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Persistent Müllerian Duct Syndrome
Persistent Müllerian duct syndrome (PMDS) is the presence of Müllerian duct derivatives (fallopian tubes, uterus, and/or the upper part of the vagina) in what would be considered a genetically and otherwise physically normal male. In humans, PMDS typically is due to an autosomal recessive congenital disorder and is considered by some to be a form of pseudohermaphroditism due to the presence of Müllerian derivatives. PMDS can also present in non-human animals. Typical features include undescended testes ( cryptorchidism) and the presence of a small, underdeveloped uterus in an XY infant or adult. This condition is usually caused by deficiency of fetal anti-Müllerian hormone (AMH) effect due to mutations of the gene for AMH or the anti-Müllerian hormone receptor, but may also be as a result of insensitivity to AMH of the target organ. Presentation The first visible signs of PMDS after birth is cryptorchidism (undescended testes) either unilaterally or bilaterally, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inheritance
Inheritance is the practice of receiving private property, titles, debts, entitlements, privileges, rights, and obligations upon the death of an individual. The rules of inheritance differ among societies and have changed over time. Officially bequeathing private property and/or debts can be performed by a testator via will, as attested by a notary or by other lawful means. Terminology In law, an "heir" ( heiress) is a person who is entitled to receive a share of property from a decedent (a person who died), subject to the rules of inheritance in the jurisdiction where the decedent was a citizen, or where the decedent died or owned property at the time of death. The inheritance may be either under the terms of a will or by intestate laws if the deceased had no will. However, the will must comply with the laws of the jurisdiction at the time it was created or it will be declared invalid (for example, some states do not recognise handwritten wills as valid, or only in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y Chromosome
The Y chromosome is one of two sex chromosomes in therian mammals and other organisms. Along with the X chromosome, it is part of the XY sex-determination system, in which the Y is the sex-determining chromosome because the presence of the Y chromosome causes offspring produced in sexual reproduction to be of male sex. In mammals, the Y chromosome contains the SRY gene, which triggers development of male gonads. The Y chromosome is passed only from male parents to male offspring. Overview Discovery The Y chromosome was identified as a sex-determining chromosome by Nettie Stevens at Bryn Mawr College in 1905 during a study of the mealworm ''Tenebrio molitor''. Edmund Beecher Wilson independently discovered the same mechanisms the same year, working with Hemiptera. Stevens proposed that chromosomes always existed in pairs and that the smaller chromosome (now labelled "Y") was the pair of the X chromosome discovered in 1890 by Hermann Henking. She realized that th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Testing
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup. Genetic testing can also be used to determine biological relatives, such as a child's biological parentage (genetic mother and father) through DNA paternity testing, or be used to broadly predict an individual's ancestry. Genetic testing of plants and animals can be used for similar reasons as in humans (e.g. to assess relatedness/ancestry or predict/diagnose genetic disorders), to gain information used for selective breed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seminal Vesicles
The seminal vesicles (also called vesicular glands or seminal glands) are a pair of convoluted tubular accessory glands that lie behind the urinary bladder of male mammals. They secrete fluid that largely composes the semen. The vesicles are 5–10 cm in size, 3–5 cm in diameter, and are located between the bladder and the rectum. They have multiple outpouchings, which contain secretory glands, which join together with the vasa deferentia at the ejaculatory ducts. They receive blood from the vesiculodeferential artery, and drain into the vesiculodeferential veins. The glands are lined with column-shaped and cuboidal cells. The vesicles are present in many groups of mammals, but not marsupials, monotremes or carnivores. Inflammation of the seminal vesicles is called seminal vesiculitis and most often is due to bacterial infection as a result of a sexually transmitted infection or following a surgical procedure. Seminal vesiculitis can cause pain in the lower abdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vas Deferens
The vas deferens (: vasa deferentia), ductus deferens (: ductūs deferentes), or sperm duct is part of the male reproductive system of many vertebrates. In mammals, spermatozoa are produced in the seminiferous tubules and flow into the epididymal duct. The end of the epididymis is connected to the vas deferens. The vas deferens ends with an opening into the ejaculatory duct at a point where the duct of the seminal vesicle also joins the ejaculatory duct. 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" while ''ductus deferens'', also Latin, means "carrying-away duct". Structure The human vas deferens measures 30–35 cm in length, and 2–3 mm in diameter. It is continuous proximally with the tail of the epididymis, and exhibits a tortuous, convoluted initial/proximal section (which measures 2–3 cm in length). Distally, it forms a dilated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epididymis
