Objectives
Skeletal Cartilages
1. Describe the functional properties of the three types of cartilage tissue.
2. Locate the major cartilages of the adult skeleton.
3. Explain how cartilage grows.
Classification of Bones
4. Name the major regions of the skeleton and describe their relative
functions.
5. Compare and contrast the four bone classes and provide examples of each
class.
Functions of Bones
6. List and describe seven important functions of bones.
Bone Structure
7. Describe the gross anatomy of a typical flat bone and a long bone. Indicate
the locations and functions of red and yellow marrow, articular cartilage,
periosteum, and endosteum.
8. Indicate the functional importance of bone markings.
9. Describe the histology of compact and spongy bone.
10. Discuss the chemical composition of bone and the advantages conferred by
its organic and inorganic components.
Bone Development
11. Compare and contrast intramembranous ossification and endochondral
ossification.
12. Describe the process of long bone growth that occurs at the epiphyseal
plates.
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Bone Homeostasis: Remodeling and Repair
13. Compare the locations and remodeling functions of the osteoblasts,
osteocytes, and
osteoclasts.
14. Explain how hormones and physical stress regulate bone remodeling.
15. Describe the steps of fracture repair.
Homeostatic Imbalances of Bone
16. Contrast the disorders of bone remodeling seen in osteoporosis,
osteomalacia, and
Paget’s disease.
Developmental Aspects of Bones: Timing of Events
17. Describe the timing and cause of changes in bone architecture and bone
mass throughout life.
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Skeletal Cartilages (pp. 173–174; Fig. 6.1)
Basic Structure, Types, and Locations
Skeletal cartilages are made from _______________________________, surrounded by a layer
of dense _______________________ connective tissue called the _______________________________.
Three types of cartilage tissue in the body:
1. __________________________________________________
2. __________________________________________________
3. __________________________________________________
All three types of cartilage have the same basic components:

_________________________________________________

_________________________________________________

_________________________________________________
Hyaline Cartilages
Hyaline cartilages, which look like frosted glass when freshly exposed, provide
__________________________ with ____________________________ and resilience. They are the
most ______________________ skeletal cartilages.
Their chondrocytes are __________________________, and the only fiber type in their
matrix is ___________________________________ fibers.
The types of hyaline cartilage include:
 Articular cartilages:

Costal cartilages:

Respiratory cartilages:

Nasal cartilages:
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Elastic Cartilages
Contain more stretchy ___________________ fibers and are better able to stand up to
repeated __________________________________.
Found in two locations:

_______________________________________________

_______________________________________________
Fibrocartilages
Highly __________________________________ with great _______________________ strength.
Consists of roughly _________________________ rows of chrondrocytes alternating with
______________ collagen fibers.
Occur in sites subjected to both ___________________________ and stretch, such as:

Padlike ______________________________ (menisci)

Disk between __________________________________
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Figure 6.1 The bones and cartilages of the human skeleton
Growth of Cartilage
__________________________________ growth results in outward expansion due to the
production of cartilage matrix on the outer face of the tissue.
__________________________________ growth results in expansion from within the cartilage
matrix due to division of lacunae-bound chondrocytes and secretion of matrix.
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Classification of Bones (pp. 174–176; Figs. 6.1–6.2)
The human skeleton has ____________ bones. These bones are divided into two groups:

___________________________________________________

___________________________________________________
Axial skeleton (shown in orange in figure 6.1):
Appendicular Skeleton (shown in gold in figure 6.1):
Bones come in many sizes and shapes. Generally, bones are classified by their shape
as:
1. ____________________________________________________
2. ____________________________________________________
3. ____________________________________________________
4. ____________________________________________________
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Figure 6.2 Classification of bones on the basis of shape.
Long bones:
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Short bones:
Flat bones:
Irregular bones:
Functions of Bones (pp. 176–177)
Our bones perform seven important functions:
1. Support:
2. Protection:
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3. Movement:
4. Mineral and growth factor storage:
5. Blood cell formation (hematopoiesis):
6. Triglyceride (fat) storage:
7. Hormone production:
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Bone Structure (pp. 177–183; Figs. 6.3–6.7; Table 6.1)
Because they contain different types of tissues, bones are ________________, (recall that
an organ contains several different tissues).
Bones are dominated by bone ( _______________________) tissue, but also contain
______________________ tissue in their nerves, cartilage in their ______________________
cartilages, _______________________ connective tissue lining their cavities, and muscle
and _________________________ tissue in their blood vessels.
The structure of bone can be evaluated from three levels:

