In normal individuals, there is a constant production of ketone bodies by the liver and their utilization by extrahepatic tissues. The concentration of ketone bodies in blood is maintained around 1 mg/dl. Their excretion in urine is very low and undetectable by routine urine tests (Rothera's test).
A: Examples of involuntary muscles, also known as smooth muscles, are the muscles of the urogenital tract, digestive tract, circulatory system and respiratory tract. Involuntary muscles are not controlled by the organism's will. Their actions are automatic and facilitated by the autonomic nervous system.
Muscle tissues are derived from the mesodermal layer of embryonic germ cells in a process known as myogenesis. There are three types of muscle, skeletal or striated, cardiac, and smooth. Muscle action can be classified as being either voluntary or involuntary. Cardiac and smooth muscles contract without conscious thought and are termed involuntary, whereas the skeletal muscles contract upon command.