Download Anatomy of Arm

Anatomy of Arm
Dr. Fadel Naim
Orthopedic Surgeon
Islamic University
Faculty of Medicine
Veins of the Arm

Two sets of veins, superficial and
deep, anastomose freely with each
other.

The superficial veins are in the
subcutaneous tissue

The deep veins accompany the
arteries.

Both sets of veins have valves

They are more numerous in the
deep veins

The smooth muscles of the veins
are innervated by sympathetic
postganglionic nerve fibers
Superficial Veins

The two main superficial veins
of the arm:
1.
2.
The cephalic vein
The basilic vein
Superficial Veins
1.
The cephalic vein
–
–
–
–
Located in the subcutaneous
tissue along the anterolateral
surface of the proximal
forearm and arm
Often visible through the skin
Passes superiorly between
the deltoid and pectoralis
major in the deltopectoral
groove
It empties into the termination
of the axillary vein in the
deltopectoral triangle
Superficial Veins
2. The basilic vein
– located in the subcutaneous
tissue and passes on the medial
side of the inferior part of the
arm
– Often it is also visible through the
skin.
– Near the junction of the middle
and inferior thirds of the arm, the
basilic vein penetrates the
brachial (deep) fascia and runs
superiorly into the axilla
– Where it merges with the
accompanying veins of the
brachial artery to form the
axillary vein
Deep Veins of the Arm
 The brachial veins:
– The paired veins accompanying
the brachial artery
– Their frequent connections
encompass the artery, forming an
anastomotic network within a
common vascular sheath.
– The pulsations of the brachial
artery help move the blood through
this venous network.
– Begin at the elbow by union of the
accompanying veins of the ulnar
and radial arteries.
– End by merging with the basilic
vein to form the axillary vein.
Venipuncture of the Upper Limb
Because of the prominence and accessibility of
the superficial veins of the upper limb, they are
commonly used for venipuncture
These veins may be embedded with the
subcutaneous tissue (fat), making them difficult
to see
 By applying a tourniquet to the arm, the
venous return is occluded and the veins
distend and are usually visible and/or palpable.
Venipuncture of the Upper Limb
 The median cubital vein is commonly used for venipuncture
for:
– Drawing blood
– Inserting a catheter for right cardiac catheterization
 The dorsal venous network and the cephalic and basilic veins
arising from it are commonly used for intravenous feeding
Lymphatic Drainage of the Upper Limb
 Superficial lymphatic
vessels
– Arise from lymphatic plexuses in:
• The digits
• The palm
• The dorsum of the hand
– Ascend mostly with superficial
veins
 Deep lymphatic vessels:
– Less numerous than superficial
vessels
– Accompany the major deep veins
in the upper limb
– Terminate in the humeral group of
axillary nodes.
Lymphatic Drainage of the Upper Limb
 Some vessels accompanying the
basilic vein enter the cubital nodes,
located:
– proximal to the medial epicondyle
– medial to the basilic vein.
 Efferent vessels from these lymph
nodes ascend in the arm and
terminate in the humeral (lateral)
axillary lymph nodes.
 Most lymphatic vessels
accompanying the cephalic vein
cross the proximal part of the arm
and anterior aspect of the shoulder
to enter the apical group of
axillary nodes; however, some
vessels previously enter the
deltopectoral nodes.
Lymphangitis, Lymphadenitis, and Lymphedema
 Lymphangitis:
– The inflammation of lymphatic vessels
 Lymphadenitis:
– The inflammation of lymph nodes
 These conditions may occur when the lymphatic system
is involved in the spread (metastasis) of cancer cells or
infection
Fascial compartments of the Upper Limb
 The brachial fascia:
– A sheath of deep fascia encloses the arm like a sleeve
– It is continuous superiorly with the pectoral and axillary layers of
fascia.
– It is attached inferiorly to the epicondyles of the humerus and
the olecranon of the ulna and is continuous with the antebrachial
fascia
 Intermuscular septa:
– The medial and lateral intermuscular septa extend from the deep
surface of the brachial fascia to the medial and lateral
supracondylar ridges of the humerus
– Dividing the arm into
• Anterior (flexor) fascial compartment
• Posterior (extensor) fascial compartment
• Each of which contains muscles serving similar functions, nerves, and
blood vessels that supply
•Lateral
•head
•Triceps •Long
•brachii •head
•Medial
•head
•Humerus
•Extensors
•Brachialis
•Flexors
•Others
•Posterior
•compartment
•of arm (extends
•elbow); innervation:
•radial nerve
•Short head
•Biceps brachii
•Long head
•(a)
•(a) Muscles of the arm
•Anterior compartment
•of arm (flexes elbow);
•innervation:
•musculocutaneous
•nerve
Muscles of the Arm
 4 arm (brachial) muscles:
– 3 flexors in the anterior
compartment
• Supplied by the
musculocutaneous nerve
– Biceps brachii
– Brachialis
– Coracobrachialis
– 1 extensor in the
posterior compartment
• Triceps brachii
– Supplied by the radial
nerve.
BICEPS BRACHII
 ORIGIN
– Long head:
• supraglenoid tubercle of scapula.
– Short head:
• coracoid process of scapula with
coracobrachialis
 INSERTION
– posterior border of bicipital tuberosity of
radius (over bursa)
– bicipital aponeurosis to deep fascia and
subcutaneous ulna
 ACTION
– Supinator of the forearm
– Flexion of the elbow
– weakly flexes shoulder
 NERVE
– Musculocutaneous nerve (C5, 6) (from
lateral cord)

