MEDICAL TERMINOLOGY
Cell, Tissue, and Organs
The Cell
The body can be studied from its simplest to its most complex level, beginning with the cell, the basic unit of living organisms (Fig. 4-1). Cells carry out metabolism, which is the sum of all physical and chemical activities that occur in the body. Providing the energy for metabolic reactions is the chemical ATP (adenosine triphosphate), commonly described as the energy compound of the cell. The main categories of organic compounds in the body are:
• Proteins, which include the enzymes, some hormones, and structural materials.
• Carbohydrates, which include sugars and starches. The primary carbohydrate is glucose, a sugar that circulates in the blood to provide energy to cells.
• Lipids, which include fats. Some hormones are derived from lipids, and adipose (fat) tissue is designed to store lipids.
Within the cytoplasm that fills the cell are subunits called organelles, each with a specific function. The main cell structures are named and described in Display 4-1.
All body functions derive from the activities of billions of specialized cells. The nucleus is the control region of the cell. It contains the chromosomes, which carry genetic information (Fig. 4-2). Each human cell, except for the sex cells, contains 46 chromosomes. The chromosomes are composed of a complex organic substance, DNA (deoxyribonucleic acid), which is organized into separate units called genes. Genes control the formation of enzymes, the catalysts needed for metabolic reactions. To help manufacture enzymes, the cells use a compound called RNA (ribonucleic acid), which is chemically related to DNA.
When a body cell divides, by the process of mitosis, the chromosomes are doubled and then equally distributed to the two daughter cells (Fig. 4-3). Sex cells (egg and sperm) divide by another process (meiosis) that halves the chromosomes in preparation for fertilization.
FIGURE 4-1. Diagram of a typical animal cell showing the main organelles. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Display 4-1 Cell Structures
Name | Description | Function |
|---|---|---|
Plasma membrane | Outer layer of the cell; composed mainly of lipids and proteins | Limits the cell; regulates what enters and leaves the cell |
Cytoplasm | Colloidal suspension that fills cell | Holds cell contents |
Nucleus | Large, dark-staining body near the center of the cell; composed of DNA and proteins | Contains the chromosomes with the genes (the hereditary material that directs all cell activities) |
Nucleolus | Small body in the nucleus; composed of RNA, DNA, and protein | Needed for protein manufacture |
Endoplasmic reticulum (ER) | Network of membranes in the cytoplasm | Used for storage and transport; holds ribosomes |
Ribosomes | Small bodies attached to the ER; composed of RNA and protein | Manufacture proteins |
Mitochondria | Large organelles with folded membranes inside | Convert energy from nutrients into ATP |
Golgi apparatus | Layers of membranes | Put together special substances such as mucus |
Lysosomes | Small sacs of digestive enzymes | Digest substances within the cell |
Centrioles | Rod-shaped bodies (usually two) near the nucleus | Help separate the chromosomes in cell division |
Cilia | Short, hairlike projections from the cell | Create movement around the cell |
Flagellum | Long, whiplike extension from the cell | Moves the cell |
FIGURE 4-2. Human chromosomes. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
FIGURE 4-3. The stages in cell division (mitosis). (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.
Tissues
Cells are organized into four basic types of tissues that perform specific functions (Fig. 4-4)
• Epithelial (ep-i-THE-le -al) tissue covers and protects body structures and lines organs, vessels, and cavities.
• Connective tissue supports and binds body structures. It contains fibers and other nonliving material between the cells. Included are adipose (fat) tissue, cartilage, bone (Chapter 19), and blood (Chapter 10).
• Muscle tissue (root my/o) contracts to move. There are three types of muscle tissue:
• Skeletal or voluntary muscle moves the skeleton. Skeletal muscle is discussed in greater detail in Chapter 20.
• Cardiac muscle forms the heart. It functions without conscious control and is described as involuntary.
• Smooth, or visceral, muscle forms the walls of the abdominal organs; it is also involuntary.
• Nervous tissue (root neur/o) makes up the brain, spinal cord, and nerves. It coordinates and controls body responses by the transmission of electrical impulses. The nervous system and senses are discussed in Chapters 17 and 18.
