abdomen: This region of the body starts along the bottom of the ribcage and extends to the hips. It’s visible from the front.

abdominopelvic splanchnic nerves: These sympathetic (fight-or-flight) nerves of the abdomen carry the presynaptic fibers to the abdomen and pelvis.

anastomose : To join together.

androgen hormones: Male sex hormones.

ankylosing spondylitis : An arthritic disease of the vertebral joints that results in hyperkyphosis and may restrict lung expansion if the disease spreads superiorly. It may lead to fusion of intervertebral joints and spinal column rigidity.

anterior: In clinical anatomy, closer to the front of the body. For instance, the abdominal muscles are anterior to the spine.

aponeurosis : The broad tendinous structure that attaches a muscle to another muscle.

articulate: In clinical anatomy, to form a joint.