z
z4. In about 60% of men, the
nipples become more erect.
z
z5. Areas of the skin become
reddened due to dilatation of the blood vessels. This sex flush occurs
in about 50 to 60% of men.
z
z6. The heart rate, blood
pressure, and depth and rate of breathing begin to increase.
z
z7. There is an increase in tension of voluntary and involuntary muscles (myotonia).
z