1. SKELETAL SYSTEM

2. Functions of the Skeletal System
A. Bones are made of OSSEOUS TISSUE
FUNCTIONS:
1.Support
2. Protection
3.Body movement
4. Blood cell formation (bone marrow) - hematopoiesis
5. Storage of inorganic materials                     (salt, calcium, potassium….)

3. 2. 2 Main Divisions – Axial & Appendicular
B. ORGANIZATION
1. About 206 bones
2. 2 Main Divisions – Axial & Appendicular

4. Classification of Bones: BASED ON SHAPE
There is 2 basic types of osseus, or bone, tissue:
a. COMPACT BONE – dense, looks smooth, homogeneous
b. SPONGY BONE – composed of small needlelike pieces of bone and open space

5. 2. Long bones – longer than they are wide, have shaft with heads at both ends; have mostly compact bone
a. all limbs - ex, humerus and femur
3. Short bones – cube-shaped and contain mostly spongy bone.
a. Wrist and ankle
4. Flat bones – thin, flattened, usually curved.
a. Skull, ribs, sternum are flat
5. Irregular bones– do not fit into another category
a. Vertebrae

6. 1. Compact (wall of the diaphysis)
Types of Bone Tissue
1. Compact (wall of the diaphysis)
2. Spongy (cancellous, epiphysis) - red marrow

7. 1. Medullary Cavity – hollow chamber filled with bone marrow
Inside the Long Bone
1. Medullary Cavity – hollow chamber filled with bone marrow
2. Red Marrow - (red blood cell formation)
3. Yellow Marrow - (fat replaces much of the red marrow in diaphysis throughout childhood )
4. Endosteum– lining of the medullary

8. BONE STRUCTURE – 5 PARTS of a Long Bone
Epiphysis – on each end
Diaphysis – main body/shaft of bone
Articular Cartilage –
on ends for joint movement
4. Periosteum – outer covering
5. Medullary cavity – hollow chamber within diaphysis that connect to spaces in spongy bone. Filled with bone marrow.

9. * Assignment
– Coloring of a Long Bone

10. Structure of a Long Bone
Figure 6.3a-c

11. Review the Structure of a Long Bone
Matching quiz at

12. Axial Skeleton 1. Head, neck, trunk a. Skull b. Hyoid Bone
c. Vertebral Column
d. Thoracic Cage
(ribs, 12 pairs including true and false and floating ribs)
e. Sternum

13. Hyoid Bone – closely related to mandible and temporal bone
Unique that it is the only bone of the body that does not articulate directly with any other bone.
2. Serves as a movable base for the tongue and attachment point for neck muscles that raise and lower the larynx when we speak and swallow.
3. Is more prominent in males than females.

14. Appendicular Skeleton
Limbs & Bones that connect to the
Pectoral Girdle (shoulders)
Pelvic Girdle (hips)

15. Microscopic Structure – of Bone Growth and Development
1. MATRIX - where the bone cells live
2. OSTEOCYTES  - mature bone cells, enclosed in tiny chambers called LACUNAE
3. OSTEOCYTES form rings (LAMELLAE) around a HAVERSIAN CANAL which houses blood vessels
4. Osteocytes are linked by CANALICULI
5. Haversian Canals are linked by VOLKMAN's CANALS

16. Compact Bone
BONE COLORING!

17. Test Yourself
Find the...
Haversian Canal
Volkman's Canal
Lamellae
Spongy Bone
Compact Bone

19. BONE DEVELOPMENT & GROWTH
Intramembranous bones –
are flat, ex. Skull
2. Endochondral bones –
all other bones
3. ALL BONES start as
hyaline cartilage, areas
gradually turn to bone (through the process of OSSIFICATION)      
4. PRIMARY ossification center (shaft)       
5. SECONDARY ossification center(ends)

20. Bone Development & Growth
6. EPIPHYSEAL DISK  (growth plate) is a band of cartilage between the epiphysis and diaphysis
7. These areas increase bone length as the cells ossify
8. Cartilage becomes OSTEOBLASTS become OSTEOCYTES

