Vet Terminology

1. Vet Terminology • Anaplasia (ahn-ah-plā-zē-ah) is a change in the structure • of cells and their orientation to each other. • ■ Aplasia (ā-plā-zē-ah) is lack of development of an organ • or a tissue or a cell. • ■ Dysplasia (dihs-plā-zē-ah) is abnormal growth or development • of an organ or a tissue or a cell. • ■ Hyperplasia (hī-pər-plā-zē-ah) is an abnormal increase • in the number of normal cells in normal arrangement in • an organ or a tissue or a cell. • ■ Hypoplasia (hī-pō-plā-zē-ah) is incomplete or less than • normal development of an organ or a tissue or a cell.

2. Vet Terminology • Neoplasia (nē-ō-plā-zē-ah) is any abnormal new • growth of tissue in which multiplication of cells is • uncontrolled, more rapid than normal, and progressive. • Neoplasms usually form a distinct mass of tissue • called a tumor (too-mər). Tumors may be benign • (beh-nīn), meaning not recurring, or malignant • (mah-lihg-nahnt), meaning tending to spread and • be life threatening. The suffix -oma (ō-mah) means • tumor or neoplasm. • ■ Atrophy (ah-tō-fē) is decrease in size or complete wasting • of an organ or tissue or cell.

3. Vet Terminology • Dystrophy (dihs-trō-fē) is defective growth in the size of an organ or tissue or cell. • ■ Hypertrophy (hī-pər-tō-fē) is increase in the size of an organ or tissue or cell. • The prefix a- means without, hypo- means less than normal, • hyper- means more than normal, dys- means bad, ana- means without, and neo- means new.

4. Vet Terminology • Glands (glahndz) are groups of specialized cells that • secrete material used elsewhere in the body. Aden/o is the combining form for gland. Glands are divided into two categories: exocrine and endocrine (Figure 2–15). Exocrine (ehck-sohkrihn) glands are groups of cells that secrete their chemical substances into ducts that lead out of the body or to another organ. Examples of exocrine glands are sweat glands, sebaceous glands, and the portion of the pancreas that secretes digestive chemicals. Endocrine (ehn-dō-krihn) glands are groups of cells that secrete their chemical substances directly into the bloodstream, which transports them throughout the body

5. Vet Terminology • An organ (ohr-gahn) is a part of the body that performs a special function or functions. • bicornuate uterus (bi = two, corn = horn) is a uterus with two horns. Knowing that lateral means pertaining to the side, it would make sense that unilateral (yoo-nihlah- tər-ahl) means pertaining to one side. Bilateral (bī-lahtər- ahl) means pertaining to two sides.

6. Vet Terminology • Joints • Joints or articulations (ahr-tihck-yoo-lā-shuhns) are connections • between bones. Articulate means to join in a way that • allows motion between the parts. Th e combining form for joint • is arthr/o. Th e diff erent types of joints are based on their • function and degree of movement. • Joints are classified based on their degree of movement • (Figure 3–4). Synarthroses (sihn-ahrth-rō-sēz) allow no • movement, amphiarthroses (ahm-fi h-ahrthr-ō-sēz) allow • slight movement, and diarthroses (dī-ahrth-rō-sēz) allow • free movement.

7. Vet Terminology • Synarthroses are immovable joints usually united with • fibrous connective tissue. An example of a synarthrosis is a • suture. A suture (soo-chuhr) is a jagged line where bones join • and form a nonmovable joint. Sutures typically are found in the • skull. A fontanelle (fohn-tah-nehl) is a soft spot remaining at • the junction of sutures that usually closes aft er birth.

8. Vet Terminology • Amphiarthroses are semimovable joints. An example of an • amphiarthrosis is a symphysis. A symphysis (sihm-fi h-sihs) • is a joint where two bones join and are held firmly together so • that they function as one bone. Another term for symphysis is • cartilaginous joint. Th e halves of the mandible fuse at a • symphysis to form one bone. Th is fusion is the mandibular • symphysis. Th e halves of the pelvis also fuse at a symphysis, • which is called the pubic symphysis.

9. Vet Terminology • Diarthroses are freely movable joints. Examples of diarthroses • are synovial joints. Synovial (sih-nō-vē-ahl) joints • are further classified as ball-and-socket joints (also called • enarthrosis (ehn-ahr-thrō-sihs) or spheroid joints), • arthrodial (ahr-thrō-dē-ahl) or condyloid (kohn-dih-loyd) • joints, trochoid (trō-koyd) or pivot (pih-voht) joints, ginglymus • (jihn-glih-muhs) or hinge joints, and gliding joints.

10. Vet Terminology • Ball-and-socket joints allow a wide range of motion • in many directions, such as the hip and shoulder joints. • Arthrodial or condyloid joints are joints with oval projections • that fi t into a socket, such as the carpal joints (where • the radius meets the carpus). Trochoid joints include articulating process between successive vertebrae. Primates • have an additional joint called the saddle joint. The only • saddle joint is located in the carpometacarpal joint of the • thumb. This saddle joint allows primates to flex, extend, • abduct, adduct, and circumduct the thumb.

