Final answer:
Guarding refers to the rigid contraction of abdominal muscles to protect the underlying organs from further irritation. The abdominal wall muscles, which include the rectus abdominis, external oblique, internal oblique, and transversus abdominis, facilitate this protective response.
Step-by-step explanation:
When the abdominal muscles become rigid in an effort to protect the abdomen from further irritation such as from inflammation or infection, this is referred to as guarding. This is a reflex contraction of the abdominal wall muscles that occurs when the abdomen is touched or when an internal organ is inflamed. The abdominal wall consists of four main pairs of muscles which are the rectus abdominis, the external oblique, the internal oblique, and the transversus abdominis. These muscles work together to protect internal organs, maintain posture, and help with movements such as flexing the spine or rotating the torso.
Referred pain is the conscious perception of visceral sensation projected to a different region of the body, such as when pain from a heart attack is felt in the left shoulder and arm. The most accepted explanation for this phenomenon is that the visceral and somatosensory fibers enter into the same level of the spinal cord, causing the brain to misinterpret the source of pain as being from the area where the somatosensory fibers originate.