The simplest tissues are membranes. Mucous membranes secrete mucus, a thick fluid that lubricates surfaces and protects underlying tissue. Serous membranes, which secrete a thin, watery fluid, line body cavities and cover organs.
FIGURE 4-4. The four basic types of tissues. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Organs and Organ Systems
Tissues are arranged into organs, which serve specific functions (Fig. 4-5). The organs, in turn, are grouped into systems. Each of the body systems is discussed in Part 3. Bear in mind, however, that the body functions as a whole—no system is independent of the others. They work together to maintain the body’s state of internal stability, termed homeostasis.
FIGURE 4-5. Organs of the digestive tract. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Key Terms
Term | Pronunciation | Definition |
|---|---|---|
ATP (adenosine triphosphate) | a-DEN-o-sēn tri-FOS-fāt | The energy compound of the cell stores energy needed for cell activities. ATP stands for adenosine triphosphate (a-DEN-o-sen tri-FOS-fat). |
Carbohydrate | kar-bō-HI-drāt | A category of organic compounds that includes sugars and starches. |
Cell | sel | The basic structural and functional unit of the living organism; it combines with other cells to form tissues. (root cyt/o) |
Chromosome | KRŌ-mō-sōm | A threadlike body in the nucleus of a cell that contains genetic information. |
Cytoplasm | SĪ-tō-plazm | The fluid that fills a cell and holds the organelles. |
DNA (deoxyribonucleic acid) | de-OK-sē-rī-bō-nū-KLĒ-ik acid | The genetic compound of the cell makes up the genes. DNA stands for deoxyribonucleic (de -ok-se -ri -bo -nu-KLE-ik) acid. |
Enzyme | EN-zīm | An organic substance that speeds the rate of metabolic reactions. |
Gene | jēn | A hereditary unit composed of DNA and combined with other genes to form the chromosomes. |
Glucose | GLŪ-kōs | A simple sugar that circulates in the blood; the main energy source for metabolism. (roots gluc/o, glyc/o) |
Homeostasis | hō-mē-ō-STA-sis | A steady state: a condition of internal stability and constancy. |
Lipid | LIP-id | A category of organic compounds that includes fats. (root lip/o) |
Metabolism | me-TA-bo-lizm | The sum of all the physical and chemical reactions that occur within an organism. |
Mitosis | mi-TO-sis | Cell division. |
Mucus | MŪ-kus | A thick fluid secreted by cells in membranes and glands that lubricates and protects tissues (roots muc/o, myx/o); the adjective is mucous. |
Nucleus | NŪ-klē-us | The control center of the cell directs all activities based on chromosome information (roots nucle/o, kary/o). |
Protein | PRO-tēn | A category of organic compounds that includes structural materials, enzymes, and some hormones. |
RNA (ribonucleic acid) | rī-bō-nū-KLĒ-ik acid | An organic compound involved in protein manufacture within cells. RNA stands for ribonucleic (ri -bo -nu-KLE-ik) acid. |
Tissue | TISH-ū | A group of cells that act together for a specific purpose (root hist/o, histi/o). |
Word Parts Pertaining to Cells, Tissues, and Organs
Root | Meaning | Example | Definition of Example |
|---|---|---|---|
morph/o | form | polymorphic (pol-e-MOR-fik) | Having many forms |
cyt/o, -cyte | cell | cytogenesis (si-to-JEN-e-sis) | The formation (-genesis) of cells |
nucle/o | nucleus | nuclear (NU-kle-ar) | Pertaining to a nucleus |
kary/o | nucleus | karyotype (KAR-e-o-tīp) | Picture of the chromosomes of a cell, organized according to size |
hist/o, histi/o | tissue | histologist (his-TOL-o-jist) | Specialist in the study of tissue |
fibr/o | fiber | fibrosis (fi-BRO-sis) | Abnormal formation of fibrous tissue |
reticul/o | network | reticulum (re-TIK-u-lum) | A network |
aden/o | gland | adenoma (ad-e-NO-ma) | Tumor (-oma) of a gland |
papill/o | nipple | papilliform (pa-PIL-i-form) | Resembling a nipple |
myx/o | mucus | myxadenitis (miks-ad-e-NI-tis) | Inflammation of a gland that secretes mucus |
muc/o | mucus, mucous membrane | mucorrhea (mu-ko-RE-a) | Increased flow (-rhea) of mucus |
somat/o, -some | body | somatic (so-MAT-ik) | Pertaining to the body (as compared with germ cells or the mind) |
BOX 4-1 Laboratory Study of Tissues
A biopsy is the removal and examination of living tissue to determine a diagnosis. The term is also applied to the specimen itself. Biopsy comes from the Greek word bios, meaning “life,” plus opsis, meaning “vision.” Together, they mean the visualization of living tissue. Some other terms that apply to cells and tissues come from Latin. In vivo means “in the living body,” as contrasted with in vitro, which literally means “in glass” and refers to procedures and experiments done in the labo
ratory, as compared with studies done in living organisms. In situ means “in its original place,” and is used to refer to tumors that have not spread. In toto means “whole” or “completely,” as in referring to a structure or organ removed totally from the body. Postmortem literally means “after death,” as in referring to an autopsy performed to determine the cause of death.
