3. Male Reproductive Structures
• Testis – site of sperm production
– produces hormone testosterone
• Scrotum – sac containing testes
– maintains testis at 1-3°C below body
temperature
• Epididymus – site of sperm
maturation
• Vas deferens – carries sperm
from testes to urethra
4. Male Reproductive Structures
• Fluid from 3 glands combine with sperm to make
semen
• Seminal vesicle, prostate gland, and
bulbourethral (Cowper’s) gland
– Adds sugar, lubricants, and neutralizing fluid
– Sperm + fluids = semen
8. Female Reproductive Structures
• Ovaries – contains follicles where eggs
(ova) mature
– produces estrogen
and progesterone
•
Egg travels down the
fallopian tube
(oviduct) to the uterus
9. Female Reproductive Structures
• Cilia lining fallopian tubes - sweeps egg
into the uterus
– Fertilization is usually here
• Uterus (womb)
– Muscular organ where fetus develops
– Contracts during birth
• The cervix connects the
uterus/vagina
• Vagina – birth canal
13. Menstrual Cycle Summary
• Luteal Phase – corpus
luteum releases estrogen
and progesterone
– Uterine lining builds up
– Fertilization may occur
• Menstruation occurs if
egg isn’t fertilized
– Corpus luteum breaks down
– Estrogen and progesterone decrease
– Blood, tissue, and egg leave thru the vagina
• Low estrogen levels cause pituitary to release
FSH & LH… the cycle repeats
14. Fertilization and Implantation
• Fertilization occurs in the oviduct
– Zygote – a fertilized egg, diploid cell
• Cell division begins
– Embryo - > 1 cell
– Morula – solid ball of 64 cells
– Blastocyst – hollow ball of cells
• Blastocyst takes ~7
days to implant in the
uterine lining
• Differentiation
begins, cells
specialize
Oviduct
4 cells 2 cells
Morula Fertilization
Zygote
Blastocyst
Implantation
Uterine
wall
Ovary
Egg
15.
16.
17. Embryonic Development
• Gastrulation is the formation of 3 embryonic
germ layers
• Endoderm – lining of digestive, reproductive,
respiratory systems
• Mesoderm – muscles, blood, and bones
• Ectoderm – skin and nervous system
19. Placental Mammals
For complete internal
development to occur,
there must be a
continuous food
supply, gas exchange,
and waste removal.
Placental mammals
supply these needs
with a placenta.
Examples: humans,
dogs, rats, horses, and
deer.
21. Pregnancy and Development
• Specialized embryonic membranes develop to protect
and nourish the embryo
• Chorion – develops into the placenta
• Placenta and umbilical cord connect fetus to mother
– Provides energy and O2, removes wastes and CO2
23. Placenta and Umbilical Cord
The embryo is
connected to the
placenta by an
umbilical cord which
contains large blood
vessels that transport
food, oxygen, carbon
dioxide, and wastes
between the mother and
fetus.
Embryo = 0-8 weeks
Fetus = after 8 weeks
25. Fetal Growth and Development
• 1 st Trimester – all organ systems formed by 7th week
• 2 nd Trimester – organs mature, heart can be heard
• 3 rd Trimester – greatest size and mass increase
27. Birth
The hormone oxytocin
causes a series of uterine
contractions to begin (labor.)
The amniotic sac breaks,
the cervix dilates, and as the
contractions become more
intense the fetus is pushed
head first and face down
through the birth canal.
The birth is followed by
afterbirth or expulsion of the
placenta. The umbilical cord is
cut and tied immediately after
birth.