21. RESORPTION
Bone tissue is constantly being replaced as special cells called OSTEOCLASTS dissolve bone tissue from within the medullary cavity and releases minerals- a process called RESORPTION.
At the same time new bone tissue is being added to the outside of the bone.
Assignment: Coloring of an Aging Hand

22. Bone Growth

23. Bone Growth

24. Function of Joints Hold bones together securely
Give the rigid skeleton mobility.

25. Types of Joints (Also called Articulations!)
Synarthrotic (not moveable, ex. sutures of the skull)
Amphiarthrotic (slightly moveable,
ex. vertebrae)
3. Diarthrotic (moveable joint, ex. synovial joints like knee or hips)

26. Synovial fluid - fluid within the joints that helps to lubricate
Types of Joints:
1.  Ball and Socket
(example – shoulder/hip)
2.  Hinge
(example – knee)
3.  Pivot
(example – elbow)
4.  Saddle
(example – fingers)

27. BONES OF THE SKULL (Lab Test)
1. Frontal - 2. Parietal Occipital - 4. Temporal Sphenoid Maxilla Mandible -
8. Zygomatic -

28. More Bones of the Skull to know!
9. Lacrimal
10. Ethmoid
11. Nasal
12. External
Auditory meatus
13. Mastoid process
14. Styloid Process
15. Temporo-mandibular joint
16. Sagittal suture
17. Lambdoid suture
18. Squamous suture
19. Coronal suture
20. Foramen magnum
21. Mental foramen

29. TOPOGRAPHY OF THE SKULL
Foramen - refers to any tiny opening, nerves and blood vessels leave this opening to supply the face
Mental Foramen

30. Suture - refers to any connection between large bones (in fetal skulls, these are called fontanels)
Fissure - any wide gap between bones

31. Sutures
1. Coronal - between frontal and parietal bones 2. Lambdoid - between occipital and parietal bones 3. Squamous - between temporal and parietal bones 4. Sagittal - between parietal bones

32. Bones of the Skull & Sutures

33. Foramen Magnum
* Assignment: Skull Labeling

35. Figure 6.10

36. Figure 6.10

38. Fetal Skull
5. The largest fontanels are the anterior fontanel and posterior fontanel; which allows the skull to be compressed slightly during birth.
6. Allows the brain to grow and develop in the womb and infancy.
The adult skull represents only 1/8 of the total body length.
The newborn infant skull is only 1/4 as long as its entire body.
Areas of newborn’s skulls are still hyaline cartilage, called fontanels. (until age 2)
4. The rhythm of the baby’s pulse can be felt in these “soft spots”

39. The Rest of the Bones

40. Vertebrae Neck = cervical (C1 – C7) Middle Back = thoracic (T1 – T12)
Middle Back = thoracic
(T1 – T12)
Lower Back = lumbar (L1 – L5)
Sacrum = 5 fused vertebrae
Coccyx = tailbone

41. Thoracic Cage

42. Pectoral Girdle

43. Bones of the Arm a. Humerus – upper arm
b. Ulna goes to pinky  (P-U or “UP”)
c. Radius goes to thumb (RT)

44. Wrist Bones
For test:
a. Carpals
b. Metacarpals
c. Phalanges

45. Name the carpals for extra credit on test.

46. Pelvic Girdle – Wider in females than males Sacrum – 5 fused vertebrae

47. Bones of the Leg

48. Bones of the Ankle For Test: Calcaneous Tarsals Metatarsals Phalanges
Assignment – Skeleton Labeling

50. What you should have on your “Mr. Bones” labeling sheet!

51. https://youtube.googleapis.com/v/btMq9BYziIQ

52. Broken Bones – heal faster than ligaments or tendons because they have a greater or richer blood supply

55. *A compound fracture is most dangerous.
1. Because it’s an open fracture that may result in a severe bone infection (osteomyelitis), requiring massive doses of antibiotics.
2. While a simple fracture is incomplete, not breaking the skin.
A simple fracture is sometimes called a “closed fracture”.

