Remove Watermark
1
Introduction
One pronates while giving, and supinates while getting
—Anonymous
The fore- and hindlimbs were evolved basically for PARTS OF THE UPPER LIMB
bearing the weight of the body and for locomotion as It has been seen that the upper limb is made up
is seen in quadrupeds, e.g. cows or dogs. The two pairs four parts: (1) Shoulder region; (2) arm or brachi
of limbs are, therefore, built on the same basic principle. (3) forearm or antebrachium; and (4) hand or ma
Each limb is made up of a basal segment or girdle, Further subdivisions of these parts are given in T
and a free part divided into proximal, middle and distal 1.2 and Fig. 1.1.
segments. The girdle attaches the limb to the axial
skeleton. The distal segment carries five digits.
Table 1.1 shows homologous parts of upper and lower
limbs.
However, with the evolution of the erect posture in
man, the function of weight-bearing was taken over by
the lower limbs. Thus the upper limbs, especially the
hands, became free and gradually evolved into organs
having great manipulative skills.
This has become possible because of a wide range of
mobility at the shoulder. The whole upper limb works
as a jointed lever. The human hand is a grasping tool.
It is exquisitely adaptable to perform various complex
functions under the control of a large area of the brain.
The unique position of man as a master mechanic of
the animal world is because of the skilled movements
of his hands.
Table 1.1: Homologous parts of the limbs
Upper limb Lower limb
1. Shoulder girdle Hip girdle
2. Shoulder joint Hip joint
3. Arm with humerus Thigh with femur
4. Elbow joint Knee joint
5. Forearm with radius and ulna Leg with tibia and fibula
6. Wrist joint Ankle joint
7. Hand with Foot with
a. Carpus a. Tarsus
b. Metacarpus b. Metatarsus
c. 5 digits c. 5 digits
Fig. 1.1: Parts and 32 bones of the upper limb
3
, Remove Watermark
UPPER LIMB
4
Table 1.2: Parts of the upper limb
Parts Subdivisions Bones Joints
1. Shoulder region a. Pectoral region on the Bones of the shoulder girdle • Sternoclavicular join
front of the chest a. Clavicle • Acromioclavicular jo
b. Axilla or armpit b. Scapula
c. Scapular region on the
back
2. Upper arm (arm or brachium) — Humerus Shoulder joint
from shoulder to the elbow (scapulohumeral joint)
3. Forearm (antebrachium) — a. Radius • Elbow joint
from elbow to the wrist b. Ulna • Radioulnar joints
4. Hand a. Wrist • Carpus, made up of • Wrist joint
8 carpal bones (radiocarpal joint)
• Intercarpal joints
b. Hand proper • Metacarpus, made up of • Carpometacarpal joi
5 metacarpal bones
c. Five digits, numbered • 14 phalanges—two for • Intermetacarpal join
from lateral to medial side the thumb, and three for
First = Thumb or pollex each of the four fingers • Metacarpophalange
Second = Index or forefinger joints
Third = Middle finger • Proximal and distal
Fourth = Ring finger interphalangeal join
Fifth = Little finger
1 The shoulder region includes: 4 The hand (manus) includes:
a. The pectoral or breast region on the front of the chest; a. The wrist or carpus, supported by 8 carpal bo
b. The axilla or armpit; and arranged in two rows.
c. The scapular region on the back comprising parts b. The hand proper or metacarpus, supported b
around the scapula. metacarpal bones.
The bones of the shoulder girdle are the clavicle and c. Five digits (thumb and four fingers). Each fin
the scapula. is supported by three phalanges, but the thu
Of these, only the clavicle articulates with the axial has only 2 phalanges (there being 14 phalan
skeleton at the sternoclavicular joint. The scapula is in all).
mobile and is held in position by muscles. The The carpal bones form the wrist joint with the rad
clavicle and scapula articulate with each other at the intercarpal joints with one another, and carpom
acromioclavicular joint. carpal joints with the metacarpals.
2 The arm (upper arm or brachium) extends from the The phalanges form metacarpophalangeal joints w
shoulder to the elbow (cubitus). The bone of the arm the metacarpals and interphalangeal joints with
is the humerus. Its upper end meets the scapula and another.
forms the shoulder joint. The shoulder joint permits Movements of the hand are permitted chiefly at
wrist joint. The thumb moves at the first carpom
Upper Limb
movements of the arm.