12. Vet Terminology • Ligaments and Tendons • A ligament (lihg-ah-mehnt) is a band of fibrous connective • tissue that connects one bone to another bone. Ligament/o • is the combining form for ligament. A ligament is diff erent from • a tendon. A tendon (tehn-dohn) is a band of fibrous connective • tissue that connects muscle to bone. Th e combining forms • for tendon are ten/o, tend/o, and tendin/o.

13. Vet Terminology • Bursa • A bursa (bər-sah) is a fibrous sac that acts as a cushion to • ease movement in areas of friction. Within the shoulder • joint is a bursa where a tendon passes over bone. The combining • form for bursa is burs/o. More than one bursa is • bursae (bər-sā).

15. Vet Terminology • Synovial Membrane and Fluid • Bursae and synovial joints have an inner lining called the • synovial (sih-nō-vē-ahl) membrane. Th e synovial membrane • secretes synovial fl uid, which acts as a lubricant to make joint • movement smooth. Synovi/o is the combining form for • synovial membrane and synovial fl uid.

16. Vet Terminology • Th e cranium (krā-nē-uhm) is the portion of the skull that • encloses the brain. Th e combining form crani/o means skull. • Th e cranium consists of the following bones (Figure 3–5): • ■ frontal (frohn-tahl) = forms the roof of the cranial cavity • or “front” or cranial portion of the skull. In some species, • the horn, or cornual (kohrn-yoo-ahl) process, arises • from the frontal bone (Figure 3–6). • ■ parietal (pah-rī-ih-tahl) = paired bones that form the • roof of the caudal cranial cavity.

17. Vet Terminology • Skull shapes in dogs can vary by breed. Examples • of skull shapes in dogs include the following: • ■ Brachycephalic (brā-kē-seh-fahl-ihck) dogs • have short, wide heads, as do pugs and • Pekingese. • ■ Dolichocephalic (dō-lih-kō-seh-fahl-ihck) • dogs have narrow, long heads, as do collies • and greyhounds. • ■ Mesocephalic (mehs-ō-seh-fahl-ihck) dogs • have average width to their heads, as do • Labrador retrievers. Also called mesaticephalic • (mehs-āt-ih-seh-fahl-ihck).

18. Vet Terminology • ■ occipital (ohck-sihp-ih-tahl) = forms the caudal aspect • of the cranial cavity where the foramen magnum, or • opening for the spinal cord, is located. Foramen • (fō-rā-mehn) is an opening in bone through which • tissue passes. Magnum (māg-nuhm) means large. • ■ temporal (tehm-pohr-ahl) = paired bones that form the • sides and base of the cranium. • ■ sphenoid (sfeh-noyd) = paired bones that form part of • the base of the skull and parts of the floor and sides of • the bony eye socket. • ■ ethmoid (ehth-moyd) = forms the rostral part of the cranial • cavity. • ■ incisive (ihn-sīs-ihv) = forms the rostral part of the hard • palate and lower edge of nares.

19. Vet Terminology • ■ pterygoid (tahr-ih-goyd) = forms the lateral wall of the • nasopharynx. • In addition to bones, the skull also has air- or fl uid-filled spaces. • These air- or fl uid-filled spaces are called sinuses (sīn-uhs-ehz). • Let’s Face It • Th e bones of the face consist of the following: • ■ zygomatic (zī-gō-mah-tihck) = projections from the • temporal and frontal bones to form the cheekbone. • ■ maxilla (mahck-sih-lah) = forms the upper jaw. • ■ mandible (mahn-dih-buhl) = forms the lower jaw. • ■ palatine (pahl-ah-tihn) = forms part of the hard palate.

20. Vet Terminology • lacrimal (lahck-rih-mahl) = forms the medial part of the • orbit. • ■ incisive (ihn-sī-sihv) = forms the rostral part of the hard • palate and lower edge of nares. • ■ nasal (nā-sahl) = forms the bridge of the nose. • ■ vomer (vō-mәr) = forms the base of the nasal septum. • Th e nasal septum (nā-sahlsehp-tuhm) is the cartilaginous • structure that divides the two nasal cavities. • ■ hyoid (hī-oyd) = bone suspended between the mandible • and the laryngopharynx.

21. Vet Terminology • The vertebral formulas for diff erent species are as • follows: • ■ dogs and cats: C = 7, T = 13, L = 7, S = 3, • Cy = 6–23 • ■ equine: C = 7, T = 18, L = 6 (or L = 5 in some • Arabians), S = 5, Cy = 15–21 • ■ bovine: C = 7, T = 13, L = 6, S = 5, • Cy = 18–20 • ■ pigs: C = 7, T = 14–15, L = 6 – 7, S = 4, • Cy = 20–23 • ■ sheep and goats: C = 7, T = 13, L = 6–7, • S = 4, Cy = 16–18 • ■ chicken: C = 14, T = 7, LS = 14, Cy = 6 • (lumbar and sacral vertebrae are fused)

22. Vet Terminology • The vertebral (vər-teh-brahl) column (also called the • spinal column and backbone) supports the head and body • and protects the spinal cord. Th e vertebral column consists of • individual bones called vertebra (vər-teh-brah). Th e combining • forms for vertebra are spondyl/o and vertebr/o. More • than one vertebra are called vertebrae (vər-teh-brā).