1. The Skeletal System Chapter 5 Medical Assisting
PowerPoint® presentation to accompany:
Medical Assisting
Third Edition
Booth, Whicker, Wyman, Pugh, Thompson

2. Learning Outcomes 5.1 Describe the parts of a long bone.
5.2 List the substances that make up bone tissue.
5.3 List the functions of bones.
5.4 Identify bones by their classifications.
5.5 Describe how long bones grow.

3. Learning Outcomes (cont.)
5.6 List and describe the skeletal structures and one location of each structure.
5.7 List the bones of the skull, spinal column, rib cage, shoulders, arms, hands, hips, legs, and feet. Describe the location of each bone.
5.8 Define fontanels and explain their importance.

4. Learning Outcomes (cont.)
5.9 Describe the three major types of joints and give examples of each.
5.10 Describe the structure of a synovial joint.
5.11 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the skeletal system.

5. Introduction Bones provide the body with structure and support
206 bones with joints and connective tissue
Divisions
Axial – 80 bones
Skull
Vertebral column
Rib cage
Appendicular – 126 bones
Arms and legs
Pectoral girdle
Pelvic girdle

6. The Skeletal System

7. Bone Structure Bones contain various kinds of tissues, including
Osseous tissue
Blood vessels
Nerves
Osseous tissue can appear compact or spongy

8. Bone Structure (cont.) Compact bone looks solid
Structures can be observed with a microscope
All bones are made up of both compact and spongy bone

9. Bone Structure (cont.) Classification by shape
Long bones – located primarily in the arms and legs
Femur (thigh bone)
Humerus (upper arm bone)
Short bones – small bones located in the wrists and ankles
Carpals (wrist bones)
Tarsals (ankle bones)

10. Bone Structure (cont.) Flat bones – located in the skull and rib cage
Ribs
Frontal bone
Irregular bones
Vertebrae
Bones of the pelvic girdle

11. Bone Structure: Gender Differences
Male Skull
Larger and heavier
Forehead shorter
Face less round
Jaw larger
Mastoid processes more prominent
Male pelvic bones
Heavier and thicker
Obturator foramina and acetabula are larger and closer together

12. Bone Structure: Gender Differences (cont.)
Male pelvic cavity
Narrower and longer
Less roomy and more funnel shaped
Male sacrum
Narrower
Sacral promontory projects forward
Sacral curvature is less sharp posteriorly
Male coccyx
Less movable

13. Apply Your Knowledge Very Good! ANSWER: Match bone to classification.
___ Humerus L. Long bones
___ Rib S. Short bones
___ Femur F. Flat bones
___ Pelvic bones I. Irregular bones
___ Carpals
___ Frontal bone
___ Vertebra
___ Tarsals F L
Very Good! I S F I S

14. Functions of Bones Give shape to body parts
Support and protect soft structures
Examples – brain, lungs, heart
Allow body movement, because skeletal muscles attach to them
Allow for voluntary movement

15. Functions of Bones (cont.)
Red bone marrow of bone produces new blood cells – hematopoiesis
Store calcium

16. Correct! Apply Your Knowledge
Why is it important for the bones to store calcium?
ANSWER: Every cell in the body needs calcium, so the body must have a large supply readily available.
Correct!

17. Bone Growth Ossification – process of bone growth
Intramembranous ossification
Bones begin as tough, fibrous membrane
Bone-forming cells called osteoblasts turn the membrane to bone (located in skull)

18. Bone Growth (cont.) Endochondral ossification
Bones begin as cartilage models
Primary ossification center
Bone formed in the diaphysis
Secondary ossification center
Epiphyses turn to bone
Bones with some cartilage between an epiphysis and the diaphysis will continue to grow
Medullary cavity and spaces in cancellous bone form
Cells that form holes in bone are called osteoclasts

19. Bone Growth: Building Better Bones
Teach healthy behaviors
Bone-healthy diet with calcium and vitamin D
Bone-health exercises
Weight-bearing
Strength training
Bone-healthy lifestyle
Avoid smoking
Avoid alcohol

20. Bone Growth (cont.) Bone tests Bone density Bone scans
Diagnose causes of
Bone pain
Arthritis
Bone infections
Bone cancers

21. Good Job! Apply Your Knowledge What are the two types of bone growth?
ANSWER: Intramembranous ossification, in which bones begin as tough membrane and are turned to bone by osteoblasts, and endochondral ossification, in which primary ossification occurs in the diaphysis of the of the bone and secondary ossification occurs in the epiphysis.
Good Job!

