18.1 Medical Terminology I: Word Parts, Directions & Anatomy
Key Takeaways
Most medical terms combine a root with prefixes and suffixes: arthr/o (joint) + -itis (inflammation) = arthritis; -ectomy means surgical removal and -otomy means cutting into.
The spine has 7 cervical, 12 thoracic and 5 lumbar vertebrae, plus the sacrum and coccyx; levels are written as in C5-6 or L4-L5.
Directional pairs such as anterior/posterior, medial/lateral, proximal/distal and ipsilateral/contralateral describe locations and must not be confused.
Hyper- means above or excessive and hypo- means below or deficient, so hypertension and hypotension are opposites that sound alike.
Blueprint topic 50301 asks you to define basic medical terminology commonly heard in judicial proceedings. You do not need clinical knowledge; you need to recognize, spell and punctuate what doctors, nurses and injured witnesses say. Word parts let you decode and spell terms you have never heard.
Word parts
Common roots (combining forms)
| Root | Meaning | Example |
|---|---|---|
| arthr/o | joint | arthroscopy, arthritis |
| cardi/o | heart | cardiology, tachycardia |
| cephal/o | head | cephalgia (headache) |
| cerv/ic | neck (or cervix) | cervical strain |
| chondr/o | cartilage | chondromalacia |
| crani/o | skull | craniotomy |
| derm/o, dermat/o | skin | dermatitis |
| gastr/o | stomach | gastritis |
| hepat/o | liver | hepatitis |
| lumb/o | lower back | lumbar |
| my/o | muscle | myalgia |
| nephr/o, ren/o | kidney | nephrology, renal |
| neur/o | nerve | neuropathy |
| oste/o | bone | osteoarthritis, osteoporosis |
| pneum/o, pulmon/o | lung, air | pneumonia, pulmonary |
| radicul/o | nerve root | radiculopathy |
| spondyl/o, vertebr/o | vertebra | spondylosis, vertebral |
| thorac/o | chest | thoracic |
Prefixes
| Prefix | Meaning | Example |
|---|---|---|
| a-, an- | without | anemia, aphasia |
| brady- | slow | bradycardia |
| tachy- | fast | tachycardia |
| dys- | bad, difficult | dysphagia (difficult swallowing) |
| hyper- | above, excessive | hypertension (high blood pressure) |
| hypo- | below, deficient | hypotension (low blood pressure) |
| inter- | between | intervertebral |
| intra- | within | intramuscular |
| peri- | around | pericardium |
| sub- | below | subdural |
| supra- | above | suprapatellar |
| hemi- | half | hemiplegia |
| bi-, bilateral | two, both sides | bilateral fractures |
Suffixes
| Suffix | Meaning | Example |
|---|---|---|
| -itis | inflammation | tendinitis (also spelled tendonitis) |
| -algia | pain | myalgia, neuralgia |
| -ectomy | surgical removal | discectomy, laminectomy |
| -otomy | cutting into | tracheotomy |
| -ostomy | making an opening | colostomy |
| -plasty | surgical repair | arthroplasty (joint replacement) |
| -scopy | viewing with an instrument | arthroscopy |
| -gram / -graphy | record / recording process | myelogram, electromyography |
| -osis | abnormal condition | stenosis, scoliosis |
| -pathy | disease | radiculopathy, neuropathy |
| -plegia / -paresis | paralysis / weakness | paraplegia, hemiparesis |
| -emia | blood condition | anemia |
Spelling from parts: if a doctor says "lam-in-ECK-tuh-mee," the parts lamin- (lamina, part of a vertebra) and -ectomy give laminectomy.
Directions and positions
| Term | Meaning | Opposite |
|---|---|---|
| anterior (ventral) | front | posterior (dorsal): back |
| superior | above | inferior: below |
| medial | toward the midline | lateral: away from the midline |
| proximal | nearer the trunk | distal: farther from the trunk |
| ipsilateral | same side | contralateral: opposite side |
| supine | lying face up | prone: lying face down |
| flexion | bending | extension: straightening |
| abduction | moving away from the midline | adduction: moving toward it |
"Abduction" and "adduction" sound nearly alike. Some doctors say "A-B-duction" and "A-D-duction" to make the difference clear. Type the word, not the spelling-out, unless the speaker is spelling on the record.
The spine
Injury testimony constantly refers to spinal levels:
| Region | Vertebrae | Abbreviation |
|---|---|---|
| Cervical (neck) | 7 | C1 to C7 |
| Thoracic (mid-back) | 12 | T1 to T12 |
| Lumbar (low back) | 5 | L1 to L5 |
| Sacrum | 5 fused | S1 to S5 |
| Coccyx (tailbone) | usually 4 fused |
Transcribing levels: "C five six" is commonly typed C5-6; "L four L five" as L4-L5; "L five S one" as L5-S1. Follow the style the speaker's words suggest and stay consistent. The disc between two vertebrae is named for both: "the L4-5 disc."
Body systems at a glance
| System | Key terms |
|---|---|
| Musculoskeletal | fracture, ligament, tendon, cartilage, meniscus, rotator cuff |
| Nervous | concussion, traumatic brain injury (TBI), radiculopathy, neuropathy, EMG |
| Cardiovascular | myocardial infarction (heart attack), arrhythmia, hypertension |
| Respiratory | pneumothorax, pulmonary embolism |
| Integumentary (skin) | laceration, abrasion, contusion (bruise), avulsion |
| Gastrointestinal | laparoscopy, bowel obstruction |
Decoding unfamiliar terms: worked examples
When a doctor uses a term you have never heard, break it into parts, form a candidate spelling, then confirm it in a medical dictionary.
- "spon-dih-LO-sis": spondyl- (vertebra) + -osis (abnormal condition) = spondylosis, degeneration of the spine.
- "kon-dro-muh-LAY-shuh pa-TELL-ee": chondr/o (cartilage) + -malacia (softening), plus patellae (of the kneecap) = chondromalacia patellae.
- "hemi-PAIR-uh-sis": hemi- (half) + -paresis (weakness) = hemiparesis, weakness on one side of the body. Contrast hemiplegia, paralysis on one side.
- "sub-DOO-rul hee-MAT-oh-muh": sub- (below) + dura (the brain's outer covering) = subdural hematoma, a collection of blood below the dura.
- "brady-CAR-dee-uh": brady- (slow) + cardi/o (heart) = bradycardia, a slow heart rate. Contrast tachycardia, a fast one.
Two cautions:
- Word parts give a candidate, not a certainty. Always confirm the spelling in a medical dictionary, because many terms have irregular forms (tendinitis, not tendonitis, is the more common spelling in medical dictionaries, though both appear).
- Keep the witness's words. A layperson who says "my tailbone" has not said coccyx. Do not substitute the medical term for the everyday word, or the reverse.
Why it matters
A misspelled or misheard medical term can change a damages claim. "Hypertension" and "hypotension" are opposite conditions, and "ileum" (intestine) and "ilium" (hip bone) are different body parts. Section 18.2 covers these sound-alikes and the conditions, procedures and medications heard most often.
An orthopedic surgeon testifies that she performed a "laminectomy." What does the suffix -ectomy indicate?
Surgical repair
Surgical removal
Inflammation
Viewing with an instrument
How many lumbar vertebrae does the typical human spine have?
Seven
Twelve
Four
Five
A witness's doctor says the injury is "contralateral" to the impact. What does that mean?
On the opposite side of the body from the impact
On the same side as the impact
Toward the front of the body
Nearer to the trunk
Sections you finish are checked off in the contents.