1. KEY CONCEPT Female and male reproductive organs fully develop during puberty.

2. Human Reproductive Systems and Offspring Development

3. The female reproductive system produces ova.
There are two main functions of the female reproductive system.
produce ova, or egg cells
provide a place where a zygote develops
uterus
cervix
rectum
vagina
urethra
urinary bladder
pubic bone
ovary
fallopian
tube

4. Female Reproductive Structures
The female reproductive system contains two ovaries, two fallopian tubes, and a uterus.

5. The male reproductive system produces sperm.
There are two main functions of the male reproductive system.
produce sperm cells
deliver sperm to the female reproductive system
urinary bladder
vas deferens
pubic bone
prostate gland
penis
urethra
testis
scrotum
epididymis
bulbourethral
gland
rectum
seminal vesicle

6. Human reproductive processes depend on cycles of hormones.
Estrogen is a hormone that serves three main functions. (in females)
- develop female sexual characteristics
- develop eggs
- prepare uterus for pregnancy
Testosterone is the main hormone that serves two main functions. (in males)
developing male sexual characteristics
producing sperm

7. Eggs mature and are released according to hormonal cycles.
potential
egg
first polar
body
second polar
ovum (egg)
Meiosis I
Completed
Meiosis II
only after
sperm
enters
Follicle-stimulating hormone (FSH) and lutenizing hormone (LH) regulate egg production in the ovaries of females.
Hormones FSH and LH are secreted from the pituitary gland in the brain.
meiosis produces eggs and polar bodies (small eggs that disintegrate)
each egg has 23 chromosomes
meiosis is completed at fertilization

8. FSH, LH, and estrogen stimulate the release of eggs.
follicle ruptures at ovulation
egg travels into fallopian tube
Ovulation video clip
fallopian
tube
egg cell
egg released
corpus luteum
uterine wall
ovary
follicle
uterus
5 to 7 days to uterus

9. Female Reproductive System

10. Eggs mature and are released according to hormonal cycles.
The menstrual cycle has three phases.
flow phase: endometrium sheds
follicular phase: ovulation occurs
luteal phase: corpus luteum forms

11. The menstrual cycle stops at menopause.
cycle continues until a woman’s mid-40’s or 50’s
decline in hormone levels make cycles irregular
eventually, cycle stops altogether

12. Sperm production is also controlled by hormones.
Testosterone, FSH, and LH stimulate sperm production in the testes of males.
one sex cell divides into four sperm
each sperm has 23 chromosomes
potential
sperm
4 sperm cells
Meiosis I
Meiosis II
Spermatogenesis animation

13. Sperm cells fully mature in the epididymis.
acrosome
head
midpiece
tail
mitochondria
nucleus with 23 chromosomes
head contains acrosome
(enzyme to break through wall of ovum)
midpiece contains ATP
tail allows mobility

14. Male Reproductive System

15. Fertilization occurs when a sperm cell joins an egg cell.
Sperm penetrates an egg.
Chemical reaction releases a membrane barrier that keeps out other sperm
nucleus of sperm joins with egg
zygote formed
Multiple zygotes can result from fertilization.
- identical twins: splitting apart from the same egg
- fraternal twins: fertilization of two separate eggs
Fertilization of Sea Urchin Eggs

16. KEY CONCEPT Development progresses in stages from zygote to fetus.

17. ectoderm develops into skin and nervous system
The fertilized egg implants into the uterus and is nourished by the placenta and umbilical cord.
The zygote becomes a blastocyst (mass of cells through mitosis) and implants in the uterus.
ectoderm develops into skin and nervous system
mesoderm develops into Internal tissues and organs
endoderm develops into digestive organs and their lining
blastocyst
uterine wall
Implantation of blastocyst

18. Early Zygote Development

19. Embryonic membranes protect and nourish the embryo.
Once implanted in the female's uterus, the blastocyst becomes an embryo.
Embryonic membranes protect and nourish the embryo.
amniotic sac (membrane surrounding fetus with amniotic fluid) cushions embryo.
placenta connects mother and embryo.
umbilical cord connects embryo to placenta.
placenta
umbilical cord
uterus
amniotic sac

21. A zygote develops into a fully formed fetus in about 38 weeks.
Human pregnancies are divided into trimesters.
1st trimester: body plan and early development

22. 2nd trimester: fetus more active, developed

23. 3rd trimester: all organs fully formed
After about 38 weeks, fetus is ready to be born.

24. A surge of oxytocin hormone causes uterine muscle contractions to begin the birthing process.

25. The mother affects the fetus, and pregnancy affects the mother.
The fetus depends on the mother for all its nutrition.
mother's diet must support fetal health (prescription for prenatal vitamins)
mother must avoid toxic chemicals (alcohol, caffeine)

26. The mother’s health is affected by pregnancy in a number of ways.
increase in Calories and body weight
pregnancy hormones affecting homeostasis
regular medical checkups needed

27. Sexually transmitted diseases affect fertility and overall health.
Sexually transmitted diseases (STDs) are passed from one person to another during sexual contact.
bacterial STDs include chlamydia, syphilis, gonorrhea
viral STDs include hepatitis B, genital herpes, human papillomavirus, and HIV
HIV

28. STDs attack reproductive organs. can cause infertility
Bacterial STDs can be treated, and in many cases, cured with antibiotics
A parasite causes trichomoniasis, which can affect fertility.
Viral STDs can be treated with medicine to regulate symptoms, but there is no cure for these diseases.
STDs attack reproductive organs.
can cause infertility
untreated, some can be fatal
Most STDs can be avoided and prevented.