|
Perineal Raphe
The perineal raphe is a visible line or ridge of tissue on the body that extends from the anus through the perineum to scrotum (male) or labia majora (female). It is found in both males and females, arises from the fusion of the urogenital folds, and is visible running medial through anteroposterior, to the anus where it resolves in a small knot of skin of varying size. In males, this structure continues through the midline of the scrotum (scrotal raphe) and upwards through the posterior midline aspect of the penis (penile raphe). It also exists deeper through the scrotum where it is called the scrotal septum. It is the result of a fetal developmental phenomenon whereby the scrotum and penis close toward the midline and fuse. See also * Raphe * Linea nigra * Embryonic and prenatal development of the male reproductive system in humans * Frenulum of prepuce of penis The frenulum of prepuce of penis, often known simply as the frenulum, is a highly erogenous elastic band of tissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urogenital Folds
The development of the reproductive system is the part of embryonic growth that results in the sex organs and contributes to sexual differentiation. Due to its large overlap with development of the urinary system, the two systems are typically described together as the urogenital or genitourinary system. The reproductive organs develop from the intermediate mesoderm and are preceded by more primitive structures that are superseded before birth. These embryonic structures are the mesonephric ducts (also known as ''Wolffian ducts'') and the paramesonephric ducts, (also known as ''Müllerian ducts''). The mesonephric duct gives rise to the male seminal vesicles, epididymes and vas deferens. The paramesonephric duct gives rise to the female fallopian tubes, uterus, cervix, and upper part of the vagina. Mesonephric ducts The mesonephric duct originates from a part of the pronephric duct. Origin In the outer part of the intermediate mesoderm, immediately under the ectoderm, in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anus
The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, depending on the type of animal, includes: matter which the animal cannot digest, such as bones; Summary at food material after the nutrients have been extracted, for example cellulose or lignin; ingested matter which would be toxic if it remained in the digestive tract; and dead or excess gut bacteria and other endosymbionts. Amphibians, reptiles, and birds use the same orifice (known as the cloaca) for excreting liquid and solid wastes, for copulation and egg-laying. Monotreme mammals also have a cloaca, which is thought to be a feature inherited from the earliest amniotes via the therapsids. Marsupials have a single orifice for excreting both solids and liquids and, in females, a separate vagina for reproduction. Female placental mamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perineum
The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), including the perineal body and surrounding structures. There is some variability in how the boundaries are defined. The perineal raphe is visible and pronounced to varying degrees. The perineum is an erogenous zone. The word perineum entered English from late Latin via Greek περίναιος ~ περίνεος ''perinaios, perineos'', itself from περίνεος, περίνεοι 'male genitals' and earlier περίς ''perís'' 'penis' through influence from πηρίς ''pērís'' 'scrotum'. The term was originally understood as a purely male body-part with the perineal raphe seen as a continuation of the scrotal septum since masculinization causes the development of a large anogenital distance in men, in comparison to the corresponding lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrotum
The scrotum or scrotal sac is an anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scrotum contains the external spermatic fascia, testes, epididymis, and ductus deferens. It is a distention of the perineum and carries some abdominal tissues into its cavity including the testicular artery, testicular vein, and pampiniform plexus. The perineal raphe is a small, vertical, slightly raised ridge of scrotal skin under which is found the scrotal septum. It appears as a thin longitudinal line that runs front to back over the entire scrotum. In humans and some other mammals the scrotum becomes covered with pubic hair at puberty. The scrotum will usually tighten during penile erection and when exposed to cold temperatures. One testis is typically lower than the other to avoid compression in the event of an impact. The scrotum is biologicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labia Majora
The labia majora (singular: ''labium majus'') are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva. The labia majora are homologous to the male scrotum. Etymology ''Labia majora'' is the Latin plural for big ("major") lips; the singular is ''labium majus.'' The Latin term ''labium/labia'' is used in anatomy for a number of usually paired parallel structures, but in English it is mostly applied to two pairs of parts of female external genitals (vulva)—labia majora and labia minora. Labia majora are commonly known as the outer lips, while labia minora (Latin for ''small lips''), which run alongside between them, are referred to as the inner lips. Traditionally, to avoid confusion with other lip-like structures of the body, the labia of female genitals were termed by anatomists in Latin as ''labia majora (''or ''minora) pudendi.'' Embryology Embryolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Penis
