1. Skeletal System

2. Function of the Skeletal System
Support- framework that supports body and cradles its soft organs
Protection- for delicate organs, heart, lungs, brain
Movement- bones act as levers for muscles
Mineral storage- calcium & phosphate
Blood cell formation- hematopoiesis in flat bones

3. Types of Bones
Long Bones- metacarples, metatarsals, phelangies, humerus, ulna, radius, tibia, fibula
Short Bones- carpals, tarsals
Flat Bones- rib, scapula, skull, sternum
Irregular Bones- vertebrae, some facial bones
Sesamoid- patella

4. Bone Classification

5. Accessory Structures Tendon: connects muscles to bones
Ligaments: connect bone to bone

6. Anatomy of a Long Bone spongy bone Proximal compact bone epiphysis
Endosteum
diaphysis
epiphyseal line
yellow marrow
Sharpey’s fibers
Distal
epiphysis
periosteum
hyaline cartilage

7. Structure of Bones
Outside – has layer of fibrous connective tissue that helps rebuild if broken called periosteum
Ends – called epiphysis. Cartilage for cushion-spongy bone-red marrow-RBC
Shaft – called diaphysis. Ca / P – makes it hard, collagen makes it flexible/ compact bone / yellow marrow-fat

9. Red blood cells, platelets and most white blood cells arise in red marrow .
* some white blood cells develop in yellow marrow.
The color of yellow marrow is due to the much higher number of fat cells.
Both types of bone marrow contain numerous blood vessels and capillaries.
At birth, all bone marrow is red.
With age, more and more of it is converted to the yellow type.

10. Adults have on average about 2. 6kg (5
Adults have on average about 2.6kg (5.7 lbs) of bone marrow, with about half of it being red.
Red marrow is found mainly in the flat bones, and in the spongy bone at the proximal ends of the long bones called femur and humerus.
In cases of severe blood loss, the body can convert yellow marrow back to red marrow in order to increase blood cell production.

12. Axial Skeleton
The bones that extend through the center of the body.

13. Appendicular Skeleton
The bones of your appendages and the bones that connect them to the axial skeleton.

14. Why do skull bones start out separate and unfused?
Fetal Skull
Why do skull bones start out separate and unfused?

15. Adult skulls have all the skull plates fused together

16. Sinal Cavities Frontal Sinus Ethmoid Sinus Sphenoid Sinus
Maxillary Sinus
Warm and moisten air
Lighten the skull
Enhance voice resonance

17. The Vertebral Column Cervical Vertebrae (7) Thoracic Vertebrae (12)
Axial Skeleton
The Vertebral Column
Cervical Vertebrae (7)
Thoracic Vertebrae (12)
Lumbar Vertebrae (5)
Sacrum
Coccyx

18. Vertebrae in each region are shaped different to accommodate different ranges of motion. More movements happening at neck and head than lower in back

19. Sacrum & Coccyx Axial Skeleton
The sacrum contains Haversian Canals. Haversian canals are holes in the bone that both blood vessels and nerves will exit the vertebral column from.

20. The Thoracic Cage Sternum True Ribs (7) False Ribs (3)
Axial Skeleton
The Thoracic Cage
Sternum
True Ribs (7)
False Ribs (3)
Floating Ribs (2)

21. Bones of the Pectoral Girdle
Appendicular Skeleton
Bones of the Pectoral Girdle

22. The Upper Limb (Forelimb)
Appendicular Skeleton
The Upper Limb (Forelimb)
Humerus
Ulna
Radius
Carpals
Metacarpals
Phalanges

23. Humerus

24. Ulna & Radius

25. Hand Bones

26. Appendicular Skeleton
Pelvis

27. Appendicular Skeleton
The Lower Limb (Legs)
Femur
Patella
Tibia
Fibula
Tarsals
Metatarsals
Phalanges

28. Femur

29. Patella

30. Tibia & Fibula

31. Foot
phelangies
metatarsals
tarsals
tarsals
metatarsals
phelangies

32. Types of Joints
Hinge Joint

33. Ball and Socket Joint

34. Fibrous Joints
Immovable Joints
suture
pubis symphisis

35. Slightly Movable Joint
Cartilagenous Joints
Slightly Movable Joint

36. 275 bones 12 weeks (6-9 inches long)
Fetal Skeleton
275 bones 12 weeks (6-9 inches long)

37. bone cartilage calcified cartilage epiphyseal line epiphyseal plate
Fetus: 1st 2 months
Endochondral Ossification
2o ossification center
bone
cartilage
calcified cartilage
Just before birth
epiphyseal line
epiphyseal plate
Childhood
Adult

38. Broken bones Can heal on their own cause they are living cells.
Once healed, usually stronger

39. Bone cells that aid in remodeling
Osteoblast
Builds new bone
Mature bone cell
Osteocyte
OsteoblastsOsteoblasts are responsible for building new bone and lie at the centre of bone physiology. Their functions include the synthesis of collagen and the control of mineralisation.
OsteoclastsOsteoclasts are specialised cells that resorb bone. They work by sealing off an area of bone surface then, when activated, they pump out hydrogen ions to produce a very acid environment, which dissolves the hydroxyapatite.
OsteocytesBone adapts to applied forces by growing stronger in order to withstand them; it is known that exercise can help to improve bone strength. Osteocytes are thought to be part of the cellular feed-back mechanism which directs bone to form in the places where it is most needed. They lie within mineralised bone and it is thought that they may detect mechanical deformation and mediate the response of the osteoblasts.
Osteoclast
Eats bone

40. Repair of Fractures
hematoma
callus
bony callus
bone
remodeling

41. Types of bone breaks
Stress factures: minute breaks in bone caused by constant overuse. (Happens a lot in the feet)
Break is hard to see on X-ray but becomes worse if not treated quickly.

42. Diseases of the Skeletal System:
Osteoporosis- bone reabsorption outpaces bone deposit; bones become lighter and fracture easier
Factors:
age, gender (more in women)
estrogen and testosterone decrease
insufficient exercise (or too much)
diet poor in Ca++ and protein
abnormal vitamin D receptors
smoking

44. Osteoporosis 29 40 84 92