1. Bones and Skeletal Tissues: Part A6
Bones and Skeletal Tissues: Part A

2. Moving on to chapter 11 after chapter 6
Begin on p. 389 Neurons.
Thru p. 414
Stop at Neurotransmitters and their receptors
This is online as 11b.
We will cover other neurotransmitters and the rest of chapter 11 at a later date, time permitting.
The study guide for chapter 5 is now available
6 will follow soon.

3. Two main groups, by location
Bones of the Skeleton
Two main groups, by location
Axial skeleton (brown)
Appendicular skeleton (yellow)

4. Cartilage in Cartilages in external ear nose Articular Cartilage
of a joint
Cartilage in
Intervertebral disc
Costal
cartilage
Pubic
symphysis
Meniscus
Articular cartilage
of a joint
Figure 6.1

5. Classification of Bones by Shape
Long bones
Longer than they are wide
Short bones
Cube-shaped bones (in wrist and ankle)
Sesamoid bones (within tendons, e.g., patella)

6. Classification of Bones by Shape
Flat bones
Thin, flat, slightly curved
Irregular bones
Complicated shapes

7. Figure 6.2

8. Functions of Bones Support Protection Movement
For the body and soft organs
Protection
For brain, spinal cord, and vital organs
Movement
Levers for muscle action

9. Blood cell formation (hematopoiesis) in marrow cavities
Functions of Bones
Storage
Minerals (calcium and phosphorus) and growth factors
Blood cell formation (hematopoiesis) in marrow cavities
Triglyceride (energy) storage in bone cavities

10. Bulges, depressions, and holes serve as
Bone Markings
Bulges, depressions, and holes serve as
Sites of attachment for muscles, ligaments, and tendons
Joint surfaces
Conduits for blood vessels and nerves

11. Spongy (cancellous) bone
Bone Textures
Compact bone
Dense outer layer
Spongy (cancellous) bone
Honeycomb of trabeculae

12. Structure of a Long Bone
Diaphysis (shaft)
Compact bone collar surrounds medullary (marrow) cavity
Medullary cavity in adults contains fat (yellow marrow)

13. Structure of a Long Bone
Epiphyses
Expanded ends
Spongy bone interior
Epiphyseal line (remnant of growth plate)
Articular (hyaline) cartilage on joint surfaces

14. Articular cartilage Compact bone Proximal epiphysis Spongy bone
Epiphyseal
line
Periosteum
Compact bone
Medullary
cavity (lined
by endosteum)
(b)
Diaphysis
Distal
epiphysis
(a)
Figure 6.3a-b

15. Figure 8.1

16. Membranes of Bone Periosteum Outer fibrous layer
Inner osteogenic layer
Osteoblasts (bone-forming cells)
Osteoclasts (bone-destroying cells)
Osteogenic cells (stem cells)
Nerve fibers, nutrient blood vessels, and lymphatic vessels enter the bone via nutrient foramina
Secured to underlying bone by Sharpey’s fibers

17. Membranes of Bone Endosteum
Delicate membrane on internal surfaces of bone
Also contains osteoblasts and osteoclasts

18. Endosteum Yellow bone marrow Compact bone Periosteum Perforating
(Sharpey’s) fibers
Nutrient
arteries
(c)
Figure 6.3c

19. Structure of Short, Irregular, and Flat Bones
Periosteum-covers compact bone on the outside
Endosteum-covers spongy bone within
Spongy bone called diploë in flat bones
Bone marrow between the trabeculae

20. Spongy bone
(diploë)
Compact
bone
Trabeculae
Figure 6.5

21. Location of Hematopoietic Tissue (Red Marrow)
Red marrow cavities of adults
Trabecular cavities of the heads of the femur and humerus
Trabecular cavities of the diploë of flat bones
Red marrow of newborn infants
Medullary cavities and all spaces in spongy bone

22. Microscopic Anatomy of Bone
Cells of bones
Osteogenic (osteoprogenitor) cells
Stem cells in periosteum and endosteum that give rise to osteoblasts
Osteoblasts
Bone-forming cells

23. (a) Osteogenic cell (b) Osteoblast Stem cell Matrix-synthesizing
cell responsible
for bone growth
Figure 6.4a-b

24. Microscopic Anatomy of Bone
Cells of bone
Osteocytes
Mature bone cells
Osteoclasts
Cells that break down (resorb) bone matrix

25. (c) Osteocyte (d) Osteoclast Mature bone cell that maintains the
bone matrix
Bone-resorbing cell
Figure 6.4c-d

26. Microscopic Anatomy of Bone: Compact Bone
Haversian system, or osteon — structural unit
Lamellae
Weight-bearing
Column-like matrix tubes
Central (Haversian) canal
Contains blood vessels and nerves

27. Artery with capillaries Structures in the Vein central canal
Nerve fiber
Lamellae
Collagen
fibers
run in
different
directions
Twisting
force
Figure 6.6

28. Microscopic Anatomy of Bone: Compact Bone
Perforating (Volkmann’s) canals
At right angles to the central canal
Connects blood vessels and nerves of the periosteum and central canal
Lacunae — small cavities that contain osteocytes
Canaliculi — hair-like canals that connect lacunae to each other and the central canal

29. Compact
bone
Spongy bone
Central
(Haversian) canal
Perforating
(Volkmann’s) canal
Endosteum lining bony canals
and covering trabeculae
Osteon
(Haversian system)
Circumferential
lamellae
(a)
Perforating (Sharpey’s) fibers
Lamellae
Periosteal blood vessel
Periosteum
Nerve
Vein
Artery
Lamellae
Central
canal
Canaliculi
Lacuna (with
osteocyte)
Osteocyte
in a lacuna
Lacunae
Interstitial lamellae
(b)
(c)
Figure 6.7a-c

30. Nerve Vein Lamellae Artery Central canal Canaliculus Osteocyte Lacunae
in a lacuna
Lacunae
(b)
Figure 6.3b

31. Microscopic Anatomy of Bone: Spongy Bone
Trabeculae
Align along lines of stress
No osteons
Contain irregularly arranged lamellae, osteocytes, and canaliculi
Capillaries in endosteum supply nutrients

32. Chemical Composition of Bone: Organic
Osteogenic cells, osteoblasts, osteocytes, osteoclasts
Osteoid — organic bone matrix secreted by osteoblasts
Ground substance (proteoglycans, glycoproteins)
Collagen fibers
Provide tensile strength and flexibility

33. Chemical Composition of Bone: Inorganic
Hydroxyapatites (mineral salts)
65% of bone by mass
Mainly calcium phosphate crystals
Responsible for hardness and resistance to compression

34. Figure 8.2a

35. Figure 8.2b

36. Figure 8.3a

37. Figure 8.3b

38. Figure 8.4

39. Figure 8.5