| Sexual Health |
The process of erection and return to flaccidity (detumescence) has been summarized and divided into
different phases as listed below:
• Phase 0 - This is the flaccid state.There is dominant sympathetic influence and minimal blood flow.
• Phase I - This is the latent or filling phase. Parasympathetic nervous activity dominates. Increased
parasympathetic activity results in an increased production of nitric oxide and vasoactive polypeptide. This
results in an increased production of cyclic guanidine monophosphate that reduces intracellular calcium,
resulting in smooth muscle relaxation and increased blood flow through the pudendal and cavernous arteries.
• Phase 2 - This is the tumescence (تورم) phase.The intercavernous pressure increases rapidly and penile
engorgement occurs.
• Phase 3 - In this phase, known as the full erection phase, outflow of blood is restricted. As the penis is
engorged, subtunical venules are compressed by the increased blood volume against the tunica albuginea.
The intercavernous pressure rises to 10-20 mm Hg below systemic blood pressure.
• Phase 4 - This is the skeletal or rigid erection phase. Intercavernous pressure increases well above
systemic blood pressure as a result of voluntary or reflexogenic contraction of the ischiocavernosus and
bulbocavernosus muscles. This results in a rigid erection.There is no blood flow through the cavernous artery
at this stage.
• Phase 5 - In this transitional phase, there is increased sympathetic nervous system activity. This
results in increased vascular tone and low level resumption of arterial blood flow. Blood outflow is still
restricted.
• Phase 6 - This is the initial detumescence phase. Intercavernous pressure declines and the outflow
restriction decreases.
• Phase 7 - This is known as the fast detumescence phase. Intercavernous pressures decline rapidly The
outflow restriction is inactivated, and arterial blood flow returns to normal levels. The penis returns to the
flaccid state.
• Of the three phases of normal male sexual function, erectile rigidity plays the biggest role in male
erectile dysfunction.
different phases as listed below:
• Phase 0 - This is the flaccid state.There is dominant sympathetic influence and minimal blood flow.
• Phase I - This is the latent or filling phase. Parasympathetic nervous activity dominates. Increased
parasympathetic activity results in an increased production of nitric oxide and vasoactive polypeptide. This
results in an increased production of cyclic guanidine monophosphate that reduces intracellular calcium,
resulting in smooth muscle relaxation and increased blood flow through the pudendal and cavernous arteries.
• Phase 2 - This is the tumescence (تورم) phase.The intercavernous pressure increases rapidly and penile
engorgement occurs.
• Phase 3 - In this phase, known as the full erection phase, outflow of blood is restricted. As the penis is
engorged, subtunical venules are compressed by the increased blood volume against the tunica albuginea.
The intercavernous pressure rises to 10-20 mm Hg below systemic blood pressure.
• Phase 4 - This is the skeletal or rigid erection phase. Intercavernous pressure increases well above
systemic blood pressure as a result of voluntary or reflexogenic contraction of the ischiocavernosus and
bulbocavernosus muscles. This results in a rigid erection.There is no blood flow through the cavernous artery
at this stage.
• Phase 5 - In this transitional phase, there is increased sympathetic nervous system activity. This
results in increased vascular tone and low level resumption of arterial blood flow. Blood outflow is still
restricted.
• Phase 6 - This is the initial detumescence phase. Intercavernous pressure declines and the outflow
restriction decreases.
• Phase 7 - This is known as the fast detumescence phase. Intercavernous pressures decline rapidly The
outflow restriction is inactivated, and arterial blood flow returns to normal levels. The penis returns to the
flaccid state.
• Of the three phases of normal male sexual function, erectile rigidity plays the biggest role in male
erectile dysfunction.
Phases of erection
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