Os acetabuli and mixed-type FAI. This 79yo male with a history of right hip pain for 1 month has features of both pincer and cam-type FAI. Femoral head asphericity (yellow arrow), irregular anterosuperior bump (green arrowheads), os acetabuli (yellow arrowhead) and hypertrophic acetabular rim (blue arrow).
1 The other 22 pairs are autosomes (non-sex chromosomes) and look the same for both males and females. 2  The DNA making up each of our chromosomes contains thousands of genes. 3  At the ends of each of our chromosomes are sections of DNA called telomeres.
What is a chromosome? In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. Chromosomes are not visible in the cellâs nucleusânot even under a microscopeâwhen the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.