InterActive Medical Terminology

Based on the best selling text: An Introduction to Medical terminology for Health Care (Fourth Edition) by A.R.Hutton published by Elsevier Ltd.

 

The Skeletal system

The interactive learning material in this unit is arranged into an introduction and five sections:

Click on a section and scroll down the page completing the exercises in the sequence they are presented.

Note: FlashCards and a check list of combining forms for this unit are at the end of Section 4.

Click on Pathology for exercises on symptoms and diseases of the skeletal system.

A short list of common medical words and abbreviations associated with the skeletal system is available from Word Check.

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Introduction

The supporting structure of the body consisting of 206 bones is known as the skeletal system, they have several main functions including:

In this unit we will study the two major divisions of the skeletal system:

Axial Skeleton

Appendicular Skeleton

 

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Section 1 Bone,cartilage and the structure of joints

 

In this first section we will examine the tissues that form a typical joint such as the one shown in AnatomyExercise 1:

 

Anatomy Exercise 1

Next we'll examine words associated with the tissues and structures that form a joint.

Bone

Bone is a type of connective tissue that forms the separate bones of the skeleton. Every connective tissue contains cells plus an intercellular matrix. In bone, calcium salts deposited in the matrix makes bones hard and strong in tension and compression; this enables the skeleton to support all tissues and organs in the body. Two combining forms are used to indicate bone tissue, in Roots 1 and 2.

 

Root 1 Oste-
from a Greek word osteon meaning bone. Here oste/o means bone.
Combining form Oste/o bone

 

Root 2 Osse-
from a Latin word os meaning bone. Here osse/o means bone.
Combining form Osse/i/o bone

 

Surprisingly bones are not the dry looking structures we associate with skeletal remains; instead the cells are very active and receive a good blood supply. The cavities within bones are filled with marrow that forms our blood cells and acts as an energy store.

Anatomy Exercise 2 below shows an animation of materials entering a long bone such as a femur.

 

Anatomy Exercise 2

As we grow bones are continuously remodeled and change their shape, in some areas new bone matrix forms whilst in other areas it is broken down. To carry out these activities several types of cell are involved:

Those cells that form bone matrix as we grow are called osteoblasts and those that destroy the matrix osteoclasts. Mature bone cells that maintain the day to day metabolism of bones are simply called osteocytes.

The cells in bone are found in spaces in the hard matrix called lacunae connected to each other by little canals (canaliculi). These spaces are necessary to allow oxygen and nutrients to reach the living cells in the bone. The osteocytes develop extensions that connect to other cells within the canals to enable materials to reach all parts of the bone.

Anatomy Exercise 3 shows an animation of a tiny cross-section of bone being supplied with nutrients and wastes being removed.

 

Anatomy Exercise 3

Quick reference

Oss/e/i/o
=
 bone
Oste/o
=
 bone

 

Now learn the first set of suffixes by completing Dictionary Exercise 1. Remember repetition is very important as it helps fix the meanings into your memory. When you are satisfied you can remember their meanings continue with the exercises.

 

Dictionary Exercise 1

Using your knowledge of these suffix complete Word Exercise 1.

 

Word Exercise 1

Now learn the second set of suffixes in Dictionary Exercise 2. When you are satisfied you can remember their meanings continue with the exercises.

 

Dictionary Exercise 2

Word Exercise 2

Joints

A joint or articulation is a point of contact between bones especially one that allows motion of one or more of the bones. There are many types of joint but here we are using a movable joint called a synovial joint as an example.

Look at the finger joint in the next diagram, notice the ends of the bone are covered with a tissue called cartilage. This forms a smooth surface and reduces friction at the joint. The synovial membrane secretes synovial fluid into the joint and this acts as a lubricant reducing friction and allows the bones of the finger to slide across each other.

The fibrous capsule is as the name suggests made of fibers of tough connective tissue. The capsule resists dislocation (separating) of the joint. When the fibers are arranged in parallel bundles they are called ligaments.

Now look at the combining form of Root 3 which is widely used when referring to joints as in arthritis a common complaint of humans.

 

Root 3 Arthr-
from a Greek word arthron meaning joint. Here arthr/o means joint.
Combining form Arthr/o joint

 

CLINICAL POINT
       
Osteoarthritis
  
Inflammation of the bones of a joint. A condition caused by degeneration of the articular cartilages at a joint thereby allowing the bones to rub against each other. Results in pain and stiffness usually in the elderly.
 