TABLE 4-2 Roots for Cell Activity
Root | Meaning | Example | Definition of Example |
|---|---|---|---|
blast/o, -blast | Immature cell, productive cell, embryonic cell | leukoblast (LU-ko-blast) | An immature white blood cell |
gen | Origin, formation | genetics (je-NET-iks) | The science of genes and heredity |
phag/o | Eat, ingest | phagocyte (FAG-o-sīt) | Cell that ingests waste and foreign matter |
phil | Attract, absorb | acidophilic (a-sid-o-FIL-ik) | Attracting acid stain |
plas | Formation, molding, development | hyperplasia (hi-per-PLA-je-a) | Overdevelopment of an organ or tissue |
trop | Act on, affect | chronotropic (kron-o-TROP-ik) | Affecting rate or timing |
troph/o | Feeding, growth, nourishment | atrophy (AT-ro-fē) | Wasting away |
TABLE 4-3 Suffixes and Roots for Body Chemistry
Word Part | Meaning | Example | Definition of Example |
|---|---|---|---|
Suffixes | |||
-ase | Enzyme | lipase (LI-pās) | An enzyme that digests fat (lipid) |
-ose | Sugar | lactose (LAK-tōs) | Milk sugar |
Roots | |||
hydr/o | Water, fluid | hydrophilic (hi-dro-FIL-ik) | Attracting water |
gluc/o | Glucose | glucosuria (glu-ko-SU-rē-a) | Presence of glucose in the urine |
glyc/o | Sugar, glucose | hyperglycemia (hi-per-gli-SE-me-a) | High blood sugar |
sacchar/o | Sugar | polysaccharide (pol-e-SAK-a-rīd) | A compound containing many sugars |
amyl/o | Starch | amyloid (AM-i-loyd) | Resembling starch |
lip/o | Lipid, fat | lipogenesis (lip-o-JEN-e-sis) | Formation of fat |
adip/o | Fat | adipocyte (AD-i-po-sīt) | A cell that stores fat |
steat/o | Fatty | steatorrhea (ste-a-to-RE-a) | Discharge (-rhea) of fatty stools |
prote/o | Protein | protease (PRO-te-ās) | An enzyme that digests protein |
Supplementary Terms
Term | Pronunciation | Definition |
|---|---|---|
Aorta | a-OR-ta | The main artery carrying blood from the left ventricle of the heart to the body. |
Septum | SEP-tum | A wall dividing two cavities. |
Amino acids | a-ME-no as-ids | Nitrogen-containing compounds that make up proteins. |
Anabolism | a-NAB-o-lizm | The type of metabolism in which body substances are made; the building phase of metabolism. |
Catabolism | ka-TAB-o-lizm | The type of metabolism in which substances are broken down for energy and simple compounds. |
Collagen | KOL-a-jen | A fibrous protein found in connective tissue. |
Cortex | KOR-tex | The outer region of an organ. |
Glycogen | GLI-ko-jen | A complex sugar compound stored in the liver and muscles; broken down into glucose when needed for energy. |
Interstitial | in-ter-STISH-al | Between parts, such as the spaces between cells in a tissue. |
Medulla | me-DUL-la | The inner region of an organ; marrow (root medull/o). |
Parenchyma | par-EN-ki-ma | The functional tissue of an organ. |
Parietal | pa-RI-e-tal | Pertaining to a wall, describes a membrane that lines a body cavity. |
Soma | SO-ma | The body. Used as the suffix -some to mean a small body, as in ribosome, lysosome, chromosome. |
Stem cell | stem sel | An immature cell that can develop into different cell types; a precursor cell. |
Visceral | VIS-er-al | Pertaining to the internal organs, a membrane on the surface of an organ. |
Body Structure
Directional Terms
