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Sinovaginal Bulb
The sinovaginal bulb is a transitional structure in the development of female genitalia, and is one of a pair of endodermal outgrowths of the urogenital sinus, which later fuse to form the lower part of the vagina In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag .... The lower third of the vagina is derived from the urogenital sinus. The hymen is formed from the same tissue as the sinovaginal bulb. References Vagina {{developmental-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endodermal
Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm. The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems. In plant biology, endoderm corresponds to the innermost part of the cortex (bark) in young shoots and young roots often consisting of a single cell layer. As the plant becomes older, more endoderm will lignify. Production The following chart shows the tissues produced by the endoderm. The embryonic endoderm develops into the interior linings of two tubes in the body, the digestive and respiratory tube. Liver and pancreas cells are believed to derive from a common precursor. In humans, the endoderm can differentiate into distinguishable organs after 5 weeks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urogenital Sinus
The urogenital sinus is a body part of a human or other Placentalia, placental only present in the development of the urinary system, development of the urinary and development of the reproductive organs, reproductive organs. It is the ventral part of the cloaca, formed after the cloaca (embryology), cloaca separates from the anal canal during the fourth to seventh weeks of development. In males, the UG sinus is divided into three regions: upper, pelvic, and phallic. The upper part gives rise to the urinary bladder and the pelvic part gives rise to the prostatic and membranous parts of the urethra, the prostate and the bulbourethral glands (Cowper's). The phallic portion gives rise to the spongy (bulbar) part of the urethra and the urethral glands (Littré's). In females, the pelvic part of the UG sinus gives rise to the sinovaginal bulbs, structures that will eventually form the inferior two thirds of the vagina. This process begins when the lower tip of the paramesonephric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagina
In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vaginal opening and hymen, vaginal introitus is normally partly covered by a thin layer of mucous membrane, mucosal tissue called the hymen. The vagina allows for Copulation (zoology), copulation and birth. It also channels Menstruation (mammal), menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle. To accommodate smoother penetration of the vagina during sexual intercourse or other sexual activity, vaginal moisture increases during sexual arousal in human females and other female mammals. This increase in moisture provides vaginal lubrication, which reduces friction. The texture of the vaginal walls creates friction for the penis during sexual intercourse and stimulates it toward ejaculation, en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hymen
The hymen is a thin piece of mucosal tissue that surrounds or partially covers the vaginal opening. A small percentage of females are born with hymens that are imperforate and completely obstruct the vaginal canal. It forms part of the vulva and is similar in structure to the vagina. The word is from the Greek ''ὑμήν'' meaning a thin skin or membrane. In children, a common appearance of the hymen is crescent-shaped, although many shapes are possible. Each shape in the natural range has a Latinate name. During puberty, estrogen causes the hymen to change in appearance and become very elastic. Normal variations of the post-pubertal hymen range from thin and stretchy to thick and somewhat rigid. Very rarely, it may be completely absent. The hymen can rip or tear during first penetrative intercourse, which usually results in pain and, sometimes, mild temporary bleeding or spotting. Minor injuries to the hymen may heal on their own, and not require surgical intervention. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
