View
2
Download
0
Category
Preview:
Citation preview
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
Recommended