External Anatomy of Domestic Animals PDF

Here is the converted text from the images into a structured markdown format: # The External Anatomy of Domestic Animals The document provides an overview of external anatomy of domestic animals, focusing on mammals and birds. It describes directional terms, planes of the animal body, and specific...

Here is the converted text from the images into a structured markdown format: # The External Anatomy of Domestic Animals The document provides an overview of external anatomy of domestic animals, focusing on mammals and birds. It describes directional terms, planes of the animal body, and specific anatomical features. **Figure 1-1.** Directional terms and planes of the animal body. The image shows diagrams illustrating directional terms and planes of animal body. ### A. External Anatomy of Mammals 1. **Head** a. Facial Region (anterior) i. External nares (nose) – large and elongated ii. Eyes – with upper and lower lids iii. Ears – with flexible external fold (pinna) which originate from the rim of the external auditory meatus. Pinna and meatus comprise the external ear a. Cranial Region (posterior) – enlarged because of well-developed brain 2. Neck - with jugular veins 3. Trunk a. Thorax (anterior) – chest supported by ribs b. Abdomen (posterior) ventral surface with teats/nipples c. Pectoral limb – composed of shoulder girdle, arm, forearm, elbow, cannon and digits. d. Pelvic limb – composed of pelvic girdle (ilium, ishium and pubis), thigh, knee, leg, hock, cannon and digits 4. Tail a. Perineum – includes the anal and urogenital openings i. Anus – located at the midventral line at the base of the tail ii. Urogenital opening – situated anterior to the anus, composed of labia and vaginal opening (vulva) in female. In males, in front of the anus and consists of penis (organ of copulation) and scrotum and scrotal sac where testes are located 5. Ungulates – slender running type of legs, raise body high above the ground. Walk on the toe nails modified into hoofs. The thigh and upper arm are more or less included with the trunk and of the visible part of the legs, the upper half of the greatly elongated metacarpals (palm) or metatarsals (sole), fused in each leg into one slender bone, the cannon bone. Divided into: a. Odd-toed type (Order Perissodactyla, i.e. horse) – 3rd toe is dominant and the others reduced b. Even-toed type (Order Artiodactyla, i. e. cattle) –3rd and 4th toes equally developed giving the "cloven hoof" effect, the others reduced Others Include: dewlap, dew claw, point of hock, pin bone, brisket, horn The images here show the external anatomy of a horse and a goat, with labeled features such as croup, loins, dock, gaskin, brisket, muzzle and more. ### B. External Anatomy of Birds 1. Body Form and Skin * Well-developed head * Long, flexible neck * Shorter and plumper trunk than normal because of fused bones * Tail reduced to a stump (uropygium) * Is covered with feathers 2. Feathers * Flight feathers – large and stout, cover wings and tails * Coverts – smaller, cover base of wings and tail and general body surface * Filoplumes – (hair feathers) * Feather follicle – deep pits in plucked chicken where feathers are attached * Pterylae – paired areas in the skin with feathers * Apterylae – paired areas in the skin without feathers 3. Head * Beak - elongated with upper and lower jaws encased in horny sheaths, no teeth * Cere - cushion-like protuberance or wax-like swelling found at the base of the upper beak (found in parrot) * External Nares – slits of ceres * Eyes - with upper and lower lids with nictitating membrane (inner eyelids) * Ears – behind and below the eyes, observed only when the animal is plucked Diagrams show a chicken labeled with comb, eye, ear lobes, back cape, saddle, wing bow, flight feathers, breast, wing bar, fluff, thigh, hock, shank, claw. In addition, there is a diagram of a Rooster labeled with Sickle Feather, Main Tail Feathers, comb, Cape, Hackle, Shoulder, Wing Front, Wing Bow, Fluff, Hock Joint, Shank, and Claw. 4. Trunk – firm and flexible due to fusion of bones at the back * Keel – breast bone * Wing (anterior pair of limb) * Upper arm * Forearm (longer than upper arm) * Carpus and metacarpus are fused * Only 3 digits * Hind limbs - covered with feathers and horny scales and extended ventrally, not laterally * Tarsus and metatarsus are fused forming a rod * Only 4 digits 5. Tail - with half circle of flight feathers (rectrices) * Under the base of the tail is the cloaca * In front of the base of the tail stump when tail coverts are lifted is the uropygial gland (oil gland) Diagrams show various images of bird feathers and anatomy. A diagram of a pigs reproductive system including labels such as Hypothalamus, Pituitary Gland, Seminal Vesicles, Bulbourethral glands, External Orifice labeled. This diagram credits W.Singleton 1997, Purdue University.