Items tagged “embryology”

15 results found
Article

Wolffian duct

The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. It also gives off a lateral branch forming the ureteric bud. In both the male and the female, the Wolffian duct develops into the trigone o...
Article

Postaxial polydactyly

Postaxial polydactyly refers to polydactyly where the additional digit is on the ulnar margin of the hand, or lateral to the 5th (little) toe. Epidemiology Postaxial polydactyly is more common than preaxial polydactyly, with an estimated incidence of 1 in 3000 5. Associations Postaxial polyd...
Case

Brain development (diagram)

  Diagnosis not applicable
Mohammad Taghi Niknejad
Published 04 Jan 2013
32% complete
Diagram
Case

Median umbilical ligament

  Diagnosis almost certain
Ian Bickle
Published 13 Jul 2013
71% complete
CT
Article

Crista terminalis

The crista terminalis is a smooth muscular ridge in the superior aspect of the right atrium, formed following resorption of the right valve of the sinus venosus. It represents the junction between the sinus venarum, the "smooth" portion of the right atrium derived from the embryologic sinus veno...
Article

Preaxial and postaxial borders

Preaxial and postaxial borders describe where the flexor and extensor compartments of the limb meet during fetal limb bud development. These borders are also conveniently marked out by veins. Preaxial (cranial) border demarcates portion of the limb bud that lies cranial to the axis of the limb...
Article

Central nervous system embryology

Central nervous system (CNS) embryology is complex, and below is a brief summary of its development.  The early CNS begins as a simple neural plate that folds to form a groove then tube, open initially at each end. Within the neural tube stem cells generate the two major classes of cells that m...
Article

Radiation effects on embryonic and fetal development

Radiation effects on embryonic and fetal development are generally considered low risk compared to the normal risks of pregnancy. Most diagnostic x-ray and nuclear medicine examinations are <50 mSv and have not been demonstrated to produce any significant impact on fetal growth and development. ...
Article

Branchial apparatus

The branchial (or pharyngeal) apparatus is the complex region in the developing embryo between the head and chest that develops in the fourth week and provides bilateral ridges and valleys that subsequently develop into numerous anatomic structures of the head, face, palate and anterior neck. Th...
Article

Germinal matrix

The germinal matrix is an embryological structure in the fetal brain which is only seen in the fetus and in premature neonates. It is the most vulnerable area of the fetal brain and associated pathology carries significant mortality and morbidity.  Gross anatomy  The germinal matrix is usually...
Article

Placode

Placode (or neural placode) refers in terms of radiology to a segment of non-neurulated neural tissue, which has had development frozen in the neural plate stage. A placode can be found in all open spinal dysraphisms and in some closed spinal dysraphisms. In the former, the placode is exposed to...
Article

Anterior meningocele

Anterior meningocele is characterized by herniation of CSF-filled sac through an anterior osseous defect. It usually occurs in the sacral region where it is termed an anterior sacral meningocele although it can also occur in other areas like the thorax 2.  When present in the sacrum, it is oft...
Case

Stages of embryonic rotation of the gut

  Diagnosis not applicable
Emma Gevorgyan
Published 10 Nov 2022
41% complete
Diagram
Article

Persistent sciatic vein

Persistent sciatic vein is one of two known embryonic veins in the lower limb which may persist, the other being the lateral marginal vein. Although both are associated with Klippel-Trenaunay syndrome 1-3, only the lateral marginal vein is also referred to as the Klippel-Trenaunay vein. The sci...
Article

Somite

Somites, also known as metameres, are paired populations of cells that arise on either side of the neural tube in the developing embryo and set out a plan for the compartmentalised development of the body 1-3. Immature somites are multipotent and can differentiate into many tissues including de...

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