Skeleton System
Classification of bone

Based on Location


Based on Shape

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Axial and Appendicular
Long, short, flat, Sesamoid, irregular
Based on Ossification

Endochondral and Intramembranous
Based on location
Axial


Formed from ~80 named bones
Consists of skull, vertebral column, and bony
thorax
 Appendicular
Remaining ~126 bones of



Thoracic girdle
Pelvic girdle
Attached limbs
5 classes based on shape
A. Long
B. Short
C. Flat bones-
D. Irregular bone
E- Sesamoids bone
Classification of Bones

Long bones –
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Longer than wide

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a shaft plus two ends
primarily compact bone
Short bones –
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
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roughly cube-shaped
- mostly spongy bone
Classification of Bones
Flat bones

•
•
thin and flattened, usually curved
contain two roughly parallel compact bone surfaces
with a layer of spongy bone between them
Irregular bones
•
•
•
various shapes, do not fit into other categories –
complicated shapes
consist mainly of spongy bone enclosed by thin layers
of compact bone
Sesamoid bone-usually small, round, flat, associated
with tendons,


patella, proximal/distal sesamoid bones
Anatomy of a long bone1. diaphysis (dy-AF-I-sis)2. epiphysis (e-PIF-I-sis)3. Epiphyseal cartilage (physis, growth
plate)plate of cartilage between diaphysis and
epiphysis of immature long bones, where
lengthening of long bones occurs
4. metaphysis (me-TAF-I-sis)The joining point of the diaphysis
and epiphysis in growing bone; the
part of the epiphyseal cartilage
being replace by bone.
3
2
1
2
. nutrient foramen-
5
7
4
6. periosteum- connective tissue
surrounding the bone that is not covered by
articular cartilage; necessary for bone
growth, repair, and attachment of
10
ligaments/tendons.
7. articular surface- smooth layer of hyaline
cartilage covering the epiphysis, involved in
joint formation.
8. medullary cavity9. endosteum10. compact bone- gross term for the part of
the bone that looks solid
11. spongy bone - gross term for the part of
the bone with visible spaces
5
6
8
9
11
Based on Ossification-
I.B.1.
Two types of Ossification:
I.B.2.
I.B.3
1. Intramembranous Ossification2. Endochondral OssificationI.B.3
(cont.)
I.B.3.b
Axial



vs. Appendicular
Skull
Vertebral column
Thoracic cage
Remaining bones of
 Thoracic girdle
 Pelvic girdle
 Attached limbs
Appendicular skeleton

Consists of:

Thoracic girdles
Clavicle
 Scapula
 Attached limbs


Pelvic girdles
Pelvic bones
 Attached limbs

The shoulder girdle and upper limb

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Clavicle
Scapula
Each upper extremity:
Humerus
 Radius
 Ulna
 Carpal bones
 Metacarpal
 Phalanges

Scapula

Is a flat triangular-shaped bone

Have
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3 borders

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3 angles

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Cranial, caudal, Dorsal
Cranial, caudal, Ventral
3 fossae
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Supraspinous, infraspinous, subscapular
The humerus


Long bone
It is consist of
Proximal end (head)
 Neck
 Shaft
 Distal end
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The ulna and Radius
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
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The two bones of the forearm
The proximal Ext. of ulna is medial to the
radius
The distal Ext. of ulna is lateral to the radius
Ulna
Proximal end, shaft, distal end (head)
 Proximal end

Olecranon process
 Trochlear notch

The Carpal bones (bones of the
wrist)

The carpal bones (are Seven in number).

Proximal row


Ulnar, accessory, Intermedioradial Carpal
Distal row
 1th
, 2nd , 3rd , 4th Carpal
The metacarpal

Five in the number
The Phalanges

There are 14 phalanges

Each finger have 3 phalanges

Thumb (have two)