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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 multiple efferent ducts at the rear of a testicle (proximally), and the vas deferens (distally). Anatomy The epididymis is situated posterior and somewhat lateral to the testis. The epididymis is invested completely by the tunica vaginalis (which is continuous with the tunica vaginalis covering the testis). The epididymis can be divided into three main regions: * The head ( la, caput). The head of the epididymis receives spermatozoa via the efferent ducts of the mediastinum testis, mediastinium of the testis at the superior pole of the testis. The head is characterized histologically by a thick epithelium with long stereocilia (described below) and a little smooth muscle. It is involved in absorbing fluid to make the sperm more concentra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Reproductive System
The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body and within the pelvis. The main male sex organs are the penis and the testicles which produce semen and sperm, which, as part of sexual intercourse, fertilize an ovum in the female's body; the fertilized ovum (zygote) develops into a fetus, which is later born as an infant. The corresponding system in females is the female reproductive system. External genital organs Penis The penis is the male intromittent organ. It has a long shaft and an enlarged bulbous-shaped tip called the glans penis, which supports and is protected by the foreskin. When the male becomes sexually aroused, the penis becomes erect and ready for sexual activity. Erection occurs because sinuses within the erectile tissue of the penis become filled with blood. The arteries of the penis are dilated while the veins are compressed s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testis
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use calipe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testicle
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosterone. Testosterone release is controlled by the anterior pituitary luteinizing hormone, whereas sperm production is controlled both by the anterior pituitary follicle-stimulating hormone and gonadal testosterone. Structure Appearance Males have two testicles of similar size contained within the scrotum, which is an extension of the abdominal wall. Scrotal asymmetry, in which one testicle extends farther down into the scrotum than the other, is common. This is because of the differences in the vasculature's anatomy. For 85% of men, the right testis hangs lower than the left one. Measurement and volume The volume of the testicle can be estimated by palpating it and comparing it to ellipsoids of known sizes. Another method is to use cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efferent Ducts
The efferent ducts (or efferent ductules or ductuli efferentes or ductus efferentes or vasa efferentia) connect the rete testis with the initial section of the epididymis.Hess 2018 There are two basic designs for efferent ductule structure: * a) multiple entries into the epididymis, as seen in most large mammals. In humans and other large mammals, 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 ...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ductus Deferens
The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube which exits the abdominal cavity through the inguinal canal. Etymology ''Vas deferens'' is Latin, meaning "carrying-away vessel"; the plural version is ''vasa deferentia''. ''Ductus deferens'' is also Latin, meaning "carrying-away duct"; the plural version is ''ducti deferentes''. Structure There are two vasa deferentia, connecting the left and right epididymis with the seminal vesicles to form the ejaculatory duct in order to move sperm. The (human) vas deferens measures 30–35 cm in length, and 2–3 mm in diameter. The vas deferens is continuous proximally with the tail of the epididymis. The vas deferens exhibits a tortuous, convoluted initial/proximal section (which measures 2–3 cm in length). Distally, it forms a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediastinum Testis
The mediastinum testis is a network of fibrous connective tissue that extends from the top to near the bottom of each testis. It is wider above than below. Numerous imperfect septa are given off from its front and sides, which radiate toward the surface of the testes and are attached to the tunica albuginea. These divide the interior of the testes into a number of incomplete spaces called lobules. These are somewhat cone-shaped, being broad at their bases at the surface of the gland, and becoming narrower as they converge to the mediastinum. The mediastinum supports 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 fem ... and blood vessels of the testis in their passage to and from the substance of the gland. Additional images File:gray1145.png, Transverse section thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vas Deferens
