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Erection - Anatomy & Physiology (view source)
Revision as of 13:40, 5 July 2012
, 13:40, 5 July 2012→Vascular and Biochemical Control of Erection
== Introduction ==
== Introduction ==
* When sexual receptivity of the female is established and sufficient arousal is accomplished in the male, erection and protrusion of the penis ensue.
* When sexual receptivity of the female is established and sufficient arousal is accomplished in the male, erection and protrusion of the penis ensue.
* Successful penile erection requires a complex series of neural and vasomotor reactions.
* Successful penile erection requires a complex series of neural and vasomotor reactions.
* Erection of the penis is necessary for copulation and deposition of [[Copulation_-Sperm_in_the_Female_Tract_-_Anatomy_%26_Physiology|semen in the female reproductive tract]].
* Erection of the penis is necessary for copulation and deposition of [[Sperm in the Female Tract - Anatomy & Physiology|semen in the female reproductive tract]].
* Erection is characterized by a marked increase in rigidity of the penis.
* Erection is characterized by a marked increase in rigidity of the penis.
* Increased rigidity is the result of increase in arterial inflow of blood compared to venous outflow.
* Increased rigidity is the result of increase in arterial inflow of blood compared to venous outflow.
* Increased blood flow to the penis is brought about by vasodilation of the arterioles supplying it.
* Increased blood flow to the penis is brought about by vasodilation of the arterioles supplying it.
== Erection of the Fibroelastic Penis ==
== Erection of the Fibroelastic Penis ==
[[Image:Erection of the Fibroelastic Penis.jpg|thumb|right|150px|<p>The Fibroelastic Penis in a Flaccid State</p><sup> Copyright Nottingham University 2008.</sup>]]
* Bull,Ram and Boar
* Bull,Ram and Boar
* Does not increase significantly in diameter during erection.
* Does not increase significantly in diameter during erection.
== Erection of the Musculovascular Penis ==
== Erection of the Musculovascular Penis ==
* Engorgement with blood plays a significant role in the highly vascular penis.
* Engorgement with blood plays a significant role in the highly vascular penis.
== Mechanism ==
== Mechanism ==
* Very high pressure results.
* Very high pressure results.
== Sensory Input and Local Vascular Response ==
== Sensory Input and Local Vascular Response ==
* Stimuli cause afferent sensory nerves to fire.
* Stimuli cause afferent sensory nerves to fire.
* Terminals synapse with neurons in the ''''behaviour centre'''' in the [[Endocrine_System_-_Hypothalamus_-_Anatomy_%26_Physiology#Hypothalamus|Hypothalamus]].
* Terminals synapse with neurons in the ''''behaviour centre'''' in the [[Hypothalamus_- Anatomy & Physiology#Hypothalamus|Hypothalamus]].
* Hypothalamic neurones synapse with parasympathetic and sympathetic efferent neurons that control penile vascular smooth muscle (vascular tone).
* Hypothalamic neurones synapse with parasympathetic and sympathetic efferent neurons that control penile vascular smooth muscle (vascular tone).
* Firing of '''Nonadrenergic, noncholinergic (NANC) parasympathetic neurones''' causes erection.
* Firing of '''Nonadrenergic, noncholinergic (NANC) parasympathetic neurones''' causes erection.
** Venous outflow blocked
** Venous outflow blocked
* Penile erection maintained for as long as vasodilation of corporal smooth muscle takes place.
* Penile erection maintained for as long as vasodilation of corporal smooth muscle takes place.
== Vascular and Biochemical Control of Erection ==
== Vascular and Biochemical Control of Erection ==
* For more information on anatomy of the penis follow [[this link]].
* For more information on anatomy of the penis follow this link.
* Pressure compresses the venules through which blood exits the penis.
* Pressure compresses the venules through which blood exits the penis.
* Blood trapped within the penis causing an erection.
* Blood trapped within the penis causing an erection.
[[Category:Reproductive Behaviour]]
[[Category:Bullet Points]]