FACTOID # 29: 73.3% of America's gross operating surplus in motion picture and sound recording industries comes from California.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Testicle" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Testicle
Testicle
Human male reproductive system and adjacent structures
Latin testis
Gray's subject #258 1236
Artery Testicular artery
Vein Testicular vein, Pampiniform plexus
Nerve Spermatic plexus
Lymph Lumbar lymph nodes
Dorlands/Elsevier t_05/12799705
Look up testes in
Wiktionary, the free dictionary.

The testicle (from Latin testis, meaning "witness",[1] plural testes) is the male generative gland in animals. This article will concentrate on mammalian testicles unless otherwise noted. Image File history File links Drawing of the Male Internal Sexual Anatomy From alt. ... For other uses, see Latin (disambiguation). ... Section of an artery For other uses, see Artery (disambiguation). ... The testicular artery (the male gonadal artery, also called the internal spermatic arteries in older texts) is a branch of the abdominal aorta that supplies blood to the testis. ... In the circulatory system, a vein is a blood vessel that carries blood toward the heart. ... It has been suggested that this article or section be merged into Gonadal vein. ... The spermatic veins emerge from the back of the testis, and receive tributaries from the epididymis: they unite and form a convoluted plexus, the plexus pampiniformis, which forms the chief mass of the cord. ... For other uses, see Nerve (disambiguation). ... The spermatic plexus (or testicular plexus) is derived from the renal plexus, receiving branches from the aortic plexus. ... In mammals including humans, the lymphatic vessels (or lymphatics) are a network of thin tubes that branch, like blood vessels, into tissues throughout the body. ... The lumbar lymph nodes are a group of lymph nodes residing in the lumbar region. ... Elseviers logo. ... Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... For other uses, see Latin (disambiguation). ... For other uses of number, see number (disambiguation). ... The gonad is the organ that makes gametes. ... For other uses, see Animal (disambiguation). ...

Contents

Anatomy and physiology

Function

Like the ovaries (to which they are homologous), testicles are components of both the reproductive system (being gonads) and the endocrine system (being endocrine glands). The respective functions of the testicles are; // For ovary as part of plants see ovary (plants) An ovary is an egg-producing reproductive organ found in female organisms. ... In biology, homology is any similarity between structures that is due to their shared ancestry. ... A pictorial illustration of the human female reproductive system. ... The gonad is the organ that makes gametes. ... The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as hormones. ... An endocrine gland is one of a set of internal organs involved in the secretion of hormones into the blood. ...

Both functions of the testicle, sperm-forming and endocrine, are under control of gonadotropic hormones produced by the anterior pituitary: A spermatozoon or spermatozoan ( spermatozoa), from the ancient Greek σπέρμα (seed) and (living being) and more commonly known as a sperm cell, is the haploid cell that is the male gamete. ... This article or section does not cite its references or sources. ... For other uses, see Hormone (disambiguation). ... Testosterone is a steroid hormone from the androgen group. ... Located at the base of the skull, the pituitary gland is protected by a bony structure called the sella turcica. ...

Luteinizing hormone (LH) is a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland. ... Follicle stimulating hormone Follicle stimulating hormone (FSH) is a hormone synthesised and secreted by gonadotropes in the anterior pituitary gland. ...

External appearance

A human scrotum, containing the testicles.

Male mammals have two testicles, which are often contained within an extension of the abdomen called the scrotum. In mammals with external testicles it is most common for one testis to hang lower than the other. It is estimated that in about 85% of men the lower hanging testicle is the left one[citation needed]. This is due to differences in the vascular anatomical structure on the right and left sides. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... In some male mammals the scrotum is a protuberance of skin and muscle containing the testicles. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including milk producing sweat glands, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... For the human abdomen, see human abdomen. ... In some male mammals the scrotum is a protuberance of skin and muscle containing the testicles. ...


In normal adult human males, testicular size ranges from the lower end of around 14 cm³ to the upper end larger than 39 cm³[citation needed]. Measurement in the living adult is done in two basic ways:

  • comparing the testicle with ellipsoids of known sizes (orchidometer).
  • measuring the length, depth and width with a ruler, a pair of calipers or ultrasound imaging.

