Parasympathetic from cavernous nerve release NO to dilate vessels
Cavernous pressure increases so compression of venousdrainage
Ejaculation?
Seminal fluid in external urethra signals from pudendal nerve enter sacral cord
Synapse in spinal cord in Onuf's nucleus
Pundenal nerve innervates muscles which contract to expel semen
Erectile tissue in females = between opening of vagina and head of clitoris
Parasympathetic to female genitalia?
S2-4 release Ach and NO to cause vasodilation and engorgement to add in attachment of penis and innervation of Bartholian glands
Stimulation of female external genitalia results in reflex motor activation from Onuf's nucleus
During menstruation Lactobacillus in vagina produces lacticacid giving vagina pH of 4.5
Seminal fluid contains fructose to give energy to sperm and can neutralise acidic environment of vagina
Sperm enter upper vagina and uterine contractions propel sperm to fallopian tubes to ampulla for fertilisation
Head of sperm (acrosome) contains enzymes which degrade corona radiata allowing sperm to access zona pellucida causing Ca spike to stop further fertilisation
