1. Ovulation
Fertilization

2. Maturation of sperm Sperms
Incapable of fertilizing the oocyte immediately after being released into the lumen of the seminefrous tubules
Maturation
In epidydimus

4. Epidydimus Fluid reabsorption Quiescence of sperms
Increase concentrations of sperm by 100 folds
Estrogen dependent
Quiescence of sperms
Slow activity
Movement depends on musculature
Addition of chemicals
Glycoproteins
Coating of sperm surface

5. Maturation of sperm Ability to move on its own
Nuclear condensation and loss of cytoplasm
Metabolism alteration
External source
Increased mobility
Changes in cell membrane
Increased charge (glycosylation)
Changes in protein profile
Changes in lipid composition (fluidity)

6. Maturation of sperm Androgen dependent
Very high concentrations (ABP)
Conversion to DHT
Increased bioactivity
Entire process will take several months to few days

7. Movement of sperms Entering vas deference from epidydimus
Muscular contraction rather than fluid movement
Dense mass
Serve as reservoir of sperms
Lost in urine if no ejaculation

8. Sperm in male reproductive tract
Semen
Sperm plus seminal plasma
Seminal plasma
Derived from accessory sex glands
Serves as fluid vesicle for transport
Unnecessary for sperm function

9. Seminal plasma Derived from accessory sex glands
Serves as fluid vesicle for transport
Serves as buffer
Basic in nature
Neutralizes acids
Provides nutrients
Fluctose
sorbitol

11. Semen composition
Immune cells
Infectious agents

12. Deposition of semen into the female reproductive tract
Coitus
Physiological changes
Genitalia
Other parts of body
Phases
Described in humans by Johnson and Masters
Four phases
Excitement (sexual arousal)
Plateau (intense arousal)
Orgasm (involuntary climax)
Resolution
Absolute refractory phase in male
Immediately after orgasm

13. Excitement Vasocongestion Vaginal expansion “Tenting effect” on uterus
Penile erection (engorgement of corpora cavanosa and corpus spongiosum)
Vaginal lubrication (transudation)
Enlargement of labia minora and clitorus
Vaginal expansion
“Tenting effect” on uterus
Upward movement of uterus and cervix
Fibrilation of uterus (contraction)
Sex flush
Myotonia
Increased muscle tension

14. Plateau Increased testis size Secretion of fluid Sex flushes
Elevated from the original position
Secretion of fluid
Cowper’s gland
Sex flushes
Engorgement of vaginal wall
Orgasmic platform
Formation of seminal pool

15. Female orgasm Rhythmic contraction Involuntary muscle spasm
Vaginal wall
Uterus
Involuntary muscle spasm

16. Male orgasm Contraction of accessory sex gland
Collection of semen into the urethral bulb
Contraction of bladder muscle
Emission stage of ejaculation
Expulsion of semen/ejaculation
Muscle contraction
Reproductive tract contraction

17. Resolution Returning of body to nonaroused state
Size of genitals
Uptake of sperm by the cervix
Dipping into the seminal pool as the uterus returns to the normal position
Opening of cervical canal

18. Site of semen deposition
Varies among species
Humans and cattle
Near external portion of cervix (cervical os)
Uterus in other species
Formation of “plug”
Enzymatic reaction
Prevent backflow of semen
Buffers
Prevent sperm from other males to fertilize eggs?

19. Transport of sperm to the oviduct
Sperm must enter female reproductive tract and reside there for some time
Maximum fertility
Sperm
Viable inside of reproductive tract
24 to 48 hours in human
30 to 48 hours in cows
Oocyte
A finite life span
6 to 24 hours after ovulation in human
Sperm must reach the oviduct at appropriate time in order to remain viable and fertile

20. Transport of sperm to the oviduct
Preovulatry
follicle
Semen pool
Semen
Deposited in the anterior part of the vagina near the cervix
The majority of the sperm
Lost because of retrograde flow of the mucus out of the vagina
Killed because of the unfavorable environment for sperm survival in the vagina.

21. Transport of sperm to the oviduct
Some of the sperm
Transported through cervical canal into the uterus within minutes after sperm deposition
Rapid transport
Rapid transport of sperm is caused by the contraction of myometrium (muscle layer of the uterus) and not by active movement of sperm
Sperm that enter the oviduct by rapid transport
Often non-viable and unlikely to participate in fertilization.

22. Transport of sperm to the oviduct
Many sperm
Trapped in the folds and crypts of the cervix
Formation of sperm reservoirs within the cervix
Critical
More sperm ultimately reach the oviduct when more sperm are available in the cervical reservoir
Folds and crypts of the cervix

23. Transport of sperm to the oviduct
Slow transport of sperm
After establishment of reservoir
Ensures the availability of sperm in the oviduct continuously
Large number of sperms
Fails to reach the oviduct
Many obstacles such as folding of the uterine endometrium and the narrow diameter of the uterotubal junction
Presumably to prevent polyspermy (more than one sperm fertilizing the oocyte)

24. Transport of sperm to the oviduct
Uterotubal
Junction
Ampullary-
isthmic Junction
Isthmus
Ampulla
Infundibulum
Aggregation of sperms
The isthmus
Sperm remain in the isthmus until ovulation
Hyperactivation
Rapid movement of tail and erratic swimming motion
Near ovulation
Essential for their upward movement toward the ampulla.

25. Transport of sperm to the oviduct
Uterotubal
Junction
Ampullary-
isthmic Junction
Isthmus
Ampulla
Infundibulum
Capacitation
Changes in cell surface of the sperm
Required for proper attachment and penetration of the zona pellucida when the sperm encounters the oocyte

26. Capacitated sperms Acrosome reaction when encountering the oocyte
Ability to bind and penetrate zona pellucida
Swelling of acrosome
Fusion of acrosomal membrane
Exocytosis of acrosomal content
Ca and cAMP dependent

28. Acrosome reaction Triggered by the protein in the zona pellucida ZP3
Sperms have receptors for ZPs
Increased Ca uptake
Release of hexosaminidase B (removal of ZP3)

29. Acrosome reaction Must take place near the oocyte
Reduced sperm viability

30. Fertilization Sperm encountering the oocyte Cumulus cells
Migration through the remaining cumulus cells that surround the oocyte
Sperm binds to the zona pellucida
Mediated by the sperm binding sites present on zona pellucida
Cumulus cells
First polar body

31. Fertilization
Within minutes of binding, the sperm begins to penetrate the zona pellucida, and eventually fuses with the oocyte
Equatorial and postacrosomal region
Ca-dependent reaction
Immediately after the sperm fuses with the oocyte, the oocyte extrudes the second polar body
Oocyte becomes a haploid cell
Zona
pellucida
Second polar body

32. Fertilization
Once a sperm fuses with the oocyte, the zona pellucida becomes hardened
Release of Ca
Sperm binding sites disappear from the zona pellucida
Hardening of zona and loss of sperm binding sites are necessary in order to prevent polyspermy
Head
of sperm

33. Fertilization Membrane of the sperm head
Degraded and replaced by a new membrane
Formation of a structure called the male pronucleus
The maternal half of chromosomes
The female pronucleus.
Male pronucleus
Female pronucleus

34. Fertilization
Male and female pronuclei move toward the center of the oocyte
Degradation of the membrane that surrounds each pronucleus
Mixing of maternal and paternal chromosomes
Restoration of the total number of chromosomes
Zygote