X- rays taken in the trauma room show a fracture dislocation of the thoracic spine between the 11 th thoracic vertebra (T11) and
the 12 th thoracic vertbra ( T12) . Am MRI confirms the clinical impression that joe’s spinal cord is completely disrupted at this level . What does the organization of white and gray matter in the spinal cord look like at the area where joe’s injury is located?
At the Joes injury, the grey matter looks like a butterfly-shaped are. While the white matter has tracts which are either ascending or descending. For example, we have corticospinal which is ascending tract. Grey matter it is the thin cerebral cortex for each hemisphere of the cerebrum and it is composed of interneurons which integrate information.
White matter consists of myelinated axons that lie low below the cerebral cortex.
The two hemisphere connects together by the corpus callosum.
Crossing over – often, the sister homologous chromosomes of a cell exchange genetic material through recombination of genes.
Independent assortment/random fertilization – there are numerous variety of ways that the chromosomes of the gametes can combine, after meiosis, through fertilization to form a zygote
Mutation – on rare occasion, there is a slight and random change in the genes of a gametic cell caused by environmental factors.