3 The forearm (antebrachium) extends from the elbow carpal joint; where an exclusive movemen
to the wrist. The bones of the forearm are the radius opposition besides the other usual movement
and the ulna. At their upper ends, they meet the permitted. Each of the second to fifth digits move
lower end of the humerus to form the elbow joint. metacarpophalangeal, proximal and distal in
Their lower ends meet the carpal bones to form the phalangeal joints. Figure 1.2 and Flowchart 1.1 sh
wrist joint. The radius and ulna meet each other at the lines of force transmission.
the radioulnar joints.
The elbow joint permits movements of the forearm, EVOLUTION OF UPPER LIMBS
1
namely flexion and extension. The radioulnar joints The forelimbs have evolved from the pectoral fin
Section
permit rotatory movements of the forearm called fishes. In tetrapods (terrestrial/land vertebrates), al
pronation and supination. In a mid-flexed elbow, the four limbs are used for supporting body weight, and
palm faces upwards in supination and downwards locomotion. In arboreal (tree-dwelling) human an
in pronation. During the movement of pronation, the tors, the forelimbs have been set free from their wei
radius rotates around the ulna (see Fig. 10.23). bearing function. The forelimbs, thus ‘emancipat
, Remove Watermark
INTRODUCTION
Flowchart 1.1: Lines of force transmission
disproportionate lengthening of the forearms, and
in elongation of the palm and fingers.
STUDY OF ANATOMY
Before studying the anatomy of any region, it is u
to begin by learning general features of the skin,
superficial fascia and its contents, the deep fascia,
bones, the muscles, joints, blood vessels and ner
All these are provided in BD Chaurasia’s Handboo
General Anatomy, 6th edition. This is followed by
Fig. 1.2: Scheme of skeleton of upper limb showing lines of study of the muscles of the region, and finally, the bl
force transmission
vessels and nerves. These descriptions should be r
only after the part has been dissected with the hel
the steps of dissection provided in the book.
acquired a wide range of mobility and were used for Before undertaking the study of any part of the bo
prehension or grasping, feeling, picking, holding, it is essential for the students to acquire so
sorting, breaking, fighting, etc. These functions became knowledge of the bones of the region. It is for this rea
possible only after necessary structural modifications: that a chapter on bones (osteology) is given at
a. Appearance of joints permitting rotatory movements beginning of each section. While reading the chap
of the forearm (described as supination and the students should palpate the various parts of bo
pronation), as a result of which food could be picked on themselves. The next chapter must be studied w
up and taken to the mouth. the help of loose human bones.
b. Addition of the clavicle, which has evolved with the
function of prehension.
c. Rotation of the thumb through 90°, so that it can be
opposed to other digits for grasping.
d. Appropriate changes for free mobility of the fingers 1. Make a flowchart to show lines of force transmiss
and hand. in upper limb.
The primitive pentadactyl limb of amphibians, 2. Tabulate the homologous parts of upper and lo
terminating in five digits, has persisted through limbs.
evolution and is seen in man. In some other species, 3. Enumerate:
however, the limbs were altogether lost, as in snakes; a. Subdivisions of shoulder region
while in others the digits were reduced in number as b. Joints related to the forearm
in ungulates. The habit of brachiation, i.e. suspending c. Name of carpal bones in order
the body by the arms, in anthropoid apes resulted in d. Joints of the hand
, Remove Watermark
UPPER LIMB
6
2
Bone
Palpation of ulnar nerve behind medial epicondyle of humerus makes some persons smile, that is why the bone is called humer
—Anonym
Competency achievement: The student should be able to: 1 The lateral end is flat, and the medial end is la
AN 8.1 Identify the given bone, its side, important features and and quadrilateral.
keep it in anatomical position.1 2 The shaft is slightly curved, so that it is con
AN 8.2 Identify and describe joints formed by the given bone.2 forwards in its medial two-thirds, and conc
forwards in its lateral one-third.
3 The inferior surface is grooved longitudinally in
INTRODUCTION
middle one-third.
Out of 206 total bones in man, the upper limbs contain as
many as 64 bones. Each side consists of 32 bones, the Peculiarities of the Clavicle
distribution of which is shown in Table 1.2 and 1 It is the only long bone that lies horizontally.
