KEY SKELETAL SYSTEM OVERVIEW OBJECTIVES
0. List
the organs and functions of the skeletal system.
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Organs |
Functions |
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Bones |
Support |
|
Cartilages |
Protection |
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Tendons |
Movement |
|
ligaments |
Hematopoiesis |
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Mineral
(calcium) store |
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|
Energy
Store |
1. Name the four classifications of bones
by shape, give an example of each, and label each in the diagram below.
|
Bone Classification by shape |
Example |
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long (a) |
femur, humerus,
tibia |
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short (b) |
carpals and tarsals |
|
flat (c) |
sternum, ribs, skull bones |
|
irregular (d) |
vertebrae, auditory ossicles |
2. Define the terms sesamoid bone and Wormian (sutural) bone,
give an example of each, and label in the diagrams above.
|
Definition |
Example |
|
Sesamoid bones (e above) develop
within a tendon |
patella |
|
Wormian (sutural)
bone are wedged between major skull bones |
sutural bone above |
3. Illustrate the major features of a long
bone including the following: diaphysis, epiphyses, epiphyseal line, periosteum, endosteum, medullary cavity,
nutrient foramen (perforating canal), and note the locations of spongy bone,
compact bone, yellow marrow, red marrow, and articular
cartilage.
4. List the functions of the periosteum.
|
protection |
|
muscle attachment |
|
bone remodeling |
5. Compare and contrast the organic and
inorganic components of bone matrix in terms of structure and function.
|
|
Organic Bone Matrix |
Inorganic Bone Matrix |
|
Structure |
cells and osteoid
– collagen |
calcium phosphate |
|
Function |
strength |
dense and solid |
6. List
the terms that are synonymous with inorganic bone matrix.
|
calcium
phosphate |
|
hydroxyapatite |
|
mineral
salts |
7. Discuss the different types of bone
cells in terms of origin, location, and function.
|
|
Origin |
Location |
Function |
|
Osteoprogenitor Cell |
from mesenchyme |
primitive bone |
gives rise to osteoblasts |
|
Osteoblast |
from osteoprogenitor |
bone |
to lay down bone matrix |
|
Osteocyte |
from osteoblast |
Bone |
|
|
Osteoclast |
from bone marrow, phagocytic
cell that left blood and traveled to bone |
bone |
bone resorption |
8. Distinguish between compact bone and
spongy bone in terms of structure and function, and label each in the diagram
above.
|
|
Compact Bone |
Spongy Bone |
|
Structure |
solid, organized, Haversian
Systems |
fragments of bone with open space
filled with red bone marrow |
|
Function |
solid and dense |
hematopoiesis |
9. Discuss the Haversian
(Osteon) System as the structural unit of compact
bone using the following terms: osteocytes, lacunae, lamellae, Haversian
canal, blood vessels, bone matrix, and canaliculi,
and label each in the diagram below.
|
osteocytes |
primary
bone cell that carries out daily activities |
|
lacunae |
“house”
within bone matrix that osteocytes live in |
|
Lamellae |
concentric
layers of bone matrix |
|
haversian canal |
center
of Haversian System filled with blood vessels and
nerves |
|
blood
vessels |
nutrient
artery and vein which lie within Haversian canal |
|
bone
matrix |
calcium
phosphate and collagen in organized lamellae |
|
canaliculi |
communicating
channels between osteocytes |
10. Explain how adjacent Haversian
Systems communicate with one another (i.e. exchange nutrients gases and
wastes), and label this “canal” above.
|
through Volkmanns’
Canals (also called perforating canals) |
11. Discuss the significance of the spongy
bone within a flat bone, and label it below.
|
filled with red bone marrow and
functions in hematopoiesis |
12. Define the term hematopoiesis and name the major
skeletal locations where it occurs.
|
Hematopoiesis
is blood cell formation that occurs in the red bone marrow in the spongy bone
of flat bones and epiphyses of long bones. |
13. Name the important function that the trabeculae in spongy or cancellous
bones allow for.
|
hematopoiesis |
14. Define the term ossification.
|
ossification is bone formation. |
15. Distinguish between intramembranous
and endochondral ossification and denote which parts
of the skeleton are formed by each.
|
|
intramembranous ossification |
endochondral ossification |
|
Description |
Bone
develops within a fibrous membrane. |
Bone
develops within a cartilage model. |
|
Bones
formed in this manner? |
flat
bones |
long,
short, and irregular bones |
16. Discuss the structure of the epiphyseal plate, explain its significance, discuss its
fate, and label each zone in the diagram below.
|
The epiphyseal
plate (growth plate) is composed of four zones of hyaline cartilage that
allow for longitudinal bone growth (length).
|
17. Compare and contrast appositional bone
growth and longitudinal bone growth.
|
Type of Bone growth |
|
|
appositional bone growth |
increases the thickness of a bone |
|
longitudinal bone growth. |
increases the length of a bone |
18. Explain why ossification is a lifelong
event.
|
Bones
are remodeled throughout life. |
19. List the vitamins and minerals involved
in bone remodeling and discuss the action (and any resulting deficiency) of each.
|
Vitamins |
Minerals |
|
D
for dietary calcium absorption; deficiency = rickets; osteomalacia |
calcium |
|
C
for collagen synthesis; deficiency = scurvy |
phosphorus |
|
B12 |
boron |
|
A |
manganese |
|
|
magnesium |
20. List the major hormones involved in bone
development and remodeling.
|
human growth hormone |
|
triiodothyronine |
|
thyroxine |
|
calcitonin |
|
parathyroid hormone |
|
estrogen |
|
testosterone |
21. Compare and contrast the functions of osteoblasts and osteoclasts in
bone remodeling.
|
Osteoblasts |
Osteoclasts |
|
Osteoblasts lay down bone matrix |
Osteoclasts resorb bone |
22. Fully
discuss the negative feedback
mechanisms involved in blood calcium (Ca2+) homeostasis and explain
how this is related to bone remodeling.
a. In a complete sentence or two, name the physiologic (homeostatic)
blood calcium range, and the antagonistic endocrine glands, hormones, and bone
cells primarily involved in its maintenance.
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b. Reproduce
the Calcium homeostasis negative feedback diagram illustrated in class.
c. In a complete sentence, explain how blood calcium homeostasis is related to bone remodeling
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23. List and discuss at least 6 functions of
bone tissue.
|
Bone
Function |
Description |
|
support |
The
bones in legs and pelvis support the trunk |
|
protection |
The
skull protects the brain |
|
movement |
Skeletal
muscles attached to bones by tendons. |
|
hematopoiesis |
Definition
= Blood Cell Formation; All blood cells are formed in the red marrow of
certain bones. |
|
mineral
store |
Bone
stores many minerals, calcium, phosphorous, and others. Also a means of calcium homeostasis |
|
snergy store |
Yellow marrow in the shaft of long
bones; serve as an important chemical energy reserve |