Chapter 7
Pages 130-175




Both you and your partner should each have 13
note cards.
Pick a side (right or left)—these will be the
terms that you write on your cards.
When both of you have finished recording the
terms, try your best to match them up (they’re
not in the correct order)!
You will be quizzed on these terms in class
next time!
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
ax-blast
carp-clast
condylcoraccribrcristfovglenmeatodontpoie-
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Axis
Break
Bud
Crest
Crow’s beak
Joint socket
Knob
Make/produce
Passage
Pit
Sieve
Tooth
Wrist

Also, don’t forget to write the correct
corresponding term on the other side of your
note card to study from!
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
ax- = axis
-blast = bud
carp- = wrist
-clast = break
condyl- = knob
corac- = a crow's beak
cribr- = sieve
crist- = crest
fov- = pit
glen- = joint socket
meat- = passage
odont- = tooth
poie- = make/produce
There are 206 bones in the body
grouped into two divisions:
Axial relating to the head, neck, and
trunk—protect, support, or carry other
body parts

1.
•
2.
E.g. head, hyoid, ribs, sternum, & vertebrae
Appendicular bones of upper & lower
limbs plus girdles that connect them—
help us get from place to place and to
manipulate our environment
Long bones- longer than wide, has shaft + 2
ends, includes all bones of limbs (- patella,
wrist, ankle)
1.
•
e.g. thigh, leg, arm, forearm, fingers & toes
Short bones- almost cube shaped
2.
•
Most wrist & ankle bones, sesamoid bones
Flat bones- thin & extensive surface
3.
•
e.g. Cranial bones, sternum, ribs & scapulae
Irregular bones- don’t fit above
4.
•
e.g. vertebrae, some facial bones, hip bone
Support
Protection
Movement
Mineral homeostasis
1.
2.
3.
4.
•
Esp. Calcium and Phosphate
Blood cell production
5.
•
Hematopoiesis in red bone marrow
Triglyceride Storage
6.
•
In yellow bone marrow


Compact bone dense outer layer—looks
smooth and solid
Spongy bone internal layer—honeycomb of
small, needle-like pieces = trabeculae
•
Open spaces filled with red/yellow marrow
Parts of a long bone:
 Diaphysis shaft; the long, cylindrical, main
portion of the bone
•

Epiphysis the distal and proximal ends of the
bone
•

Medullary cavity hollow space within diaphysis that contains
yellow bone marrow
Articular (hyaline) cartilage covers joint surface to cushion
and absorb stress
Metaphysis
•
•
Mature bone = where diaphysis joines epiphysis
Growing bone = contains epiphyseal plate to allow
diaphysis to grow

Membranes:
•
•
Periosteum dense irregular tissue that surrounds
bone surface where not covered by articular cartilage
Endosteum thin membrane lining medullary
cavity that contains bone-forming cells


Come up and pick out your own to label!
Using a pen, please label the following:
Diaphysis
 Metaphysis x2
 Epiphysis x2
 Type of bone
 Outside texture of bone


On the back of the bone, record the 6 functions
of bones!




Thin plates of periosteum-covered
compact bone on the outside,
endosteum-covered spongy bone within
Not cylindrical = no epiphyses
Bone marrow (between trabeculae), but
no marrow cavity.
Flat bones have diploë = internal layer of
spongy bone


Newborns medullary cavity and all
areas of spongy bone contain red bone
marrow
Adults medullary cavity extends into
epiphysis, and little red marrow present
in spongy bone of long bones
•
•
Blood cells produced in head of femur and humerus
(long), sternum (flat), hip (irregular)
Yellow can revert to red if needed



Osteon structural unit of compact
bone=group of hollow tubes (lamellae) of
bone matrix
Haversian canal runs through the
center of the osteon; contains blood
vessels and nerve fibers to support cells
Volkmann’s canals connect blood and
nerve supplies

Matrix=


25% water, 25% collagen fibers (flexibility and
strength), 50% crystallized mineral salts
(hardness/resist compression)
Osteogenic cells in periosteum Osteoblasts
secrete collagen fibers


Build matrix and become trapped in lacunae
Become osteocytes- maintain bone
Osteoclasts (“bone breakers”)

Digest bone matrix for normal bone turnover


Lacunae- “lakes”; contain osteocytes
Canaliculi- little canals that allow nutrient
flow from canals and between osteocytes



Units containing trabeculae to resist stress—
only a few cell layers thick
Spaces between trabeculae often contain Red
Marrow
No osteons but include lacunae & canaliculae
Pg. 179
Fig. 6.5






Ossification
1. Formation of Bony Skeleton
2. Intramembranous Ossification
3. Endochondral Ossification
4. Postnatal Bone Growth
5. Growth in length and width




