Coelomic epithelium refers to the epithelium that lines the surface of the body wall and abdominal organs. It constitutes the outermost layer of the male and female gonads, thus forming the germinal epithelium of the female or of the male. It is also called the germinal epithelium of Waldeyer or sometimes the superficial epithelial cells in embryology. It is often encountered in the medical setting as an important source of various types of ovarian cancer, primary peritoneal serous cancer and endometriosis (coelomic metaplasia). ,
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin.
The abdomen constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the frontal part of the abdominal segment of the trunk, the dorsal part of this segment being the back of the abdomen. The region occupied by the abdomen is termed the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax. The abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.
A gonad,sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are the sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells.
During gonadal sex development, the coelomic epithelium, additionally with germ cells and mesenchymal cells make the indifferent gonad. As the coelomic epithelium is confronted with XY chromosomes, they will differentiate into sertoli cells, which subsequently produce antimüllerian hormone, leading to the regression of the Müllerian duct. As the coelomic epithelium is confronted with XX chromosomes, the cells will differentiate into granulosa cells, which will not produce antimüllerian hormone and thus allow the development of the Müllerian duct.
The coelomic metaplasia theory provides a theory for the pathology of endometriosis (a condition where endometrial tissue grows outside the uterus). The coelomic epithelium develops into: peritoneum, pleura and the surface of the ovary. This combines retrograde and metaplasia and can explain the distant sites of endometriosis.
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into spermatocytes. The primary spermatocyte divides meiotically into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. The spermatids are transformed into spermatozoa(sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid cells.
Swyer syndrome, or XY gonadal dysgenesis, is a type of hypogonadism in a person whose karyotype is 46,XY. The person is externally female with streak gonads, and if left untreated, will not experience puberty. Such gonads are typically surgically removed and a typical medical treatment would include hormone replacement therapy. The syndrome was named by Gerald Swyer, an endocrinologist, based in London.
Seminiferous tubules are located within the testes, and are the specific location of meiosis, and the subsequent creation of male gametes, namely spermatozoa.
Paramesonephric ducts are paired ducts of the embryo that run down the lateral sides of the urogenital ridge and terminate at the sinus tubercle in the primitive urogenital sinus. In the female, they will develop to form the uterine tubes, uterus, cervix, and the upper two third of the vagina. Lower 1/3 of vagina is derived from sinovaginal bulb derived from urogenital sinus; in the male, they are lost. These ducts are made of tissue of mesodermal origin.
Persistent Müllerian duct syndrome (PMDS) is the presence of Müllerian duct derivatives in what would be considered a genetically and otherwise physically normal male animal by typical human based standards. 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.
Anti-Müllerian hormone (AMH), also known as Müllerian-inhibiting hormone (MIH), is a glycoprotein hormone structurally related to inhibin and activin from the transforming growth factor beta superfamily, whose key roles are in growth differentiation and folliculogenesis. In humans, the gene for AMH is AMH, on chromosome 19p13.3, while the gene AMHR2 codes for its receptor on chromosome 12.
Metaplasia is the transformation of one differentiated cell type to another differentiated cell type. The change from one type of cell to another may be part of a normal maturation process, or caused by some sort of abnormal stimulus. In simplistic terms, it is as if the original cells are not robust enough to withstand their environment, so they transform into another cell type better suited to their environment. If the stimulus causing metaplasia is removed or ceases, tissues return to their normal pattern of differentiation. Metaplasia is not synonymous with dysplasia, and is not considered to be an actual cancer. It is also contrasted with heteroplasia, which is the spontaneous abnormal growth of cytologic and histologic elements. Today, metaplastic changes are usually considered to be an early phase of carcinogenesis, specifically for those with a history of cancers or who are known to be susceptible to carcinogenic changes. Metaplastic change is often viewed as a premalignant condition that requires immediate intervention, either surgical or medical, because metaplasia is associated with cancer.