The volume is then calculated using the formula for the volume of an ellipsoid: 4/3 π × (length/2) × (width/2) × (depth/2). Definition In mathematics, an ellipsoid is a type of quadric that is a higher dimensional analogue of an ellipse. ... An orchidometer is a medical instrument used to measure the volume of the testicles. ... For other uses, see Ultrasound (disambiguation). ... 3D rendering of an ellipsoid In mathematics, an ellipsoid is a type of quadric that is a higher dimensional analogue of an ellipse. ...


To some extent, it is possible to change testicular size. Short of direct injury or subjecting them to adverse conditions, e.g., higher temperature than they are normally accustomed to, they can be shrunk by competing against their intrinsic hormonal function through the use of externally administered steroidal hormones. Steroids taken for muscle enhancement often have the undesired side effect of testicular shrinkage. Similarly, stimulation of testicular functions via gonadotropic-like hormones may enlarge their size. Testicles may shrink or atrophy during hormone replacement therapy. Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates. ... Hormone replacement therapy (HRT) is a system of medical treatment for perimenopausal and postmenopausal women, based on the assumption that it may prevent discomfort and health problems caused by diminished circulating estrogen hormones. ...


Internal structure

Transverse section through the left side of the scrotum and the left testis.
Transverse section through the left side of the scrotum and the left testis.

Image File history File links Transversetestis. ... Image File history File links Transversetestis. ...

Duct system

Histological section through testicular parenchyma of a boar. 1 Lumen of Tubulus seminiferus contortus, 2 spermatids, 3 spermatocytes, 4 spermatogonia, 5 Sertoli cell, 6 Myofibroblasts, 7 Leydig cells, 8 capillaries
Histological section through testicular parenchyma of a boar. 1 Lumen of Tubulus seminiferus contortus, 2 spermatids, 3 spermatocytes, 4 spermatogonia, 5 Sertoli cell, 6 Myofibroblasts, 7 Leydig cells, 8 capillaries

Under a tough membraneous shell, the tunica albuginea, the testis contains very fine coiled tubes called the seminiferous tubules. The tubes are lined with a layer of cells that, from puberty into old-age, produce sperm cells. The sperm travel from the seminiferous tubules to the rete testis located in the mediastinum testis, to the efferent ducts, and then to the epididymis where newly-created sperm cells mature (see spermatogenesis). The sperm move into the vas deferens, and are eventually expelled through the urethra and out of the urethral orifice through muscular contractions. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Seminiferous tubules are located in the testicles, and are the specific location of meiosis, and the subsequent creation of gametes, namely sperm. ... The term spermatid refers to the haploid male gametid that results from division of secondary spermatocytes. ... A spermatocyte is a male gametocyte which is derived from a spermatogonium. ... A Spermatogonium (plural: spermatogonia) is an intermediary male gametogonium (a kind of germ cell) in the production of spermatozoa. ... A Sertoli cell (a kind of sustentacular cell) is a nurse cell of the testes which is part of a seminiferous tubule. ... Histological section through testicular parenchyma of a boar. ... Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testes. ... The word capillary is used to describe any very narrow tube or channel through which a fluid can pass. ... The tunica albuginea is the tough fibrous covering of the testicles. ... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... Puberty refers to the process of physical changes by which a childs body becomes an adult body capable of reproduction. ... 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 vasa efferentia. ... The mediastinum testis extends from the upper to near the lower extremity of the gland, and is wider above than below. ... The efferent ducts are part of the testes and connect the rete testis with the epididymis. ... Male Anatomy The epididymis is part of the human male reproductive system and is present in all male mammals. ... Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Spermatogenesis is the process by which male spermatogonia develop into mature spermatozoa. ... The vas deferens (plural: vasa deferentia), also called ductus deferens, (Latin: carrying-away vessel) is part of the male anatomy of some species, including humans. ... In anatomy, the urethra is a tube which connects the urinary bladder to the outside of the body. ... Urethral orifice can refer to: External urethral orifice Internal urethral orifice Category: ...


Between the seminiferous tubules are special cells called Leydig cells (or "interstitial cells") where testosterone and other androgens are formed. Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testes. ... Testosterone is a steroid hormone from the androgen group. ... Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors. ...


Blood supply and lymphatic drainage

Blood supply and lymphatic drainage of the testes and scrotum are distinct: Lymph originates as blood plasma lost from the circulatory system, which leaks out into the surrounding tissues. ...

