amnion

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amnion

the innermost of two membranes (see also chorion) enclosing an embryonic reptile, bird, or mammal

Amnion

A thin, cellular, extraembryonic membrane forming a closed sac surrounding the embryo in all reptiles, birds, and mammals. It is present only in these forms; the collective term amniotes is applied to these animals. The amnion contains a serous fluid in which the embryo is immersed. See Amniota

Typically, the amnion wall is a tough, transparent, nerve-free, and nonvascular membrane consisting of two layers of cells: an inner, single-cell-thick layer of ectodermal epithelium and an outer covering of mesodermal, connective, and specialized smooth muscular tissue. Early after the formation of the amnion, waves of contraction of the muscles pass over the amniotic sac and produce a characteristic rocking of the embryo. See Germ layers

The major function of the amnion and its fluid is to protect the delicate embryo. Thus, developmental stages of terrestrial animals are provided with the same type of cushioning against mechanical shock as is provided by the water environment of aquatic forms. See Fetal membrane

Amnion

 

one of the embryonic membranes found in a number of vertebrates (reptiles, birds, mammals) and invertebrates. Depending on whether the amnion is present or absent, two groups are distinguished—the Amniota (or higher) and the Anamnia (or lower). The amnion develops around the embryo in the form of folds of the extraembryonic ectoderm and the peritoneum parietal of the lateral plates of the mesoderm—that is, the external and median germ layers. After accretion of the edges of the folds, the embryo is within two membranes—the inner membranes, or amnion, and the external, or serous, membrane (called the chorion in mammals). In reptiles the amnion is without vessels; in birds and mammals it develops vessels and contractile muscular elements. The amniotic cavity becomes filled with a large amount of exudate from the vessels—the so-called amniotic, or fetal, fluid which protects the embryo from mechanical injury and desiccation. The fluid contains organic compounds (proteins, urea, sugar, hormones) and also inorganic salts. The amnion bursts during parturition and the amniotic fluid escapes; the remnants of the amnion on the body of the newborn individual are called the rubashechka (“little shirt”). The blastoderm in insects, scorpions, nemerteans, and sea urchins is also called the amnion.

amnion

[′am·nē‚än]
(embryology)
A thin extraembryonic membrane forming a closed sac around the embryo in birds, reptiles, and mammals.
References in periodicals archive ?
The company is based on more than 10 years research with amniotic fluid and stem cells, and the primary focus on the development and commercialisation of transformative therapeutics and innovative cosmeceuticals.
We are keen to further develop the use of amniotic membrane in burn and wound care."
Baggieri added that while such special cases maybe observed in every 80,000 or 100,000 natural births, they almost never happen during C-section births because scalpels used during the surgery, typically tends to puncture the amniotic sac.
KEYWORDS: Meconium aspiration syndrome; Meconium stained amniotic fluid; gestational diabetes.
In this method, the amniotic fluid volume was firstly measured by the gray-scale sonography using the single deepest pocket measurement method, and then the same pocket was measured by colour Doppler if the foetus did not move.
We have not seen a report about isolation and culture of avian species amniotic fluid stem cells successfully nowadays.
At five months, the unborn baby's skin starts to toughen up and becomes impenetrable to the amniotic fluid, so that after 28 weeks the amount of liquid plateaus at just less than a litre.
Obstetrics experience throughout the era showed that meconium passage is a possible threatening sign of foetal asphyxia,8 while the reported incidence of meconium stained amniotic fluid is 1-18%.9 Meconium staining of liquor has long been thought to be a conventional sign of foetal distress, but now CTG is an up-to-date practical method for foetal surveillance during pregnancy and labour.10 The current study was conducted to identify the relationship between colours of liquor with the trace of CTG, whether reactive or non-reactive, as well as to APGAR score.
Sixty-three 3-week-old Sprague-Dawley rats were divided into three groups: sham surgery (SS, n = 21), bile duct ligature (BDL, n =19), and bile duct ligature plus human amniotic membrane (BDL + AM, n = 20).
Although the amniotic fluid index was normal, the intra-amniotic pressure remained as high as 20-22 mmHg because of frequent UCs on palpation even if tocolysis was performed for preventing UC during the procedure.
Summary: TEHRAN (FNA)- Amniotic fluid, the protective liquid surrounding an unborn baby, is discarded as medical waste during caesarean section deliveries.