A projecting ridge or fin on the bottom of the hull of a boat or ship that improves directional control and is often weighted for added stability. 2. The principal structural member of an aircraft, resembling a ship's keel in shape and function.
The outer, reddish region, next to the capsule, is the renal cortex. This surrounds a darker reddish-brown region called the renal medulla. The renal medulla consists of a series of renal pyramids, which appear striated because they contain straight tubular structures and blood vessels.
Darker urine can be different colors, but is usually brown, deep yellow, or maroon. Dark urine is deeper in color than urine that is usually straw to yellow in color. Darker urine can be different colors, but is usually brown, deep yellow, or maroon. Urine is produced in the kidneys.