2
5
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1 Head
2 Articular facets of head
3 Crest of head
4 Neck
5 Body or shaft
6 Tubercle
7 Articular facet of tubercle
8 Angle
9 Costal groove
10 Crest of body
11 Scalene tubercle (first rib)
12 Tuberosity of serratus anterior (second rib)
13 Costal cartilage
14 True ribs [I-VII]
15 False ribs [VII-XII]
16 Floating ribs [XI-XII]
Left ribs 1 through 12
Superior view, first rib at top, posterior to right
Rib cage
Anterior view
13
11
12
14
15
16
13
82
body, and a sharp point-like apex named the xiphoid process. A distinct angle forms at the junction of the
manubrium and the body. This angle is called the sternal angle. A horizontal plane extended posteriorly
intersects the disc between the fourth and fi fth thoracic vertebrae and marks the top of the heart in the thoracic
cavity. The lateral margins of the bone are notched for reception of the costal cartilages and clavicles. Its
anterior surface is slightly convex, while the posterior surface is weakly concave. The sternum articulates
with sixteen bones, more articulations than any other bone in the body.
The sternum is the anterior bone of the thoracic wall. It forms from six segmental
elements, or sternebrae, that fuse during development. The bone has the appearance of a sword with a wide handle called the manubrium, a tapering blade or
Sternum
1 Manubrium
2 Clavicular notch
3 Jugular or suprasternal notch
4 Sternal angle
5 Body
6 Xiphoid process
7 Costal notches
Sternum
Anterior view, superior at top
Sternum
Lateral view, anterior at left
Sternum
Posterior view, superior at top
Sternum
Superior view, posterior at top
2
1
3
1
1
1
2 2
2
3 3
4
5
5
6 6 6
7
7
7
7
2
2
3 3
4
7
7
Th e appendicular portion of the
skeleton forms the framework of the limbs. It includes the limb
girdles, or fi xed portion of the appendicular skeleton, and the
series of bones that extend distally from the girdles into the
limb proper, or free portion of the limb. Th e limb girdles,
pectoral and pelvic, help anchor the limb to the axial
skeleton. Th e free portion of each limb consists of a
large proximal element, the humerus and femur,
forming the skeleton of the arm and thigh, respectively. Next in sequence are the ulna and radius of the
forearm, and the fi bula and tibia of the leg. Th e distalmost regions of the limbs are the hand and foot consisting of the short carpal and tarsal bones, respectively,
along with the metacarpals, metatarsals, and phalanges of the digits.
As the tetrapod (land) vertebrates evolved, a
major diff erence emerged between the two
limbs. Th e anterior, or upper limb, evolved as
a steering device, while the posterior, or lower
limb, became the locomotor limb. Accompanying these evolutionary modifi cations in
limb function were important morphological
diff erences. Th e powerful locomotor hind limb
developed strong attachments to the axial skeleton.
Th e strong iliosacral joint, with its accompanying
ligaments, transfers the powerful forces generated
by the posterior limb to the axial skeleton to propel the
body forward. On the other hand, the anterior limb developed
minimal, weak skeletal attachments between the girdle and axial
skeleton while becoming a more mobile limb.
As you study the skeleton of the limbs in the photos that follow, note the
similarities and diff erences that exist between the bones of the superior and
inferior limb skeletons and think about the functional diff erences mentioned above.
Find more information
about the appendicular
skeleton in
6 Appendicular Skeleton
83
REAL ANATOMY
84
anchored to the axial skeleton by muscles rather than ligaments. The free part of the upper limb consists of
the humerus, radius, ulna, and hand. The humerus forms the skeletal framework for the brachium. Distal to
the brachium is the antebrachium containing the radius and ulna. The distal-most region of the superior limb
is the hand consisting of a wrist region of eight carpal bones, the palm region consisting of fi ve metacarpal
bones, and the fourteen phalanges of the fi ngers and thumb.
Each superior limb consists of 32 bones. The proximal end of the superior limb, the clavicle and scapula, form the pectoral or shoulder girdle.
