How the Body Is Organized, and the Words for It

This is Unit Two of Medical Assistant Prep. Unit One said a medical assistant gathers, measures and reports. Every report is written in words, and this unit supplies them: how the body is organized, and how medical words are built from parts. Carry one idea through this lecture. A medical term is a precise label that every reader decodes the same way, and decoding a term gives you its meaning, not the right to interpret it. Two constructed cases at the end show both halves of that idea. By the end you will be able to describe the body's levels and processes. To locate structures with directional terms, planes and quadrants. To take a medical word apart. And to read and record terms without interpreting them.

Six entries on organization: why shared words matter, the levels of the body, its tissues and membranes, and homeostasis.

One place, two descriptions.

MAS 026 Why Shared Words Matter

Health care runs on a shared vocabulary, so a written word means the same to every reader. "Pain low on the right of the belly" and "right lower quadrant pain" name one place, but only the second reads the same to every provider. Use a term only when you know its meaning; a wrong term misleads more than plain words.

Cells, tissues, organs, systems.

MAS 027 From Cells to Systems

The body is built in levels: cells form tissues, tissues form organs, and organs work together as body systems. Muscle cells form muscle tissue; that tissue, with others, forms the heart; the heart and the blood vessels form the cardiovascular system. The body's functions are its cells' functions, so a problem at the smallest level can become a whole-body symptom.

Covering, binding, moving, signaling.

MAS 028 Four Kinds of Tissue

The body has four main kinds of tissue: epithelial, connective, muscle and nervous. Epithelial tissue covers surfaces and lines cavities; connective tissue binds and supports; muscle tissue contracts to move parts; nervous tissue carries signals that coordinate the body. Muscle tissue itself comes in three types, skeletal, smooth and cardiac, and only skeletal muscle is under voluntary control.

Linings and coverings, and germs.

MAS 029 Membranes That Line and Cover

Membranes are thin sheets of tissue that cover the body, line its cavities and cover the organs inside. Mucous membranes line cavities open to the outside, such as the digestive tract; serous membranes line closed cavities; synovial membranes line joints; meninges cover brain and cord. Mucous membranes are an entry point for germs, so splashes to eyes, nose and mouth matter.

Vital signs as a window.

MAS 030 Homeostasis: Keeping the Inside Steady

Survival depends on homeostasis: keeping internal conditions, such as temperature and chemistry, within a narrow range. Vital signs are a window on homeostasis; a fever or racing pulse often shows the body working to restore balance, or failing to. An unusual reading is a signal for the provider to interpret, not a diagnosis for you.

Infancy and old age.

MAS 031 Function Across the Lifespan

The body performs its functions least well at the two ends of life, in infancy and in old age. Function grows more efficient through childhood, then declines gradually with age, so infants and older adults are often more vulnerable when ill. Expect normal ranges and safe techniques to differ for children and older adults.

Four entries on location: directional pairs, three planes, two cavities, and the abdominal quadrants.

Opposites that describe position.

MAS 032 Directional Terms in Pairs

Directional terms describe where one structure lies compared with another, in opposite pairs. Superior, or cranial, is toward the head and inferior, or caudal, away from it. Anterior, or ventral, is toward the front and posterior, or dorsal, toward the back. Medial is toward the midline and lateral away from it, so the nose is medial to the eyes. Proximal is nearer the trunk or a part's origin and distal farther from it, so the elbow is proximal to the wrist. All of these describe the body in its own frame. When you face a patient, their left is on your right.

Front from back, right from left, upper from lower.

MAS 033 Three Planes of the Body

The body can be divided by three planes: coronal, sagittal and transverse. The coronal, or frontal, plane separates front from back; the sagittal plane separates right from left, and through the midline it is called the median plane; the transverse plane separates upper from lower. Imaging reports name planes often. Know the three, so you can relay a report without confusing them.

The diaphragm as a wall.

MAS 034 The Body's Cavities

The internal organs sit in two main cavities: a larger ventral cavity in front and a smaller dorsal cavity behind. The diaphragm splits the ventral cavity into the thoracic cavity, holding heart and lungs, and the abdominopelvic cavity below; the dorsal cavity holds the brain and spinal cord. The diaphragm is a wall, so chest and abdomen are separate compartments.

Four regions of the abdomen.

MAS 035 Four Quadrants of the Abdomen

The abdomen is roughly divided into four quadrants: right upper, right lower, left upper and left lower. The stomach sits in the left upper quadrant; tenderness in the right lower quadrant names one specific region, often shortened to its initials. Right and left are the patient's, not yours.

Nine entries on word building: roots, prefixes and suffixes, a method for taking words apart, and the risk in abbreviations.

Root, prefix, suffix.

MAS 036 How Medical Words Are Built

Most medical words combine three kinds of parts: a root naming the body part, a prefix in front, and a suffix at the end. Carcinoma joins the root carcin and the suffix oma; pericarditis joins the prefix peri, the root card and the suffix itis. A connecting vowel, usually o, eases pronunciation, as in cardiology; it adds no meaning.

Removing, cutting, opening, rebuilding, viewing.

