Download BIOL 203 –Weeks 5 and 6

Weeks 4 and 5
The Skeletal System
Objective 1:
Bone Classification
Classification by shape:
Long bones are longer than they are wide.
phalanges
humerus
metacarpals
Short bones are roughly cubical
carpals
Flat bones are thin, with parallel surfaces, and usually a little
curved.
rib
parietal bone
sternum
Irregular bones do not fit into the other categories.
vertebra
pelvic bone
Objective 2:
Bone Markings
Bone markings are bumps, projections, openings and ridges on the surfaces of
bones. They function as passageways for nerves and blood vessels, as points of
muscle and ligament attachment, and as joint surfaces.
Projections that help form joints:
Head: a bony
expansion carried on a
narrow neck
Facet: smooth,
nearly flat
articular surface
Projections that help form joints
Condyle: rounded
articular projection
Ramus: armlike
projection of bone
Projections that serve as sites for muscle and ligament attachment
Crest: a narrow
prominent ridge
of bone
Sacrum
Line: Narrow ridge of
bone; less prominent than
a crest
Projections for muscle and ligament attachment
Trochanter: very large,
blunt, irregularly shaped
process
Tuberosity: large,
rounded projection
which may be
roughened
Femur
Fibula and Tibia
Projections for muscle and ligament attachment
Tubercle:
small, rounded
projection or
process
Epicondyle: raised
area on or above a
condyle
Humerus
Depressions and openings to allow passage of nerves and
vessels
Meatus: canal-like
passageway
Foramen:
rounded or oval
opening
through a bone
Depressions and openings
Fissure: narrow, slitlike opening
Sinus: cavity
within a bone
filled with air
Ethmoid bone
Depressions and openings
Groove: furrow
Fossa: shallow, basinlike depression in a
bone, often serving as
an articular surface
Humerus
Objective 3:
Gross Anatomy of a Long Bone
Objective 4:
Chemical Composition of Bone
Bone matrix has two components:
1. Organic ground substance (osteoid) which consists of soluble
proteins and collagen fibers
•
osteoid gives bone its tensile strength
•
in lab you will observe bone treated with heat to denature
proteins
What effect do you think heating bone will have?
2. Inorganic materials (hydroxyapatitie) which consist of a variety
of mineral salts, primarily calcium and phosphorus
•
hydroxyapatite gives bone its compressional strength
•
in lab you will observe bone that has been treated with acid to
remove minerals
What effect do you think this will have?
Objective 5:
Microscopic Structure of
Compact Bone
Human bone is primarily arranged in a ringed pattern and is called lamellar
bone:
Haversian System (Osteon)
Central (Haversian) canal
concentric
lamella
Interstitial lamella
Canaliculi
Lacunae (containing osteocytes)
Lacuna (containing an osteocyte)
Canaliculi
Haversian
canal
Perforating (Volkman’s)
canal