This girdle of bones provides a broad base of support that is primarily
Upper Limb
Left upper limb
Anterior view Left upper limb
Posterior view
1 Scapula
2 Clavicle
3 Humerus
4 Ulna
5 Radius
6 Carpals
7 Metacarpals
8 Phalanges
1
2
3
4 5
6
7
8
2
1
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5 4
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8
85
of the axial skeleton. The large triangular scapula presents an extensive surface area for muscle attachment
and a large lateral fossa that articulates with the humerus of the free part of the upper limb. Except for the weak
joint formed between the clavicle and the sternum, the pectoral girdle is essentially unattached by ligaments or
joints to the axial skeleton. This was paramount in the evolutionary role of this limb as a steering device and
shock absorber during locomotion.
The pectoral, or shoulder, girdle consisting of the scapula and the
clavicle forms the base of the upper limb skeleton. The rod-like
clavicle forms a horizontal strut that links the scapula to the sternum
Pectoral Girdle
1 Scapula
2 Clavicle
Left pectoral girdle
Superior view
Left pectoral girdle
Lateral view
1
1
2
2
86
lateral or acromial end is concave anteriorly. This is one of the more variable bones of the skeleton. It is
typically smooth and straight in females and rougher and more curved in males. The bone forms the ventral
strut of the pectoral girdle that props the shoulder joint away from the rib cage. It is subcutaneous and easily
palpable throughout its length. This combination of features makes it susceptible to fracture from falls onto
the limb. The clavicle articulates with the three bones — the scapula, sternum, and fi rst rib.
The clavicle has an S-shaped appearance that can range from an almost straight,
shallow S-curve shape to a deeper, more prominent S-curve shape. The curve at
the medial or sternal end of the bone is concave posteriorly, while the curve at the
Clavicle
1 Sternal end
2 Sternal facet
3 Impression for costoclavicular ligament
4 Shaft or body
5 Subclavian groove
6 Acromial end
7 Acromial facet
8 Tuberosity for coracoclavicular ligament
9 Conoid tubercle
10 Trapezoid line
Left clavicle
Superior view, lateral to right
Left clavicle
Inferior view, lateral to right
1
1
3
4
5
6
8 6
10
7
9
87
1
6
Left clavicle
Anterior view, lateral to right
Left clavicle
Posterior view, lateral to left
Left clavicle
Lateral view, anterior to left Left clavicle
Medial view, anterior to right
2
1
4
4
7 6
6
9
88
ferior, and lateral) and is typically a very thin plate of bone. Its lateral angle is conspicuous as it forms the glenoid fossa, or shoulder socket that articulates with the head of the humerus. Its three prominent projections are
the anterior projecting coracoid process, the posterior projecting ridge called the spine, and the fl at laterally
projecting acromion, which forms the lateral expansion of the spine. The scapula articulates with two bones — the
clavicle and the humerus.
The scapula is a fl at, triangular bone with three prominent projections. The fl attened
triangular portion of the bone, the body, spans from the second to the seventh rib and
consists of three borders (superior, lateral, and medial) and three angles (superior, inScapula
1 Subscapular fossa
2 Spine
3 Deltoid tubercle
4 Supraspinous fossa
5 Infraspinous fossa
6 Acromion
7 Clavicular facet
8 Acromial angle
9 Medial border
10 Lateral border
Left scapula
Anterior view, lateral to right Left scapula
Lateral view, anterior to right
11 Superior border
12 Suprascapular notch
13 Inferior angle
14 Superior angle
15 Glenoid cavity
16 Supraglenoid tubercle
17 Infraglenoid tubercle
18 Neck
19 Coracoid process
1
6
2
7
9
10
11
12
13
13
14 14
15
16
17 17
18
19
19
89
Left scapula
Superior view, lateral to left
Left scapula
Posterior view, Lateral to left
2
2
3
4
5
6
6
8
8
9
10
11
12
13
14
15
16
17
18
19
12
90
anterior to posterior. The ends consist of a spongy core of bone covered with a thin lamina of compact bone.
The shaft is a cylinder of thick compact bone surrounding a large medullary cavity. The humerus articulates
with three bones — the scapula, ulna, and radius.
