Bone

Modification

Function

Humerus

Has a rounded upper end head

That articulates with glenoid cavity of scapula to form a ball and socket joint

Has greater and lesser tuberosities

To increase the surface area for muscle attachment

Has deltoid ridge

To increase the surface area for muscle attachment

Has trochlea

That articulate with ulna and radius/sigmoid notch to form a hinge joint;

Has shaft

To provide the surface area for muscle attachment

Femur

Has a rounded head

To articulate with acetabulum on the pelvic girdle forming a ball and socket joint;

Has lesser and greater trochanters

To provide surfaces for attachment of thigh muscles;

Has condyles on lower end/distal (lateral and medial condyles)

For articulation with tibia and patella to form a hinge joint;

Has a patella groove separating the two condyles;

That articulates with the patella at the hinge joint;

Has a shaft

For attachment of muscles;

Tibia and Fibula

Tibia has a shaft

For attachment of muscles;

Have two slight depressions at the upper end of tibia

For articulation with condyles of the femur;

Tarsals, metatarsals and phalanges

Ulna and radius

Are slightly curved

To increase the surface area for muscle attachment

Have sigmoid notch

For articulation with trochlea of humerus to form a hinge joint

Ulna has olecranon process

To prevent overstretching/ dislocation when the arm is straightened

Radius not firmly bound to ulna

To allow muscles to rotate the radius about the ulna for manipulative skills

Carpals, metacarpals and phallanges

Pelvic girdle

Consists of ilium, pubis and ischium all fused

To give firm structure for support;

Has acetabulum

To articulate with the head of femur to form a ball and socket joint.

Ilium is broad/has a large crest

To provide a large surface area for muscle attachment;

Ilium has facet

That fuse with the transverse process of sacrum

Has obturator foramen

For passage of nerves and blood vessels

Pubic symphysis has flexible cartilage

To allow for widening of the female girdle when giving birth.

Thoracic region

Sternum has fused sternabrae with facets

To provide support for the ribs;

To protect delicate internal organs in thorax from physical damage

Scapula

Broad scapula

To provide large surface area for attachment of muscles

Has cartilage on broad end

To reduce friction;

Has a spine

To increase surface area for muscle attachment;

Has metacromion

For muscle attachment;

Has acromion

For attachment of clavicle;

Has glenoid cavity

For articulation with Humerus;

Has clavicle with facets

For articulation with acromion and sternum; and for limiting the movement;

Atlas

Has a wide neural canal

To accommodate the large spinal cord at the neck region;

Has large/broad wing-like cervical ribs

To increase the surface area for attachment of the neck muscles;

Has facets on the anterior side

For articulation with the occipital condyles of the skull to allow nodding (up and down movement) of the head;

Has posterior facets

For articulation with the anterior facets of the axis forming a joint that allows sideways movement of the head;

Axis

Has an odontoid process

For articulation with the neural canal of the atlas; a joint that allows turning of the head.

Has a large and broad neural spine and flat cervical ribs

To increase the surface area for attachment of neck muscles.

Has a wide centrum

That projects/odontoid process which articulates with the atlas

General/typical cervical vertebra

Presence of vertebraterial canals

For passage of arteries

Has wide neural canal

For passage of spinal cord

Branched transverse processes

For attachment of neck muscles

Thoracic vertebra

Long neural spine

To increase surface area for attachment of back muscles

Tuberculum facet

which articulates with the tuberculum of rib

Capitular demifacets on the centrum

Articulates with the capitulum of rib

Short transverse processes

To provide additional surface area for muscles attachment

Pre- zygapophyses and post-zygapophyses

For articulation with adjacent vertebrae

Lumbar vertebra

Wide / broad neural spine

To increase surface area for attachment of the abdominal muscles

Long transverse processes

which provides an additional surface area for muscles attachment

Broad centrum

To offer support /resists compression by spreading the force towards the sacral vertebrae

Anapophyses/ Metapophyses/ Hypapophyses

Provides additional surfaces for muscles attachment

Pre-zygapophyses and post-zygapophyses

provides articulation between vertebrae

Sacrum vertebrae

Sacral vertebrae has large and broad centrum to offer support.

Provides surfaces for muscles attachment

Fused to form a rigid structure

that make the sacrum strong and firm to bear body weight

Has large with wing-like transverse processes

To provide additional surfaces for muscles attachment;