MAS 037 Suffixes That Name Procedures

Some suffixes tell you that a word names a procedure. Ectomy means removal, otomy means cutting into, ostomy means making an opening, plasty means surgical reconstruction, and scopy means examining, often with a viewing instrument. Otomy and ostomy differ by one letter but name different procedures: cutting into an organ versus creating a lasting opening.

Inflammation, tumor, enlargement.

MAS 038 Suffixes That Name Conditions

Other suffixes tell you that a word names a condition. Itis means inflammation; osis means a condition, usually abnormal; oma means tumor; pathy means disease; megaly means enlargement; emia means a blood condition; penia means a deficiency. Oma does not by itself mean cancer. Many tumors are benign, so never voice an interpretation of a word like that to a patient.

Slow and fast, too much and too little.

MAS 039 Prefixes of Amount and Speed

Many prefixes describe amount or speed, and they often come in opposite pairs. Brady means slow and tachy means fast; hyper means excessive and hypo means deficient; poly means many and oligo means few; a or an means without; dys means difficult or abnormal. Hyper and hypo sound alike when spoken quickly. Say them distinctly, and confirm them when you hear them.

Around, under, between, within.

MAS 040 Prefixes of Place

Some prefixes tell you where something is, compared with a structure. Peri means around, sub means under, inter means between, and intra means within; an intramuscular injection goes within a muscle, and a subcutaneous injection goes under the skin. Inter and intra differ by one letter, but between and within are different places.

Roots seen constantly.

MAS 041 Roots That Name Organs

Roots name the body part a word is about, and a few roots appear constantly in medical records. Cardi means heart, gastr stomach, hepat liver, nephr kidney, derm skin, neur nerve, arthr joint, and hem or hemat blood. Learn roots with their usual connecting vowel, such as cardio or gastro, as they appear in most words.

Decoding a word you have not seen.

MAS 042 Taking a Word Apart

To read an unfamiliar word, take it apart, define each part, and read the meanings together. Find the suffix first, since it often says whether the word names a condition or a procedure: in hepatomegaly, megaly is enlargement. Find the root: hepat is liver, so the word is an enlarged liver. Look for a prefix: in tachycardia, tachy is fast and cardi is heart. Then put the parts together and check the result; pericarditis reads as inflammation around the heart. Word parts give you the meaning, not the clinical picture. Why the liver is enlarged, and what to do, stays the provider's question.

Gram, graph and graphy.

MAS 043 Words for Recordings

The word parts gram, graph and graphy all relate to recording or writing. An electrocardiogram is a recording of the heart's electrical activity: electro for electrical, cardio for heart, and gram for the recording. Decoding the parts tells you what kind of test a word names, not what its result means; results go to the provider.

Fast when shared, dangerous when not.

MAS 044 Abbreviations Save Time and Carry Risk

Medical records use many abbreviations, which save time when everyone reads them the same way. GI stands for gastrointestinal, the digestive system; IM stands for intramuscular, a type of injection; CPR stands for cardiopulmonary resuscitation. An abbreviation that two readers interpret differently is dangerous. Use only those your practice approves, and spell out anything in doubt.

What keeps a body alive.

MAS 045 The Processes of Life

Living things share basic processes that work together to keep a person alive. Five are organization, metabolism, responsiveness, movement and reproduction. Five more are growth, differentiation of unspecialized cells into specialized tissue, respiration's exchange of oxygen and carbon dioxide, digestion into molecules the body can absorb, and excretion of wastes. These processes are not enough alone. Life also needs water, oxygen, nutrients, heat and pressure from the environment, which is why trouble with any of them soon affects the whole body.

Two constructed cases close the unit: one note read aloud, and one location written down.

A provider's note, part by part.

MAS 046 Reading a Note Aloud

A constructed note pays off the opening idea. The provider writes: tachycardia, tenderness in the right lower quadrant, possible hepatomegaly, an electrocardiogram today, and follow-up in the GI clinic. The medical assistant decodes each term: a fast heart rate; the patient's own lower right abdomen; an enlarged liver the provider has not confirmed; a recording of the heart's electrical activity, which is her task today; and the digestive clinic. Now she knows to prepare the patient and equipment, and why. When the patient asks whether something is wrong with his liver, she says the provider will go over the findings, and tells the provider he is worried. She does not repeat possible, guess, or reassure, because reassurance is also a judgment.

A gesture turned into words.

MAS 047 Describing Where It Hurts

A second constructed case turns a gesture into a record. A patient points to his forearm a little below the elbow and says it hurts there. The medical assistant records his words as he said them, then adds the location: the patient's own left forearm, toward the elbow, so proximal on the forearm. She uses no term she is unsure of and writes nothing about cause. A week later another staff member reads the note and pictures the same spot. Two mistakes would undo this: describing left and right from where you stand, and adding a guess such as a strain, which turns an observation into a diagnosis. Record precisely, keep the patient's words beside it, and leave its meaning to the provider.

Look at what you can now do. You can describe how cells build tissues, organs and systems, why homeostasis matters, and the processes that keep a body alive. You can locate a structure with directional pairs, planes, cavities and quadrants, always in the patient's own frame. You can take an unfamiliar word apart by suffix, root and prefix, and you use only approved abbreviations. And you can decode a note and record a location without interpreting either. Unit Three applies these words to the body's systems, starting with skin, bone, muscle and nerve.