1. The Skeleton Bones & Joints
Chapter 7

2. Bones Main Functions: Framework for the body
Protect delicate structures (such as the brain & spinal cord)
Work with attached muscles to provide movement
Store calcium which is reabsorbed into the blood when there is not enough calcium in the diet
Produce red blood cells (in the bone marrow)

3. Skeletal Structure 206 bones
Skeleton is the complete bony framework of the body
Different shapes include:
FLAT – ribs & cranium (skull)
SHORT – wrist & ankles
IRREGULAR – face & vertebrae
LONG – arms & legs

4. Bone Tissue
Osseous Tissue (bone tissue) is made up of 2 types of tissue:
COMPACT BONE – hard & dense; makes up the main part of long bones and the outer layer of other bones
SPONGY BONE (cancellous bone) – has more spaces than compact bone & is made of a meshwork of small, bony plates filled with red marrow; found at the center of bones & ends of long bones

5. Bone Marrow
Red Marrow – found at the ends of long bones & center of other bones; manufactures blood cells
Yellow Marrow – found mainly in the central cavities of the long bones & comprised primarily of fat

6. Bone Membranes
Periosteum – covers the outside ( except at the joints) of the bone
Osteoblasts make up the inner layer
Essential in bone formation, growth and repair
Endosteum – a thinner membrane that lines the marrow cavity
Contains cells that aid in the growth and repair of bone tissue

7. Bone Growth & Repair
In the embryo, bones are composed of cartilage. During the 2nd & 3rd months of embryonic life, bones start to OSSIFY
Osteoblasts become active
OSSIFICATION – is the hardening and strengthening of bone tissue (due to the addition of minerals, such as calcium and phosphorus)
Conversion of cartilage to bone
**Long bones continue to grow into late teens

8. Bone Markings Distinguishing features that include:
Raised areas or depressions that help form joints, attach muscles and/or allow passage of nerves & blood vessels

9. Projections
Head – is the rounded, knob-like end of a bone (as in the end of the humerus)
Process – large projection of bone (as in the elbow)
Crest – a distinct border or ridge (as in the hip)
Spine – sharp projection of bone (as in the scapula “shoulder blade”)
Condyle - a rounded projection

10. Depressions or Holes
Foramen – hole that allows a vessel or nerve to pass through or between bones
Sinus – is an air space (found in some skull bones)
Fossa – a depression found on bone surfaces
Meatus - a short channel or passageway, such as the channel in the temporal bone of the skull that leads to the inner ear

11. The Axial Skeleton One of two main division of the skeleton Contains 80 bones of the skull and trunk
Cranium - 8
Facial Bones - 14
Ear Bones - 3 plus 1 for the tongue
Trunk
Vertebrae
Spine - 26 in the adult
Thorax
Ribs - 12 pairs
Sternum – anterior bone of thorax

13. The Appendicular Skeleton
Second division of the skeleton
Contains 126 bones of the extremities (limbs), shoulders and hips
Clavicle & scapula > shoulder
Humerus, ulna & radius > arm
Carpals > wrist
Metacarpals > palm
Phalanges > fingers
Os Coxae > pelvis
Femur > thigh bone
Patella > knee cap
Tibia & Fibula > bones of the lower leg
Tarsals > ankle
Metatarsals > foot
Phalanges > toes

21. Metabolic Bone Disorders
Osteoporosis is a lack of normal calcium and decrease in bone protein

22. Paget’s Disease
An abnormal calcium metabolism that causes bones to lose calcium followed by periods of excessive deposits of calcium which result in bone deformities

23. Rickets Rare childhood disease Caused by a deficiency of Vitamin D
Bones remain soft & become distorted because they cannot absorb calcium

24. Structural Bone Disorders
Scoliosis is a LATERAL curvature of the spine
Occurs during rapid growth periods
Occurs more often in girls than in boys

25. Kyphosis An exaggeration of the THORACIC curve
Also referred to as “HUNCHBACK”

26. Lordosis
An excessive LUMBAR curve
Also referred to as “SWAYBACK”

27. Cleft Palate
A congenital deformity with an opening in the roof of the mouth

28. Flat Foot Tendons & ligaments are weakened near the arch of the foot
Can be caused by:
Carrying excess weight
Poor posture
Heredity

29. The Joints Areas of junction or union between two or more bones
Three types:
Fibrous
Cartilaginous
Synovial

30. Fibrous Joints
Bones in this type of joint are held together by fibrous connective tissue
An example would be the joints that hold the bones of the skull together
This type of joint is IMMOVABLE

31. Cartilaginous Joints
Bones in this type of joint are held together by cartilage
An example would be the joints between the bodies of the vertebrae
This type of joint is SLIGHTLY movable

32. Synovial Joints
Filled with a thick, colorless fluid called synovial fluid
Bones in this type of joint have space between them called a synovial cavity
This type if joint is FREELY movable

33. Movement at Synovial Joints
Flexion – bending motion that decreases the angle between bones
Extension – straightening motion that increases the angle between bones

34. Abduction – movement away from the mid-line of the body
Adduction – movement towards the mid-line of the body

35. Circumduction is a combination of flexion, extension, abduction & adduction
Rotation is the twisting or turning of a bone on it’s axis

36. Supination is the act of turning the palm up
Pronation is the act of turning the palm down

37. Inversion is the act of turning the sole inward
Eversion is the act of turning the sole outward

38. Dorsiflexion is the act of pointing the toes upward, decreasing the angle between the lower leg and the top of the foot
Plantarflexion is the act of pointing the toes downward, increasing the angle between the lower leg and the top of the foot

39. Joint Disorders
Dislocations are a derangement of the parts of the joint

40. Arthritis
Inflammation of the joints

41. Gout
Overproduction of uric acid (a waste product in the blood) that causes crystals to form and settle around the joints

42. Backaches Causes can include: Infections Tumors Disk problems
Abnormal vertebral structure
Organ disease (especially the kidney)
Strains