The Body s Organization

Chapter 4 The Body s Organization CHAPTER CONTENTS Introduction The Major Body Cavities The Anatomic Position and Directional Terms Body Systems Exercises Pre-Quiz Checklist Chapter Quiz 28

CHAPTER 4 THE BODY S ORGANIZATION 29 To begin building medical terms, we must first come to understand how the human body is constructed and how it works. The first distinction to be made is between the terms anatomy and physiology. Briefly, anatomy is the study of the body, and physiology is the study of the body s functions. Insofar as construction is concerned, the body is like all other material objects. It is made up of atoms that can combine to become chemical molecules. The human body has a chemical basis, and the chemicals act together to form cells and to power the biologic machinery contained within them. This machinery processes the food we eat and the air we breathe. It carries away unwanted substances and enables cells to reproduce themselves, in each cell according to the DNA code it contains. The wonder of all this activity becomes even more mindboggling when one discovers that the average adult human body contains about 70 trillion cells. Those cells combine to form tissues that compose the various organs, both internal and external, about which you will learn in the chapters that follow. In this chapter, you will learn the terms associated with the general make-up of the body and the ways of discussing locations within it. THE MAJOR BODY CAVITIES The two major body cavities, one in the front of the body and one in the back, are divisible into subcavities. The front body is called the ventral. The Latin word venter means belly, and the English adjective ventral consists of a shortened version of that Latin word combined with the suffix -al, which you learned in Chapter 2. The in the back of the body is called the dorsal, from the shortened Latin word dorsum, which means back, and the suffix -al. The ventral is subdivided into the thoracic and abdominopelvic cavities. The dorsal is subdivided into the cranial and spinal cavities, as shown in Table 4-1 and Figure 4-1. TABLE 4-1 THE TWO MAJOR BODY CAVITIES AND THEIR SUBDIVISIONS Ventral Cavity Dorsal Cavity Subcavities Subcavities 1. thoracic 1. cranial 2. abdominopelvic 2. spinal

30 PART 1 Cranial Thoracic Diaphragm Spinal (canal) Dorsal Ventral Abdominal Abdominopelvic Pelvic FIGURE 4-1 The major body cavities. Reprinted with permission from: Cohen, B. Memmler s The Human Body in Health and Disease. (10th ed.) Philadelphia: Lippincott Williams & Wilkins; 2005. The new word roots used to form the adjectives referring to the subcavities of the body are listed in Table 4-2. TABLE 4-2 NEW ROOTS RELATED TO BODY CAVITIES Root Origin Meaning abdomin/o abdomen (French for abdomen ) abdomen crani/o cranium (from Greek kranion) skull thorac/o thorax (Greek for breastplate) chest The dorsal contains the brain and spinal cord, which make up the central nervous system, about which you will learn in Chapter 16. The ventral contains all the other internal organs, sometimes referred to as viscera (singular viscus). When we add the -al suffix, we get the adjective visceral. The root used in building all the related terms is viscer/o. Many of the suffixes you learned in Chapter 2 can be combined with these roots (see Exercise 4-1).

CHAPTER 4 THE BODY S ORGANIZATION 31 THE ANATOMIC POSITION AND DIRECTIONAL TERMS In the anatomic position, the body is erect and facing forward with the palms of the hands also facing forward (Figure 4-2 and Table 4-3). Referring to Figure 4-2, you can see that the ear is lateral to the nose, the elbow is proximal to the wrist, the ankle is distal to the knee, the nose is superior to the chest and medial to the ear, etc. Superior (cranial) Anterior (ventral) Posterior (dorsal) Proximal Medial Distal Lateral Inferior (caudal) FIGURE 4-2 The anatomic position with directional terms. Adapted from: Cohen, B. Memmler s The Human Body in Health and Disease. (10th ed.) Philadelphia: Lippincott Williams & Wilkins; 2005.

32 PART 1 TABLE 4-3 DIRECTIONAL ADJECTIVES Anatomic Position anterior or ventral distal inferior lateral medial posterior or dorsal proximal superior or cranial Direction toward the front and away from the back of the body away from the attachment point of a limb (arm or leg) away from the head away from the middle of and toward the side of the body toward the middle of the body toward the back and away from the front of the body toward the attachment point of a limb (arm or leg) toward the head BODY SYSTEMS Apart from their locations in body cavities, each of the organs, tissues, bones, and so on, belongs to one or more specific body systems, in which they work together to carry out physiologic functions. The body systems are listed below. Integumentary System Skeletal System Muscular System Heart Blood and Blood Vessels Respiratory System Digestive System Endocrine System Immune System Urinary System Reproductive System Nervous System Eye Ear The first unfamiliar word you encountered in the list above was probably integumentary. The Latin word integumentum means covering. Thus, the integumentary system includes the skin, fingernails, toenails, and hair. To remember that definition, all you have to do is ask yourself what makes up the outer layer of our bodies. And you will think of skin, nails, and hair. The eye and the ear are not body systems by themselves but belong to several other systems, namely, the integumentary, nervous, blood and blood vessel, and muscular systems. They are discussed separately, however, because of their complexity and importance. As a matter of fact, no system works independently. Each is a part of the living body and relies on the others for life and good health. In the chapters to come, you will learn about the organs and tissues that make up all of these systems. Table 4-4 lists a few new roots that are related to the systems listed above and are in addition to those you have already learned.