Fig. 1.1 (see Chapter 1). Since bones of the two upper limbs 2 It is subcutaneous throughout.
are similar, one needs to learn only 32 bones out of a total 3 It is the first bone to start ossifying.
64 bones. This applies to soft parts as well. One learns only 4 It is the only long bone which ossifies in membr
one upper limb, the other upper limb gets learnt on its 5 It is the only long bone which has two primary cen
own. This is true for the whole body except parts of of ossification.
abdomen. Actually, one needs to master only 50% of the 6 There is no medullary cavity.
body and other 50% gets mastered itself. The individual 7 It is occasionally pierced by the middle supraclavic
bones of the upper limb will be described one by one. nerve.
Their features and attachments should be read with the It receives weight of upper limb via lateral one-th
bones before undertaking the dissection of the part through coracoclavicular ligament and transm
concerned. The paragraphs on attachments should be weight of upper limb to the axial skeleton via me
revised when the dissection of a particular region has been two-thirds part (see Flowchart 1.1).
completed.
Features
Upper Limb
Competency achievement: The student should be able to: Shaft
AN 8.3 Enumerate peculiarities of clavicle.3 The shaft (Figs 2.1a and b) is divisible into the lat
one-third and the medial two-thirds.
The lateral one-third of the shaft is flattened from ab
CLAVICLE downwards. It has two borders—anterior
posterior. The anterior border is concave forwards.
The clavicle (Latin a small key) is a long bone. It supports posterior border is convex backwards. This part of
the shoulder so that the arm can swing clearly away bone has two surfaces—superior and inferior.
from the trunk. The clavicle transmits the weight of the superior surface is subcutaneous and the inferior sur
1
limb to the sternum. The bone has a curved part called presents an elevation called the conoid (Greek c
Section
the shaft, and two ends, lateral and medial. tubercle and a ridge called the trapezoid ridge.
The medial two-thirds of the shaft is rounded
Side Determination is said to have four surfaces. The anterior surfac
The side to which a clavicle belongs can be determined convex forwards. The posterior surface is smooth.
from the following characters. superior surface is rough in its medial part. The infe
6
1
Introduction
One pronates while giving, and supinates while getting
—Anonymous
The fore- and hindlimbs were evolved basically for PARTS OF THE UPPER LIMB
bearing the weight of the body and for locomotion as It has been seen that the upper limb is made up
is seen in quadrupeds, e.g. cows or dogs. The two pairs four parts: (1) Shoulder region; (2) arm or brachi
of limbs are, therefore, built on the same basic principle. (3) forearm or antebrachium; and (4) hand or ma
Each limb is made up of a basal segment or girdle, Further subdivisions of these parts are given in T
and a free part divided into proximal, middle and distal 1.2 and Fig. 1.1.
segments. The girdle attaches the limb to the axial
skeleton. The distal segment carries five digits.
Table 1.1 shows homologous parts of upper and lower
limbs.
However, with the evolution of the erect posture in
man, the function of weight-bearing was taken over by
the lower limbs. Thus the upper limbs, especially the
hands, became free and gradually evolved into organs
having great manipulative skills.
This has become possible because of a wide range of
mobility at the shoulder. The whole upper limb works
as a jointed lever. The human hand is a grasping tool.
It is exquisitely adaptable to perform various complex
functions under the control of a large area of the brain.
The unique position of man as a master mechanic of
the animal world is because of the skilled movements
of his hands.