The testicular artery (the male gonadal artery, also called the internal spermatic arteries in older texts) is a branch of the abdominal aorta that supplies blood to the testis. ... AORTA can also mean always-on real-time access, referring to WAN computer networks. ... The inguinal canal is a passage in the anterior abdominal wall which in men conveys the spermatic cord and in women the round ligament. ... Internal pudendal artery is the terminal branch of the anterior trunk of the internal iliac artery which supplies the external genitalia. ... The Internal iliac artery, formerly known as the hypogastric artery, supplies the walls and viscera of the pelvis, the buttock, the reproductive organs, and the medial compartment of the thigh. ... The paraaortic lymph nodes (also para-aortic, periaortic, and peri-aortic)are a group of lymph nodes that lie in front of the lumbar vertebral bodies near the aorta. ... Inguinal lymph nodes are lymph nodes found in the upper thigh near the groin. ...

Layers

Many anatomical features of the adult testis reflect its developmental origin in the abdomen. For the human abdomen, see human abdomen. ...


The layers of tissue enclosing each testicle are derived from the layers of the anterior abdominal wall. Notably, the cremasteric muscle arises from the internal oblique muscle. The abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. ... The cremaster muscle is a muscle that covers the testis. ... The internal oblique (or Obliquus internus abdominis) is the intermediate muscle of the abdomen, lying just underneath the external oblique and just above (superficial to) the transverse abdominal muscle. ...


The blood-testis barrier

Large molecules cannot pass from the blood into the lumen of a seminiferous tubule due to the presence of tight junctions between adjacent Sertoli cells. The spermatogonia are in the basal compartment (deep to the level of the tight junctions) and the more mature forms such as primary and secondary spermatocytes and spermatids are in the adluminal compartment. Tight junctions, or zonula occludens, are the closely associated areas of two cells whose membranes join together forming a virtual impermeable barrier to fluid. ... The Sertoli cell is the nurse cell of the testes. ...


The function of the blood-testis barrier (red highlight in diagram above) may be to prevent an auto-immune reaction. Mature sperm (and their antigens) arise long after immune tolerance is established in infancy. Therefore, since sperm are antigenically different from self tissue, a male animal can react immunologically to his own sperm. In fact, he is capable of making antibodies against them. The blood-testis barrier (abbreviated as BTB) is a barrier between the blood vessels and the seminiferous tubules of the animal testes. ... Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. ... An antigen or immunogen is a molecule that stimulates an immune response. ...


Injection of sperm antigens causes inflammation of the testis (autoimmune orchitis) and reduced fertility. Thus, the blood-testis barrier may reduce the likelihood that sperm proteins will induce an immune response, reducing fertility and so progeny.


Temperature regulation

The testes work best at temperatures slightly less than core body temperature (36.6 °C or 98.6 °F for humans). The spermatogenesis is less efficient at lower and higher temperatures. There are a number of mechanisms to maintain the testes at the optimum temperature. The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Spermatogenesis is the process by which male spermatogonia develop into mature spermatozoa. ...


Cremasteric muscle

The cremasteric muscle is part of the spermatic cord. When this muscle contracts, the cord is shortened and the testicle is moved closer up toward the body, which provides slightly more warmth to maintain optimal testicular temperature. When cooling is required, the cremasteric muscle relaxes and the testicle is lowered away from the warm body and is able to cool. This phenomenon is known as the cremasteric reflex. It also occurs in response to stress (the testicles rise up toward the body in an effort to protect them in a fight), and there are persistent reports that relaxation indicates approach of orgasm. There is a noticeable tendency to also retract during orgasm. The cremaster muscle is a muscle that covers the testis. ... Male Anatomy The spermatic cord is the name given to the cord-like structure formed by the vas deferens and surrounding tissue (veins, arteries, nerves, and lymphatic vessels) that run from the abdomen down to each testicle. ... Cremasteric Reflex is a reflex in males only. ...


The testicles can also be lifted voluntarily using the pubococcygeus muscle, which partially activates related muscles. This can sometimes be triggered by tightening or sucking in the stomach or abdomen. The pubococcygeus muscle or PC muscle is an important muscle in the human body. ...


Development

There are two phases in which the testicles grow substantially, namely in embryonic and pubertal age.