The humerus is the skeletal element of the brachium and it is the largest bone of
the upper limb. It has a long cylindrical shaft that expands at the proximal and
distal ends. The proximal end is rounded, while the distal end is fl attened from
Humerus
1 Head
2 Anatomical neck
3 Surgical neck
4 Greater tubercle
5 Lesser tubercle
6 Intertubercular sulcus or groove
7 Crest of greater tubercle
8 Crest of lesser tubercle
9 Shaft or body
10 Groove for radial nerve
11 Medial supracondylar ridge
12 Deltoid tuberosity
13 Capitulum
14 Trochlea
15 Olecranon fossa
16 Coronoid fossa
17 Radial fossa
18 Medial epicondyle
19 Groove for ulnar nerve
20 Lateral epicondyle
Left humerus
Anterior view, lateral to right
Left humerus
Posterior view, lateral to left
4
5
6
7
8
9
11
12
14 13
16 17
18 20
1
10
11
14
15
18
19
20
3
2
91
Left humerus
Lateral view, anterior to left
Left humerus
Medial view, anterior to right
Left humerus
Superior view, lateral to left
Left humerus
Inferior view, lateral to right
1
1
4
4
4
5
5
10
11
12
13
14
15
18
18
20
5
6
15
92
The ulna is the medial and longer bone of the antebrachium. It is thick and notched at its proximal end where it is a major contributor to the elbow joint. From the notched proximal end it
tapers to a thin shaft that ends distally as a small rounded head. The ulna articulates with two
bones— the humerus and the radius.
Ulna
1 Olecranon
2 Coronoid process
3 Ulnar tuberosity
4 Radial notch
5 Trochlear notch
6 Shaft or body
7 Interosseous border
8 Anterior border
9 Posterior border
10 Supinator crest
11 Head
12 Articular circumference
13 Ulnar styloid process
Left ulna
Posterior view, lateral to left
Left ulna
Anterior view, lateral to right
1
9
13
10
2
3
5
6
8
12
4
10
7
93
Left ulna
Lateral view, anterior to left
Left ulna
Medial view, anterior to right
Left ulna
Superior view, lateral to left
Left ulna
Inferior view, lateral to right
1
1
4
10
11
1
2 2
3
6 6
11
11
13
13 13
5 5
4
8
7
9
9
7
4
94
bone. The distal end is concave anteriorly and convex and grooved posteriorly. The ridge-like borders of the
shaft give it a triangular shape in cross section. The radius articulates with four bones — the humerus, ulna,
scaphoid, and lunate.
The radius is the lateral, slender, rod-like bone of the antebrachium. The rod-like shaft
expands at both ends. The proximal end forms a wheel-like head with a proximal concavity, while the distal end expands from medial to lateral to form the widest part of the
Radius
1 Head
2 Articular facet
3 Articular circumference
4 Neck
5 Shaft or body
6 Radial tuberosity
7 Pronator tuberosity
8 Interosseous border
9 Anterior border
10 Posterior border
11 Radial styloid process
12 Suprastyloid crest
13 Dorsal tubercle
14 Groove for extensor muscle tendons
15 Ulnar notch
16 Carpal articular surface
Left radius
Anterior view, lateral to right
Left radius
Posterior view, lateral to left
3
4
5
9
6
11
12
1
7
10
11
13 14
8
95
Left radius
Lateral view, anterior to left
Left radius
Medial view, anterior to right
Left radius
Superior view, lateral to left
Left radius
Inferior view, lateral to right
1
2
15
16
16
3
4 4
6
11
11
13
15
9
10
8
13
6
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96
and a proximal row. Distal to the carpus are the fi ve digital rays. Each digit, called a fi nger of which there are
four, consists of a metatarsal bone and three phalanges. The remaining digit, the thumb or pollex, has a metatarsal bone and only two phalanges. The photos of the hands below and on the opposing page are positioned
as if you were looking at your own hand.