The tendon of the long head of the biceps crosses the head
of the humerus within the cavity of the glenohumeral joint

The tendon, surrounded by synovial membrane, descends in
the intertubercular groove of the humerus

The bicipitoradial bursa
separates the biceps tendon
from--and reduces abrasion
against--the anterior part of the
radial tuberosity.
 When the elbow is extended
 The biceps is a simple flexor of the forearm
 When the elbow is flexed and more power is needed
against resistance
 The biceps is the primary (most powerful) supinator of the forearm
 When right-handed persons drive a screw into hard wood
 Inserting a corkscrew and pulling the cork from bottle.
 The biceps barely operates during flexion of the prone
forearm.
 To test the biceps:
– The ebow joint is flexed against resistance when the forearm is
supinated.
– If acting normally, the muscle forms a prominent bulge on the
anterior aspect of the arm that is easily palpated.
Biceps Tendinitis

The tendon of the long head of the biceps,
enclosed by a synovial sheath, moves back
and forth in the intertubercular groove of the
humerus.

Wear and tear of this mechanism is a
common cause of shoulder pain.

Inflammation of the tendon (biceps tendinitis),
usually the result of repetitive microtrauma,
is common in sports involving throwing and
use of a racquet

A tight, narrow, and/or rough
intertubercular groove may irritate and
inflame the tendon, producing tenderness and
crepitus
Rupture of the Tendon of the Long Head of the Biceps






