Zoology · Ch 4 — Organ and Organ Systems in Animals
External Features
External Features
The pigeon's body is compact, boat-shaped and streamlined for flight, and is divided into head, neck, trunk and tail. The comparatively small, spherical head sits at the front and carries a toothless beak (formed from elongated upper and lower jaws), with external nostrils at its base overhung by a soft, swollen cere; large, round, laterally placed eyes are protected by upper and lower eyelids and a transparent nictitating membrane, and just behind them, ear openings lead via a short external auditory meatus to the tympanic membrane. The long, flexible, cylindrical neck connects the head to the spindle-shaped trunk, which bears a pair of wings and a pair of legs and ends ventrally in the cloacal aperture. At the base of the tail, which acts as a rudder in flight, a knob-like papilla carries the opening of the only cutaneous gland in the bird's skin, the preen (uropygial) gland, whose oily secretion is used to lubricate and waterproof the feathers during preening. The forelimbs are modified into wings with three regions - upper arm (brachium), lower arm (ante-brachium) and hand (manus) - bearing three clawless digi …
What this figure shows. The whole bird in side view labelling the head, eye, cere, nostrils, beak, neck, breast, wing feathers (remiges) with their black bars, wing coverts, contour feathers, the position of the external ear opening, the tail feathers (rectrices), the leg with its scales, the clawed anterior toes and the hind toe (hallux). …
What this figure shows. The plucked body showing the underlying regions and soft-tissue landmarks: nostril, cere, head, eye with nictitating membrane, external ear opening, neck, upper and lower beak, tongue, throat, breast, prepatagium, the upper arm/lower arm/hand (manus) of the wing with its digits I-III and postpatagium, back, preen gland, trunk/thorax, abdomen, thigh, shank, tarsometatarsus, scales on leg, clawed anterior toes, hind toe (hallux), t …