Bursitis and tendinitis are both common conditions that cause swelling around muscles and bones. They occur most often in the shoulder, elbow, wrist, hip, knee, or ankle. A bursa is a small, fluid-filled sac that acts as a cushion between a bone and other moving body parts such as muscles, tendons, or skin.
In higher vertebrates, such as reptiles, birds and mammals, there are 12 pairs of cranial nerves. Lower vertebrates, such as fish and amphibians, have 10 pairs of cranial nerves. Continue Reading.
1 The nervous system of vertebrates has two main divisions: the central nervous system, consisting of the brain and spinal cord, and the peripheral nervous system, which in humans includes 12 pairs of cranial nerves, 31 pairs of spinal nerves, and the autonomic, or involuntary, nervous system.