Lumbar fascia Lumbar fascia The lumbar fascia is an anatomic structure of the lumbar region. It consists of a band or sheet of connective tissue fibres, primarily collagen, that attaches, stabilizes, encloses and separates muscles not limited to the lumbar region as the name suggests, but extending upwards over the thorax to the neck and downwards over the muscles covering the sacrum. The upper thoracic portion is thin while the lumbar and sacral regions are thicker and stronger. The lumbar fascia binds the deep muscles of the back to the spine and to the transverse processes of the vertebrae. Additionally the lumbar
Flatworm other animals. The space between the skin and gut is filled with mesenchyme, a connective tissue made of cells and reinforced by collagen fibers that act as a type of skeleton, providing attachment points for muscles. The mesenchyme contains all the internal organs and allows the passage of oxygen, nutrients and waste products. It consists of two main types of cell: fixed cells, some of which have fluid-filled vacuoles; and stem cells, which can transform into any other type of cell, and are used in regenerating tissues after injury or asexual reproduction. Most platyhelminths have no anus and regurgitate undigested