Table 1.1: Homologous parts of the limbs
Upper limb Lower limb
1. Shoulder girdle Hip girdle
2. Shoulder joint Hip joint
3. Arm with humerus Thigh with femur
4. Elbow joint Knee joint
5. Forearm with radius and ulna Leg with tibia and fibula
6. Wrist joint Ankle joint
7. Hand with Foot with
a. Carpus a. Tarsus
b. Metacarpus b. Metatarsus
c. 5 digits c. 5 digits
Fig. 1.1: Parts and 32 bones of the upper limb
3
, Remove Watermark
UPPER LIMB
4
Table 1.2: Parts of the upper limb
Parts Subdivisions Bones Joints
1. Shoulder region a. Pectoral region on the Bones of the shoulder girdle • Sternoclavicular join
front of the chest a. Clavicle • Acromioclavicular jo
b. Axilla or armpit b. Scapula
c. Scapular region on the
back
2. Upper arm (arm or brachium) — Humerus Shoulder joint
from shoulder to the elbow (scapulohumeral joint)
3. Forearm (antebrachium) — a. Radius • Elbow joint
from elbow to the wrist b. Ulna • Radioulnar joints
4. Hand a. Wrist • Carpus, made up of • Wrist joint
8 carpal bones (radiocarpal joint)
• Intercarpal joints
b. Hand proper • Metacarpus, made up of • Carpometacarpal joi
5 metacarpal bones
c. Five digits, numbered • 14 phalanges—two for • Intermetacarpal join
from lateral to medial side the thumb, and three for
First = Thumb or pollex each of the four fingers • Metacarpophalange
Second = Index or forefinger joints
Third = Middle finger • Proximal and distal
Fourth = Ring finger interphalangeal join
Fifth = Little finger
1 The shoulder region includes: 4 The hand (manus) includes:
a. The pectoral or breast region on the front of the chest; a. The wrist or carpus, supported by 8 carpal bo
b. The axilla or armpit; and arranged in two rows.
c. The scapular region on the back comprising parts b. The hand proper or metacarpus, supported b
around the scapula. metacarpal bones.
The bones of the shoulder girdle are the clavicle and c. Five digits (thumb and four fingers). Each fin
the scapula. is supported by three phalanges, but the thu
Of these, only the clavicle articulates with the axial has only 2 phalanges (there being 14 phalan
skeleton at the sternoclavicular joint. The scapula is in all).
mobile and is held in position by muscles. The The carpal bones form the wrist joint with the rad
clavicle and scapula articulate with each other at the intercarpal joints with one another, and carpom
acromioclavicular joint. carpal joints with the metacarpals.
2 The arm (upper arm or brachium) extends from the The phalanges form metacarpophalangeal joints w
shoulder to the elbow (cubitus). The bone of the arm the metacarpals and interphalangeal joints with
is the humerus. Its upper end meets the scapula and another.
forms the shoulder joint. The shoulder joint permits Movements of the hand are permitted chiefly at
wrist joint. The thumb moves at the first carpom
Upper Limb
movements of the arm.
3 The forearm (antebrachium) extends from the elbow carpal joint; where an exclusive movemen
to the wrist. The bones of the forearm are the radius opposition besides the other usual movement
and the ulna. At their upper ends, they meet the permitted. Each of the second to fifth digits move
lower end of the humerus to form the elbow joint. metacarpophalangeal, proximal and distal in
Their lower ends meet the carpal bones to form the phalangeal joints. Figure 1.2 and Flowchart 1.1 sh
wrist joint. The radius and ulna meet each other at the lines of force transmission.
the radioulnar joints.
The elbow joint permits movements of the forearm, EVOLUTION OF UPPER LIMBS
1
namely flexion and extension. The radioulnar joints The forelimbs have evolved from the pectoral fin
Section
permit rotatory movements of the forearm called fishes. In tetrapods (terrestrial/land vertebrates), al
pronation and supination. In a mid-flexed elbow, the four limbs are used for supporting body weight, and
palm faces upwards in supination and downwards locomotion. In arboreal (tree-dwelling) human an
in pronation. During the movement of pronation, the tors, the forelimbs have been set free from their wei
radius rotates around the ulna (see Fig. 10.23). bearing function. The forelimbs, thus ‘emancipat
, Remove Watermark
INTRODUCTION
Flowchart 1.1: Lines of force transmission
disproportionate lengthening of the forearms, and
in elongation of the palm and fingers.
STUDY OF ANATOMY
Before studying the anatomy of any region, it is u
to begin by learning general features of the skin,
superficial fascia and its contents, the deep fascia,
bones, the muscles, joints, blood vessels and ner
All these are provided in BD Chaurasia’s Handboo
General Anatomy, 6th edition. This is followed by
Fig. 1.2: Scheme of skeleton of upper limb showing lines of study of the muscles of the region, and finally, the bl
force transmission
vessels and nerves. These descriptions should be r
only after the part has been dissected with the hel
the steps of dissection provided in the book.