The hand is a composite structure consisting of 27 bones. The proximal end of the hand is the carpus or wrist. The carpal bones are
eight in number and are arranged in two rows of four, a distal row
Hand Skeleton
Left hand
Anterior view, lateral to left
1 2
3
4
5
6 7
8
9
10
11
12
13
14
14
14
14
14
15
15
15
15
16
16
16
16
16
97
1 Scaphoid
2 Lunate
3 Triquetrum
4 Pisiform
5 Trapezium
6 Trapezoid
7 Capitate
8 Hamate
9 Metacarpal I
10 Metacarpal II
11 Metacarpal III
12 Metacarpal IV
13 Metacarpal V
14 Proximal phalanx
15 Middle phalanx
16 Distal phalanx
Left hand
Posterior view, lateral to right
1 2
3
7 6 5
8
9
10
11
12
13
14
14
15
16
16
14
14
14
15
15
16 15
16
16
98
Carpal Bones The eight carpal bones form the proximal end
of the hand skeleton. The main features of this
complex little series of bones are the numerLeft trapezium
Anterior view, lateral to left
Left trapezoid
Anterior view, lateral to left
Left capitate
Anterior view, lateral to left
Left hamate
Anterior view, lateral to left
Left scaphoid
Anterior view, lateral to left
Left pisiform
Anterior view, lateral to left Left triquetrum
Anterior view, lateral to left
Left lunate
Anterior view, lateral to left
ous articular surfaces they form with one another and with the metacarpal and antebrachial bones. The carpal bones form two rows of four bones each. The two largest
bones of the proximal row, the scaphoid and the lunate, articulate with the distal end
of the radius. The row of distal bones form the skeletal foundation for the fi ngers and
articulate with the metacarpal bones of the fi ngers and thumb. The anterior surface of
the carpal bones forms the fl oor of the carpal tunnel that supports the major digital
fl exor tendons that enter the hand.
22
23
28
27
4
6
7
11
13
12
1 17
20
21
19
32 34
15
16
9
2
3
5
8
10
18
14
24
25
26
31 35
33
30
29
99
Trapezium
1 Tubercle of trapezium
2 Articular surface with scaphoid
3 Articular surface with trapezoid
4 Articular surface with first metacarpal
5 Articular surface with second metacarpal
Trapezoid
6 Articular surface with scaphoid
7 Articular surface with trapezium
8 Articular surface with capitate
9 Articular surface with first metacarpal
Capitate
10 Articular surface with scaphoid
11 Articular surface with lunate
12 Articular surface with trapezoid
13 Articular surface with hamate
14 Articular surface with second metacarpal
15 Articular surface with third metacarpal
16 Articular surface with fourth metacarpal
Hamate
17 Hook of hamate or hamulus
18 Articular surface with lunate
19 Articular surface with triquetrum
20 Articular surface with fourth metacarpal
21 Articular surface with fifth metacarpal
Scaphoid
22 Scaphoid tubercle
23 Articular surface with radius
24 Articular surface with trapezium
25 Articular surface with trapezoid
26 Articular surface with capitate
27 Articular surface with lunate
Lunate
28 Articular surface with radius
29 Articular surface with scaphoid
30 Articular surface with capitate
31 Articular surface with hamate
32 Articular surface with triquetrum
Triquetrum
33 Articular surface with lunate
34 Articular surface with pisiform
35 Articular surface with hamate
Pisiform
36 Articular surface with triquetrum
Left trapezium
Posterior view, lateral to right
Left trapezoid
Posterior view, lateral to right Left capitate
Posterior view, lateral to right
Left hamate
Posterior view, lateral to right
Left scaphoid
Posterior view, lateral to right
Left lunate
Posterior view, lateral to right Left triquetrum
Posterior view, lateral to right
Left pisiform
Posterior view, lateral to right
23
24 25
26
28 29
30 36
17
21 20
4
14
10
11
5
15
2
3
6
8
7
12
13
18 19
9
31
32
35
33
27
16
100
The fi ve digital rays of the hand consist of a series of four bones, except in the thumb
where there are only three bones, that decrease in length from proximal to distal. Forming the skeleton of the palmar region of the hand are the stout metacarpal bones. Note
their saddle-like bases and rounded heads. The anterior-posterior fl attened phalanges
project into the proper portion of the fi ngers and thumb from the metacarpal bones.
