Final answer:
The slightly swollen area a nurse finds on a patient is due to a change in capillary permeability, leading to fluid accumulation in the tissue (edema) and swelling.
Step-by-step explanation:
When the nurse assesses a patient and finds an area that is slightly swollen, this finding is interpreted as the result of a change in capillary permeability. This change is caused by injured cells, which release chemical signals that cause vasodilation and fluid leakage into the surrounding tissue. The result is swelling, or edema, which is a collection of fluid in the tissues that can cause pressure on nearby nerves and result in pain.
Inflammatory mediators such as histamine increase the permeability of blood vessels, allowing more fluid to enter the interstitial space. This process is essential for allowing immune cells to access the site of injury to fight any potential infection. However, it also contributes to the signs of inflammation, including swelling and pain.