Final answer:
The incorrect statement about muscles is that they work alone to provide movement. Muscles work together to facilitate controlled motion, and not all muscles are attached to bones; smooth muscles operate involuntarily and are found within the internal organs.
Step-by-step explanation:
The statement that is not true about muscles is: a. muscles work alone to provide movement. Muscles often work in pairs or groups, not alone, to facilitate movement. When one muscle contracts, the opposing muscle relaxes, allowing for fluid and controlled motion.
Cardiac muscles are indeed found only in the heart and are involuntary, meaning they cannot be consciously controlled. They are essential for pumping blood throughout the body. If the cardiac muscle were under voluntary control, it could lead to an inability to maintain a consistent heart rate, which could be life-threatening.
When a muscle contracts, it indeed pulls on bones, which is how movement is facilitated in the body. This action occurs via the tendons, which are robust bands of connective tissue connecting muscles to bones. This connection allows for contraction of the muscle to directly impact bone movement.
It is also true that not all muscles are connected to bones. For instance, smooth muscles are not connected to bones but are found in the walls of internal organs and control involuntary movements within the body.