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Home , Appendicular skeleton, Condyle, Long bone

The Skeletal System 206 in t he Human Skelet on

2 Bones are Organs

 Each is a complex living organ made up of many cells, protein fibers, and minerals.  They come in many sizes and shapes.  The largest bone is the and the smallest is the .  The is pictured here.

3 The Skeletal System Also Includes

 Joints   Ligaments

4 Anatomy of the Skeletal System

5 Two Divisions of the

Axial Skeleton &

Appendicular Skeleton 6

 Bones that   Vertebrae form the  longitudinal  axis of the  Bony body make  up the axial  skeleton  Cranium  Facial Bones

7 Axial Skeleton

 Vertebral Column  Bony Thorax or Cage  Skull

8 Vertebral Column

 Composed of 33 bones before birth; some later fuse to form 26 separate bones  7 (red)  12 (blue)  5 (yellow)  Sacrum – 5 fused (green)  Coccyx – 4 fused (purple)

9 Structure of a Vertebrae

10 Cervical Vertebrae

 7 vertebrae located in the neck  Smallest and lightest vertebrae

11 & Axis

The first is The second vertebra called the atlas, C1. is called the axis, C2.

12 Thoracic Vertebrae

 12 thoracic vertebrae  Articulate with ribs  Larger than cervical vertebrae  Long spinous process that hooks sharply downward

13 Lumbar Vertebrae

 5 lumbar vertebrae  Much larger than other vertebrae to support the weight of the upper body 14 Bony Thorax or

 12 pairs of ribs articulate with the 12 thoracic vertebrae posteriorly  True ribs, pairs 1-7 (red), articulate anteriorly directly to the sternum by  False ribs, pairs 8-12 (green & blue), articulate indirectly or not at all  The last 2 pair do not connect at all and are called floating ribs (blue). 15 Sternum

Manubrium

Body

Xiphoid Process

16 The Skul l

— The skull is for med by t wo set s of bones: — Cranium — Fa cial bones — All are j oined by immovable j oint s except for t he (jawbone)

17 Lateral View of Skul l

18

 No direct articulation to another bone  Provides attachment for these muscles:  Floor of mouth  Tongue  Larynx  Epiglottis  Pharynx

19 Auditory

The smallest bones in the body are located in the middle :   Stapes

20 Appendicular Skeleton

Includes the  Pectoral (Shoulder) Girdle  Collar bones limbs and the  Shoulder blades  Upper Limbs girdles which  attach the  Pelvic () Girdle  Coxal Bones limbs to the  Lower Limbs  Legs axial skeleton  Feet

21 Appendicular Skeleton

 Pectoral Girdle: ,  Upper Limbs: humerus, , , carpals, metacarpals, phalanges  Pelvic Girdle: , and  Lower Limbs: femur, , , , tarsals, metatarsals, phalanges

22 Pectoral Girdle

 The clavicle is commonly called the collar bone.  The scapula is commonly called the shoulder blade.

23 Bones

• Humerus: Upper Arm Bone • Radius: to thumb side of the • Ulna: elbow to pinkie side of the wrist

24 Bones of the

Phalanges

Metacarpals

Carpals

25 Pelvic Girdle

 The pelvic girdle consists of two coxal or hip bones.  Each hip bone is formed from the fusion of 3 bones:  Ilium  Ischium  Pubis

26 The Coxal Bones

27 Leg Bones

 Femur – bone  Patella – cap  Tibia – large bone in lower leg; sometimes called the shin bone  Fibula – smaller bone in lower leg; forms the lateral ankle

28 Bones of the

Tarsals

Metatarsals

Phalanges

29 Flat Irregular Shape s of Long Bones Short • Long • Short • Flat Sesamoid • Irregular • Sesamoid

30 Two Basic Types of Bone

Compact Bone is dense Spongy Bone is composed and looks smooth and of small pieces of bone homogeneous. and lots of open space.