Metacarpals and Phalanges
Left metacarpal bones, numbered I to V from lateral to medial
Anterior view, thumb to left
Left phalanges
Anterior view, thumb to left
1
1
1
1
1
2
2 2
2
2
3
3 3
3
3
4
5
5
5
6
6
6
7
9 9
9
9
9
8
101
1 Base of metacarpal
2 Shaft or body of metacarpal
3 Head of metacarpal
4 Styloid process of third metacarpal
Left phalanges
Posterior view, thumb to right
5 Base of phalanx
6 Shaft or body of phalanx
7 Head of phalanx
8 Trochlea of phalanx
9 Tuberosity of distal phalanx
Left metacarpal bones, numbered I to V from lateral to medial
Posterior view, thumb to right
1
1
1
1
1
2
2
2
2
2
3
3
3
3
4
5
5
5
6
6
6
7
7
3
8
102
the most obvious are those that increase the diameter of the pelvic outlet. For example, note the wider pubic
angle (1) and greater sciatic notch (2) of the female pelvis.
The characteristic features of the female pelvis are related to the
role of the female pelvis in childbirth. While there are numerous diagnostic features that help distinguish a female pelvis, some of
Pelvis - Female
Female pelvis
Posterior view, superior to top
Female pelvis
Superior view, anterior to bottom
Female pelvis
Inferior view, anterior to bottom
Female pelvis
Lateral view, anterior to left
Female pelvis
Anterior view, superior to top
1
3
2
103
The male pelvis tends to have a more narrow profi le than the pelvis of the female.
Compare the diameter of the outlet, the angle of the pubic arch, and the width of the
greater sciatic notch with those of the female pelvis. Also, note the stout, thick ishiopubic ramus (3) of the male compared to the slender ischiopubic ramus of the female
pelvis.
Pelvis - Male
Male pelvis
Anterior view, superior to top
Male pelvis
Posterior view, superior to top
Male pelvis
Superior view, anterior to bottom Male pelvis
Inferior view, anterior to bottom
Male pelvis
Lateral view, anterior to left
1
3
2
104
hip bone. The os coxae is fi rmly anchored to the sacrum via strong ligaments and a synovial joint. Distal to
the girdle is the free part of the lower limb. The bony framework of the thigh is the femur with the sesamoid
patella at its distal end. Distal to the femur, the tibia and fi bula form the skeleton of the crus or leg. The distalmost region of the inferior limb is the foot consisting of seven tarsal bones, fi ve metatarsal bones, and fourteen phalanges.
Each inferior appendage consists of 31 bones. The broad base of
the inferior limb is the pelvic girdle. This girdle is the strong fusion of
three bones, the ilium, ischium, and pubis, to form the os coxae or
Inferior Limb
1 Os coxae or hip bone
2 Femur
3 Patella
4 Tibia
5 Fibula
6 Tarsal bones
7 Metatarsal bones
8 Phalanges
Left lower limb
Anterior view, lateral to right Left lower limb
Posterior view, lateral to left
1 1
2 2
3
4 4
5 5
6 7
8
105
and transfers the forces of locomotion from the inferior limb to the vertebral column. Each os coxae articulates with
three bones — the femur, sacrum, and opposite os coxae. The photo on this page depicts the three bones of the os
coxae — the ilium (green), the ischium (blue), and the pubis (red). Landmarks that are shared by the bones are
depicted on this image. The following two pages show all the landmarks of the individual bones of the os coxae.
Each os coxae forms from three separate bony elements that fuse during development
at their site of union within the acetabulum. The three bony elements are the ilium, ischium, and pubis. This strong girdle of bone unites the inferior limb to the axial skeleton
Os Coxae
Left os coxae showing individual bones
Lateral view, anterior to left
1 Acetabulum
2 Acetabular notch
3 Lunate surface
4 Ischiopubic ramus
5 Obturator foramen
6 Greater sciatic notch
1
2
3
4
5
6
106
Os Coxae Ilium
1 Body of ilium
2 Supra-acetabular groove
3 Ala or wing
4 Arcuate line
5 Iliac crest
6 Outer lip of crest
7 Intermediate zone of crest
8 Inner lip of crest
9 Tuberculum of crest
10 Anterior superior iliac spine
11 Anterior inferior iliac spine
12 Posterior superior iliac spine
13 Posterior inferior iliac spine
14 Iliac fossa
15 Anterior gluteal line
16 Posterior gluteal line
17 Inferior gluteal line
18 Auricular surface
19 Iliac tuberosity
Left os coxae
Anterior view, lateral to right
Left os coxae
Posterior view, lateral to right
1
1
3
5
5
3
8 7
9
10
11
12
13
14
15
16
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