Often as the result of prolonged tendinitis
that weakens it.
May result from repetitive overhead
motions, such as occurs in swimmers
May result from forceful flexion of the arm
against excessive resistance, as occurs in
weight lifters
Usually the tendon is torn from its attachment
to the supraglenoid tubercle of the
scapula.
Commonly dramatic and is associated with a
snap or pop.
The detached muscle belly forms a ball near
the center of the distal part of the anterior
aspect of the arm ("popeye deformity")
BRACHIALIS
 ORIGIN
– Anterior lower half of humerus
– medial and lateral intermuscular septa
 INSERTION
– Coronoid process and tuberosity of
ulna
 ACTION
– Flexes elbow
 NERVE
– Musculocutaneous nerve (C5, 6) ( from
lateral cord).
– Also small supply from radial nerve
(C7)
 The brachialis is the main flexor of the forearm
 Flexes the forearm in all positions and during slow
and quick movements.
 When the forearm is extended slowly, the brachialis
steadies the movement by slowly relaxing
(picking up and put down a teacup carefully)
 The brachialis always contracts during flexion of
the elbow joint and is primarily responsible for
maintaining flexion
 Because of its many functions, it is regarded as the
workhorse of the elbow flexors
CORACOBRACHIALIS
 ORIGIN
– Coracoid process of scapula with biceps
brachii
 INSERTION
– Upper half medial border of humerus
 ACTION
– Flexes and weakly adducts arm
 NERVE
– Musculocutaneous nerve (C5, 6, 7) (from
lateral cord)
•Bicep
s
brachi
i
•Long
head
•Coracobrachialis
•Short
head
•Biceps
tendon
•Aponeurosis of
biceps brachii
•Acromion process
•Coracoid process
•Humerus
•Coracobrachialis
•Musculocutaneous n.
•Brachialis
•Radius
•Ulna
TRICEPS
 ORIGIN
– Long head:
• infraglenoid tubercle of scapula.
– lateral head:
• upper half posterior humerus (linear origin).
– medial head:
• lies deep on lower half posterior humerus inferomedial to spiral groove and
both intermuscular septa
 INSERTION
– Posterior part of upper surface of olecranon process of ulna and posterior
capsule
 ACTION
– Extends elbow
– Long head stabilizes shoulder joint
– medial head retracts capsule of elbow joint on extension
 NERVE
– Radial nerve (C7, 8) (from posterior cord ), four branches
 The triceps is the main extensor of the elbow
joint.
 Aids in extension and adduction of the arm.
 Long head of the triceps helps stabilize the
adducted glenohumeral joint by serving as a
shunt muscle, resisting inferior displacement of
the head of the humerus.
 Just proximal to its distal attachment is a frictionreducing subtendinous olecranon bursa between
the triceps tendon and the olecranon.
 To test the triceps lesion
– the arm is abducted 90 ° and then the flexed forearm is
extended against resistance
– If acting normally, the triceps can be seen and palpated.
•Deltoid
(cut)
•Long
head
•Lateral
head
•Olecranon
•Anconeus
•Triceps brachii
•Dorsal scapular nerve
•Suprascapular nerve
•Axillary nerve
•Lateral head
•Triceps brachii
•Long head
•Medial head
•Anconeus
•Radial nerve
Humeral Shaft Fracture
 Fracture above the level of
pectoralis major
– proximal fragment abduct and
rotate internally due to the action of
the rotator cuff
 Fracture above the deltoid and
below pectoralis major
– deltoid pulls the distal fragment
laterally, pectoralis major pulls
the proximal fragment medially
 Fracture below deltoid
– proximal fragment abducts due
to deltoid, distal fragment pulled
medially and proximally by
biceps/ brachialis and
coracobrachialis
Arteries of the arm
1.
2.
Brachial
Deep (profunda) brachial
–
–
3.
4.
5.
Anterior branch
Posterior branch
Superior ulnar collateral
Inferior ulnar collateral
Recurrent branches
from:
–
–
–
The radial artery
Ulnar artery
Interosseous artery
•
These arteries anastomose
with descending articular
branches of the deep artery
of the arm and the ulnar
collateral arteries
Brachial Artery




The brachial artery provides
the main arterial supply to
the arm
The brachial artery, the
continuation of the axillary
artery
Begins at the inferior border of
the teres major and ends in the
cubital fossa opposite the neck
of the radius
Under cover of the bicipital
aponeurosis, the brachial
artery divides into the radial
and ulnar arteries
 The brachial artery, superficial and
palpable throughout its course
 Lies anterior to the triceps and
brachialis.
 At first it lies medial to the humerus,
and then anterior to it.
 As it passes inferolaterally, the brachial
artery accompanies the median
nerve, which crosses anterior to the
artery
 During its course through the arm, the
brachial artery gives rise to:
– Many unnamed muscular branches
– Humeral nutrient arteries, which arise
from its lateral aspect
Deep Artery of the Arm




The largest branch of the
brachial artery
Most superior origin
Accompanies the radial
nerve through the radial
groove and passes around
the body of the humerus
Divides into anterior and
posterior descending
branches that participate in
the arterial anastomoses
around the elbow.
Nutrient Humeral Artery