31 Compact Bone • In long bones, surrounds spongy bone at ends • Along shaft surrounding Spongy Bone • At ends of long bones 32 Microscopic Anatomy of Spongy Bone

 The open spaces keep bones light  Found in the ends of long bones  Also fills short bones, flat bones and some parts of irregular bones  Contains red marrow

33 Microscopic Anatomy of Compact Bone

 Composed of a matrix of hard mineral salts reinforced with tough collagen fibers  Bone cells are called  Osteocytes are found in tiny cavities within the matrix called lacunae

34 bone cell 35 Gross Anatomy of a

 Shaft  Composed of compact bone   Ends of the bone  Composed mostly of spongy bone

36 Other Features of Long Bones • Articular Cartilages: cover epiphyses for smooth movement • : marking left from growth at • : fibrous, connective tissue that covers the diaphysis 37

 Red Marrow – in cavities of spongy bone in flat bones and epiphyses of long Red Marrow bones, site of hematopoiesis Medullary Cavity Yellow Marrow  Yellow Marrow – fat storage in medullary Compact Bone

cavity Periosteum

38 Bone Markings

 Bumps, holes, and ridges Projections: where muscles, tendons,  Tuberosity and ligaments are  Trochanter attached and where blood  Tubercle vessels and nerves pass  Process through   Two categories: Depressions or  projections or Openings: processes  Meatus  depressions or cavities  Fossa  Foramen

39 Examples of Bone Markings

Styloid Process

Olecranon Process Fossa

40 Bone Markings on the Femur

Proximal Posterior Distal Anterior

41 Joints

 Also called Three Types: articulations 1. Fibrous – no movement, ex: skull  Where two 2. Cartilaginous – slightly bones meet moveable, ex: pubic  Hold bones symphysis, vertebrae together, but 3. Synovial – bones also give separated by cavity mobility filled with synovial fluid, allow the most movement 42 Synovial Joints

 Articular cartilage  Fibrous articular capsule  Joint cavity – contains fluid  Reinforced by ligaments

43 Types of Synovial Joints

44 Ball and Socket Joints

 The most moveable type of joint  Found in the shoulder and hip

45 Physiology of the Skeletal System

46 Function Overview Support Protection Movement Hematopoiesis Storage

47 Support Internal framework that supports and anchors all soft organs.

48 Protection Protects soft body organs

49 Movement

 Skeletal muscles attach to bones by tendons  Tendons use the bones as levers to move body parts

50 Storage

 Fat storage in yellow marrow  The minerals calcium and phosphorous are stored in bone tissue

51 Hematopoiesis

Blood cell formation occurs in red marrow.

52 Developmental Aspects

53 Fontanels

 Spaces between bones of the skull in an infant  Commonly called soft spots  Fully ossified by 2 years  Allows for growth of the brain and skull 54

 Ossification is the formation of bone from cartilage  At birth, bones are part cartilage and part bone  The skeleton is fully ossified by age 2 except for epiphyseal (growth) plates

55 Longitudinal Growth

 X-ray of 12 year old showing epiphyseal (growth) plates at the distal ends of the tibia & fibula  Epiphyseal plates are fully ossified by the end of adolescence 56 Bone Formation & Growth Key Terms:

 Ossification – bone formation  Epiphyseal plates – provide for longitudinal growth; increase in length  Appositional growth – increase in diameter  – bone-building cells  – bone-destroying cells

57 Bone Remodeling

 Breaking down & reforming of bone that occurs throughout life to maintain proportion & strength as well as healthy calcium levels

58 Osteoporosis • Weakening of the bone that occurs with aging • One in two women and one in four men over age 50 will have an osteoporosis- related fracture.

59 Hip Fracture

 A hip fracture is actually a femoral fracture that occurs in the proximal end of the femur near the hip  The 1-year mortality rate after a hip fracture is 20% X-ray following hip replacement 60 Diseases and Conditions

61 Types of Fractures

62 Arthritis

Osteoarthritis usually Rheumatoid Arthritis part of aging autoimmune disease

Arthritis is an inflammation of the joints. 63 Rickets

 Lack of vitamin D, calcium, or phosphorous  Bones fail to calcify; stay soft  Usually in children ages 3-36 months  Rare in developed countries

64 Herniated Disc

 Protruding discs of cartilage between the vertebrae  Can irritate nearby nerves and result in pain, numbness or weakness in an arm or leg

65

 Abnormal curvature of the spine  May be congenital or result from disease or trauma

66

The Skeletal Syst em

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