In describing the location or direction of a given point in the body, it is always assumed that the subject is in the anatomical position, that is, upright, with face front, arms at the sides with palms forward, and feet parallel, as shown in the small diagram in Figure 5-1. In this stance, the terms illustrated in Figure 5-1 and listed in Display 5-1 are used to designate relative position. Figure 5-2 illustrates planes of section, that is, directions in which the body can be cut. A frontal plane, also called a coronal plane, is made at right angles to the midline and divides the body into anterior and posterior parts. A sagittal (SAJ-i-tal) plane passes from front to back and divides the body into right and left portions. If the plane passes through the midline, it is a mid-sagittal or medial plane. A transverse plane passes horizontally, dividing the body into superior and inferior parts.
FIGURE 5-1. Directional terms. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
FIGURE 5-2. Planes of division. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Body Cavities
Internal organs are located within the dorsal and ventral cavities (Fig. 5-3). The dorsal cavity contains the brain in the cranial cavity and the spinal cord in the spinal cavity (canal). The uppermost ventral space, the thoracic cavity, is separated from the abdominal cavity by the diaphragm. There is no anatomical separation between the abdominal cavity and the pelvic cavity, which together make up the abdominopelvic cavity. The large membrane that lines the abdominopelvic cavity and covers the organs within it is the peritoneum (peri-to-NE-um).
FIGURE 5-3. Side view of the body cavities. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Body Regions
For orientation, the abdomen can be divided by imaginary lines into nine regions, which are shown in Figure 5-4.
The sections down the midline are the:
• epigastric (ep-i-GAS-trik) region, located above the stomach
• umbilical (um-BIL-i-kal) region, named for the umbilicus, or navel
• hypogastric (hi -po -GAS-trik) region, located below the stomach
The lateral regions are the:
• right and left hypochondriac (hi -po -KON-dre-ak) regions, named for their position near the ribs, specifically near the cartilages (root chondr/o) of the ribs,
• right and left lumbar (LUM-bar) regions, which are located near the small of the back (lumbar region of the spine)
• right and left iliac (IL-e-ak) regions, named for the upper bone of the hip, the ilium. These regions are also called the inguinal (ING-gwi-nal) regions, with reference to the groin.
More simply, but less precisely, the abdomen can be divided by a single vertical line and a single horizontal line into four sections (Fig. 5-5), designated the right upper quadrant (RUQ), left upper quadrant (LUQ), right lower quadrant (RLQ), and left lower quadrant (LLQ).
Additional terms for body regions are shown in Figures 5-6 and 5-7. You may need to refer to these illustrations as you work through the book.
FIGURE 5-4. The nine regions of the abdomen. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
FIGURE 5-5. Quadrants of the abdomen, showing the organs within each quadrant. (Reprinted with permission from Cohen BJ, Wood DL. Memmler’s The Human Body in Health and Disease. 9th Ed. Philadelphia: Lippincott Williams & Wilkins, 2000.)
Positions
In addition to the anatomical position, there are other standard positions in which the body is placed for examination or medical procedures. The most common of these are described in Display 5-2.
FIGURE 5-6. Common terms for body regions, anterior view. Anatomical terms for regions are in parentheses.
FIGURE 5-7. Common terms for body regions, posterior view.
