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.
Kidney and urinary system parts and their functions. Two kidneys. This pair of purplish-brown organs is located below the ribs toward the middle of the back. Their function is to: Remove waste products and drugs from the body. Balance the body's fluids. Release hormones to regulate blood pressure.