56. Fractures are treated by reduction.
Closed Reduction:
The bone ends are coaxed back into their normal position by the physician’s hands.
Open Reduction:
Surgery is performed and the bone ends are secured together with pins or wires, then immobilized by a cast or traction for healing.

57. Abnormal Bone Conditions
1. BONE SPURS: abnormal growth. Can occur on any bone (e.g. heel).
2. OSTEOPOROSIS: Increased activity of osteoclasts cause a break down bone, and the subsequent fewer minerals in the extracellular matrix make it fragile. The spongy bone especially becomes more porous.
3. Men get it as well as women. What’s the best way to prevent osteoporosis? Exercise! What does exercise do? Makes bones bigger.
4. The most common bone used for a bone graft is the iliac bone of the hip.

58. Osteoporosis
Figure 6.15

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60. Arthritis 60

61. 61

62. 62

63. Rheumatoid arthritis is an autoimmune disease which causes joint stiffness and bone deformity
Source: 

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65. ABNORMALITIES OF THE SPINE
1. SCOLIOSIS is a lateral curve in the spine
2. KYPHOSIS is a hunchback curve
3. LORDOSIS is a swayback in the lower region.
4. ANKYLOSIS is severe arthritis in the spine and the vertebrae fuse.

66. SCOLIOSIS

67. LORDOSIS

68. ANKYLOSIS

69. Rickets – disease of children which bones fail to calcify resulting in bone softening and bowing of the weight-bearing bones of legs. Is due to a lack of Vitamin D and calcium in the blood.

70. Bursitis
Inflammation of the Bursa (fluid filled sac surrounding the joint).
A bursa can become inflamed from injury, infection (rare in the shoulder), or due to an underlying rheumatic condition.
Bursitis is typically identified by localized pain or swelling, tenderness, and pain with motion of the tissues in the affected area. 70

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72. Tendonitis
Sometimes the tendons become inflamed for a variety of reasons, and the action of pulling the muscle becomes irritating.
If the normal smooth gliding motion of your tendon is impaired, the tendon will become inflamed and movement will become painful.
This is called tendonitis, and literally means inflammation of the tendon.
The most common cause of tendonitis is overuse. 72

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74. Carpal Tunnel Syndrome
Any condition that causes swelling or a change in position of the tissue within the carpal tunnel can squeeze and irritate the median nerve. Irritation of the median nerve in this manner causes tingling and numbness of the thumb, index, and the middle fingers, a condition known as "carpal tunnel syndrome." 74

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76. Gout
Gout is a disease that results from an overload of uric acid in the body. This overload of uric acid leads to the formation of tiny crystals of urate that deposit in tissues of the body, especially the joints.
When crystals form in the joints it causes recurring attacks of joint inflammation (arthritis).
Chronic gout can also lead to deposits of hard lumps of uric acid in and around the joints and may cause joint destruction, decreased kidney function, and kidney stones. 76

77. GOUT 77

78. Leukemia
Leukemia is cancer of the blood cells. It starts in the bone marrow, the soft tissue inside most bones. Bone marrow is where blood cells are made.
When you are healthy, your bone marrow makes:
･White blood cells, which help your body fight infection.
･Red blood cells, which carry oxygen to all parts of your body.･Platelets, which help your blood clot.
When you have leukemia, the bone marrow starts to make a lot of abnormal white blood cells, called leukemia cells. They don't do the work of normal white blood cells, they grow faster than normal cells, and they don't stop growing when they should. 78

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80. Bone Marrow Biopsy 80

81. FUN FACTS ABOUT BONES
Bone is made of the same type of minerals as limestone.
Babies are born with 300 bones, but by adulthood we have only 206 in our bodies.
The giraffe has the same number of bones in its neck as a human: seven in total.
The long horned ram can take a head butt at 25 mph. The human skull will fracture at 5mph.