I'm pretty sure it's smooth muscles.
The answer for this is Connective
From the 118 known elements, 25 elements are believed to be essential to human biology.
Out of 25 elements , 6 elements namely – carbon, oxygen, hydrogen, nitrogen, calcium and phosphorus , they make up about 99% of the human body. Some other elements like - potassium, sulfur, sodium, chlorine, and magnesium, they are also found in the human biology.
There may be some strains of bacteria that are naturally resistant to these antibiotics, or there may be some that mutate to become resistant. This means that as antibiotics are used more and more, those that can be killed using the antibiotics die out, but those that are resistant will remain, and will reproduce. Over time, it will be the resistant species that predominate.