         

 

Synovia

This is the transparent fluid secreted by the synovial membrane that is found in joint cavities; it acts a a lubricant to reduce friction and maintain the joint surfaces. The combining form of Root 4 refers specifically to synovial fluid and to synovial membranes.

 

Root 4 Synov-
from a New Latin word synovis meaning synovia. Here synov/i/o means synovial fluid secreted by a synovial membrane into a joint.
Combining form Synov/i/o synovial fluid, synovial membrane

 

Cartilage

Cartilage is a connective tissue found in at the end of bones in joints. It is made of cartilage cells known as chondrocytes plus a smooth plastic-like matrix that forms a smooth surface. Cartilage reduces friction allowing the bones to slide over each other. When cartilage degenerates as in the elderly friction is reduced and movement at joints may become difficult and painful.

The combining form of Root 5 refers specifically to cartilage found in joints.

 

Root 5 Chond-
from a Greek word chondros meaning cartilage. Here chondr/o means cartilage, the plastic-like connective tissue found at the ends of long bones.
Combining form Chondr/o cartilage

 

Ligaments

Ligaments are bands of tough,fibrous connective tissue that join bones together. Notice the hip joint shown in Anatomy Exercise 1 is stabilized and prevented from separating by ligaments. Note two different combining forms are used for ligament as shown in Root 6.

 

Root 6 Desm-
from a Greek word desmos meaning band and syndesmos meaning ligament. Here desm/o and syndesm/o mean ligament.
Combining form Desm/o, syndesm/o ligament

 

Bursae

Sac-like structures called bursae alleviate friction in some joints such as the knee and shoulder; they resemble fibrous joint capsules and are filled with fluid similar to synovial fluid.They are located in places near joints where skin rubs over bone. The are also found between tendons and bones, muscles and bone and ligaments and bone; they act to cushion the movement of one part of the body over another. See the combining form of Root 7:

 

Root 7 Burs-
from a Latin word bursa meaning purse. Here burs/o means a bursa, a sac-like, fluid-filled structure found near joints that acts to reduce friction.
Combining form Burs/o bursa

 

 

Quick reference

Arthr/o
=
 joint
Burs/o
=
 bursa
Chondr/o
=
 cartilage
Desm/o
=
 ligament
Fibr/o
=
 fiber / fibrous
Syndesm/o
=
 ligament
Synov/i/o
=
 synovial joint / fluid or synovia

 

Now continue the Word Exercises that use these combining forms:

 

Word Exercise 3

Next try spelling words associated with Roots 1 - 7 from their definitions in Word Exercise 4.

 

Word Exercise 4 Spelling

Next learn the third set of suffixes in Dictionary Exercise 3. When you are satisfied you can remember their meanings continue with the exercises.

 

Dictionary Exercise 3

Word Exercise 5

Now learn the final set of suffixes for this section in Dictionary Exercise 4. When you are satisfied you can remember their meanings continue with the exercises.

 

Dictionary Exercise 4

Word Exercise 6

Next practice spelling words associated with bone, joints and ligaments from their definitions in Word Exercise 7.

 

Word Exercise 7 Spelling

 

Bone Marrow

Within the long bone shown above there is a marrow cavity or medullary cavity (medull/o = central part of a structure). In adults this contains yellow, fatty bone marrow that acts as an energy reserve.

Red bone marrow found in the spongy bone at the end of long bones contains the cells that form our blood cells. One type called a myeloblast can form several types of white blood cell another type called an erythroblast forms red cells.

 

Root 8 Myel-
from a Greek word myelos meaning marrow. Here myel/o means the marrow of bone.
Combining form Myel/o marrow

 

Quick reference

Medull/o
=
 central part, medulla
Myel/o
=
 bone marrow

 

Now try spelling words associated with bone, marrow and cartilage from their definitions in Word Exercise 8.

 

Word Exercise 8 Spelling

 

Finally in this section spell words associated with bone, cartilage and joints from dictation in Word Exercises 9 and 10.

 

Word Exercise 9 Dictation

Word Exercise 10 Dictation

This exercise ends Section 1.

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