2. Orgasm follows… • Emotional intensity, hard breathing, heart pounding, contraction of skeletal muscle and rhythmic throbbing of pelvic muscles. • Strong sensations of physical release, warmth and relaxation dominate.

3. Fertilization • Ejaculation-150 to 350 mil. sperms into the vagina. • Only few hundred reaches the upper region of the oviduct for fertilization. • Sperm reaches oocyte-releases digestive enzyme (from the cap); pass through the zonapellucida. • Usually ONLY ONE sperm fuses with the oocyte. • Zonapellucida becomes impermeable to other sperms. • Penetration of the sperm-stimulates the completion of meiosis II to form a mature ovum/egg. • Sperm nucleus fuses with egg nucleus to restore the diploid chromosome number; forms zygote.