The human penis is an external male intromittent organ that additionally serves as the urinary duct. The main parts are the root (radix); the body (corpus); and the epithelium of the penis including the shaft skin and the foreskin (prepuce) covering the glans penis. The body of the penis is made up of three columns of tissue: two corpora cavernosa on the dorsal side and corpus spongiosum between them on the ventral side. The human male urethra passes through the prostate gland, where it is joined by the ejaculatory duct, and then through the penis. The urethra traverses the corpus spongiosum, and its opening, the meatus (), lies on the tip of the glans penis. It is a passage both for urination and ejaculation of semen (''see'' male reproductive system.) Most of the penis develops from the same embryonic tissue as the clitoris in females. The skin around the penis and the urethra share the same embryonic origin as the labia minora in females. An erection is the stiffening e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penile Raphe
The penile raphe is a visible line or ridge of tissue that runs on the ventral side of the human penis beginning from the base of the shaft and ending in the prepuce. The line is typically darker than the rest of the shaft skin, even though its shape and pigmentation may vary among males. The penile raphe is part of a broader line in the male reproductive organs, that runs from the anus through the perineum (perineal raphe) and continues to the scrotum and penis, collectively referred to as median raphe. The line consists of a subcutaneous fibrous plate, which may vary in prominence and thickness in various areas of the genitals. In the scrotum, the line is located over the internal scrotal septum that divides the two sides of the sac and is densely occupied by nerve fibers. The raphe may become more prominent and darker when the scrotal sac tightens due to contractions. Behind the scrotum it continues as the perineal raphe. The raphe results as a manifestation of the fusion of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrotal Septum
The septum of the scrotum is a vertical layer of fibrous tissue that divides the two compartments of the scrotum. It consists of flexible connective tissue. Its structure extends to the skin surface of the scrotum as the scrotal raphe. It is an incomplete wall of connective tissue and nonstriated muscle (dartos fascia) dividing the scrotum into two sacs, each containing a testis. Histological septa are seen throughout most tissues of the body, particularly where they are needed to stiffen soft cellular tissue, and they also provide planes of ingress for small blood vessels. Because the dense collagen fibres of a septum usually extend out into the softer adjacent tissues. A septum is a cross-wall. Thus it divides a structure into smaller parts. The scrotal septum is used in reconstructive surgery to restore tissue and or reproductive organs injured or severed by trauma.Male Sexual Dysfunction: Pathophysiology and Treatment, edited by Fouad R. Kandeel, Edition: 1st, 2007. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal development begins from the ninth week after fertilization (or eleventh week gestational age) and continues until birth. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final anatomical location. Etymology The word ''fetus'' (plural ''fetuses'' or '' feti'') is related to the Latin '' fētus'' ("offspring", "bringing forth", "hatching of young") and the Greek "φυτώ" to plant. The word "fetus" was used by Ovid in Metamorphoses, book 1, line 104. The predominant British, Irish, and Commonwealth spelling is '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphe
Raphe (; from Greek ῥαφή, "seam"Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press.) has several different meanings in science. In botany and planktology it is commonly used when describing a seam or ridge on diatoms or seeds. In animal anatomy it is used to describe a ridged union of continuous biological tissue. There are several different significant anatomical raphes: * The raphe nucleus is a moderate-size cluster of nuclei found in the brain stem that releases serotonin to the rest of the brain. Selective serotonin reuptake inhibitor (SSRI) antidepressants are believed to act at these nuclei. * The buccal raphe, which is on the cheek and evidence of the fusion of the maxillary and mandibular processes * The lingual raphe on the tongue. Obvious physical evidence of the lingual raphe includes the frenulum (also called the frenum), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linea Nigra
Linea nigra (Latin for "black line"), often referred to as a pregnancy line, is a linear hyperpigmentation that commonly appears on the abdomen. The brownish streak is usually about a centimeter (0.4 in) in width. The line runs vertically along the midline of the abdomen from the pubis to the umbilicus, but can also run from the pubis to the top of the abdomen. For pregnant women, linea nigra is attributed to increased melanocyte-stimulating hormone made by the placenta, which also causes melasma and darkened nipples. Fair-skinned women show this phenomenon less often than women with darker pigmentation. Linea nigra typically disappears within a few months after delivery. Although linea nigra is rarely discussed outside pregnancy, males and females of all ages may have it. Except in pregnancy, both sexes have highest and equal prevalence of linea nigra from age 11 to 15. This increase in prevalence could be the result of hormonal changes during puberty. After age 15, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic And Prenatal Development Of The Male Reproductive System In Humans
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] |
