I just thought of this question. You know when you fall down and scrape your knees or something like that? Why does it hurt when you touch it? (you have a little blood going also)
Torn nerve endings??
http://www.stjohn.org/HealthInfoLib/swArticle.aspx?2,29
Pain is a very complicated sensation. Basically, there are special nerve receptors in your body for pain. When your tissues are damaged, this causes a release of chemicals called cytokines that bind to the pain receptors and send a message to your brain that you are in pain. This stimulation of your pain receptors puts them on high alert, making them extra sensative to any stimulation. So, when you touch your "ouchie," you are creating stimulation to those over-sensitive receptors, as well as causing more release of the cytokines from the damaged tissue.
One extra tidbit, pain can also be inhibited (or less severe) if you provide stimulation to another area of your body. This can be with touch, pressure, or warmth. But, the most effective is with pain. This can cause certain parts of the pain pathway to be blocked leading to less pain. This is one reason they think that accupuncture works. So, the next time you hit your finger with a hammer, have someone pinch your other arm. Well, it may help. :O)
When you scrape your knees or any other part of your body, it can cause damage to your skin and underlying tissues. The pain you feel when you touch the scraped area is a result of various factors.
Firstly, when you scrape your knee, the outermost layer of your skin, called the epidermis, gets damaged or removed. This exposes the nerve endings in the deeper layers of your skin, which are more sensitive to touch, pressure, and temperature. When you touch the scraped area, these nerve endings are stimulated, sending signals to your brain that you interpret as pain.
Secondly, the damaged blood vessels under the scraped skin can leak into the surrounding tissues. This leakage of blood creates inflammation, which further contributes to the pain and tenderness when you touch the wounded area.
Additionally, when a scrape occurs, your body's natural defense mechanism is triggered. White blood cells rush to the site of the injury to clean up any bacteria or foreign particles that might have entered the wound. This immune response causes swelling, redness, and further sensitivity to touch.
To alleviate the pain, you can take several steps. First, thoroughly clean the scraped area with mild soap and water to prevent infection. You can also apply an antiseptic or antibiotic ointment to the wound. Covering the scrape with a sterile bandage or dressing will protect it from further irritation and contamination. Over-the-counter pain relievers like acetaminophen or ibuprofen can help manage the discomfort. Keep an eye on the wound for signs of infection, such as increased pain, redness, warmth, or pus, and seek medical attention if necessary.
Remember, if you have a more severe injury, uncontrolled bleeding, or persistent pain, it is always best to consult a healthcare professional.