Final answer:
Abdominal guarding is a reflex response triggered by inflammation or injury in the abdomen. The muscles become tense and rigid to limit movement and protect the internal organs.
Step-by-step explanation:
When the abdominal muscles become rigid in an effort to protect the abdomen from further irritation, it is known as abdominal guarding. Abdominal guarding is a reflex response triggered by inflammation or injury in the abdomen. The muscles become tense and rigid to limit movement and protect the internal organs. For example, if someone has appendicitis, the abdominal muscles may become rigid to prevent further irritation of the inflamed appendix.