Abnormal Embryological Development

Spina bifida (occulta) and situs inversus are two distinct anomalies of anatomic structure which result from abnormal embryological development. Type one, or insulindependent, diabetes mellitus (IDDM) is a disease which may occur at any age, but typically makes its initial presentation in adolescents and young adults. Chromatopsia is a visual disturbance sometimes associated with retinal pathology.

The term "dysraphism" refers to any lack of closure of two structures which are normally fused (18:349). Spina bifida involves dysraphism of the bones that enclose the vertebral canal. Typically this occurs posteriorly and usually involves the neural arches of the vertebrae (pedicles, laminae, articular processes and spinous processes) (18:349).

It has been estimated that in the United States, two out of every 1,000 babies born have some sort of neural tube defect (NTD) (16:791). In Britain, this incidence has been reported to be as high as 7 to 8 per 1,000 births. Half of these defects involve anencephaly, or the congenital absence of the brain and spinal cord (16:791). The remainder consist of overt and occult spinal dysraphism. James and Lassman found a 5% incidence of spina bifida in autopsied adults (18:350).

Overt spinal dysraphism, or spina bifida cystica, is the well known myelomeningocele or meningocele that typically protrudes grotesquely through a defective vertebral column (18:349). The less common, spina bifida

. . .
ptomatic and no treatment is necessary (11:1034). The condition may only become hazardous to the patient if it remains unrecognized during abdominal and thoracic surgery. Approximately 20%25% of patients have an immotile cilia syndrome (1:307). The defect results in a characteristic phenotype including bronchiectasis with chronic cough, rhinitis, sinusitus, male infertility due to sperm immotility, and variable impairment of female fertility (1:312). Patients with situs inversus usually have a low incidence of other structural malformations (1:308). Some families, however, have had recurrence of the malformations that are often associated with partial situs inversus, such as congenital heart disease and polyasplenia, with both complete and partial situs inversus. In such families, asplenia in particular is usually associated with additional birth defects (1:310). Thus, when partial situs inversus defects occur in patients with total situs inversus, asplenia may be associated with spina bifida. Out of 37 cases reported by Fonkalsrud, however, only 1 was found to have meningomyelocele (9:960). Any suspicion of total or partial situs inversus should lead to further physical examination and, perhaps, to diagnostic
. . .

Some common words found in the essay are:
Mayo Clinic, James Lassman, Sweden Finland, Moreover Hall, Abnormalities Spina, Davidson John, Publishers Inc, Bergsma Daniel, situs inversus, Scientific Publications, spina bifida, Liss Inc, diabetes mellitus, york ny, bifida occulta, spina bifida occulta, davidson john, edition york ny, edition york, mellitus problemoriented approach, clinical diabetes, mellitus problemoriented, eds clinical, problemoriented approach edition, diabetes mellitus problemoriented,
Approximate Word count = 2506
Approximate Pages = 10 (250 words per page)

More Essays on Abnormal Embryological Development