1. Includes bones, cartilage, and joints
The SKELETAL System
Includes bones, cartilage, and joints

2. Functions of the Skeletal System
Support
Protection
Movement Facilitation
Mineral Storage and Homeostasis
Storage of energy
Hematopoiesis

3. Support
Bones are as strong or stronger than reinforced concrete.
The skeletal system provides structural support for the entire body.
Protection
Delicate tissues and organs are surrounded by skeletal elements

4. Movement
The bones serves as points of attachment for muscle tendons.
Bones act as levers that convert muscle action to movement.
Storage
Bones store minerals that can be distributed to other parts of the body upon demand.

5. Hemopoiesis Energy storage
Red bone marrow produces red blood cells, white blood cells, and platelets.
Energy storage
Yellow bone marrow stores fats for energy

6. Types of Bone Cells Osteogenic Cells = bone stem cells
Osteoblasts = deposit Ca+ & P & collagen fibers--bone builders
Osteocytes = mature bone cells-maintain tissue
Osteoclasts = break down bone tissue

7. Bone Growth aka Ossification
Bone formation (Osteogenesis)
Replacement of pre-existing connective tissue with bone

8. Intramembraneous ossification
Intramembranous Ossification
Membranes ----> Bone
(Periosteum - Width-wise Growth)

9. Endochondral ossification
Cartilage ----> Bone
Epiphyseal (growth) Plate - Length-wise Growth

10. Bone Structure Periosteum – outside membrane
--Fibrous Layer-protection
--Osteogenic Layer-stem cells
Diaphysis = shaft of a long bone
Epiphysis = ends of long bones

11. Bone Structure Medullary Cavity or Canal
Yellow Marrow-in cavity--fat storage
Articular (joint) Cartilage (Hyaline Cartilage)
Red marrow--blood cell forming tissue (where hematopoiesis takes place)
Endosteum

12. Compact Bone Structure
Dense & organized
Lamellae: layers of bone
circular or interstial
Osteons (Haversian canals)--contains, vertical canals - blood vessels and circular lamellae with lacunae

13. Compact bone structure
Perforating or Volkman’s Canals - horizontal canals with blood vessels
Lacunae: spaces that hold osteocytes
Canaliculi: minute canals where osteocytes stretch out
FYI: connect to other Lacunae and eventually with Central or Perforating Canals
Gives bone strength

14. Spongy bone Spongy Bone (Trabecular Bone) irregular network
thin plates of bone with lots of intercellular space
Spaces filled with Red Bone Marrow
Responsible for Hematopoiesis

15. Types of Bones
Long Bones: Longer than wide, have a shaft, slightly curved –spongy bone on ends
Short Bones: cube shaped, near equal in length and width, spongy bone on inside
Flat Bones: thin and flat, compact bone outside & spongy bone inside, provide protection

16. Types of Bones Irregular Bones: various shapes
Sesmoid Bones: Embedded in tendons

17. Bone Markings
Foramen= a hole for blood vessels, nerves, or ligaments

18. Bone Markings
Meatus= canal or passageway through bone

19. Sinuses Sinus= cavity or space in a bone, lightens the skull Frontal
Sphenoid
Ethmoid
Maxillary

20. Fossa A fairly deep pit or depression
Examples include the olecranon fossa of the humerus
mandibular fossa of the temporal bone

21. Bone Markings
Process = any projection from the surface of a bone EX spinous processes
Condyle = “Knuckle” - a large rounded prominence on a bone
EX Found in femur

22. Bone Markings cont
Trochanter = a large blunt process found only on the femur
Tubercle = a small rounded process

23. Bone Markings cont
Tuberosity = an elevated, rounded, usually roughened area of a bone
Facet = a smooth articular surface

24. Bone Markings
Head= proximal end of bone, rounded projection

25. Sutures Immovable joint Saggital: separates parietal bones
Coronal: separates frontal from parietal
Lamdoid: separates occipital from parietal
Squamous: Separates temporal from parietal

26. Fontanels Provide room for rapid brain growth Make childbirth easier
Move during childbirth
Used for access to blood sampling and IV’s

27. Axial vs. Appendicular Appendicular Axial Appendages Axis of the body
Connected to trunk
Shoulder girdle
Pelvic girdle
Upper limbs
Lower limbs
Axial
Axis of the body
Three regions
Skull
Vertebral column
Bony thorax

28. Axial Skeleton Axis of the body--through the midline Three regions
Skull
Vertebral column
Bony thorax

29. Skull Cranial Bones: six external bones and two internal bones
Facial Bones: 14 Facial bones

30. Vertebral Column Divided into five regions Cervical (7 bones)
Thoracic (12)
Lumbar (5)
Sacrum
Coccyx

31. Intervertebral Disks Made of fibrocartilage
Provide cushioning and shock absorption for vertebrae

32. Vertebral Column Vertebrae can be identified by three criteria:
1. Shape and angle of the spinous process
2. Size of the vertebral body
3. Presence or absence of transverse foramen

33. Hyoid Bone Does not articulate with any other bones
Tongue muscles attach here
Aids in swallowing

34. Bony Thorax (freehand notes)
Sternum--Manubrium, body and xiphoid process
12 pair of ribs
7 pair of true ribs
5 pair of false ribs
2 pair of floating ribs

35. Appendicular Skeleton
Attached to Axial
Three regions
Pectoral girdle
Pelvic Girdle
Upper and Lower Extremities

36. Exercise and Bones Wolff’s Law says that function determines form.
Bone responds to physical stresses or the lack of them. Bone is deposited on areas subjected to stress and reabsorbed from areas where little stress is present.

37. Take freehand notes on back of note paper

38. The Pectoral Girdle
attaches the bones of the upper extremities to the axial skeleton
Clavicle & scapula

39. Upper extremities

40. The Pelvic girdle (Hip girdle)
attaches the bones of the lower extremities to the axial skeleton
Pelvic bone or coxal

41. Female Vs. Male Pelvis Light and thin Wide illium
Pubic arch greater than 90o
Wide sciatic notch
Pelvic outlet wide
Coccyx more moveable
Heavy and thick
Narrow illium
Pubic arch less than 90o
Narrow sciatic notch
Narrow pelvic outlet
Coccyx less moveable and less curved

42. Names for thumb and big toe
Thumb: Pollex
Big toe: Hallux

43. Lower Extremities

44. Medial and Lateral Malleolus
Medial malleolus on the tibia
Lateral malleolus on the fibula
Make the ankle bones

45. END OF SKELETAL
Stop! we will continue this part of the notes on a new notes sheet, on a different day!

46. JOINTS

47. Fibrous Joints Immovable Thin layer of fibrous connective tissue
Sutures
Gomphosis

48. Cartilaginous Joints Bones connected by cartilage Slightly moveable
Pubic Symphysis
Intervertebral joints

49. Synovial Joints Contain synovial cavity Ligaments Freely moveable
Several different kinds based on degree of motion

50. Supporting structures in synovial joints
Bursa: small sack filled with synovial fluid
Meniscus: Pad of cartilage in the knee joint

51. Types of Synovial Joints
Saddle / Ball and Socket
Gliding /Hinge
Pivot / Condyloid
Ligaments