4 Types of Bones
&
Skeletal
Organization
ACOS OBJ 6.4)identifying the
four bone types. 6) Identify
bones that compose the
skeletal system. 6.2)
identifying subdivisions of the
skeleton as axial &
appendicular skeletons.
4 Types of Bones
• 1. Long Bones: Hard dense bones that consist of a shaft & two ends.
Composed mostly of compact bone.
– EX: Femur, Humerus, Tibia
2. Short Bones: length and width are the close to the same. Composed
mostly of spongy bone.
(cube-shaped)
-EX: Carpals(wrist bones), and tarsals(ankle bones)
3. Flat Bones: relatively thin and FLAT.
-EX: sternum, ribs, scapula, and Cranial bones
4. Irregular Bones: Odd shaped bones
-EX: Facial Skeleton, Vertebrae, and Sacrum
•
Examples of Long Bones
Examples of Short Bones
Examples of Flat Bones
Examples of Irregular Bones
Skeletal Organization
• There are 2 major portions of the skeletal system.
– 1. Axial Skeleton (Ax-?): Bony & cartilaginous
parts that support & protect organs of the head
neck and trunk.
– 2. Appendicular Skeleton: Bones of the upper &
lower limbs
–Bones that anchor limbs to the axial
skeleton
Axial Skeleton
• 1. Skull
– Composed of the cranium & facial bones.
2. Hyoid Bone- located in the neck between the lower jaw &
larynx.
- Supports the tongue & is an attachment for certain
muscles that help move the tongue during swallowing.
3. Vertebral Column ( Backbone) – Many vertebrae
separated by intervertebral discs.
-Distal end several vertebrae fuse together to form the
SACRUM
- Coccyx: Located at the end of the sacrum.
Axial Skeleton Continued
• 4. Thoracic Cage: Protects organs of thoracic cavity &
the upper abdominal cavity.
– 12 Pairs of Ribs ( Articulate posteriorly w/ thoracic
vertebrae & anteriorly w/ the sternum.
Axial Skeleton
Appendicular Skeleton
• 1. Pectoral Girdle
– Composed of the SCAPULA & CLAVICLE
- connects the bones of upper limbs to the axial skeleton
Appendicular Skeleton Continued
• 2. Upper Limbs
– Consist of:
• 1 humerus
• 2 forearm bones ( Radius & Ulna)
• A Wrist ( 8 carpals)
• A Hand ( 14 Phalanges)
• 5 Metacarpals in the palm
-Radius
- Ulna
- Humerus→ Articulate w/ each other at
- The elbow joint
Distal Upper Limb
• 3. Pelvic Girdle
– 2 Coxae ( hipbones)
• Connects bones of lower limbs to the axial skeleton
- Sacrum
- Coccyx
• 4. Lower Limbs
– Femur ( Thighbone)
– 2 leg bones ( Large TIBIA & slender FIBULA )
– Ankle ( 7 Tarsals) Distil end of Tibia & Fibula
– 5 Metatarsals
– 14 phalanges
Lower Limbs
Pg.137 Table 7.2