1. Skeletal System
Chapter 6
Pages 86 – 117

2. Page 87
Functions
Support – it supports body structures & provides shape to the body
Protect – it protects the soft & delicate internal organs
Movement & anchorage of muscles.
Mineral storage (calcium & phosphorus) – in case of inadequate nutrition, the body is able to draw upon these reserves.
Hematopoiesis (formation of blood cells) – occurs in red bone marrow
There are 206 individual bones in the adult. Some bones are hinged; others are fused to one another.
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3. Muscles that are attached to the skeleton are called skeletal muscles. Upon contraction, these muscles exert a pull on a bone & so move it. In this manner, bones play a vital part in body movement, serving as passively operated levers.
Ligaments are fibrous bands that connect bones to bones & cartilage & serve as support for muscles. Joints are also bound together by ligaments.
Tendons are fibrous cords that connect muscles to bone.
5. Stem cells in the red marrow tissue of the bone differentiate into red blood cells, white blood cells, & platelets.
In an adult, the ribs, sternum, & bones of the pelvis contain red marrow.
Red bone marrow at the ends of the humerus & femur are plentiful at birth but gradually decrease as we age.

3. Structure & Formation of Bone
Chapter 6
Structure & Formation of Bone
Osteocytes – Mature bone cell
Bone is made of:
35% Organic material (flexibility)
Collagen – a fibrous material
Jellylike material – resides between the collagen
65% Inorganic material (hardness & durability)
calcium phosphate, calcium carbonate, calcium fluoride, magnesium phosphate, sodium oxide, & sodium chloride
Water
When pressure is applied to a bone, the flexible organic material prevents bone damage, while the mineral elements resist crushing or bending under pressure.

4. Page 87
Bone Formation
Embryonic skeletons initially consists of collagenous protein fibers secreted by osteoblasts.
Later, during embryonic development, cartilage is deposited between the fibers.
During the eighth week of embryonic development, ossification begins. (mineral matter starts to replace previously formed cartilage, creating bone). Infant bones are very soft & pliable because of incomplete ossification at birth.
Cartilage, a connective tissue, is also found at the ends of certain bones in adults, providing a smooth surface for adjacent bones to move against each other.
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A familiar example is the soft spot on a baby’s head, the fontanel. The bone has not yet been formed there, although it will become hardened later.
Ossification due to mineral deposits continues through childhood. As bones ossify, they become hard & more capable of bearing weight.

5. Structure of Long Bone Page 88
Diaphysis (Shaft) – Hollow cylinder made of compact bone
Epiphysis – Each end of the long bone (Covered by articular cartilage – which acts as a shock absorber)
Medullary canal – The center of the shaft of a long bone (contains Yellow bone marrow)
Endosteum – lining of the marrow canal
Haversian canal: carries blood vessels that nourish bone cells (osteocytes)

6. Structure of Long Bone (Cont’d)
Page 88
Structure of Long Bone (Cont’d)
Spongy (cancellous) bone – at the ends of long bones contains Red marrow where red blood cells & some white blood cells are manufactured
Periosteum – covers the outside of the bone; contains blood vessels, lymph vessels, & nerves.
Necessary for bone growth, repair & nutrition

7. Page 88
Figure 6-1

8. Pages 88 – 89
Growth
Bones grow in length; Ossify from the center outward
Osteoblasts = Deposit new bone
Osteoclasts = Large cells that secrete enzymes that break down bone
Growth stops when all the epiphyseal cartilage (also known as the growth plate) is ossified
Females grow until about 18 years of age
Males grow until about 20–21 years of age
Medullary canal gets larger as the diameter of the bone increases. It eventually fills with yellow marrow

9. Page 89
Bone Types
Long bones
Flat bones
Irregular bones
Short bones

10. Page 90
Skeletal System
Axial skeleton – Skull, spinal column, ribs, sternum, & hyoid bone
Appendicular skeleton – Upper & lower extremities

11. Axial Skeleton Pages 90 – 94 22 bones of the skull 14 facial bones
Spinal column (vertebra)
Cervical 7 vertebrae
Thoracic 12 vertebrae
Lumbar 5 vertebrae
Sacrum 5 fused bones
Coccyx 4 fused bones
Ribs (12) & sternum

12. Page 92
Figure 6-4

13. Page 93
Figure 6-5

14. Page 94
Figure 6-7

15. Appendicular Skeleton – Upper Extremities
Page 94 – 95
Appendicular Skeleton – Upper Extremities
Shoulder girdle – 2 clavicles & 2 scapulae
Arm – Humerus, radius, ulna
Hand – Carpals, metacarpals & phalanges (fingers)

16. Page 94 – 95

17. Page 95

18. Page 95
Figure 6-9

19. Page 94 – 95

20. Appendicular Skeleton – Lower Extremities
Pages 96 – 99
Appendicular Skeleton – Lower Extremities
Pelvic girdle – Ilium, ischium & pubis
Upper leg – Femur
Lower leg – Tibia, fibula & patella
Ankle – 7 tarsal bones
Foot – Metatarsal & phalanges (toes)

