Skeletal System

Chapter 14


Skeletal System



Learning Objectives



image Define at least 10 terms relating to the skeletal system.


image Describe the five functions of the skeletal system.


image Identify at least 10 structures of the skeletal system.


image Identify at least three methods of assessment of the skeletal system.


image Describe at least five disorders of the skeletal system.



Key Terms


















Skeletal System Terminology*







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Osteoarthritis may cause Heberden’s nodes to form around the knuckles. (From Kamal A, Brocklehurst JD: A color atlas of geriatric medicine, ed 2, St. Louis, 1991, Mosby.)






































































Term Definition Prefix Root Suffix
Arthritis Inflammation of the joint   arthr itis
Arthrodesis Surgical union or fixation of the joint   arthr/o desis
Arthroplasty Plastic reconstruction of the joint   arthr/o plasty
Cervical Pertaining to the neck   cervic al
Chondrectomy Removal of the cartilage   chondr ectomy
Intercostal Between the ribs inter cost al
Odontology Study of the tooth   odont ology
Orthopedics Pertaining to correcting or straightening the bones ortho ped ics
Osteoarthritis Inflammation of the bones and joints osteo arthr itis
Periodontal Around the tooth peri/o dont al


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*A transition syllable or vowel may be added to or deleted from the word parts to make the combining form.



Abbreviations of the Skeletal System






































Abbreviation Meaning
AKA Above knee amputation
Amb Ambulatory
Bil Bilateral
CAT Computed axial tomography
CXR Chest x-ray
Ext Extremity
Fx Fracture
Lat Lateral
Lt Left
Ortho Orthopedics



Structure and Function of the Skeletal System


The human body has more than 200 bones (Table 14-1). The skeletal system works directly with the muscular system to perform many functions, including the following:




Bone tissue is composed of inorganic salts (particularly calcium phosphate), water, and organic material such as bone cells, blood vessels, nerves, and elastic material (collagen). Like other body cells, bone cells must continuously receive food and oxygen. However, bones and their adjoining structures, ligaments, and tendons have fewer nerves and blood vessels than other body structures.


Bones continue to grow for the first 18 to 20 years of life. Even after growth stops, bone cells die and are replaced by new cells throughout life. Osteoblasts are cells in the bone tissue that produce new cells. Osteoclasts are cells that break down bone cells (resorption).



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Most people reach peak bone density around age 20.


Bones may have cartilage, a fibrous connective tissue, on some surfaces to prevent friction. Bones are attached to other bones by ligaments. A sheet of fibrous tissue connecting bone to bone is called an aponeurosis (ap-o-noo-RO-sis). Bones are joined to muscles by tendons. Fascia (FASH-ee-uh) is a variable fibrous connective tissue that joins organs. Chapter 15 provides more information about the muscular system. The two major types of bone tissue are dense (compact) and loosely packed or spongy (cancellous).



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When a person is born, the body has more than 300 separate bones. After some fuse, there are only 206.



Types of Bones


The skeletal system consists of two major groups of bones (Fig. 14-1):


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FIGURE 14-1 Common skeletal bones. A, Front view. B, Back view.


Bones are also classified by shape (Table 14-2):





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The longest bone is the femur of the leg, and the shortest is the stapes (stirrup) of the ear.



Skull


The skull includes the bones of the cranium, face, and ear. The cranium is made up of eight bones (Fig. 14-2). The sinus cavities make the skull lighter and the voice sound stronger. At birth, the bones of the cranium have two openings called fontanels. These close by 2 years of age. The face is made up of 13 bones (Fig. 14-3). The lower jaw (mandible) is the only movable bone of the skull.


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FIGURE 14-2 The bones of the skull include the cranium, face, and ears.

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FIGURE 14-3 The skull includes the bones of the face. (The palate [2] and inferior turbinate [2] are not visible.)


Teeth


The adult has 32 teeth after the deciduous or primary teeth are replaced (Fig. 14-4). Each tooth has a number of parts (Fig. 14-5):


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FIGURE 14-4 Tooth development.

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FIGURE 14-5 Parts of a tooth. (From Bird DL, Robinson DS: Torres and Ehrich modern dental assisting, ed 7, Philadelphia, 2003, Saunders.)


The four major types of teeth have different shapes and functions (Table 14-3).


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Apr 15, 2017 | Posted by in MEDICAL ASSISSTANT | Comments Off on Skeletal System

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