___________________________________________

___________________________________________

___________________________________________
Gross Anatomy of Bone
Bone Texture: Compact and Spongy Bone
All bone has a dense outer layer consisting of _________________________________ bone
that appears smooth and solid.
Internal to compact bone is _________________________ bone, which consists of
honeycomb, needle-like, or flat pieces, called ___________________________.
In living bones the open spaces between trabeculae are filled with __________ or
__________________________ bone marrow.
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Structure of Short, Irregular, and Flat Bones
Short, irregular, and flat bones consist of thin plates of ______________________-covered
compact bone on the outside and __________________________-covered spongy bone
inside, which houses bone marrow between the trabeculae, but no well defined
marrow cavity.
These bones have no ___________________ or epiphyses.
Where they form movable joints with their neighbors, _____________________ cartilage
covers their surfaces.
In flat bones, the spongy bone is called the ______________ and the whole arrangement
resembles a stiffened sandwich.
Figure 6.3 Flat bones consist of a layer of spongy bone sandwiched between
two thin layers of compact bone.
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Structure of a Typical Long Bone
With a few exceptions, all long bones have the same general structure:

_________________________________________________

_________________________________________________

_________________________________________________
Figure 6.4 The structure of a long bone (humerus of arm).
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Diaphysis:

Medullary cavity:

Yellow marrow cavity:
Epiphyses:

Epiphyseal line:

Epiphyseal plate:
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Membranes:

Periosteum:
o Nutrient foramen:
o Perforating (Sharpey’s) fibers:

Endosteum:
Location of Hematopoietic Tissues in Bones
Red bone marrow =
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Red bone marrow is located within the _________________________ cavities of the spongy
bone in long bones and in the _________________________ of flat bones.
In long bones, red bone marrow is found in all _________________________ cavities and all
areas of spongy bone of infants, but in adults, distribution is restricted to the
proximal __________________________ of the humerus and femur.
The red bone marrow found in the _____________ of flat bones (such as the sternum)
and in some ___________________________ bones (such as the hip) is much more
_______________________ in hematopoiesis.
Bone Markings
Bone markings are the external features of the bones: projections,
_____________________, and openings.
Bone markings serve as sites of _____________________________, _____________________________,
and ___________________________ attachment, as joint surfaces, or as conduits for blood
vessels and nerves.

Projection:

Depressions and Openings:
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Microscopic Anatomy of Bone
Cells of Bone Tissue
Five major types of cells populate bone tissue:
1. ______________________________________________________
2. ______________________________________________________
3. ______________________________________________________
4. ______________________________________________________
5. ______________________________________________________
Figure 6.5 Comparison of different types of bone cells.
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Compact Bone
Osteon (Haversian System):
The structural unit of compact bone is the ____________________, or Haversian
system, a series of concentric tubes of bone matrix (the _______________________)
surrounding a central Haversian canal.
Figure 6.6 A single osteon.
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Canals and Canaliculi:
Running through the core of each osteon is the _____________________ canal,
or _______________________________ canal, containing small blood vessels and
nerve fibers that serve the osteon’s cells.
Perforating __________________, or _____________________’s, canals lie at right
angles to the long axis of the bone, and connect the blood and nerve
supply of the periosteum to that of the central canals and medullary
cavity.
Lacunae, small holes housing the osteocytes, are found at the junctions of
the lamellae and are connected to each other and the central canal via a
series of hairlike channels, _________________________________.
Interstitial and Circumferential Lamellae:
Lamellae located just beneath the periosteum, extending around the
entire circumference of the bone are called _________________________________
lamellae, while ___________________________________ lamellae lie between intact
osteons, filling the spaces in between.
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Figure 6.7 Microscopic Anatomy of Compact Bone
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Spongy Bone
Spongy bone lacks osteons but has trabeculae that align along lines of stress, which
contain irregular lamellae and osteocytes connected with canaliculi.
Chemical Composition of Bone
__________________________ components of bone include cells and osteoid (ground
substance and collagen fibers), which contribute to the flexibility and tensile
strength of bone.
__________________________ components make up _______% of bone by mass, and consist
of hydroxyapatites, mineral salts (largely calcium phosphates), that account for the
hardness and compression resistance of bone.
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