Musculoskeletal System

This is Unit Six: the musculoskeletal system — bones, muscles, joints, and the connective tissue holding them together. Units One through Four built the machinery. This unit supplies the roots, so most terms here are a familiar suffix on a new stem. Three suffixes are numbered here rather than in Unit Two: physis, porosis and clasia work in bone and nowhere much else. The unit is dense with pairs the book expects to be confused: tendon against ligament, sprain against strain, abduction against adduction. Two runs are learned together or not at all: the three directions a spine curves, and six movements in three opposed pairs. By the end you can do five things. One: name the tissue forms, and separate the confused pairs. Two: name a bone from its root, and place both vertebral forms. Three: name the three curvatures and the six movements. Four: apply the three suffixes, and tell a sprain from a strain. Five: describe a fracture, and build or decode a term.

Ten combining forms to begin, and they name tissues rather than named bones. Two problems sit inside the run. Tendon and ligament attach different things and are swapped anyway, and one form carries two meanings that have nothing to do with each other.

Bone as a material.

MedTerm 0321 oste/o: Bone

The combining form oste slash o names bone. Attach itis, the Unit Two suffix for inflammation, and you have osteitis. Oste slash o names the tissue itself rather than any one named bone of the skeleton.

Muscle, in two letters.

MedTerm 0322 my/o: Muscle

My slash o names muscle. With algia, Unit Two's suffix for pain, it gives myalgia. My slash o is short and sits inside longer terms, where a named muscle is easy to read past.

Where two bones meet.

MedTerm 0323 arthr/o: Joint

Arthr slash o names a joint, the point where two bones meet. It names the junction itself and not the bones forming it, which is why arthrodesis fuses a joint rather than a bone.

The cushion at the joint.

MedTerm 0324 chondr/o: Cartilage

Chondr slash o names cartilage, the firm tissue cushioning joints. With malacia, Unit Two's suffix for softening, it gives chondromalacia. The ch is spoken as a k, so the term opens kondro.

Muscle to bone.

MedTerm 0325 ten/o and tendin/o: Tendon

Two combining forms, ten slash o and tendin slash o, both name a tendon, the band attaching muscle to bone. A different structure joins bone to bone, and it has a combining form of its own.

Bone to bone.

MedTerm 0326 ligament/o: Ligament

Ligament slash o names a ligament, the band joining bone to bone. Tendons attach muscle to bone; ligaments attach bone to bone. The two are routinely swapped, and the swap changes which structure a record describes.

Inside the bone.

MedTerm 0327 myel/o: Bone Marrow

Myel slash o names bone marrow, the tissue inside bone where blood cells form. Myeloma, built on Unit Two's suffix oma, is a marrow tumour. This same form also names a second structure, unrelated to bone.

The same form again.

MedTerm 0328 myel/o: Spinal Cord

Myel slash o also names the spinal cord. Myelitis may name inflammation of the spinal cord or of bone marrow. One form, two structures — and context does the work the word part cannot.

The sac beside the joint.

MedTerm 0329 burs/o: Bursa

Burs slash o names a bursa, a fluid-filled sac reducing friction at a joint. A bursa sits near a joint without being part of it, so bursitis and arthritis name inflammation in two different places.

The lining inside.

MedTerm 0330 synovi/o: Synovial Membrane

Synovi slash o names the synovial membrane, which lines a joint and produces its lubricating fluid. The membrane lines the joint from inside and the bursa sits outside it — three neighbours, three separate roots.

Five bones, each with a combining form. The last two are the interesting ones. Vertebr slash o and spondyl slash o both name a vertebra, and the choice between them is not free.

The bone of the head.

MedTerm 0331 crani/o: Skull

Crani slash o names the skull. With otomy, Unit Two's suffix for incision, it gives craniotomy. Crani slash o names the bone; the space it encloses is the cranial cavity, numbered in Unit Four.

The bones of the chest wall.

MedTerm 0332 cost/o: Rib

Cost slash o names a rib. Intercostal muscles use inter, the Unit Three prefix for between. Cost slash o has no relation to the English word cost, and reading it that way misleads.

The breastbone.

MedTerm 0333 stern/o: Sternum

Stern slash o names the sternum, the breastbone. Retrosternal, built on retro, the Unit Three prefix for behind, describes a position behind it. The sternum is anterior, so a finding behind it lies deeper.

One bone of the spine.

MedTerm 0334 vertebr/o: Vertebra

Vertebr slash o names a vertebra, one bone of the spinal column. A second combining form names the same structure in a different class of terms, which is why both are numbered here.

The same bone, other root.

MedTerm 0335 spondyl/o: Vertebra

Spondyl slash o also names a vertebra, and it appears chiefly in terms naming conditions. Vertebr slash o belongs to anatomical terms and spondyl slash o to disease terms — one structure carrying a Latin root and a Greek one.

