Changes

==Penis and Prepuce==

==Penis and Prepuce==

The penis is the male copulatory organ. It is formed from three parts; two Corpora cavernosa, comprising of cavernous tissue and a connective tissue sheath the tunica albuginea, and the single Corpus Spongiosum which contains the urethra encased in a vascular tissue sleeve. The horse has a musculovascular penis.

The penis is the male copulatory organ. It is formed from three parts; two Corpora cavernosa, comprising of cavernous tissue and a connective tissue sheath the tunica albuginea, and the single Corpus Spongiosum which contains the urethra encased in a vascular tissue sleeve. The horse has a musculovascular penis. In the musculovascular penis, there is only a small amount of connective tissue, allowing them to be flaccid when not erect. Erection is accomplished by engorgement of the tissue with blood and a relatively larger ammount of blood is required to achieve erection than for a fibroelastic penis (ruminants, boar). Engorgement with blood increases the length and diameter of the penis.

===Corpus Cavernosum===

===Corpus Cavernosum===

The corpus cavernosum is made up from the paired columns of cavernous tissue surrounded by connective tissue known as the crura of the penis or corpora cavernosa.  

The corpus cavernosum is made up from the paired columns of cavernous tissue surrounded by connective tissue known as the crura of the penis or corpora cavernosa.