The efferent ducts (or efferent ductules or ductuli efferentes or ductus efferentes or vasa efferentia) connect the

rete testis The rete testis ( ) is an anastomosing network of delicate tubules located in the hilum of the testicle (mediastinum testis) that carries sperm from the seminiferous tubules to the efferent ducts. It is the counterpart of the rete ovarii in females ...

with the initial section of the

epididymis The epididymis (; plural: epididymides or ) is a tube that connects a testicle to a vas deferens in the male reproductive system. It is a single, narrow, tightly-coiled tube in adult humans, in length. It serves as an interconnection between the ...

.Hess 2018 There are two basic designs for efferent ductule structure: * a) multiple entries into the epididymis, as seen in most large mammals. In

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s and other large

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s, there are approximately 15 to 20 efferent ducts, which also occupy nearly one third of the head of the epididymis. * b) single entry, as seen in most small animals such as

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s, where by the 3–6 ductules merge into a single small ductule prior to entering the epididymis. The ductuli are unilaminar and composed of columnar ciliated and non-ciliated (absorptive) cells. The ciliated cells serve to stir the luminal fluids, possibly to help ensure homogeneous absorption of water from the fluid produced by the testis, which results in an increase in the concentration of luminal sperm. The epithelium is surrounded by a band of

smooth muscle Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit mus ...

that helps to propel the sperm toward the epididymis.

Additional images

File:illu_testis_cross_section.jpg

External links

* – "Mammal, testis overview" * – "Inguinal Region, Scrotum and Testes: Reflection of the Head of the Epididymis" *
Diagram/Quiz (cancer.gov)

References

{{Reflist Hess RA 2018. Efferent ductules: structure and function. Encyclopedia of Reproduction. Skinner MK. San Diego, Academic Press: Elsevier. 1: 270-278. Scrotum