Human Reproduction(second part)

Battle of the sexes!!!Are males and females all that different?

Well…..

Yes

And

No!

Anatomy

Male Female

Similarities

2 pouches

Testicles

Ovaries

Start out inside body

Testicles “descend” before birth

Fetus begins with “starter parts” that could develop into either gender.

Anatomy – similaritiesFunction – VERY different!

Male

Uncomplicated

Produce sperm

2-4 MILLION every day

Female

Very Complicated!

One egg

Once a month

Careful coordination of hormones & body

Timing perfect!

FemalesOvaries

2 pouchesContain ova

Born with all of her eggs (~ 400,000)

Use up ~500

Won’t run out!

OvulationOne egg released from ovary to oviduct(fallopian tube)

After OvulationEgg pushed along by cilia

Few days travel time to arrive in uterus

Cervix – Opening between uterus & vagina

Normally tiny

At birth – muscles pull open (dilation) cervix to allow baby to pass through = Labor

Menstrual Cycle

Complex combination of 10-12 chemicals (hormones)

Usually one egg once a month

All about timing!!!

Uterus must be ready when egg gets there in case it was fertilized

If no fertilization, tear down lining of uterus and rebuild for next month

28-Day Cycle (average)

Three Stages

1. Tear Down

2. Rebuild

3. Extra nutrients/blood for potential baby

No Baby?

Back to #1

Chemicals (hormones)

Regulate events in the body

Estrogen

Progesterone

LH (leuteinizing hormone)

FSH (follicle stimulating hormone)

Many others

Day 1

First menstrual blood & tissue

No baby = breaks down lining of uterus

5-7 days of blood/tissue exits body

Pre-Ovulation

~Day 14Ovulation = Egg released

Temp spikes slightly

Most fertile in next few days!

Able to get pregnant

Egg gets fertilized while traveling through oviduct.

Post-Ovulation

Birth Control Pills“Trick” body into thinking it’s pregnant

Extra hormones

No ovulation occurs

No ovulation = no egg = no fertilization = no baby!

No hormones taken for 7 days = menstruation

MaleTestes

Produce 2-4 million sperm every day

Outside body – why?Sperm like temps 1-2 cooler than body temp

Vas DeferensTube sperm travel through

VasectomyCut/tie off tube – sperm can’t get out!

Semen

Contains

300-500 million sperm

Sperm food

pH buffers

Allows sperm to survive for a couple of days inside female’s body (hostile environment)

What is sperm?Then…

Used to think it was a tiny human inside each cell

Spermists vs. Ovists

Now…Contains Several Parts:

HeadChemical to dissolve egg goo

Dad’s genetic information (DNA)

MitochondriaEnergy

TailSwimming

Prostate Gland

Adds non-sperm stuff to semen

pH buffers

Nourishment

Cancer very common

Slower-growing (usually)

Surgery for removal

Bulbourethral gland

Adds lubricant to aid travel of semen through the urethra