22. Bony Structures Rigid foundation
Projections and processes for muscle and ligament attachment
Depressions and hollows for articulations – the connection of bones at joints
Openings for blood vessels and nerves

23. Bony Structures (cont.)
Term
Definition
Condyle
A rounded process that usually articulates with another bone
Crest
A narrow, ridge-like projection
Epicondyle
A projection situated above a condyle
Foramen
An opening through a bone that is usually a passageway for blood vessels, nerves, or ligaments
Fossa
A relatively deep pit or depression

24. Bony Structures (cont.)
Term
Definition
Head
An enlargement on the end of a bone
Process
A prominent projection on a bone
Suture
An interlocking line of union between bones
Trochanter
A relatively large process
Tubercle
A small, knoblike process
Tuberosity
A knoblike process, usually larger than a tubercle

25. The Skull Two bone types:
Cranial – form the top, sides, and back of the skull
Facial – form the face
“Soft spots” felt on an infant's skull are actually fontanels
Tough membranes that connect the incompletely developed bones

26. Apply Your Knowledge GREAT! ANSWER: Match the following:
___ Epicondyle A. A relatively deep pit or depression
___ Fontanels B. An interlocking line of union between bones
___ Fossa C. “Soft spots” felt on an infant’s skull
___ Process D. A knoblike process, usually larger than a tubercle
___ Suture E. A projection situated above a condyle
___ Tuberosity F. A prominent projection on a bone C A F B D

27. The Skull: Cranial Bones
Frontal – anterior
Parietal – top and most of the sides
Occipital – back
Temporal – form the lower sides of the skull
Sphenoid and ethmoid bones – floor
Ear ossicles are the smallest bones of the body
Malleus
Incus
Stapes

28. The Skull (cont.) Palatine – form the anterior portion of the palate
Vomer – a thin bone that divides the nasal cavity
Mandible – forms the lower jaw bone
Maxillae – form the upper jawbone
Zygomatic – form the prominence of the cheeks
Nasal bones – fuse together to form the bridge of the nose
Click to see Skull

29. Very Good! Apply Your Knowledge ANSWER: Match the bones of the skull:
___ Occipital A. Form the upper jawbone
___ Sphenoid B. A thin bone that divides the nasal cavity
___ Mandible C. Part of floor of skull
___ Maxillae D. Form the prominence of the cheeks
___ Zygomatic E. Back of skull
___ Vomer F. Lower jaw bone C F A
Very Good! D B

30. The Spinal Column 7 cervical vertebrae 12 thoracic vertebrae
5 lumbar vertebrae
Sacrum
Coccyx

31. The Spinal Column (cont.)
Cervical vertebrae
Smallest and lightest
Located in the neck region
First one is atlas
Second one is axis
Thoracic vertebrae
Join the 12 pairs of ribs
Lumbar vertebrae
Have very sturdy structures

32. The Spinal Column (cont.)
Sacrum
A triangular-shaped bone that consists of five fused vertebrae
Coccyx
A small, triangular-shaped bone made up of 3 to 5 fused vertebrae
Considered unnecessary
More commonly called the tailbone

33. Right! Apply Your Knowledge ANSWER:
Cervical – 7
ANSWER:
Identify the sections of the spinal column and give the number of vertebrae for each.
Thoracic – 12
Sacrum – 5 fused
Lumbar – 5
Right!
Coccyx – 3 to 5 fused

34. The Rib Cage Sternum Breastplate
Forms the front middle portion of the rib cage
Joins with the clavicles and most ribs
Xyphoid process
Cartilaginous tip

35. The Rib Cage (cont.) 12 pairs of ribs False
All are attached posteriorly to thoracic vertebrae
True
First seven pairs of ribs
Attach to sternum by costal cartilage
False
Rib pairs 8, 9, and 10
Attach to the costal cartilage of rib pair 7
Floating
Rib pairs 11 and 12
Do not attach anteriorly to any structure

36. Apply Your Knowledge BRAVO! ANSWER: T F F T F True or False:
___ The sternum forms the front middle portion of the rib cage.
___ The xyphoid process is a boney tip of the sternum.
___ The true ribs are the first five pairs of ribs.
___ False ribs attach to the costal cartilage of rib pair seven.
___ Floating ribs attach to the xyphoid process. F
cartilaginous F
seven T F
do not attach anteriorly to any structure.

