1. The Reproductive System16
The Reproductive System

2. The Reproductive System
I. PARTS
A. Gonads:
Testes: Sperm—male gametes
Ovaries:Ova (eggs)—female
gametes
B. TESTES
1. Seminiferous Tubules
Produce sperm & Androgens
Outside Body:
Testes

3. Male Reproductive System Overview
2. Spermatogenesis: at
puberty to death
Sperm—23 chromosomes (half as much as other cells)
Head & Tail
Seminiferous Tubules

4. Accessory Organs Seminal vesicles– substances that nourish sperm
Prostate– fluid that helps activate sperm
Bulbourethral glands– mucus which cleanses urethra of acidic urine, lubricant
Semen = sperm & secretions
Ureter
Urinary bladder
Seminal vesicle
Urethra
Pubis
Sperm movement
Ejaculatory duct
Rectum
Erectile tissue
of the penis
Prostate
Bulbourethral gland
Spongy urethra
Shaft of the penis
Ductus (vas) deferens
Epididymis
Glans penis
Testis
Prepuce
(a)
Scrotum
External urethral
orifice

5. Urinary
bladder
Ureter
Ampulla
of ductus
deferens
Prostate
Seminal
vesicle
Prostatic
urethra
Ejaculatory
duct
Orifices of
prostatic ducts
Bulbourethral
gland
Membranous
urethra
Ductus
deferens
Root of
penis
Erectile
tissue
of penis
Epididymis
Shaft (body)
of penis
Testis
Spongy
urethra
Glans penis
Prepuce
External
urethral
orifice
(b)
Figure 16.2b

6. Testosterone Production
During Puberty
Functions
reproductive organ development
sex drive
secondary sex characteristics
Production of sperm

7. Female Reproductive System
Ovaries
ovarian follicles (sac-like structures) with Oocyte (immature egg)
Ovulation—when egg is mature, follicle ruptures; every 28 days
Primary follicle
Blood
vessels
Mature vesicular
(Graafian) follicle
Corpus luteum
Ovulation
oocyte

8. Uterine (Fallopian) Tubes
Receives oocyte
site for fertilization
Attached to the uterus
Uterine (fallopian) tube
Ovarian
blood
vessels
Ovary
Infundibulum
Uterine
tube
Fimbriae
Body of
uterus
Endometrium
Myometrium
Wall of
uterus
Perimetrium
Ureter
Cervical canal
Cervix
Vagina

9. Uterus between bladder and rectum Hollow Functions
Receives fertilized egg  embryo  fetus
Cervix—narrow outlet that protrudes into the vagina
Endometrium
Inner layer for
implantation of
fertilized egg
Uterus
Endometrium
Cervix

10. Vagina cervix to exterior of body between bladder and rectum
Receives the penis and serves as birth canal
Vagina

11. Oogenesis and the Ovarian Cycle
total eggs present at birth
Egg release at puberty
Menopause– no more eggs
Oocytes mature, then ovulated
Have 23 chromosomes
Large cells
Oocyte

12. Oocyte
Figure 16.11

13. Hormone Production by the Ovaries
Estrogens
Cause secondary sex characteristics
Progesterone
Helps maintain pregnancy
Prepare breasts for milk production

14. Mammary Glands Modified sweat glands Function: Adipose tissue
Lactiferous duct
Nipple
Lobule containing
alveoli

15. Mammography X-ray examination that detects breast cancers
Recommended: every 2 years for years > 49 = yearly
Malignancy
(a) Mammogram procedure
(b) Film of normal breast
(c) Film of breast with tumor

16. Human Life Cycle Sperm (23) with Egg (23) creates Zygote (46) =
1st Cell

17. Accomplishing Fertilization
Oocyte lives 12 to 24 hr
Sperm lives 24 to 48 hr
Sperm must get to uterine tube
For fertilization:
2 days before ovulation 3 days
24 hours after ovulation
oocyte membrane does not permit second sperm to enter
Fertilization = Sperm DNA combines with oocyte DNA  Zygote

18. Introduction to Pregnancy and Development
Cleavage: Rapid cell division of embryo
4 days after ovulation, it reaches uterus
7 days after ovulation, embryo implants
Embryo—fertilization to week 8
Fetus—week 9 to birth
Gestation period—280 days
Cleavage
Embryo
Fertilization
1-week
conceptus
3-week
embryo
(3 mm)
5-week embryo
(10 mm)
8-week embryo
(22 mm)
12-week fetus
(90 mm)

19. Development After Implantation
Placenta:
Amnion—fluid-filled sac that surrounds the embryo
Umbilical cord
Blood vessel-containing stalk of tissue
Attaches the embryo to the placenta
Umbilical cord
Amnion
Chorionic
villi
Uterine
cavity
Chorion
Ectoderm
Forming
mesoderm
Embryo
Endoderm

20. Amniotic sac Umbilical cord Umbilical vein Chorionic villi Yolk sac
Cut edge
of chorion
Figure 16.18

21. Functions of the Placenta
Forms barrier: blood is not mixed
Delivers nutrients & oxygen
Removes waste
Produces Estrogen & Progesterone to maintain pregnancy

22. Effects of Pregnancy on the Mother
Enlargement of uterus
Accentuated lumbar curvature
Morning sickness (elevated progesterone & estrogens)
Heartburn: crowding by the fetus
Constipation

23. Effects of Pregnancy on the Mother …
Kidneys: produce more urine
Bladder squeezed: incontinence
Blood volume increases
Blood pressure and pulse increase
Childbirth (Parturition)
Initiation of labor
Uterine contractions begin
Oxytocin is released by the pituitary  stronger contractions
Hypothalamus sends efferent
impulses to posterior pituitary,
where oxytocin is stored 4
Posterior pituitary releases
oxytocin to blood; oxytocin
targets mother’s uterine
muscle 5
Uterus responds
by contracting more
vigorously 6
Baby moves
deeper into
mother’s birth
canal 1
Afferent
impulses to
hypothalamus 3
Pressoreceptors
in cervix of uterus
excited 2
Positive feedback
mechanism continues
to cycle until
interrupted by birth of
baby

24. Placenta Umbilical cord Uterus Cervix Vagina Sacrum Stages of Labor
Dilation
Cervix becomes dilated to 10 cm
The amnion ruptures (“breaking the water”)
Placenta
Umbilical cord
Uterus
Cervix
Vagina
Sacrum

25. Perineum Expulsion Infant passes through the cervix & vagina
Stages of Labor …
Expulsion
Infant passes through the cervix & vagina
head first
Perineum
Placental stage
Delivery of the placenta
Perineum

26. End