acquired a wide range of mobility and were used for Before undertaking the study of any part of the bo
prehension or grasping, feeling, picking, holding, it is essential for the students to acquire so
sorting, breaking, fighting, etc. These functions became knowledge of the bones of the region. It is for this rea
possible only after necessary structural modifications: that a chapter on bones (osteology) is given at
a. Appearance of joints permitting rotatory movements beginning of each section. While reading the chap
of the forearm (described as supination and the students should palpate the various parts of bo
pronation), as a result of which food could be picked on themselves. The next chapter must be studied w
up and taken to the mouth. the help of loose human bones.
b. Addition of the clavicle, which has evolved with the
function of prehension.
c. Rotation of the thumb through 90°, so that it can be
opposed to other digits for grasping.
d. Appropriate changes for free mobility of the fingers 1. Make a flowchart to show lines of force transmiss
and hand. in upper limb.
The primitive pentadactyl limb of amphibians, 2. Tabulate the homologous parts of upper and lo
terminating in five digits, has persisted through limbs.
evolution and is seen in man. In some other species, 3. Enumerate:
however, the limbs were altogether lost, as in snakes; a. Subdivisions of shoulder region
while in others the digits were reduced in number as b. Joints related to the forearm
in ungulates. The habit of brachiation, i.e. suspending c. Name of carpal bones in order
the body by the arms, in anthropoid apes resulted in d. Joints of the hand
, Remove Watermark
UPPER LIMB
6
2
Bone
Palpation of ulnar nerve behind medial epicondyle of humerus makes some persons smile, that is why the bone is called humer
—Anonym
Competency achievement: The student should be able to: 1 The lateral end is flat, and the medial end is la
AN 8.1 Identify the given bone, its side, important features and and quadrilateral.
keep it in anatomical position.1 2 The shaft is slightly curved, so that it is con
AN 8.2 Identify and describe joints formed by the given bone.2 forwards in its medial two-thirds, and conc
forwards in its lateral one-third.
3 The inferior surface is grooved longitudinally in
INTRODUCTION
middle one-third.
Out of 206 total bones in man, the upper limbs contain as
many as 64 bones. Each side consists of 32 bones, the Peculiarities of the Clavicle
distribution of which is shown in Table 1.2 and 1 It is the only long bone that lies horizontally.
Fig. 1.1 (see Chapter 1). Since bones of the two upper limbs 2 It is subcutaneous throughout.
are similar, one needs to learn only 32 bones out of a total 3 It is the first bone to start ossifying.
64 bones. This applies to soft parts as well. One learns only 4 It is the only long bone which ossifies in membr
one upper limb, the other upper limb gets learnt on its 5 It is the only long bone which has two primary cen
own. This is true for the whole body except parts of of ossification.
abdomen. Actually, one needs to master only 50% of the 6 There is no medullary cavity.
body and other 50% gets mastered itself. The individual 7 It is occasionally pierced by the middle supraclavic
bones of the upper limb will be described one by one. nerve.
Their features and attachments should be read with the It receives weight of upper limb via lateral one-th
bones before undertaking the dissection of the part through coracoclavicular ligament and transm
concerned. The paragraphs on attachments should be weight of upper limb to the axial skeleton via me
revised when the dissection of a particular region has been two-thirds part (see Flowchart 1.1).
completed.
Features
Upper Limb
Competency achievement: The student should be able to: Shaft
AN 8.3 Enumerate peculiarities of clavicle.3 The shaft (Figs 2.1a and b) is divisible into the lat
one-third and the medial two-thirds.
The lateral one-third of the shaft is flattened from ab
CLAVICLE downwards. It has two borders—anterior
posterior. The anterior border is concave forwards.
The clavicle (Latin a small key) is a long bone. It supports posterior border is convex backwards. This part of
the shoulder so that the arm can swing clearly away bone has two surfaces—superior and inferior.
from the trunk. The clavicle transmits the weight of the superior surface is subcutaneous and the inferior sur
1
limb to the sternum. The bone has a curved part called presents an elevation called the conoid (Greek c
Section
the shaft, and two ends, lateral and medial. tubercle and a ridge called the trapezoid ridge.
The medial two-thirds of the shaft is rounded
Side Determination is said to have four surfaces. The anterior surfac
The side to which a clavicle belongs can be determined convex forwards. The posterior surface is smooth.
from the following characters. superior surface is rough in its medial part. The infe
6