Embryonic

During mammalian development, the gonads are at first capable of becoming either ovaries or testes.[2] In humans, starting at about week 4 the gonadal rudiments are present within the intermediate mesoderm adjacent to the developing kidneys. At about week 6, sex cords develop within the forming testes. These are comprised of early Sertoli cells that surround and nurture the germ cells that migrate into the gonads shortly before sex determination begins. In males, the sex-specific gene SRY that is found on the Y-chromosome initiates sex determination by downstream regulation of sex-determining factors, (such as GATA4, SOX9 and AMH), which leads to development of the male phenotype, including directing development of the early bipotential gonad down the male path of development. // For ovary as part of plants see ovary (plants) An ovary is an egg-producing reproductive organ found in female organisms. ... Intermediate mesoderm is a type of mesoderm that is located between the paraxial mesoderm and the lateral plate. ... In embryology, the sex cords (or primitive sex cords) are structures that develop from the gonadal ridge. ... A germ cell is part of the germline and is involved in the reproduction of organisms. ... This article is about the SRY gene. ...


Pubertal

The testicles grow in response to the start of spermatogenesis. Size depends on lytic function, sperm production (amount of spermatogenisis present in testis), interstitial fluid, and Sertoli cell fluid production. After puberty, the volume of the testicles can be increased by over 500% as compared to the pre-pubertal size.[citation needed] In humans the average testicle size after puberty measures up to around 2 inches long, 0.8 inch in breadth, and 1.2 inches in diameter (5 x 2 x 3 cm). Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Spermatogenesis is the process by which male spermatogonia develop into mature spermatozoa. ... Interstitial fluid (or tissue fluid, or intercellular fluid) is a solution which bathes and surrounds the cells of multicellular animals. ... A Sertoli cell (a kind of sustentacular cell) is a nurse cell of the testes which is part of a seminiferous tubule. ...


Evolution

External testicles

The basal condition for mammals is to have internal testicles. Only the Boreoeutherian land mammals, the large group of mammals that includes humans, have externalized testicles. Indeed their testicles function best at temperatures lower than their core body temperature. Their testes are located outside of the body, suspended by the spermatic cord within the scrotum. The testes of the non-boreotherian mammals such as the monotremes, armadillos, sloths, elephants remain within the abdomen.[3] There are also some Boreoeutherian mammals with internal testes, such as the rhinoceros. Boreoeutheria (synonymous with Boreotheria) is a clade that is composed of the sister taxa Laurasiatheria and Euarchontoglires (Supraprimates). ...


Marine boreotherian mammals such as whales and dolphins, also have internal testes, but it has recently been shown (e.g., for dolphins) that they use elaborate vascular networks to provide the necessary temperature lowering for optimum function. As external testes would increase drag, many boreotherian aquatic mammals have internal testes which are kept cool by special circulatory systems that cool the arterial blood going to the testes by placing the arteries near veins bringing cooled venous blood from the skin.


There are several hypotheses why most boreotherian mammals have external testes which operate best at a temperature that is slightly less than the core body temperature, e.g. that it is stuck with enzymes evolved in a colder temperature due to external testes evolving for different reasons, that the lower temperature of the testes simply is more efficient for sperm production.


1) More efficient. The classic hypothesis is that cooler temperature of the testes allows for more efficient fertile spermatogenesis. In other words, there are no possible enzymes operating at normal core body temperature that are as efficient as the ones evolved, at least none appearing in our evolution so far. Cross section of the epithelium of a seminiferous tubule showing various stages of spermatocyte development Spermatogenesis is the process by which male spermatogonia develop into mature spermatozoa. ...


The early mammals had lower body temperatures and thus their testes worked efficiently within their body. However it is argued that boreotherian mammals have higher body temperatures than the other mammals and had to develop external testicles to keep them cool. It is argued that those mammals with internal testicles, such as the monotremes, armadillos, sloths, elephants, and rhinoceroses, have a lower core body temperatures than those mammals with external testicles.


However, the question remains why birds despite having very high core body temperatures have internal testes and did not evolve external testes.[4] It was once theorized that birds used their air sacs to cool the testes internally, but later studies revealed that birds' testes are able to function at core body temperature.[4]. Air sac is an anatomical term with several meanings: Pulmonary alveolus, informally known as an air sac, one of innumerable spherical outcroppings of the respiratory bronchioles in the mammalian lung, the primary sites of gas exchange with the blood an anatomical structure continuous with the trachea found in some insects...


