We begin with Take 2 filming of a cockroach dissection.

Dr. Richard Fell performs the procedure. The cockroach is chilled on ice to slow its activity. The underside of the wings are then pinned to the dissection plate.

The legs are removed

and additional pins are inserted at the base of the wings. Once the cockroach is securely fastened to the plate, the side or ventral cuts along the abdomen are made to remove the exoskeleton.

The fat body is teased apart with forceps and removed to expose the internal organs more clearly.

The most noticeable system of organs we see once the fat body is removed is the digestive system. The major structures include the crop, gastric caeca, midgut, Malpighian tubules and hindgut.

The crop, an enlargement of the foregut, serves as temporary storage for undigested food. Digestion of complex sugars begins in the foregut. Gastric caeca, the elongated pouches at the beginning of the midgut, contain bacteria which aid in digestion.

The midgut is the primary area for digestion and absorption. Contents from the midgut and Malpighian tubules empty into the hindgut, where final resorption of water, salts, and nutrients from the feces and urine takes place before excretion.

The Malpighian tubules are actually the primary organs of the excretory system. Their function is to remove nitrogen-containing wastes and regulate water and salts in an insect's blood, called hemolymph.

In the image above, the segmented structure to the right of the digestive organs is the heart. The heart and aorta make up the main blood vessel of an insect. Hemolymph flows through this blood vessel but also throughout the insect's body cavity, making the circulatory system open.

The heart is divided into a series of chambers, and lining each chamber is a pair of thin, sheetlike muscle bands. The movement of these muscles pumps hemolymph throughout the blood vessel.

The other major system we can readily see is the respiratory system. The spiracles, trachea, and tracheoles are the main structures in this system, which function in gas transport and exchange.

Air enters the insect's body through the spiracles, trachea, tracheal branches and tracheoles (not shown here), respectively, and oxygen eventually diffuses to cells in the body. Carbon dioxide leaves the body through the spiracles.