THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The lumbar vertebrae are the largest and carry most of the body’s weight. This region allows more range of motion than the thoracic spine, but less than the cervical. Lumbar facet joints enable significant flexion and extension movement, but limits rotation.

Detailed explanation-2: -The reason behind the enlargement of the cervical region is because of the increased neural input and output to the upper limbs. An analogous region in the lower limbs occurs at the lumbar enlargement.

Detailed explanation-3: -This foramen gets progressively smaller as one moves inferiorly. The large size is not necessary in the inferior regions because the spinal cord becomes smaller in diameter (tapers like a carrot) as it moves inferiorly. This occurs because the spinal nerves are leaving it at each intervertebral foramen.