Smooth muscle tissues are involuntary. And so is cardiac muscle tissue. So why doesn’t heart have smooth muscle tissues like most organs? I know that they are visually different (branched vs non-branched, striated vs non-striated) but how does that affect the heart?
1 Answer
Striated muscle contraction is synchronized by the structure at the individual fiber level, this also produces a lot more force. They also have a faster recovery time than smooth muscle. Presumably the heart needs that higher power, synchronization, and/or quick response to pump blood under high pressure. I would put money on synchronization at the individual fiber level being the main factor, but I could find no definitive study, possibly because the effects can't easily be separated.
https://journals.physiology.org/doi/full/10.1152/advan.00152.2018 https://www.ncbi.nlm.nih.gov/books/NBK526125/