Some mammals which seasonal breeding cycles keep their testes internal until the breeding season when their testes descend and increase in size and become external [5].


2) Irreversible adaptation to sperm competition. It has been suggested that the ancestor of the boreoeutherian mammals was a small mammal that required very large testes (perhaps rather like those of a hamster) for sperm competition and thus had to place its testes outside the body.[5] This led to enzymes involved in spermatogenesis, spermatogenic DNA polymerase beta and recombinase activities evolving a unique temperature optimum, slightly less than core body temperature. When the boreoeutherian mammals then diversified into forms that were larger and/or did not require intense sperm competition they were stuck with enzymes that operated best at cooler temperatures and had to keep their testicles outside the body. This position is made less parsimonious by the fact that the kangaroo, a non-boreoeutherian mammal, has external testicles. The ancestors of kangaroos might, separately from boreotherian mammals, have also been subject to heavy sperm competition and thus developed external testes, however, kangaroo external testicles are suggestive of a possible adaptive function for external testes in large animals. Genera Mesocricetus Phodopus Cricetus Cricetulus Allocricetulus Cansumys Tscherskia Hamsters are rodents belonging to the subfamily Cricetinae. ... Sperm competition is competition between sperm of two or more males for the fertilization of an ovum (Parker 1970). ... Species Macropus rufus Macropus giganteus Macropus fuliginosus Macropus antilopinus A kangaroo is a marsupial from the family Macropodidae (macropods, meaning large foot). In common use the term is used to describe the largest species from this family, the Red Kangaroo, the Antilopine Kangaroo, and the Eastern and Western Grey Kangaroo...


3) Protection from abdominal cavity pressure changes. One argument for the evolution of external testes is that it protects the testes from abdominal cavity pressure changes caused by jumping and galloping.[6]


Testicular size

Testicular size as a proportion of body weight varies widely. In the mammalian kingdom, there is a tendency for testicular size to correspond with multiple mates (e.g., harems, polygamy). Production of testicular output sperm and spermatic fluid is also larger in polygamous animals, possibly a spermatogenic competition for survival. The testicles of the right whale are likely to be the largest of any animal, each weighing around 500 kg (1,100 lb). Polygamy, literally many marriages in ancient Greek, is a marital practice in which a person has more than one spouse simultaneously (as opposed to monogamy where each person has a maximum of one spouse at any one time). ... Polygamy, literally many marriages in ancient Greek, is a marital practice in which a person has more than one spouse simultaneously (as opposed to monogamy where each person has a maximum of one spouse at any one time). ... Sperm competition is competition between sperm of two or more males for the fertilization of an ovum (Parker 1970). ... It has been suggested that Balaenidae be merged into this article or section. ...


Health issues

The testicles are well-known to be very sensitive to impact and injury. Blue balls is a slang term for a temporary fluid congestion in the testicles and prostate region caused by prolonged sexual arousal. A groin attack is an attempt to cause pain to the groin area of ones opponent, either through punching, kicking, grappling, squeezing or biting. ... Blue balls is a slang term for a temporary fluid congestion in the testicles and prostate region caused by prolonged sexual arousal in the human male. ... Human male anatomy The testicles, known medically as testes (singular testis), are the male generative glands in animals. ... The prostate is a compound tubuloalveolar exocrine gland of the male mammalian reproductive system. ... Turn on redirects here. ...


The most prominent diseases of testicles are:

The removal of one or both testicles is termed: Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. ... Neoplasia (literally: new growth) is abnormal, disorganized growth in a tissue or organ, usually forming a distinct mass. ... A hydrocele testis is an accumulation of clear fluid in the tunica vaginalis, the most internal of membranes containing a testicle. ... Orchitis is an often very painful condition of the testicles involving inflammation, swelling and frequently infection. ... Epididymitis is a medical condition in which the epididymis becomes inflamed. ... 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 vasa efferentia. ... Male Anatomy The epididymis is part of the human male reproductive system and is present in all male mammals. ... Spermatocele is a retention cyst of a tubule of the rete testis or the head of the epididymis distended with a milky fluid that contains spermatozoa. ... Spermatic Cord Torsion is a swelling in the spermatic cord resulting from an amount of sperms trapped in the canals from the testicles to the scrotum. ... In testicular torsion the spermatic cord that provides the blood supply to a testicle is twisted, cutting off the blood supply, often causing orchalgia. ... Cross section showing the pampiniform plexus Varicocele is an abnormal enlargement of the veins in the scrotum draining the testicles. ...

