identify the external and internal features of the kidney;

The kidneys are two bean-shaped organs in the abdomen. Their function is to filter blood and produce urine. One of their main functions is to remove the waste products from the body's bloodstream, so that these can be excreted as urine.

Internal:

The kidney filters about 120 to 150 quarts of blood every day - it weighs about 1.3 pounds or 600 to 650 grams. One kidney is sufficient for survival if the other is removed because of disease, injury, or surgical removal.

The kidneys are located just under the rib cage in an area called the retroperitoneum. They may be felt as two soft lumps on either side of the spine when pressed gently.

Each kidney is about 11/2 inch (4 cm) long and 3/4 inch (1.5 cm) wide. The outside covering of the kidneys is an area called the parietal peritoneum, which reflects back from the surface to enclose a space that contains fat, blood vessels, nerves, lymph nodes, and connective tissue.

The kidneys rest in a rounded depression called the renal fossa, which forms the front part of the abdominal cavity next to the vertebral column and is formed by two projections of lumbar vertebrae (L4 and L5). The kidneys are slightly higher at their back than in their front to make room for the abdominal aorta and the renal vessels.

The kidneys are enclosed in a tough fibrous capsule that extends into the substance of each organ as an eggshell-like covering called Gerota's fascia. The part of this covering between the two organs is quite thin and allows external pressure to be transmitted equally to both kidneys. Within this covering, each kidney is divided into a number of wedge-shaped lobes by a tough fibrous band called the renal fascia.

The renal arteries arise from the abdominal aorta, and bring blood to each kidney through its own renal artery. The ureters are two narrow tubes about 4 inches (10 cm) long that run from the kidneys down to the bladder. The ureters carry urine from the kidneys to the urinary bladder.