Positional Changes Of The Spinal Cord Figure 123

Fetal Conus Medullaris

At week 8, the spinal cord extends the entire length of the vertebral canal as spinal nerves exit the intervertebral foramina near their level of origin. This condition does not persist owing to the disproportionate growth of the vertebral column during the fetal period. Neural Tube Vesicles and Their Adult Derivatives Neural Tube Vesicles and Their Adult Derivatives Cerebral hemispheres, caudate, putamen amygdaloid, claustrum, lamina terminalis, olfactory bulbs, hippocampus Epithalamus,...

Numerical Chromosomal Abnormalities

Trisomy Zygote

POLYPLOIDY is the addition of extra haploid sets of chromosomes i.e., 23 to the normal diploid set of chromosomes i.e., 46 . A. Triploidy is a condition in which cells contain 69 chromosomes. It results in spontaneous abortion of the conceptus or only brief survival of the liveborn infant after birth. Triploidy occurs as a result of either a failure of meiosis in a germ cell e.g., fertilization of a diploid egg by a haploid sperm or dispermy two sperm that fertilize one egg . B. Tetraploidy...