1. CHAPTER 14 SKELETAL SYSTEM

2. Chapter 14 Learning Objectives
Define at least 10 terms relating to the skeletal system.
Describe the five functions of the skeletal system.
Identify at least 10 structures of the skeletal system.

3. Chapter 14 Learning Objectives
Identify at least three methods of assessment of the skeletal system.
Describe at least five disorders of the skeletal system.

4. Skeletal System The human body has more than 200 bones.
Ask the students to name as many bones in the human body as they can. Write their answers on the chalk/white board.

5. Common Skeletal Bones
Babies are born with more than 300 bones in their body. As we grow into adults, some of the bones grow together, and an adult skeleton has 206 bones.
FIGURE 14-1 Common skeletal bones. A, Front view. B, Back view.

6. Structure and Function
The skeletal system works directly with the muscular system to perform the following functions:
Provide shape and support
Protect internal organs
Store minerals and fat
Produce blood cells and platelets
Assist in movement
What role does the muscular system play in helping the skeletal system perform these functions?
Have students give examples of each of these functions.

7. Bones Bone tissue contains
Inorganic salts (calcium phosphate)
Water
Organic material (bone cells, blood vessels, nerves, and collagen)
Bone cells must continually receive food and oxygen.
Bone cells die and are replaced by new ones.
Bones continue to grow for the first 18 to 20 years of life.
Bones are alive! They are growing, living tissue.
99% of the calcium in your body is found in your bones and teeth.

8. Bones Bones may have cartilage.
Bones are attached to other bones by ligaments.
Bones are joined to muscles by tendons.

9. Types of Bones Two major groups of bones Axial skeleton
Includes 80 bones of the head and trunk
Appendicular skeleton
Includes 126 bones of the pelvis, shoulders, arms, and legs
How do the types bones found in the two major groups of bones differ?

10. Bones of the Body Ask students to name the biggest bone in the body.
More than one half of the bones in the skeleton are found in the hands and feet. Each hand has 27 bones.

11. Bones by Shape
Name a shape of a bone (long, short, flat, irregular), and have students give an example of a bone with that shape.

12. Skull Includes bones of the
Cranium
Eight bones
Face
13 bones
Ear
The mandible is the only movable bone of the skull.
The bones in the skull fit together like a jigsaw puzzle.
The smallest bone is located in the ear, the stirrup bone, which is the size of a half a grain of rice.
The strongest bone in the human body is the jaw bone.

13. Teeth Adults have 32 teeth. Each tooth has parts.
The crown is the white section above the gum.
The root is below the gum.
Enamel, the hardest substance in the body, covers the crown.
Cementum is the hard, bonelike substance covering the root.
Dentin is located between the enamel and the pulp.
The pulp is the soft living portion of the tooth, containing the nerves and blood vessels.

14. Tooth Development Teeth are the hardest substance in the human body.
FIGURE 14-4 Tooth development

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

16. Types of Teeth
Four major types of teeth (each has a different shape and function):
Incisor
Cuspid
Bicuspid
Molar

17. Teeth Types

18. Thorax Thorax includes Ribs Sternum Vertebral bones
Seven pairs of true ribs, five pairs of false ribs, and two pairs of floating ribs
Sternum
Vertebral bones
Protect the lungs and heart
Your ribs move about 5 million times per year, every time you breathe.
Discuss the terms true ribs, false ribs, and floating ribs.

19. Thorax
FIGURE 14-6 The thorax.

20. Vertebral Column Five parts (total of 26 vertebrae)
Cervical vertebrae (7 vertebrae)
Thoracic vertebrae (12 vertebrae)
Lumbar vertebrae (5 vertebrae)
Sacrum
Coccyx
Curvature gives it strength and flexibility.
Cartilage between vertebrae cushions bones
and allows movement.

21. Vertebral Column
Adults have 26 vertebrae, and children have 33 vertebrae. In adults, five sacral bones form one bone, and four coccyx bones fuse to form one bone.
FIGURE 14-7 The lateral view of the vertebral column shows its five major parts. These five parts contain a total of 26 vertebrae.

22. Long Bones of the Extremities
Long bones of the arms and legs contain marrow, which produces blood cells.
Long bones grow and lengthen from a layer of cartilage (epiphyseal plate).
Shaft of the long bone (diaphysis) contains fatty tissue and yellow marrow.
Fatty tissue provides stored energy.
Ask students to name the long bones of the arms and legs and then discuss the slide.

23. Long Bones of the Extremities
End of the long bone contains red marrow that produces red blood cells.
Red marrow destroys old red blood cells, forms white blood cells, and produces platelets.
Periosteum (membrane)
Covers the bone
Contains osteoblasts
Medullary cavity
Contains osteoclasts that enlarge the diameter of the cavity by removing bone cells.
Every second, our bone marrow produces two million red blood cells.

