That would be a Boner. Its not really a "Bone" but when blood floods the flaccid penis it becomes hard and erect. Common name for this is a "Boner", in the scientific world it is called a skeletal muscle, because its like a skeleton bone but its a muscle. These are facts.
SKELETAL (:
skeletal muscles
smooth muscle, cardiac muscle and most glands
Skeletal muscle
A skeletal muscle cell is a cell of a skeletal muscle.
A skeletal muscle.
straited muscle are another form of skeletal muscle.
The skeletal muscle is heavily stratified
Skeletal muscle is voluntary muscle.
no skeletal muscles are voluntary smooth muscles are not
A skeletal muscle
You are in direct control of skeletal muscle.