• At that time, maternal/fetal ultrasonography was being refined, and for the first time, we were diagnosing birth defects in utero . (medscape.com)
  • NCPs account for one third of the defects in children with birth defects. (chinagene.cn)
  • The mildest form is spina bifida aperta, in which osseous fusion of one or more vertebral arches is lacking, without involvement of the underlying meninges or neural tissue. (medscape.com)
  • A slightly more severe form of spina bifida, which is discussed in detail in this article, is spina bifida cystica, or myelomeningocele, in which a saclike casing is filled with cerebrospinal fluid (CSF), spinal cord, and nerve roots that have herniated through a defect in the vertebral arches and dura, as shown below. (medscape.com)
  • Improper closure of the neuropores can result in neural tube defects such as anencephaly or spina bifida. (wikipedia.org)
  • Open spina bifida, or myelomeningocele , is a congenital neural tube defect caused by primary failure of neural tube closure during the embryologic period. (medscape.com)
  • As described, the primary defect is a failure of the neural folds to fuse in the midline and form the neural tube, which is neuroectoderm. (medscape.com)
  • They can be ventral or dorsal midline defects. (medscape.com)
  • The neural folds pinch in towards the midline of the embryo and fuse together to form the neural tube. (wikipedia.org)
  • When the folds meet at midline, the groove becomes a closed tube, the neural tube. (lecturio.com)
  • Anencephaly and rachischisis are extremely severe forms of neural tube defects, in which an extensive opening in the cranial and vertebral bone is present with an absence of variable amounts of the brain, spinal cord, nerve roots, and meninges. (medscape.com)
  • In the head: Neural crest cells migrate Neural tube closes Overlying ectoderm closes In the trunk: Overlying ectoderm closes Neural tube closes Neural crest cells migrate Four neural tube subdivisions each eventually develop into distinct regions of the central nervous system by the division of neuroepithelial cells: the forebrain (prosencephalon), the midbrain (mesencephalon), the hindbrain (rhombencephalon) and the spinal cord. (wikipedia.org)
  • The spinal cord develops from the posterior neural tube. (wikipedia.org)
  • As the spinal cord develops, the cells making up the wall of the neural tube proliferate and differentiate into the neurons and glia of the spinal cord. (wikipedia.org)
  • [ 3 ] After birth, pediatric neurosurgeons perform surgical closure of the spinal defect. (medscape.com)
  • These folds then fuse with each other in the mid line beginning at the junction of the future brain and spinal cord to form the neural tube. (medscape.com)
  • The neural tube patterns along the dorsal-ventral axis to establish defined compartments of neural progenitor cells that lead to distinct classes of neurons. (wikipedia.org)
  • Other factors shown to provide positional information to the neural progenitor cells include fibroblast growth factors (FGFs) and retinoic acid. (wikipedia.org)
  • Neural crest cells (NCCs) are multipotent progenitor cells unique to vertebrates, and they have the ability to differentiate into a variety of cells, such as chondrocytes, neurons, and melanocytes. (chinagene.cn)
  • Primary neurulation divides the ectoderm into three cell types: The internally located neural tube The externally located epidermis The neural crest cells, which develop in the region between the neural tube and epidermis but then migrate to new locations Primary neurulation begins after the neural plate forms. (wikipedia.org)
  • Most connective and skeletal tissues of the cranium and face ultimately come from the derivatives of neural crest cells. (medscape.com)
  • Research progress on neural crest cells and neurocristopathies and its pathogenesis[J]. Hereditas(Beijing), 2022, 44(2): 117-133. (chinagene.cn)
  • Also, note the neural placode plastered to the dorsal surface of the sac. (medscape.com)
  • The dorsal part of the neural tube contains the alar plate, which is associated primarily with sensation. (wikipedia.org)
  • The precise etiology and the specific genes that may be involved during this abnormal neural ontogenesis have not yet been elucidated. (medscape.com)
  • The ventral part of the neural tube contains the basal plate, which is primarily associated with motor (i.e., muscle) control. (wikipedia.org)
  • The following is a proposed mechanism for how Shh patterns the ventral neural tube: A gradient of Shh that controls the expression of a group of homeodomain (HD) and basic Helix-Loop-Helix (bHLH) transcription factors is created. (wikipedia.org)