Osteogenesis and Ossification indicate the
process of bone tissue formation
In embryos this leads to formation of the bony
skeleton
Bone growth goes on until early adulthood
Ossification in adults is mainly for remodeling
and repair of bones
Mesenchyme model - replaced with bone
1. Intramembranous - Bone forms directly in
mesenchyme layers (membrane like) -membrane

bone
2. Endochondral - forms within hyaline cartilage
developed from mesenchyme- cartilage or
endochondral, bone

Development of ossification center


Calcification- cells become osteocytes



Cells differentiate=> osteogenic=> osteoblasts
Osteoblasts secrete organic matrix
In lacunae they extend cytoplasmic processes to each other
Deposit calcium & other mineral salts
Formation of trabeculae- spongy bone
 Blood vessels grow in and marrow
 Mesenchyme=> periosteum

is formed
Bone Collar of compact bone forms and red
marrow appears

Uses hyaline cartilage “bones”


Primary Ossification Center



Cartilage must break down as process proceeds
Center of hyaline cartilage shaft
Blood vessels fill perichondrium
The mesenchymal cells specialize into
osteoblasts





Bone Collar forms around diaphysis of
hyaline cartilage
Cartilage in center of diaphysis calcifies and
forms cavities
Periosteal bud invades internal cavities
spongy bone forms
Diaphysis elongates and a medullary cavity
forms
The epiphyses ossify
Fig. 7.5 pg. 134





Length- chondrocytes in the epiphyseal
plate divide and increase cartilage layer –
zone 1 - Growth
On diaphyseal side they die and are
replaced by bone - zone 2 – transformation
Eroded by osteoclasts, then quickly
covered with bone matrix, forming
spongy bone – zone 3 – osteogenic
Stops during adolescence
Periosteum supports surface growth for
thickness – bones widen as they lengthen




A symphony of hormones regulate bone
growth during youth
Infancy and childhood – growth hormone
– released by pituitary gland this is
regulated by Thyroid hormones (T3 and T4)
Puberty – testosterone and estrogen promote
adolescent growth spurt
Excess or deficits of hormones result in
abnormalities – gigantism or dwarfism




5 to 7% of bone mass recycled weekly
½ gram of calcium may enter or leave the
skeleton each day
Spongy bone replaced every 3 to 4yrs.
Compact bone every 10 years




Bone deposit & bone resorption (removal) occur
at the periosteal and endosteal surfaces.
Coordinated by “packets” of osteoblasts called
remodeling units
Occurs where bone is injured or added strength
is needed
Optimal bone deposit = diet of protein, adequate
minerals (Ca, Mg, P), and Vitamins A, C, D




Done by osteoclasts= large
multinucleate cells
Osteoclasts move along bone digging
pits, resorption bays, breaking down
bone matrix
The ruffled border secretes lysosomal
enzymes and acids
These break down the organic matrix
and calcium salts into a solution that
can be transported into the interstitial
fluid then the blood




1. Nondisplaced or displaced
2. Complete (bone in two or more
pieces) or Incomplete (partial break
(crack))
3. Orientation of break – linear or
transverse
4. Closed (simple)- not through skin or
Open (compound)- broken ends break
skin




Greenstick incomplete break (children—
more matrix = more flexibility)
Fissured incomplete longitudinal break
Comminuted bone fragments into 3 or more
pieces (elderly—brittle bones)
Transverse complete, with break at right
angle to axis of bone





Oblique occurs at an angle other than a right
angle
Compression bone crushed (porous bones—
extreme trauma)
Spiral ragged break from twisting forces
(sports fracture)
Epiphyseal separates along epiphyseal plate
Depressed broken bone pressed inward
(skull fracture)





Involves 4 major phases
1. Hematoma formationmass of clotted
blood forms at the fracture point
2. Fibrocartilaginous callus formation for
debris cleanup, bone reconstruction, bone
splint
3. Bony callus formation 3-4 weeks after
injury to 2-3 months later
4. Bone Remodelingexcess material
removed, compact bone reconstructed

Imbalances between bone formation and bone
resorption underlie nearly all diseases that
influence the adult skeleton


1. Osteomalacia – inadequately mineralized bones
2. Rickets – analogous disease, but in children, very
severe

3. Osteoporosis – refers to a group of disorders in
which bone resorption outpaces bone deposit
 Occurs most often in aged, most often in
postmenopausal women
 Traditionally treated with calcium and vitamin D
supplements
Pg. 190 – fig. 6.14 – similar photo

4. Paget’s Disease – excessive bone formation and
breakdown
 Often discovered by accident when X rays taken for
another reason
 “Spotty” weakening of bone
 Can affect any part of the skeleton
 Spine, pelvis, femur & skull most commonly affected



Bone strengthened in response to use
Reabsorbed during disuse
e.g. Bone loss during bed rest, fractures in cast,
astronauts with no gravity
Osteon
(with osteocyte inside)
Pg. 179
Fig. 6.5
Spongy bone
Red marrow
(spaces)
Blood vessels
Compact bone
Periosteum
Skeletal
Muscle