1. A patient goes to the emergency room because she has a sharp pain in the lower right portion of her abdominal wall, near her hip. She is diagnosed with appendicitis and has to undergo surgery to remove it. Why was the pain localized in the lower right quadrant?
The patient experienced referred pain
Because the inflamation from the appendix caused an inflamation of other neurons
2. Your little brother has been suffering from a bad respiratory infection. He has a fever, an ear ache,a bad cough and severe congestion. He is not having a good time. On top of it, he is having trouble hearing out of one ear and is irritated because he can't hear the TV or you very well. Why can't he hear you?
He is ignoring you because he feels ill.
Pain receptors from his ear are inhibiting input from his cochlea
Function of his middle ear is compromised due to the infection.
3.
You are correct. Feeling pain in the lower right quadrant as a result of appendicitis is due to referred pain. Another example of referred pain is that associated with a heart attack. A patient feels the pain radiating down their left arm. Referred pain is felt in an area remote from the actual site of tissue damage. In other words, the pain is "referred" from the damaged area to a healthy area. The area of the skin in which the pain is felt is usually innervated by neurons of the same segment of the spinal cord as the damaged tissue. Referred pain is said to follow the dermatome rule. That is, both the damaged tissue and the healthy tissue, in which you feel pain, arose from the same embryological segment.
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This is incorrect. A spread of inflamation would not account for why you could not sense pain from the damaged tissue. A ruptured appendix could result in an expansion of the area of infection and inflamation.
Don't you wish. No, he's not ignoring you. In fact, he wants your attention because he feels ill.
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Sorry, this is incorrect. Pain receptors from his ear are sending information to the brain but these pathways should not interfere with sensory input coming from the cochlea. They travel via separate neural pathways.
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This is correct. He has a condition called Otitis Media. In this condition, frequently seen in children suffering from respiratory infections, the infection has spread via the pharyngotympanic tube (eutachian tube) to the middle ear. As part of normal immune system function white blood cells are attracted to the site to combat the infection. The middle ear becomes filled with pus (YUK!). With the buildup of pus the ossicular system of the middle ear cannot transduce sound waves from the tympanic membrane to the cochlea efficiently. Therefore, the signal getting to the cochlea is reduced. If pressure due to the buildup of pus becomes excessive, the tympanic membran may rupture. Repeated infections and rupturing of the tympanic membrane can cause scaring and may permanently impair tympanic function.
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