CHAPTER 4 THE BODY S ORGANIZATION 33 TABLE 4-4 NEW ROOTS RELATED TO BODY SYSTEMS Root System Meaning angi/o blood and immune vessel my/o muscular muscle pneum/o, respiratory lung pneumon/o, pneumat/o A STUDY TABLE 4-1 TERMS RELATED TO BODY ORGANIZATION Term and Pronunciation abdominopelvic (ab-dom-ih-no-pelv-ihk) angiography (an-jee-og-ruh-fee) angioid (AN-jee-oyd) angioplasty (AN-jee-oh-plass-tee) anterior (an-teer-ee-uhr) ventral (VEHN-trahl) cranial (CRAY-nee-ahl) craniopathy (cray-nee-op-ah-thee) craniotomy (cray-nee-ot-oh-mee) distal (DISS-tahl) dorsal (DOR-sahl) inferior (ihn-feer-ee-ohr) integumentary (in-tehg-yu- MEN-tah-ree) lateral (LAT-eh-rahl) medial (MEE-dee-ahl) myalgia (my-al-jee-ah) myocele (MY-oh-seel) pneumatocele (nu-mat-oh-seel) pneumonopexy (NOO moh noh pex ee) posterior (poss-tee-ree-ohr) proximal (PROX-ih-mahl) superior (soo-peer-ee-ohr) thoracic (tho-rass-ik) ventral (VEHN-trahl) visceromegaly (VISS-heroh-MEG-ah-lee) Meaning adjective meaning abdomen and pelvis; used to describe one of the body subcavities contained in the ventral x-ray of vessels resembling blood vessels surgical repair effected by opening a clogged blood vessel by means of balloon dilation toward the front of the body; can be a noun or an adjective adjective meaning toward the front and away from the back of the body adjectival form of cranium or skull abnormal condition of any of the cranial bones incision into the cranium away from the attachment point to the body; can be a noun or an adjective adjective meaning the back below or in the direction away from the cranium; can be a noun or an adjective adjectival form of integument, meaning the covering of the body adjective meaning away from the middle of and toward the side of the body toward the midline of the body muscle pain protrusion of muscle tissue through surrounding tissue protrusion of lung tissue through the chest wall fixation of two layers of the lung toward the back of the body toward the point of fixation to the body above; toward the cranium adjective for chest area toward the front of the body abnormal enlargement of an organ

34 PART 1 c Exercises Exercise 4-1 Defining Terms Constructed of New Roots and Old Suffixes Recalling the meanings of the suffixes you learned in Chapter 2, write definitions for the following terms. Term 1. visceromegaly Definition 2. craniotomy 3. craniopathy Exercises Exercise 4-2 Defining Terms Constructed of New Roots and Old Suffixes Recalling the meanings of the suffixes you learned in Chapter 2, write definitions for the following terms. Term 1. angioplasty Definition 2. angiography 3. angioid 4. myalgia 5. myocele 6. pneumatocele 7. pneumonopexy

CHAPTER 4 THE BODY S ORGANIZATION 35 Pre-Quiz Checklist Review the names and locations of the major body cavities, as shown in Figure 4-1 and Table 4-1, along with the roots in Table 4-2. Review the anatomic position, shown in Figure 4-2, and its associated directional terms, listed in Table 4-3. Review the body systems. Check your answers to the exercises with the Appendix and correct any errors before attempting the quiz. Chapter Quiz Write the answers to the following ten questions using the spaces provided to the right of each question. 1. What is the difference between anatomy and physiology? 1. 2. What are the names of the two main body cavities? 2. 3. Which of the two main body cavities is located in 3. the front of the body? 4. What word describes the position of the ear in relation 4. to the nose? 5. What does posterior mean? 5. 6. What word describes the position of the elbow in 6. relation to the wrist? 7. When the body is in the anatomic position, which 7. direction are the palms of the hands facing? 8. What does myalgia refer to? 8. 9. What does visceromegaly mean? 9. 10. What does superior to mean in the context 10. of body location?