Charecteristic of smooth muscle cells in intestineMarch 2005
**Core Concept**
Smooth muscle cells in the intestine, also known as intestinal smooth muscle, play a crucial role in propelling food through the digestive system. They are characterized by their unique properties that distinguish them from skeletal and cardiac muscle cells.
**Why the Correct Answer is Right**
Intestinal smooth muscle cells exhibit a slow and rhythmic contraction, known as peristalsis, which is essential for the movement of food through the digestive tract. This is due to the presence of a unique electrical activity called the slow wave, which is generated by the interstitial cells of Cajal. The slow wave triggers the contraction of smooth muscle cells, leading to the movement of food through the intestines. Additionally, intestinal smooth muscle cells are also characterized by their ability to relax and contract in response to various stimuli, such as hormones and neurotransmitters, allowing for the regulation of intestinal motility.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the characteristic of smooth muscle cells in the intestine. While skeletal muscle cells do exhibit rapid contraction and relaxation, this is not a characteristic of smooth muscle cells in the intestine.
**Option B:** This option is incorrect because it is not a specific characteristic of smooth muscle cells in the intestine. While cardiac muscle cells do exhibit rhythmic contraction, this is primarily due to the sinoatrial node and not the slow wave generated by interstitial cells of Cajal.
**Option C:** This option is incorrect because it is not a specific characteristic of smooth muscle cells in the intestine. While smooth muscle cells in other parts of the body, such as the uterus, do exhibit rapid contraction and relaxation, this is not a characteristic of smooth muscle cells in the intestine.
**Option D:** This option is incorrect because it is not a specific characteristic of smooth muscle cells in the intestine. While smooth muscle cells in other parts of the body, such as the airways, do exhibit rapid contraction and relaxation, this is not a characteristic of smooth muscle cells in the intestine.
**Clinical Pearl / High-Yield Fact**
The unique properties of intestinal smooth muscle cells, such as the slow wave and ability to relax and contract in response to various stimuli, allow for the regulation of intestinal motility and the movement of food through the digestive tract. This is essential for proper digestion and absorption of nutrients.
**Correct Answer: C.**