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.
straited muscle are another form of skeletal muscle.
The skeletal muscle is heavily stratified
no skeletal muscles are voluntary smooth muscles are not
Skeletal muscle is voluntary muscle.
You are in direct control of skeletal muscle.
A skeletal muscle
Skeletal muscle.