DISPLAY 5-1 Anatomical Directions
Term | Definition |
|---|---|
Anterior (ventral) | Toward the front (belly) of the body |
Posterior (dorsal) | Toward the back of the body |
Medial | Toward the midline of the body |
Lateral | Toward the side of the body |
Proximal | Nearer to the point of attachment or to a given reference point |
Distal | Farther from the point of attachment or from a given reference point |
Superior | Above |
Inferior | Below |
Cephalad (cranial) | Toward the head |
Caudal | Toward the lower end of the spine (Latin cauda = “tail”) |
Superficial (external) | Close to the surface of the body |
Deep (internal) | Close to the center of the body |
DISPLAY 5-2 Body Positions
Position | Pronunciation | Description |
|---|---|---|
Anatomical position | — | Standing erect, facing forward, arms at sides, palms forward, legs parallel, toes pointed forward |
Decubitus position | de-KU-bi-tus | Lying down, specifically according to the part of the body resting on a flat surface (e.g., left or right lateral decubitus, dorsal or ventral decubitus) |
Dorsal recumbent position | — | On back, with legs bent and separated, feet flat |
Fowler position | — | On back, head of bed raised about 18 inches, knees elevated |
Kraske (Jackknife) position | KRAS-ke | Prone with the buttocks raised |
Knee-chest position | — | On knees, head, and upper chest on the table, arms crossed above head |
Lateral recumbent position | — | On the side with one leg flexed; arm position may vary |
Lithotomy position | li-THOT-o-me | On back, legs flexed on abdomen, thighs apart |
Prone | — | Lying face down |
Sims position | — | On the left side, the right leg is drawn up high and forward, the left arm is along the back, chest forward, resting on the bed |
Supine* | SU-pi-n | Lying face up (remember: "up" in supine = facing up) |
Trendelenburg position | tren-DEL-en-berg | On back with head lowered by tilting the bed back at a 45° angle |
*To remember the difference between prone and supine, look for the word up in supine.
Key Terms
Term | Pronunciation | Definition |
|---|---|---|
Abdominal cavity | ab-DOM-i-nal | Large ventral cavity below the diaphragm and above the pelvic cavity |
Abdominopelvic cavity | ab-dom-i-no-PEL-vik | Large ventral cavity between the diaphragm and pelvis; includes abdominal and pelvic cavities |
Anatomic position | an-a-TOM-ik | Standard position for anatomical studies: body erect, facing forward, arms at sides with palms forward, feet parallel |
Cranial cavity | KRA-ne-al | The dorsal cavity contains the brain |
Diaphragm | DI-a-fram | The muscle that separates the thoracic cavity from the abdominal cavity |
Frontal (coronal) plane | ko-RO-nal | The plane that separates the body into anterior (front) and posterior (back) portions |
Pelvic cavity | PEL-vik | The ventral cavity is below the abdominal cavity |
Peritoneum | per-i-to-NE-um | A large serous membrane lines the abdominopelvic cavity and covers the organs within it |
Sagittal plane | SAJ-i-tal | The plane that divides the body into right and left portions |
Spinal cavity (canal) | SPI-nal | The dorsal cavity contains the spinal cord |
Thoracic cavity | tho-RAS-ik | Ventral cavity above the diaphragm; the chest cavity |
Transverse (horizontal) plane | trans-VERS | The plane that divides the body into superior (upper) and inferior (lower) portions |
Word Parts Pertaining to Body Structure
TABLE 5-1 Roots for Regions of the Head and Trunk
Root | Meaning | Example | Definition of Example |
|---|---|---|---|
cephal/o | Head | microcephaly (mi-kro-SEF-a-le) | Abnormally small head |
cervic/o | Neck | cervicofacial (ser-vi-ko-FA-shal) | Pertaining to the neck and face |
thorac/o | Chest, thorax | extrathoracic (eks-tra-tho-RAS-ik) | Outside the thorax |
abdomin/o | Abdomen | intra-abdominal (in-tra-ab-DOM-i-nal) | Within the abdomen |
celi/o | Abdomen | celiac (SE-le-ak) | Pertaining to the abdomen |
lapar/o | Abdominal wall | laparoscope (LAP-a-ro-skop) | An instrument for viewing the peritoneal cavity through the abdominal wall |
lumb/o | Lumbar region, lower back | thoracolumbar (tho-rak-o-LUM-bar) | Pertaining to the chest and lumbar region |
periton-, peritone/o | Peritoneum | peritoneal (per-i-to-NE-al) | Pertaining to the peritoneum |
BOX 5-1 Cutting the Job in Half
A beginning student in medical science may be surprised by the vast number of names and terms that he or she is required to learn. This responsibility is lightened somewhat by the fact that we are bilaterally symmetrical. That is, aside from some internal organs such as the liver, spleen, stomach, pancreas, and intestine, nearly everything on the right side can be found on the left as well. The skeleton can be figuratively split down the center, giving equal structures on both sides of the midline. Many blood vessels and nerves are paired. This cuts the learning in half.