  • The neural groove gradually deepens as the neural fold become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into the closed neural tube. (wikipedia.org)
  • Between the ridges is a neural groove which deepens as the fold become elevated. (lecturio.com)
  • The primary embryologic defect in all neural tube defects is failure of the neural tube to close, affecting neural and cutaneous ectodermal structures. (medscape.com)
  • A midsagittal groove appears as a result of invagination of the ectoderm centrally and simultaneous elevation of ectodermal tissue alongside the groove to form the neural folds. (medscape.com)
  • A population of ectodermal cells adjacent to the neural fold and not included in the overlying surface (somatic) ectoderm gives rise to the formation of the neural crest. (medscape.com)
  • The center of the neural plate remains grounded, allowing a U-shaped neural groove to form. (wikipedia.org)
  • This neural groove sets the boundary between the right and left sides of the embryo. (wikipedia.org)
  • Specifically, the amniotic fluid can have a caustic and destructive effect on the open neural structures. (medscape.com)
  • However, the subsequent defect is the maldevelopment of the mesoderm, which, in turn, forms the skeletal and muscular structures that cover the underlying neural structures. (medscape.com)
  • These neural tube defects can be open (neural structures that communicate with the atmosphere) or closed (skin covered). (medscape.com)
  • The 5 pairs of branchial arches, corresponding to the primitive vertebrae gill bars, that form on either side of the pharyngeal foregut on day 22 are the embryologic basis of all the differentiated structures of the head and neck. (medscape.com)
  • This article summarizes the chronologic sequence of the embryologic development of the head and neck with respect to the branchial arches. (medscape.com)
  • The aim of the present study is to investigate the effects of different sugammadex doses on embryologic and neural tube development in an early-stage chick embryo model. (bvsalud.org)
  • The embryo begins as a two-dimensional planar structure, and just prior to the third week, the stage is set for the development of the central nervous system in the area of ectoderm thickening known as the neural plate. (medscape.com)
  • These deformities are not only disorders of embryologic induction but also disorders of cellular migration and include the secondary mechanical complications that occur with an unprotected nervous system. (medscape.com)
  • The edges of the neural plate start to thicken and lift upward, forming the neural folds. (wikipedia.org)
  • These cell types are specified by the secretion of the Shh from the notochord (located ventrally to the neural tube), and later from the floor plate cells. (wikipedia.org)
  • The ridges are formed by folding of neural plate. (lecturio.com)
  • At four weeks of pregnancy, a small oval-shaped disk called the neural plate starts to form. (babycentre.co.uk)
  • After the sperm enters the oval cytoplasm in the uterine tube, the maternal and paternal chromosomes combine to form a zygote, completing fertilization. (medscape.com)
  • The consequences of myelomeningocele depend on the proximal anatomical extent of the defect and include hindbrain herniation, hydrocephalus , motor and cognitive impairments, orthopedic abnormalities, bladder and bowel incontinence, social and emotional challenges, and lifelong quality-of-life issues. (medscape.com)
  • Findings include a paraumbilical wall defect with uncovered herniated intestines. (lecturio.com)
  • The first morphologic evidence of the optic primordia is seen as a thickened area with a shallow sulcus on the lateral forebrain of the neural tube in the region of the future diencephalon. (medscape.com)
  • Most malformations, especially those such as neural tube defects, occur early in embryogenesis and are likely the result of aberrant expression of a yet undefined developmental gene or family of genes. (medscape.com)
  • Gastroschisis is a full-thickness defect of the anterior abdominal wall Anterior abdominal wall The anterior abdominal wall is anatomically delineated as a hexagonal area defined superiorly by the xiphoid process, laterally by the midaxillary lines, and inferiorly by the pubic symphysis. (lecturio.com)
  • The neural tube defect discussed in this article is classified as an embryologic induction disorder. (medscape.com)
  • Mammalian neural tubes close in the head in the opposite order that they close in the trunk. (wikipedia.org)