why does rigor mortis start at the head
Rigor mortis At the time of death, a condition called "primary flaccidity" occurs. Following this, the muscles stiffen in rigor mortis. All muscles in the body are affected. Starting between two and six hours following death, rigor mortis begins with the eyelids, neck, and jaw. The sequence may be due to different lactic acid levels among different muscles, which is directly related to the difference in glycogen levels and different types of muscle fibers.
Horse hoof The third phalanx (coffin bone; pedal bone; P3;) is completely (or almost completely) covered by the hoof capsule. It has a crescent shape and a lower cup-like concavity. Its external surface mirrors the wall's shape. The corium, a dermo-epidermal, highly vascularized layer between the wall and the coffin bone, has a parallel, laminar shape, and is named the laminae. Laminar connection has a key role in the strength and the health of the hoof. Beneath the rear part of the sole, there is the digital cushion, which separates the frog and the bulb from underlying tendons, joints and bones, providing cushioning protection. In foals and yearlings, the digital cushion is composed of fibro-fatty, soft tissue. In the adult horse, it hardens into a fibrocartilaginous tissue when sufficient, consistent concussion stimulates the back of the hoof. Normal transformation of the digital cushion into fibrocartilagineous tissue is now considered a key goal, both for prevention of, and for rehabilitation of recovering cases of navicular syndrome. The flexor tendon lays deeper, just along the posterior surface of the small pastern bone (PII) and navicular bone, and it connects with posterior surface of P3; the navicular functions as a pulley.