Anterior/posterior (front/back): In humans the most an- terior structures are those that are most forward—the face, chest, and abdomen. Posterior structures are those toward the backside of the body. For instance, the spine is posterior to the heart. Medial/lateral (toward the midline/away from the midline or median plane): The sternum (breastbone) is medial to the ribs; the ear is lateral to the nose. The terms of position just described assume the per- son is in the anatomical position. The next four term pairs are more absolute. They apply in any body position, and they consistently have the same meaning in all vertebrate animals. Cephalad (cranial)/caudal (toward the head/toward the tail): In humans these terms are used interchangeably with superior and inferior, but in four-legged animals they are synonymous with anterior and posterior, respectively. Dorsal/ventral (backside/belly side): These terms are used chiefly in discussing the comparative anatomy of animals, Figure 1.1 Surface anatomy. (a) Anatomical position. (b) Heels are raised to illustrate the plantar surface of the foot. Cervical Cervical Dorsum (a) Anterior/Ventral (b) Posterior/Dorsal Pubic Cephalic Frontal Orbital Nasal Buccal Oral Mental Thoracic Sternal Axillary Mammary Scapular Vertebral Lumbar Sacral Gluteal Perineal Abdominal Umbilical Pelvic Inguinal Upper limb Acromial Brachial Antecubital Olecranal Antebrachial Carpal Manus (hand) Pollex Palmar Digital Lower limb Coxal Femoral Patellar Popliteal Crural Sural Fibular or peroneal Pedal (foot) Tarsal Calcaneal Digital Plantar Hallux Cephalic Otic Occipital Thorax Abdomen Back (Dorsum) MARI2192_11_C01_pp001-014.indd 3 10/29/12 12:31 PM
1 4 Exercise 1 assuming the animal is standing. Dorsum is a Latin word meaning “back.” Thus, dorsal refers to the animal’s back or the back side of any other structures; for example, the poste- rior surface of the human leg is its dorsal surface. The term ventral derives from the Latin term venter, meaning “belly,” and always refers to the belly side of animals. In humans the terms ventral and dorsal are used interchangeably with the terms anterior and posterior, but in four-legged animals ven- tral and dorsal are synonymous with inferior and superior, respectively. Proximal/dista l (nearer the trunk or attached end/farther from the trunk or point of attachment): These terms are used primarily to locate various areas of the body limbs. For ex- ample, the fingers are distal to the elbow; the knee is proximal to the toes. However, these terms may also be used to indicate regions (closer to or farther from the head) of internal tubular organs. Superficial (external)/deep (internal) (toward or at the body surface/away from the body surface): These terms locate body organs according to their relative closeness to the body surface. For example, the skin is superficial to the skel- etal muscles, and the lungs are deep to the rib cage.
You've reached the end of your free preview.
Want to read all 14 pages?