21. Chapter 6

22. Chapter 6

23. Chapter 6

24. Chapter 6

25. Page 99
Figure 6-15

26. Joints (Articulations)
Chapter 6
Joints (Articulations)
Diarthroses – movable joint – most common
Articular cartilage – smooth, slippery cap of cartilage
Articular capsule – tough, fibrous connective tissue; encloses the articular surfaces of bone
Synovial membrane – lines articular capsules; secretes Synovial fluid (lubricating substance) into the Synovial cavity (area between 2 articular cartilages) reduces friction
Bursae – found in spaces of connective tissue between muscles, tendons, ligaments, & bones.
Amphiarthroses – partially movable joints
Synarthroses – immovable joints
Points of contact between two bones
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Articular cartilage – helps absorb shocks & prevent friction
Bursae (closed sacs with a synovial membrane lining)

27. Page 100
Figure 6-16

28. Diarthroses Joints (Moveable)
Page 101
Diarthroses Joints (Moveable)
Ball-and-socket joints – Shoulder, hip
Allow the greatest freedom of movement.
Hinge joints – Knees, elbows, fingers
Move in one direction or plane
Pivot joints – Radius & ulna; atlas & head
Allows the joint to rotate
Gliding joints – vertebrae
Allow bend forward, backward, & sideways as well as rotate
Ball & socket joints = one bone has a ball-shaped head that nestles into a concaved socket of the second bone.

29. Amphiarthroses Joints
Page 101
Amphiarthroses Joints
Partially movable joints
Cartilage between their articular surfaces
Examples:
Ribs to the spine
Symphysis pubis

30. Synarthroses Joints Page 101 Immovable joints
Connected by tough, fibrous connective tissue
Example:
Adult cranium (Cranial joints are called sutures)

31. Page 101
Types of Motion
Flexion – Decreasing the angle between 2 bones
Extension – Increasing the angle between 2 bones
Abduction – Away from the midline
Adduction – Towards the midline
Circumduction – full range of motion
Rotation – Movement around a central axis
Pronation – Palm down & back
Supination – Palm up & forward

32. Page 102
Figure 6-18

33. Disorders of the Bones & Joints
Page 102
Disorders of the Bones & Joints
Fracture (same as a “break”)
Hairline – a tiny crack that usually heals itself
Greenstick – simplest type of fracture. The bone is partially bend but never completely separates.
Closed/simple – the broken ends do not piece through the skin to form external wounds
Open/compound – broken ends piece & protrude through the skin.
Comminuted – bone is splintered or broken into many pieces that can become embedded in the surrounding tissue

34. Page 103
Figure 6-19

35. Repairing Fractures Page 103
The process of restoring bone occurs through three main methods:
Closed reduction – the bony fragments are brought into alignment by manipulation, & a cast or splint is applied
Open reduction – through surgical intervention, devices such as wires, metal plates, or screws are used to hold the bone in alignment & a cast or splint may be applied
Traction – a pulling force is used to hold the bones in place (used for fractures of the long bone)

36. Aging of the Bones & Joints
Page 104 SB
Aging of the Bones & Joints
Bone mass & density decline
External surfaces of the bones thicken
Intervertebral cartilage disks shrink
Center of balance is altered
Joints less mobile
Increased rigidity & decreased flexibility
Fear of falling

37. Other Bone & Joint Injuries
Page 104 – 105
Other Bone & Joint Injuries
Dislocation – Displacement of a bone from its proper position
Sprain – Ligament injury with pain & swelling
Hammer toe – Curled toe due to a bend in the middle phalanx from abnormal pressure on the toe
Whiplash – Neck (cervical) injury from car accident or fall
RICE Treatment – Rest, ice compression, elevation

38. Diseases of the Bone Page 104 – 106
Arthritis – 20 different kinds most common:
Rheumatoid arthritis = autoimmune disease affects the connective tissue
Osteoarthritis = degenerative joint disease
Gout
Due to high levels of uric acid in the blood
Usually affects the great toe
Painful swollen red joint
Rickets
Lack of vitamin D in children
Lifestyle & Home remedies = Weight loss, physical activity, rest, & heat & cold packs – use a cane
Complementary & Alternative Therapies = Yoga & tai chi; Acupuncture; Supplement but do your research
Surgical procedure = Joint replacement

39. Abnormal Curvatures of the Spine
Page 107
Abnormal Curvatures of the Spine
Kyphosis = hunchback
Lordosis = swayback
Scoliosis = side-to-side or lateral curvature of the spine

40. Page 108 – 109
Other Disorders
Osteoporosis = Low bone mass with structural deterioration of the bone
Osteomyelitis = Infection in the bone
Osteosarcoma = Cancer of the bone