An aponeurosis (/ˌæpənjʊəˈroʊsɪs/; plural: aponeuroses) is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether it be bone or other muscles. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, and the palmar (palms) and plantar (soles) regions. An aponeurosis (/ˌæpənjʊəˈroʊsɪs/; plural: aponeuroses) is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether it be bone or other muscles. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, and the palmar (palms) and plantar (soles) regions. The anterior abdominal aponeuroses are located just superficial to the rectus abdominis muscle. It has for its borders the external oblique, pectoralis muscles, and the latissimus dorsi. The posterior lumbar aponeuroses are situated just on top of the epaxial muscles of the thorax, which are multifidus spinae and sacrospinalis. The palmar aponeuroses occur on the palms of the hands. The extensor hoods are aponeuroses at the back of the fingers.The plantar aponeuroses occur on the plantar aspect of the foot. They extend from the calcaneal tuberosity then diverge to connect to the bones, ligaments and the dermis of the skin around the distal part of the metatarsal bones.