Testicular prostheses are available to mimic the appearance and feel of one or both testicles, when absent as from injury or as treatment for gender identity disorder. There have also been some instances of their implanting in dogs. The Inguinal Orchiectomy is a relatively minor surgery, generally performed by a Urologist. ... Castration (also referred as: gelding, neutering, orchiectomy, orchidectomy, and oophorectomy) is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testes or a female loses the functions of the ovaries. ... Castration, gelding, neutering, orchiectomy or orchidectomy is any action, surgical or otherwise, by which a biological male loses use of the testes. ... Veterinary medicine is the application of medical diagnostic and therapeutic principles to companion, domestic, exotic, wildlife, and production animals. ... A gelding is a castrated animal—in English, a castrated male horse. ... Gender identity disorder, as identified by psychologists and physicians, is a condition in which a person has been assigned one gender, usually on the basis of their sex at birth (compare intersex disorders), but identifies as belonging to another gender, and feels significant discomfort or being unable to deal with...


Other testicular issues:

  • Cryptorchidism or "undescended testicles", when the testicle does not descend into the scrotum of the infant boy.
  • Retractile testicle, when the testicle occasionally moves up into the lower abdomen as the cremaster muscle contracts. [8]

Cryptorchidism is a medical term referring to absence from the scrotum of one or both testes. ... For the human abdomen, see human abdomen. ... The cremaster muscle is a muscle that covers the testis. ...

Consumption of testicles

See animelles. Animelles is the culinary term used for the testicles of male animals, especially young rams, when they are used as food. ...


Additional images

References

  1. ^ [1]
  2. ^ Online textbook: "Developmental Biology" 6th ed. By Scott F. Gilbert (2000) published by Sinauer Associates, Inc. of Sunderland (MA).
  3. ^ [2]
  4. ^ a b http://www.biolreprod.org/cgi/reprint/56/6/1570.pdf BIOLOGY OF REPRODUCTION 56, 1570-1575 (1997)- Determination of Testis Temperature Rhythms and Effects of Constant Light on Testicular Function in the Domestic Fowl (Gallus domesticus)
  5. ^ [3]
  6. ^ Newscientist.com - bumpy-lifestyle-led-to-external-testes
  7. ^ [4]
  8. ^ http://embarrassingproblems.co.uk/problems/problempage040505.htm

See also

Find more about Testicle on Wikipedia's sister projects:
Dictionary definitions
Textbooks
Quotations
Source texts
Images and media
News stories
Learning resources

The hypothalamic-pituitary-gonadal axis (also HPTA) is a way of referring to the combined effects of the hypothalamus, pituitary gland, and gonads as if these individual endocrine glands were a single entity. ... // For ovary as part of plants see ovary (plants) An ovary is an egg-producing reproductive organ found in female organisms. ... The corpus luteum (Latin for yellow body) is a small, temporary endocrine structure in animals. ... The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. ... A porcine islet of Langerhans. ...


  Results from FactBites:
 
Retractile testicle: Complications - MayoClinic.com (387 words)
In approximately 30 percent to 50 percent of boys with a retractile testicle, the testicle permanently retracts up into the groin, referred to as an acquired undescended testicle.
A retractile testicle that becomes permanently retracted (an undescended testicle) and remains untreated may affect a boy's future fertility.
The risk of a testicular tumor is 35 times greater in males with an undescended testicle — a testicle that remains in the groin instead of moving down into the scrotum.
InteliHealth: (801 words)
An undescended testicle increases the risk of infertility (not being able to have children), testicular cancer, hernias and testicular torsion (twisting).
This is thought to occur when, for unknown reasons, the spermatic cord attached to the testicle does not grow as quickly as the rest of the child does.
After treatment, 50% to 65% of males with 2 undescended testicles are fertile, and 85% with a single undescended testicle are fertile.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m