The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube which exits the abdominal cavity through the inguinal canal. Etymology ''Vas deferens'' is Latin, meaning "carrying-away vessel"; the plural version is ''vasa deferentia''. ''Ductus deferens'' is also Latin, meaning "carrying-away duct"; the plural version is ''ducti deferentes''. Structure There are two vasa deferentia, connecting the left and right epididymis with the seminal vesicles to form the ejaculatory duct in order to move sperm. The (human) vas deferens measures 30–35 cm in length, and 2–3 mm in diameter. The vas deferens is continuous proximally with the tail of the epididymis. The vas deferens exhibits a tortuous, convoluted initial/proximal section (which measures 2–3 cm in length). Distally, it form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appendix Of The Epididymis
The appendix of the epididymis (or pedunculated hydatid) is a small stalked appendage (sometimes duplicated) on the head of the epididymis. It is usually regarded as a detached efferent duct. This structure is derived from the Wolffian duct (Mesonephric Duct) as opposed to the appendix testis which is derived from the Müllerian duct (Paramesonephric Duct) remnant. See also * Appendix testis The appendix testis (or hydatid of Morgagni) is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time. Clinical significance Torsion The appe ... References External links * - Torsion of Appendix Epididymis * * () Mammal male reproductive system {{Portal bar, Anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolffian Duct
The mesonephric duct (also known as the Wolffian duct, archinephric duct, Leydig's duct or nephric duct) is a paired organ that forms during the embryonic development of humans and other mammals and gives rise to male reproductive organs. Structure The mesonephric duct connects the primitive kidney, the '' mesonephros'', to the cloaca. It also serves as the primordium for male urogenital structures including the epididymis, vas deferens, and seminal vesicles. Development In both male and female the mesonephric duct develops into the trigone of urinary bladder, a part of the bladder wall, but the sexes differentiate in other ways during development of the urinary and reproductive organs. Male In a male, it develops into a system of connected organs between the efferent ducts of the testis and the prostate, namely the epididymis, the vas deferens, and the seminal vesicle. The prostate forms from the urogenital sinus and the efferent ducts form from the meso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudostratified Epithelium
A pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia. As it rarely occurs as squamous or cuboidal epithelia, it is usually considered synonymous with the term pseudostratified columnar epithelium. The term ''pseudostratified'' is derived from the appearance of this epithelium in the section which conveys the erroneous (''pseudo'' means almost or approaching) impression that there is more than one layer of cells, when in fact this is a true simple epithelium since all the cells rest on the basement membrane. The nuclei of these cells, however, are disposed at different levels, thus creating the illusion of cellular stratification. All cells are not of equal size and not all cells extend to the luminal/apical surface; such cells are capable of cell division providing replacements for cells lost or damaged. Pseudostratified epithelia function in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesonephros
The mesonephros ( el, middle kidney) is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in reptiles, birds, and mammals. The mesonephros is included in the Wolffian body after Caspar Friedrich Wolff who described it in 1759. (The Wolffian body is composed of: mesonephros + paramesonephrotic blastema) Structure The mesonephros acts as a structure similar to the kidney that, in humans, functions between the sixth and tenth weeks of embryological life. Despite the similarity in structure, function, and terminology, however, the mesonephric nephrons do not form any part of the mature kidney or nephrons. In humans, the mesonephros consists of units which are similar in structure and function to nephrons of the adult kidney. Each of these consists of a glomerulus, a tuft of capillaries which arises from lateral branches of dorsal aorta and drains into the inferior cardinal vein; a Bowman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereocilia
Stereocilia (or stereovilli or villi) are non-motile apical cell modifications. They are distinct from cilia and microvilli, but are closely related to microvilli. They form single "finger-like" projections that may be branched, with normal cell membrane characteristics. They contain actin. Stereocilia are found in the vas deferens, the epididymis, and the sensory cells of the inner ear. Structure Stereocilia are cylindrical and non-motile. They are much longer and thicker than microvilli, form single "finger-like" projections that may be branched, and have more of the characteristics of the cellular membrane proper. Like microvilli, they contain actin and lack an axoneme. This distinguishes them from cilia. They do not have a Basal body at their base since they do not contain microtubules. They may or may not be covered by a glycocalyx coating. They have no fixed arrangement, different to the structure present in kinocilium. Function Stereocilia are found in: *the vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