37. Bones of the Shoulders, Arms, and Hands
Shoulders – pectoral girdles
Clavicles
Scapulae
Upper limb or arm bones
Humerus
Radius
Ulna

38. Bones of the Shoulders, Arms, and Hands (cont.)
8 carpals per hand
5 metacarpals per hand
14 phalanges per hand
3 in each finger
2 in each thumb

39. Apply Your Knowledge Excellent! ANSWER: A B B C A B C C
Match the following:
___ Clavicle A. Pectoral girdle
___ Radius B. Arm bones
___ Humerus C. Hands
___ Carpals
___ Scapula
___ Ulna
___ Phalanges
___ Metacarpals A
ANSWER: B B
Excellent! C A B C C

40. Bones of the Hips, Legs, and Feet
Hipbones
Coxal bones form the pelvic girdle
Ilium
Ischium
Pubis

41. Bones of the Hips, Legs, and Feet (cont.)
Bones of leg
Femur
Patella
Tibia
Fibula

42. Bones of the Hips, Legs, and Feet (cont.)
Bones of the foot
Tarsals
Metatarsals
Phalanges

43. Super! Apply Your Knowledge ANSWER: B Match the following:
A. Coxal bones B. Leg bones C. Foot bones
___ Tibia ___ Patella
___ Ilium ___ Ischium
___ Femur ___ Metatarsals
___ Pubis ___ Fibula
___ Calcaneus ___ Tarsals B A A C B A B
Super! C C

44. Joints Junctions between bones Classification based on structure
Fibrous joints
Connected together with short fibers
Between cranial bones and facial bones
Sutures – fibrous joints in the skull

45. Joints Cartilaginous joints
Connected together with a disc of cartilage
Between vertebrae

46. Joints Synovial joints Covered with hyaline cartilage
Held together by a fibrous joint capsule lined with synovial membrane
Secretes synovial fluid so bones move easily against each other
Freely movable
Bones are also held together through tough, cord-like structures called ligaments

47. Apply Your Knowledge Yippee! ANSWER: A C B C A Match the following:
A. Fibrous joints B. Cartilaginous joints C. Synovial joints
____ Between cranial bones and facial bones
____ Covered with hyaline cartilage
____ Between vertebrae
____ Freely movable
____ Sutures in the skull C B
Yippee! C A

48. Common Diseases and Disorders
Arthritis – general term meaning joint inflammation
Osteoarthritis – degenerative joint disease, primarily of weight-bearing joints
Rheumatoid Arthritis – chronic systemic inflammatory disease of smaller joints and surrounding tissues

49. Common Diseases and Disorders (cont.)
Bursitis – inflammation of a bursa (fluid-filled sac that cushions tendons)
Carpal Tunnel Syndrome – overuse of wrist; the median nerve in the wrist becomes compressed
Ewing’s Family of Tumors (EFT) – a group of tumors that affect different tissue types; primarily bone
Gout – a type of arthritis; deposits of uric acid crystals in the joints

50. Common Diseases and Disorders (cont.)
Kyphosis – abnormal curvature of the spine (humpback)
Lordosis – exaggerated inward curvature of the lumbar spine (swayback)
Osteogenesis imperfecta – brittle-bone disease
Osteoporosis – a condition in which bones thin (become porous) over time

51. Common Diseases and Disorders (cont.)
Osteosarcoma – a type of bone cancer that originates from osteoblasts, the cells that make bony tissue
Paget’s disease – causes bones to enlarge and become deformed and weak
Scoliosis – an abnormal S-shaped curvature of the spine

52. Nice Work! Apply Your Knowledge
The doctor has told your patient that he has an osteosarcoma. What do you know about this disorder?
Osteosarcoma is a type of bone cancer that originates from osteoblasts, the cells that make bony tissue.
Nice Work!

53. In Summary Skeletal system Two divisions
Bone growth through ossification
Functions
Supports the body
Protects internal organs
Attachment for muscles for movement
Stores minerals
Produces new blood cells by hematopoiesis
Joined by three types of joints

54. Rigid, the skeleton of habit alone upholds the human frame.
End of Chapter
End of Chapter 25
Rigid, the skeleton of habit alone upholds the human frame.
~ Virginia Woolf