Which of the following function or activity is not affected by smooth muscles in human ?

Options

A. Transportation of food through the digestive tract
B. Transport of gametes through the genital duct
C. Transportation of urine through the ureter and bladder
D. Chewing and swallowing of food through buccal cavity .

Answer

To solve the question regarding which function or activity is not affected by smooth muscles in humans, we can follow these steps:

### Step 1: Understand Smooth Muscles
Smooth muscles are also known as involuntary muscles. They are not under our conscious control and are responsible for various automatic functions in the body.

**Hint:** Remember that smooth muscles control involuntary actions in the body.

### Step 2: Analyze Each Option
We will evaluate each option to determine if it is affected by smooth muscles or not.

- **Option 1: Transportation of food through the digestive tract**
- Smooth muscles are involved in peristalsis, which moves food through the digestive system. Therefore, this activity is affected by smooth muscles.

**Hint:** Think about how food moves through the esophagus and intestines.

- **Option 2: Transport of gametes through the genital tract**
- The movement of gametes is also facilitated by smooth muscles in the reproductive system. Thus, this activity is affected by smooth muscles.

**Hint:** Consider how sperm travels through the male reproductive tract.

- **Option 3: Transportation of urine through the ureter and bladder**
- Smooth muscles in the ureters and bladder help transport urine from the kidneys to the bladder. Hence, this activity is affected by smooth muscles.

**Hint:** Recall how urine is expelled from the body and the role of muscles in this process.

- **Option 4: Chewing and swallowing of food through the buccal cavity**
- Chewing is a voluntary action controlled by skeletal muscles, not smooth muscles. Swallowing begins as a voluntary action but involves both voluntary and involuntary processes. However, the initial chewing is not affected by smooth muscles.

**Hint:** Think about which muscles you consciously control when eating.

### Step 3: Conclusion
After analyzing all the options, we find that the activity that is not affected by smooth muscles is **Option 4: Chewing and swallowing of food through the buccal cavity**.

**Final Answer:** Option 4