The corpus spongiosum is the mass of spongy tissue surrounding the male

urethra The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which Placentalia, placental mammals Urination, urinate and Ejaculation, ejaculate. The external urethral sphincter is a striated ...

within the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

. It is also called the corpus cavernosum urethrae in older texts.

Structure

The proximal part of the corpus spongiosum is expanded to form the urethral bulb, and lies in apposition with the inferior fascia of the urogenital diaphragm, from which it receives a fibrous investment. The urethra enters the bulb nearer to the superior than to the inferior surface. On the latter there is a median sulcus (groove), from which a thin fibrous septum (wall) projects into the substance of the bulb and divides it imperfectly into two lateral lobes or hemispheres. The portion of the corpus spongiosum in front of the bulb lies in a groove on the under surface of the conjoined corpora cavernosa penis. It is cylindrical in form and tapers slightly from behind forward. Its anterior end is expanded in the form of an obtuse cone, flattened from above downward. This expansion, termed the

glans penis In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...

, is moulded on the rounded ends of the

corpus cavernosum penis A corpus cavernosum penis (singular) (from Latin, characterised by "cavities/ hollows" of the penis, : corpora cavernosa) is one of a pair of sponge-like regions of erectile tissue, which contain most of the blood in the penis of several animal ...

, extending farther on their upper than on their lower surfaces. At the summit of the glans is the slit-like vertical opening known as the external urethral orifice, or the

urinary meatus The urinary meatus (, ; : meati or meatuses), also known as the external urethral orifice, is the opening of the penis or vulva where urine exits the urethra during urination. It is also where semen exits during male ejaculation, and other fluids ...

. The circumference of the base of the glans forms a rounded projecting border, the

corona of glans penis The corona of glans penis (or, directly from the Latin, the corona glandis penis) or penis crown refers to the rounded projecting border or flare that forms at the base of the glans in human males. The corona overhangs a mucosal surface, known ...

, overhanging a deep retroglandular sulcus, behind which is the neck of the penis.

Function

The function of the corpus spongiosum in erection is to prevent the urethra from pinching closed, thereby maintaining the urethra as a viable channel for ejaculation. To do this, the corpus spongiosum remains pliable during erection while the corpora cavernosa penis become engorged with blood.

Additional images

File:Illu penis.jpg, Structure of the penis File:Gray588.png, The penis in transverse section, showing the blood vessels. File:Gray1158.png, Diagram of the arteries of the

. File:Gray1156.png, Vertical section of bladder, penis, and urethra. File:Penis_cross_section.svg, Cross section of penis File:Gray1155 a.png, Transverse section of the penis. File:Gray1154.png, The constituent cavernous cylinders of the penis. File:Normal penis ultrasound.jpg,

Medical ultrasonography Medical ultrasound includes Medical diagnosis, diagnostic techniques (mainly medical imaging, imaging) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of ...

of a normal penis. File:Grant 1962 198.png, Dissection of the penis.

References

External links

* - "The Male Pelvis: The Urethra" {{Authority control Mammal male reproductive system Human penis anatomy fr:Corps spongieux pl:Ciało gąbczaste

Structure

Function

Additional images

See also

References

External links