The development of the urinary system begins as a part of prenatal development, and relates to the development of both the urinary system and the sex organs. It continues as a part of sexual differentiation.
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 human reproductive system usually involves internal fertilization by sexual intercourse. In this process, the male inserts his penis into the female's vagina and ejaculates semen, which contains sperm. A small proportion of the sperm pass through the cervix into the uterus, and then into the Fallopian tubes for fertilization of the ovum. Only one sperm is required to fertilize the ovum. Upon successful fertilization, the fertilized ovum, or zygote, travels out of the Fallopian tube and into the uterus, where it implants in the uterine wall. This marks the beginning of gestation, better known as pregnancy, which continues for around nine months as the foetus develops. When the foetus has developed to a certain point, pregnancy is concluded with childbirth, involving labor. During labor, the muscles of the uterus contract and the cervix dilates over the course of hours, and the baby passes out of the vagina. Human infants are nearly helpless and require high levels of parental care. Infants rely on their caregivers for comfort, cleanliness, and food. Food may be provided by breastfeeding or formula feeding.
Gonadal dysgenesis is classified as any congenital developmental disorder of the reproductive system in the male or female. It is the defective development of the gonads in an embryo, with reproductive tissue replaced with functionless, fibrous tissue, termed streak gonads. Streak gonads are a form of aplasia, resulting in hormonal failure that manifests as sexual infantism and infertility, with no initiation of puberty and secondary sex characteristics.
Sexual differentiation in humans is the process of development of sex differences in humans. It is defined as the development of phenotypic structures consequent to the action of hormones produced following gonadal determination. Sexual differentiation includes development of different genitalia and the internal genital tracts, breasts, body hair, and plays a role in gender identification.
Defeminization and masculinization are the processes that a fetus goes through to become a male.
The development of the reproductive system is a part of prenatal development, and concerns the sex organs. It is a part of the stages of sexual differentiation. Because its location, to a large extent, overlaps the urinary system, the development of them can also be described together as the development of the urinary and reproductive organs.
The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testes in males and the ovaries in females. The gonads initially develop from the mesothelial layer of the peritoneum.
In cell biology and pathophysiology, cellular adaptation refers to changes made by a cell in response to adverse environmental changes. The adaptation may be physiologic(al) (normal) or pathologic(al) (abnormal). Five minor types of adaptation include atrophy, hypertrophy, hyperplasia, dysplasia, and metaplasia.
The uterus-like mass (ULM) is a tumorlike anatomical entity originally described in the ovary in 1981 and thereafter reported in several locations of the pelvis and abdominal cavity including broad ligament, greater omentum, cervix, small intestine, mesentery and conus medullaris. Basically, it is represented by a miniature uterus comprising a smooth muscle wall lined by endometrium thus outlining a uterus anatomical structure. Some of the reported cases have been associated to urinary tract and internal genitalia malformations whereas others appeared as a solitary finding. The term endomyometriosis has also been applied to this lesion.
45,X/46,XY mosaicism, also known as X0/XY mosaicism and mixed gonadal dysgenesis, is a rare disorder of sex development in humans associated with sex chromosome aneuploidy and mosaicism of the Y chromosome. This is called a mosaic karyotype because, like tiles in mosaic floors or walls, there is more than one type of cell.
Thoracic endometriosis is a rare form of endometriosis where endometrial tissue is found in the lung parenchyma and/or the pleura. It can be classified as either pulmonary, or pleural, respectively. Endometriosis is characterized by the presence of tissue from the lining of the uterus forming abnormal growths elsewhere in the body. Usually these growths are found in the pelvis, between the rectum and the uterus, the ligaments of the pelvis, the bladder, the ovaries, and the sigmoid colon. The cause is not known. The most common symptom of thoracic endometriosis is chest pain occurring right before or during menstruation. Diagnosis is based on clinical history and examination, augmented with X-ray, CT scan, and magnetic resonance imaging of the chest. Treatment options include surgery and hormones.
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