1.
KEY SKELETAL SYSTEM OVERVIEW OBJECTIVES
List the organs and functions of the skeletal system.
Organs
Functions
Bones
Support
Cartilages
Protection
Tendons
Movement
ligaments
Hematopoiesis
Mineral (calcium) store
Energy Store
2.
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
long (a)
femur, humerus, tibia
short (b)
carpals and tarsals
flat (c)
sternum, ribs, skull bones
irregular (d)
vertebrae, auditory ossicles
3.
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 sutural
bones
above
bone
4.
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.
5.
List the functions of the periosteum.
protection
muscle attachment
bone remodeling
6.
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
7.
List the terms that are synonymous with inorganic bone matrix.
calcium phosphate
hydroxyapatite
mineral salts
8.
Discuss the different types of bone cells in terms of origin, location, and function.
Origin
Location
Function
Osteoprogenitor from mesenchyme
primitive bone
gives
rise
to
Cell
osteoblasts
Osteoblast
from
bone
to lay down bone
osteoprogenitor
matrix
Osteocyte
from osteoblast
Bone
Osteoclast
from bone marrow, bone
bone resorption
phagocytic cell that
left blood and
traveled to bone
9.
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 fragments of bone with
Systems
open space filled with red
bone marrow
Function
solid and dense
hematopoiesis
10.
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
11.
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)
12.
Discuss the significance of the spongy bone within a flat bone, and label it below.
filled with red bone marrow and functions in hematopoiesis
13.
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.
14.
Name the important function that the trabeculae in spongy or cancellous bones
allow for.
hematopoiesis
15.
Define the term ossification.
ossification is bone formation.
16.
Distinguish between intramembranous and endochondral ossification and denote
which parts of the skeleton are formed by each.
intramembranous
endochondral ossification
ossification
Description
Bone develops within a Bone develops within a
fibrous membrane.
cartilage model.
Bones formed in flat bones
long, short, and irregular
this manner?
bones
17.
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).
18.
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
19.
Explain why ossification is a lifelong event.
Bones are remodeled throughout life.
20.
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; calcium
deficiency = rickets; osteomalacia
C
for
collagen
synthesis; phosphorus
deficiency = scurvy
B12
boron
A
manganese
magnesium
21.
List the major hormones involved in bone development and remodeling.
human growth hormone
triiodothyronine
thyroxine
calcitonin
parathyroid hormone
estrogen
testosterone
22.
Compare and contrast the functions of osteoblasts and osteoclasts in bone
remodeling.
Osteoblasts
Osteoclasts
Osteoblasts lay down bone matrix
Osteoclasts resorb bone
23.
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.
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
24.
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
Energy store
Yellow marrow in the shaft of long bones; serve as an
important chemical energy reserve