Explain why part of the spine bends and part of it does not?

Your spine is one of the most important parts of your body. It gives your body structure and support. Without it you could not stand up or keep yourself upright. Your spine allows you to move about freely and to bend with flexibility. Your spine also protects your spinal cord. The spinal cord is a column of nerves that connects your brain to the rest of your body, allowing you to control your movements. Without a spinal cord you could not move any part of your body, and your organs could not function.

Keeping your spine healthy is vital if you want to live an active life.

The spine is made up of 24 bones, called vertebrae. Ligaments and muscles connect these bones together and form what is called the spinal column. The spinal column has three main segments. From top to bottom they are the cervical spine, the thoracic spine, and the lumbar spine. Each of these segments is discussed in detail below.

The normal spine has an "S"-like curve when looking at it from the side. This allows for an even distribution of weight. The "S" curve helps a healthy spine withstand all kinds of stress. The cervical spine curves slightly inward, the thoracic spine curves slightly outward, and the lumbar spine curves slightly inward. Even though the lower portion of your spine holds most of the body's weight, each segment relies upon the strength of the others to function properly.

answer; i believe that the correct answer is (b) is a factor associated with physical activity and heart disease;