine lining build up prepares it for implantation of fertilised egg

Day 14- ovulation take place (egg released from one ovary )

Day 14-28

If no fertilise egg made to uterus then uterus wall break down to stage 1 and repeats

If fertilisation occur implant to uterus lining and develop to foetus cylce stop as woman is pregnant

Oestrogen and progesterone

Both produced in ovaries -stimulated thickening of uterine lining for potential pregnancy (rise during first half of cycle leading to ovulation cycle )

Maintain uterine lining (if pregnant don’t occur uterine lining break down)progesterone level drop lead to menstruation

LH AND FSH

both produced in pituitary gland (stimulate release of egg) in day 14 ovulation

stimulate follicle development stimulate ovaries to produces more oestrogen as oestrogen increase inhibit FSH(negative feedback relationship) when oestrogen level rise stimulate release of LH which result in ovulation PROGESTERONE INHIBIT BOTH LH AND FSH

Identical and fraternal twin

1 zygote is formed separate into 2 embryo —2 zygote is formed separate 2 embryo different

Same genetic makeup —2 genetically different individual

Placenta function

Site of exchange of nutrients and waste

Produce sex hormones

Umbilical cord

Carry nutrients and oxygen to foetus and carbon dioxide away from foetus

Amniotic fluid

Acts as shock absorber

Allow baby move freely

Maintain stable temp for growth of baby

Prevent desiccation (drying up ) of embryo

Significance of parental care

Protect baby from danger

Food and protection provide to young offspring

Survival skills are taught to offspring

Breast feeding significance

Contain antibodies to protect baby from diseases

Help development of brain of baby

Stimulate recovery of uterine lining

Adv and disadvantages

Rhythm method

Withdrawal method

Condom

Avoid sex around ovulation Take out penis before ejaculation (sperm may leaked)

Prevent sperm entry

(cheap and natural ) (high failure rate)

(Cheap and protect std) (may tear on use

Diaphragm contraceptive pill and iud adv and disadvantages

Placed at cervix prevent sperm entry(reusable )(uncomfortable)

Prevent ovulation (reliable) (take everyday)

Prevent implantation (last long time) (uncomfortable

Vasectomy and tubal ligation adv and disadvantages

Cut and tie sperm duct (reliable )cannot reverse

Cut and tie oviduct (reliable ) (cannot reverse