In addition, many of the blood vessels and nerves in a region have the same name. The radial artery, radial vein, and radial nerve are parallel, and all are located along the radius of the forearm. Vessels are commonly named for the organ they supply: the hepatic artery and vein of the liver, the pulmonary artery and vein of the lungs, the renal artery and vein of the kidney.
No one could say that the learning of medical terminology is a snap, but it could be harder!
TABLE 5-2 Roots for the Extremities
Root | Meaning | Example | Definition of Example |
|---|---|---|---|
acro | Extremity, end | acrodermatitis (ak-ro-der-ma-TI-tis) | Inflammation of the skin of the extremities |
brachi/o | Arm | antebrachium (an-te-BRA-ke-um) | Forearm |
dactyl/o | Finger, toe | polydactyly (pol-e-DAK-til-e) | Having more than the normal number of fingers or toes |
ped/o | Foot | dextropedal (deks-TROP-e-dal) | Using the right foot in preference to the left |
pod/o | Foot | podiatric (po-de-AT-rik) | Pertaining to the study and treatment of the foot |
TABLE 5-3 Prefixes for Position and Direction
Prefix | Meaning | Example | Definition of Example |
|---|---|---|---|
circum- | Around | circumoral (ser-kum-OR-al) | Around the mouth |
peri- | Around | perivascular (per-e-VAS-ku-lar) | Around a vessel (vascul/o) |
intra- | In, within | intrauterine (in-tra-U-ter-in) | Within the uterus |
epi- | On, over | epithelium (ep-i-THE-le-um) | Tissue that covers surfaces |
extra- | Outside | extracellular (eks-tra-SEL-u-lar) | Outside a cell or cells |
infra-* | Below | infrapatellar (in-fra-pa-TEL-ar) | Below the kneecap (patella) |
sub-* | Below, under | sublingual (sub-LING-gwal) | Under the tongue (lingu/o) |
inter- | Between | intercostal (in-ter-KOS-tal) | Between the ribs (cost/o) |
juxta- | Near, beside | juxtaposition (juks-ta-po-ZI-shun) | A location near or beside another structure |
para- | Near, beside | parasagittal (par-a-SAJ-i-tal) | Near or beside a sagittal plane |
retro- | Behind, backward | retroperitoneal (re-tro-per-i-to-NE-al) | Behind the peritoneum |
supra- | Above | suprascapular (su-pra-SKAP-u-lar) | Above the scapula (shoulder blade) |
*Also indicates degree.
Supplementary Terms
Term | Pronunciation | Definition |
|---|---|---|
digit | DIJ-it | A finger or toe (adjective: digital) |
epigastrium | ep-i-GAS-tre-um | The epigastric region |
fundus | FUN-dus | The base or body of a hollow organ; the area of an organ farthest from its opening |
hypochondrium | h-po-KON-dre-um | The hypochondriac region (left or right) |
lumen | LU-men | The central opening within a tube or vessel |
meatus | me-A-tus | A passage or opening |
orifice | OR-i-fis | The opening of a cavity |
os | — | Mouth; any body opening |
septum | SEP-tum | A wall dividing two cavities |
sinus | SI-nus | A cavity, as within a bone |
sphincter | SFINK-ter | A circular muscle that regulates an opening |
ABBREVIATIONS
Abbreviation | Meaning |
|---|---|
LLQ | Left lower quadrant |
LUQ | Left upper quadrant |
RLQ | Right lower quadrant |
RUQ | Right upper quadrant |