Arises from the brachial
artery around the
middle of the arm and
enters the nutrient
canal on the
anteromedial surface
of the humerus.
The artery runs distally
in the canal toward the
elbow
Superior Ulnar Collateral Artery
 This artery arises from the
medial aspect of the brachial
artery near the middle of the
arm and accompanies the
ulnar nerve posterior to the
medial epicondyle of the
humerus
 It anastomoses with the :
– posterior ulnar recurrent artery
– inferior ulnar collateral artery
Inferior Ulnar
Collateral Artery



Arises from the brachial artery
approximately 5 cm proximal to
the elbow crease
Passes inferomedially anterior to
the medial epicondyle of the
humerus
Joins the anastomoses of the
elbow region by anastomosing
with the anterior ulnar
recurrent artery
Measuring Blood Pressure






Arterial blood pressure measurement using
sphygmomanometer.
A cuff is placed around the arm and inflated with air until it
compresses the brachial artery against the humerus and
occludes it.
A stethoscope is placed over the artery in the cubital
fossa, the pressure in the cuff is gradually released
The examiner detects the sound of blood beginning to spurt
through the artery.
The first audible spurt indicates systolic blood
pressure.
As the pressure is completely released, the point at which
the pulse can no longer be heard is the diastolic blaod
pressure.
Compressing the Brachial Artery

The best place to compress the brachial
artery to control hemorrhage is near the
middle of the arm

The brachial artery may be clamped
distal to the deep artery of the arm
without producing tissue damage

The anatomical basis for this is that the
ulnar and radial arteries still receive
sufficient blood through the
anastomoses around the elbow

Ischemia of the elbow and forearm
results from clamping of the brachial
artery proximal to the deep artery of
the arm for an extended period
Nerves of the Arm
4 main nerves pass
through the arm:
–
–
–
–
Median
Ulnar
Musculocutaneous
Radial
 The median and ulnar
nerves supply no
branches to the arm.
Musculocutaneous Nerve




One of the terminal branches of
the lateral cord
Supplies all the muscles in the
anterior (flexor) compartment of
the arm.
Begins opposite the inferior
border of the pectoralis minor,
pierces the coracobrachialis, and
continues distally between the
biceps and brachialis
After supplying all three of these
muscles, it becomes the lateral
cutaneous nerve of the forearm
Radial Nerve
 The direct continuation of the posterior
cord
 Supplies all the muscles in the posterior
compartment of the arm.
 It enters the arm
– Posterior to the brachial artery
– Medial to the humerus
– Anterior to the long head of the triceps
 The radial nerve descends inferolaterally with
the deep brachial artery and passes
around the humeral body in the radial
groove
 Before entering the groove, it gives branches
to the long and lateral heads of the triceps.
Radial Nerve
 At the lateral border of the humerus, it
pierces the lateral intermuscular
septum and continues inferiorly in
the anterior compartment of the arm
between the brachialis and
brachioradialis to the level of the
lateral epicondyle of the humerus.
 It then divides into deep and
superficial branches
– The deep branch is entirely muscular and
articular in its distribution.
– The superficial branch is entirely
cutaneous in its distribution, supplying
sensation to the dorsum of the hand and
digits.
Median Nerve

Formed in the axilla by the union of a
lateral root from the lateral cord and
a medial root from the medial cord

It runs distally in the arm, initially on
the lateral side of the brachial artery
until it reaches the middle of the arm
,where it crosses to the medial side
and contacts the brachialis.

The median nerve then descends to
the cubital fossa, where it lies deep
to the bicipital aponeurosis and
medial to cubital vein.

The median nerve has no branches
in the axilla or the arm, but it
supplies articular branches to the
elbow joint.
Ulnar Nerve






This is the larger of the two terminal
branches of the medial cord
It passes distally, anterior to the triceps, on
the medial side of the brachial artery
Around the middle of the arm it pierces the
medial intermuscular septum with the
superior ulnar collateral artery and
descends between the septum and the
medial head of the triceps.
The ulnar nerve passes posterior to the
medial epicondyle and medial to the
olecranon to enter the forearm
Posterior to the medial epicondyle where the
ulnar nerve is referred to in lay terms as the
“funny bone“
The ulnar nerve has no branches in the
arm, but it supplies articular branches to
the elbow joint.