The tension of voluntary and involuntary muscles is heightened, and there may be almost spastic contractions in several muscle groups in the face, hands, ribs, back, and abdomen. The sphincter muscle in the anus may tighten up, and some women tighten it intentionally to further heighten tension. The swelling of the areolas may initially mask the erection of the nipples, causing them to appear shorter, however further swelling of the areolas and erection of the nipples may occur. This is the engorgement and swelling of the tissues surrounding the outer third of the vaginal barrel. Thus, during intercourse, at this time the vagina actually grips the penis, and the erotic stimulation of the man increases greatly.
Further changes occur in the internal sexual organs of the female.
The uterus becomes elevated and enlarged, as much as twice its normal size, and the inner vagina balloons even more than before. The clitoris, at this point, may become elevated, rising from its normal position over the pubic bone, becoming retracted behind the clitoral hood. During this elevation, it is drawn away from the vaginal entrance, however it remains extremely sensitive to stimulation, either directly or indirectly through the thrusting of the penis around the pubic bone into the vagina. Aside from these changes, color changes, if not present before, may become more pronounced at this point as the pinkish tissue of all the visible organs may become darker, especially is stimulation is prolonged. In both genders it seems logical that readiness for orgasm is reached after these tensions reach an adequate peak.