Ten bones now, shoulder to fingers and thigh to ankle. Almost every entry places its bone with a direction from Unit Four, so the run is a second pass through orientation. Two of Unit One's plural rules surface as well.

The shoulder blade.

MedTerm 0336 scapul/o: Scapula

Scapul slash o names the scapula, the shoulder blade, a flat bone on the posterior chest wall. It lies on the back rather than on top of the shoulder, where the everyday sense points.

The collarbone.

MedTerm 0337 clavicul/o: Clavicle

Clavicul slash o names the clavicle, the collarbone, which joins the sternum to the scapula. Clavicle and scapula form the shoulder girdle, so the two forms often turn up in one word.

The upper arm.

MedTerm 0338 humer/o: Humerus

Humer slash o names the humerus, the bone of the upper arm. Humerus is the bone; humorous is an unrelated English word. Unit One numbered the sound-alike problem, and this is a clean instance.

The wrist bones.

MedTerm 0339 carp/o: Wrist

Carp slash o names the carpus, the bones of the wrist. The wrist is distal to the elbow and proximal to the fingers, using the Unit Four pair that is always stated against a named point.

Fingers and toes.

MedTerm 0340 phalang/o: Phalanges

Phalang slash o names the phalanges, the bones of the fingers and toes. One bone is a phalanx; several are phalanges, following Unit One's nx to nges rule. The g softens, so phalanges carries a j sound.

The thigh bone.

MedTerm 0341 femor/o: Femur

Femor slash o names the femur, the thigh bone and the longest bone in the body. The root is femor rather than femur when a combining form is built, so terms read femoral.

The kneecap.

MedTerm 0342 patell/o: Patella

Patell slash o names the patella, the kneecap. One patella; two patellae, following Unit One's a to ae plural rule. Anterior places the kneecap in front of the joint rather than on it.

The shin bone.

MedTerm 0343 tibi/o: Tibia

Tibi slash o names the tibia, the shin, the larger bone of the lower leg. The tibia is medial, toward the midline. The other bone of the lower leg is lateral and smaller.

The bone beside it.

MedTerm 0344 fibul/o: Fibula

Fibul slash o names the fibula, the smaller and lateral bone of the lower leg. Tibia is medial and larger, fibula lateral and smaller, so the pair is carried as a pair.

The ankle bones.

MedTerm 0345 tars/o: Ankle

Tars slash o names the tarsus, the bones of the ankle. Tars slash o also names the edge of the eyelid in a few terms, so the ankle reading is usual but not automatic.

Five more combining forms, and none of them names a bone. One names movement, one the sheet wrapping muscle, and three name spinal curvatures — outward, inward, and sideways. Those three are numbered together, because a curvature means little without the directions it is not.

Motion itself.

MedTerm 0346 kinesi/o: Movement

Kinesi slash o names movement. With brady, the Unit Three prefix for slow, it gives bradykinesia, abnormally slow movement. Kinesi slash o names the movement itself and not the muscle producing it.

The sheet around muscle.

MedTerm 0347 fasci/o: Fascia

Fasci slash o names fascia, the sheet of connective tissue enclosing muscle. Fascia surrounds muscle without being muscle tissue, so fasciitis names inflammation of the wrapping rather than of what it encloses.

Curving outward.

MedTerm 0348 kyph/o: Hunchback Curvature

Kyph slash o names an outward curvature of the upper spine. Kyphosis is built with osis, Unit Two's suffix for an abnormal condition. Three combining forms name three different curvatures, and this is the first.

Curving inward.

MedTerm 0349 lord/o: Swayback Curvature

Lord slash o names an inward curvature of the lower spine. Kyphosis curves outward at the back; lordosis curves inward at the front. Same suffix, opposite direction, and a different region of the spine.

Curving sideways.

MedTerm 0350 scoli/o: Lateral Curvature

Scoli slash o names a sideways curvature of the spine. Kyphosis and lordosis curve front to back; scoliosis curves side to side, using lateral in exactly the sense Unit Four gave that word.

Six terms, three opposed pairs, and no word parts to decode. Flexion and extension work at one joint. Abduction and adduction are measured from the midline and differ by a single letter. Supination and pronation rotate the forearm.

The angle closes.

MedTerm 0351 Flexion

Flexion is a movement that decreases the angle at a joint. Flexion describes direction and says nothing about force, so a slight bend and a hard one are both flexion. Its opposite carries the next number.

The angle opens.

MedTerm 0352 Extension

Extension is a movement that increases the angle at a joint. Flexion and extension are opposites, and each describes one joint at a time, so a record naming flexion still has to name the joint that is flexed.

Away from the middle.