The epididymis (; : epididymides or ) is an elongated tubular genital organ attached to the posterior side of each one of the two male reproductive glands, the testicles. It is a single, narrow, tightly coiled tube in adult humans, in length; uncoiled the tube would be approximately 6 m (20 feet) long. It connects the testicle to the vas deferens in the male reproductive system. The epididymis serves as an interconnection between the multiple efferent ducts at the rear of a testicle (proximally), and the vas deferens (distally). Its primary function is the storage, maturation and transport of sperm cells. Structure The human 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 (). The head of the epididymis receives spermatozoa via the efferent ducts of the medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of androgenic hair, body hair. It is associated with increased aggression, sex drive, Dominance hierarchy, dominance, courtship display, and a wide range of behavioral characteristics. In addition, testosterone in both sexes is involved in health and well-being, where it has a significant effect on overall mood, cognition, social and sexual behavior, metabolism and energy output, the cardiovascular system, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty, accumulation of adipose fat tissue within the body, anxiety and depression, sexual performance issues, and bone loss. Excessiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leydig Cell
Leydig cells, also known as interstitial cells of the testes and interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle and produce testosterone in the presence of luteinizing hormone (LH). They are polyhedral in shape and have a large, prominent nucleus, an eosinophilic cytoplasm, and numerous lipid-filled vesicles. Males have two types of leydig cells that appear in two distinct stages of development: the fetal type and the adult type. Structure The mammalian Leydig cell is a polyhedral epithelioid cell with a single eccentrically located ovoid nucleus. The nucleus contains one to three prominent nucleoli and large amounts of dark-staining peripheral heterochromatin. The acidophilic cytoplasm usually contains numerous membrane-bound lipid droplets and large amounts of smooth endoplasmic reticulum (SER). Besides the abundance of SER with scattered patches of rough endoplasmic reticulum, several mitochondria are also prominent within the cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramesonephric Duct
The paramesonephric ducts (or Müllerian ducts) are paired ducts of the embryo in the reproductive system of humans and other mammals that run down the lateral sides of the genital ridge and terminate at the sinus tubercle in the primitive urogenital sinus. They form in both sexes during 6th week of fetal development. In the female, go on to form the fallopian tubes/oviducts, uterus, cervix, and the upper one-third of the vagina. In males fetuses, they are normally made to regress by anti-Müllerian hormone which begins to be secreted by the testes during 8th week of fetal development. Each maramesonephric duct is situated just lateral to the mesonephric ducts, mesonephric ducts (Wolffian duct) of the same side. Development The female reproductive system is composed of two embryological segments: the urogenital sinus and the paramesonephric ducts. The two are conjoined at the sinus tubercle. Paramesonephric ducts are present on the embryo of both sexes. Only in females do they d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesonephric Duct
The mesonephric duct, also known as the Wolffian duct, archinephric duct, Leydig's duct or nephric duct, is a paired organ that develops in the early stages of embryonic development in humans and other mammals. It is an important structure that plays a critical role in the formation of male reproductive organs. The duct is named after Caspar Friedrich Wolff, a German physiologist and embryologist who first described it in 1759. During embryonic development, the mesonephric ducts form as a part of the urogenital system. 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 epididymides, vasa deferentia, and seminal vesicles. Development In both males and females, the mesonephric ducts develop 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotypically
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properties, and its behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code (its genotype) and the influence of environmental factors. Both factors may interact, further affecting the phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and again in his 1982 book ''The Extended Phenotype'' suggested that one can regard bird nests and other built structures such as caddisfly larva cases and beaver dams as "ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genotypically
The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a specific gene depends on the number of copies of each chromosome found in that species, also referred to as ploidy. In diploid species like humans, two full sets of chromosomes are present, meaning each individual has two alleles for any given gene. If both alleles are the same, the genotype is referred to as homozygous. If the alleles are different, the genotype is referred to as heterozygous. Genotype contributes to phenotype, the observable traits and characteristics in an individual or organism. The degree to which genotype affects phenotype depends on the trait. For example, the petal color in a pea plant is exclusively determined by genotype. The petals can be purple or white depending on the alleles present in the pea plant. However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