24. Anatomy of a Long Bone
FIGURE 14-8 The anatomy of a long bone.

25. Bone Markings Four major types of bone markings
Projections bulge from a bone and attach to muscles, ligaments, and tendons.
Openings are holes or spaces in bones.
Depressions include openings and cavities in bone.
Ridges are lines on a bone surface.

26. Bone Markings
Discuss the types of bone markings.

27. Joints Articulation Joints are named by the bones that are joined.
Two or more bones join together at a joint.
Joints are named by the bones that are joined.

28. Types of Joints Three types of joints Immovable (synarthrosis)
Example: sutures of the cranium
Slightly movable (amphiarthrosis)
Example: pelvic bones
Freely movable (diarthrosis)
Example: hip joint
Discuss differences between these three types of joints.
Discuss why the bones of the pelvis would be considered slightly movable.
Have students pair off and locate examples of the three types of joints on each other.

29. Six Types of Diarthrotic Joints
Ball-and-socket joints of the shoulders and hips
Hinge joints of the elbow and knee
Gliding joints of the wrists
Pivot joint at the base of the skull
Saddle joint of the thumb
Gomphosis, such as the attachment of a tooth in its socket in the jaw

30. Six Types of Diathrotic Joints
FIGURE 14-9 Types of joints. A, Ball and socket. B, Hinge. C, Gliding. D, Pivot. E, Saddle. F, Gomphosis.

31. Assessment Techniques
Bone x-ray studies
Bone marrow aspiration
Bone marrow biopsy
Radionuclide bone scan
Computed tomography (CT)
Magnetic resonance imaging (MRI)
Bone densitometry
Discuss assessment techniques. Ask students who have experienced any of the assessment techniques mentioned to talk about their expereince.

32. Disorders of the Skeletal System
Ankylosing spondylitis
Hereditary chronic spinal disease
Arthritis
Group of disorders evidenced by inflammation of a joint, pain, and stiffness during movement
Avulsion fracture
Occurs when a ligament or tendon pulls off part of a bone during an injury
Bursitis
Inflammation of the sac around a joint that is caused by trauma or irritation
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.

33. Disorders of the Skeletal System
Caries
Also called cavities, they are the major cause of tooth loss.
Carpal tunnel syndrome
Disorder caused by pressure on the median nerve of the wrist because of repetitive use or trauma
Degenerative joint disease
Also called osteoarthritis, it usually is associated with aging; it is the most common form of arthritis.
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.

34. Disorders of the Skeletal System
Dislocation
When bones move out of their proper location; usually occurs in the shoulder or hip
Fracture
Broken bone caused by trauma
Gout
Painful swelling of a joint that results from the buildup of uric acid crystals, most commonly in the great toe
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.
A broken bone takes about 12 weeks to heal.

35. Disorders of the Skeletal System
Herniated disk
A ruptured or “slipped” disk between vertebrae
Kyphosis
Also called hunchback or humpback, it is an abnormal curvature of the thoracic part of the spine.
Lordosis
Also called swayback, it is an abnormal curvature of the lumbar spine.
Discuss the causes, symptoms, and treatment of these disorders.

36. Disorders of the Skeletal System
Meningomyelocele
Also called spina bifida, it is a congenital condition of the spinal column.
Osteoma
Bone tumor
Osteomalacia
Also called rickets in children, it is softening of the bones caused by vitamin D and calcium deficiency.
Discuss the causes, symptoms, and treatment of these disorders.

37. Disorders of the Skeletal System
Osteomyelitis
Bacterial infection of the bone
Osteoporosis
Weakening of the bones
Paget’s disease
Also called osteitis deformans, it is caused by excessive destruction of bone cells.
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.

38. Disorders of the Skeletal System
Periodontitis
Inflammation of the tissues that keep teeth in place
Rheumatoid arthritis
Pain and stiffness in the joints caused by thickening of the synovial membrane
Rickets
A painless deformity at the epiphysis of the bones caused by insufficient vitamin D
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.

39. Disorders of the Skeletal System
Scoliosis
Abnormal lateral spinal curvature
Subluxation
Partial dislocation of a joint, such as in the neck in a whiplash injury
Talipes
Congenital deformity involving the foot and ankle
Discuss the causes, symptoms, treatment, and possible prevention of these disorders.

40. Issues and Innovations
Progress in dental care
Corrective measures, including bonding, bleaching, and implants
• Bone substitutes and repairs
Bone-replacing material, including organometals, ceramics, and coral
Surgical implants for cranial and joint injuries
Bone regeneration

41. Summary
Functions of the skeletal system include protecting internal organs, storing minerals and fat, producing blood cells and platelets, and assisting in movement.
The skeletal system is divided into the axial and appendicular skeletons, which include bones such as the cranium, humerus, femur, and ulna.

42. Summary
Methods of assessment of the skeletal system include x-ray studies, bone marrow aspiration, biopsy (bx), CT, and MRI.
Disorders of the skeletal system include avulsions, fractures, caries, carpel tunnel syndrome, and kyphosis.