MedTerm 0353 Abduction

Abduction is a movement carrying a body part away from the midline, which is Unit Four's reference. A term differing from this one by a single letter names the opposite movement, and it carries the next number.

Back toward it.

MedTerm 0354 Adduction

Adduction is a movement carrying a body part toward the midline. Abduction and adduction differ by one letter and reverse the movement entirely, which makes them the hardest pair in this unit to hear apart.

Palm turns up.

MedTerm 0355 Supination

Supination is rotation of the forearm so the palm turns upward. Supination and supine, the Unit Four position term, share a root and both involve facing upward, which is the link the pair rewards.

Palm turns down.

MedTerm 0356 Pronation

Pronation is rotation of the forearm so the palm turns downward. Supination and pronation are opposites and match supine and prone in direction, so the forearm pair and the Unit Four position pair agree.

Three suffixes numbered inside this unit rather than in Unit Two, because each works in bone and nowhere much else. Growth, a porous condition, and a surgical breaking. The middle one is built on a Unit Two suffix, which is the pattern worth watching.

A site of growth.

MedTerm 0357 -physis: Growth

The suffix physis names growth, and in bone terms a site where growth occurs. Physis is specific to growth: trophy, Unit Two's suffix, names development in general, and the two are not interchangeable.

Full of small spaces.

MedTerm 0358 -porosis: Porous Condition

The suffix porosis names an abnormal condition of becoming porous, and it is built on osis, Unit Two's suffix for an abnormal condition. Porous means full of small spaces — a change in the structure of bone, not in its size.

Breaking on purpose.

MedTerm 0359 -clasia: Breaking

The suffix clasia names a surgical breaking of the structure its root identifies. Clasia is a deliberate procedure and never an accidental break. Accidental breaks are fractures, and they are described in a different way.

Three entries. The first two are the unit's sharpest twin pair: a sprain and a strain injure different structures, and the words are swapped constantly. The third is the three-part description any fracture receives.

Ligament injured.

MedTerm 0360 A Sprain

A sprain is an injury to a ligament, the band joining bone to bone. A similar-sounding term names injury to a different structure altogether, and it carries the next number. The two are this unit's canonical confusion.

Muscle or tendon injured.

MedTerm 0361 A Strain

A strain is an injury to a muscle or a tendon. Sprains involve ligaments; strains involve muscles and tendons. The words are constantly swapped, and the swap survives into records because the two sound alike.

A fracture on three axes.

MedTerm 0362 Naming a Fracture

Naming a fracture means stating three things. Whether the skin is broken: a closed fracture leaves it intact, an open fracture breaks through. The pattern: transverse runs across the bone, oblique at an angle, comminuted leaves more than two pieces. And the location. Each of these describes what happened to the bone. None of them names what follows.

Two entries to close. The first builds four terms join by join and ends on one the rules cannot finish. The second decodes twelve, suffix first, by Unit One's method.

Four terms, join by join.

MedTerm 0363 Building Musculoskeletal Terms

Building a term means choosing the combining form, then the suffix, then applying Unit One's joining rules. Arthritis takes a vowel suffix, so the root links it. Arthroplasty takes a consonant suffix, so arthr slash o links it. Myelotomy is an incision into either bone marrow or the spinal cord: the parts are unambiguous, and the root is not.

The capstone. Twelve terms decoded.

MedTerm 0364 Capstone: Twelve Musculoskeletal Terms Decoded

Twelve terms, decoded suffix first, using Unit One's method with the word parts of Units Two through Six. The last one is the finding to keep. Myeloma reads as bone marrow rather than spinal cord because convention names it a marrow tumour. The parts alone would not settle it.

Five things to carry out of Unit Six. The tissue forms name bone, muscle, joint, cartilage, tendon and ligament. Tendons attach muscle to bone; ligaments attach bone to bone. And myel slash o names bone marrow at one number and the spinal cord at the next. Each named bone carries a root, and one structure carries two: vertebr slash o in anatomical terms, spondyl slash o in terms naming conditions. Tibia is medial and larger, fibula lateral and smaller. The limb run places nearly every bone with a Unit Four direction. Three curvatures: kyphosis outward at the back, lordosis inward at the front, scoliosis side to side. Six movements in three pairs: flexion and extension, abduction and adduction from the midline, supination and pronation of the forearm. Physis names growth, porosis a condition of becoming porous, clasia a surgical breaking — deliberate, never accidental. A sprain injures a ligament and a strain a muscle or a tendon, and the swap changes the structure a record names. A fracture is described on three axes: skin broken or intact, the pattern of the break, and the location. Myelotomy is unambiguous in its parts and ambiguous in its root — the point where the decoding machine stops and convention takes over. Unit Seven turns to the cardiovascular system and blood.