All the following Nemalodes resides in small intestine except
**Core Concept**
The nematode parasites, also known as roundworms, reside in various parts of the human body, including the small intestine, where they can cause significant morbidity. The small intestine is a common site for nematode infections due to its large surface area and rich blood supply, which facilitate the absorption of nutrients and the survival of these parasites.
**Why the Correct Answer is Right**
The small intestine is a primary site for the residence of nematodes, such as Ascaris lumbricoides, Trichuris trichiura, and Strongyloides stercoralis. These parasites attach to the mucosa of the small intestine, where they feed on the host's nutrients and evade the immune system. The small intestine's unique environment, including its pH, temperature, and nutrient-rich environment, allows these nematodes to thrive and cause disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Ascaris lumbricoides, a common intestinal nematode, resides in the small intestine and can cause significant morbidity.
**Option B:** This option is incorrect because Strongyloides stercoralis, another intestinal nematode, also resides in the small intestine and can cause symptoms such as diarrhea and abdominal pain.
**Option C:** This option is incorrect because Trichuris trichiura, also known as the whipworm, resides in the small intestine and can cause symptoms such as diarrhea, abdominal pain, and weight loss.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that nematode infections can cause significant morbidity, particularly in developing countries. The small intestine is a common site for these infections, and understanding the pathophysiology and clinical presentation of these parasites is crucial for diagnosis and treatment.
**Correct Answer: D.**