Cutaneous innervation of the arm.
Lateral side of arm :
1-supraclavicular :supply skin over
shoulder & upper ½ of deltoid.
2-upper lateral cutaneous N. of
arm: a branch of axillary, supplies
skin over lower ½ of deltoid.
3-lower lateral cutaneous N. of
arm : a branch of radial, supplies
skin over lateral side of arm below
deltoid.
Medial side of arm :
1-inter-costo-brachial N. : supplies skin
of upper part of medial side of arm
(close to axilla).
2-medial cutaneous N. of arm : a
branch of medial cord, supplies medial
side of arm below axilla.
Superficial & deep veins of the arm.
Deep veins
1-venae comitantes, which
accompany large arteries.
2-axillary vein.
superficial veins
1-cephalic vein : ascends in superficial fascia
on lateral side of biceps, then it piercec clavipectoral fascia to end in axillary V.
2-Basilic vein : ascends in superficial fascia on
medial side of biceps, halfway up the arm, it
pierces deep fascia to join venae cometantes of
brachial artery and its continuation forms axillary
vein at the lower border of teres major.
Note the common variations seen in
the region of elbow.
Superficial & Deep lymphatics of the
arm
 Superficial L.Vs. :
1-from lateral side of arm accompany the
cephalic vein and end in infraclavicular lymph
nodes.
2-from medial side of arm accompany the
basilic vein, and end in lateral group of
axillary L.Ns.
Deep L.Vs. :
axillary L.Ns.
end in lateral group of
The Arm
Fascial compartment of
upper arm :
The upper arm is enclosed in a
sheath of deep fascia.
2 fascial septa on the medial &
lateral sides extend from this
sheath into medial & lateral
supracondylar ridges of humerus
respectively.
Cross section of arm .Note division of arm by the
humerus , medial & lateral intermuscular septa
into anterior & posterior compartements.
so., the arm is divided into an
anterior & posterior fascial
compartment containing Ms.,
nerves & vessles.
Front of the arm
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Biceps brachii.
Coracobrachialis.
Brachialis.
Brachial artery.
Musculocutaneous nerve.
Median nerve.
Upper part of ulnar nerve.
Front of the Arm
Supraglenoid tubercle
of scapula
Into middle of medial border
of humerus.
Into deep fascia on medial side
of forearm.
By strong Tendon into
Biceps & Coracobrachialis
Nerve Supply : Musculocutaneous N. Action : Biceps : flexion of elbow +
powerful supinator of radioulnar joint.s.
Coracobrachialis + short head of biceps : help
in flexion of shoulder joint.
Front of lower ½ of shaft of
humerus
Middle of
medial border of humerus
Coracobrachialis
Brachialis
Nerve Supply : Musculocutaneous N. Its
lateral fibres are supplied by Radial N.
Action : Flexion of Elbow j.
Back of the Arm
Triceps Muscle
Origin : by 3 heads : Long Head : from infraglenoid tubercle of scapula.
Lateral Head : from olique ridge on posterior surface of humerus above spiral groove. It covers
the Radial nerve. Medial Head : from posterior surface of humerus below spiral groove.
Insertion : Olecranon process of ulna (upper surface).
Nerve Supply : Radial N.
Action : extension of elbow j. - long head supports head of humerus in abducted shoulder.
Muscles of Arm
Powerful
powerful
Middle of
Its lateral part is
supplied by radial N.
Oliquee ridge on
Above spiral groove
Below spiral groove
Structures passing through anterior
fascial compartment :
1- Brachial artery :
It begins at lower border of
teres major as a continuation of axillary
artery.
It terminates opposite neck of radius
by dividing into radial & ulnar arteries.
Anteriorly :
At its upper part : it is overlapped
lateraly–By medial margin of biceps &
coracobrachialis.
At its middle part :
It is crossed by Median N.
At its lower part (at the cubital fossa) :
It is crossed by Biciptal aponeurosis.
Posteriorly : triceps + radial N.
insertion of coracobrachialis
+brachialis.
Medially : ulnar N.(at its upper
part) + median N.(at its lower part).
Laterally : above…median N.,
biceps & coracobrachialis.
below… biceps tendon.
Branches of brachial artery :
1-muscular-----2-nutrient to humerus.
3-profunda brachii A.----arise near
origin of brachial artery , following
radial N. into spiral groove of
humerus.
4-superior ulnar collateral A.—
it follows ulnar N. and shares in
anastomosis around elbow joint.
5-inferior ulnar collateral A.-arises
near termination of the artery and
shares in anastomosis around elbow
Anastomosis around elbow
In front of lateral epicondyle :
between anterior descending branch of
profunda artery & radial recurrent artery.
Behind lateral epicondyle :
between posterior descending branch of
profunda artery & interosseous recurrent
artery.
In front of medial epicondyle
: between anterior branch of inferior ulnar
branch of posterior
interosseous artery (branch of
ulnar artery)
collateral artery & anterior ulnar recurrent
artery.
Behind medial epicondyle :
between superior ulnar collateral + posterior
branch of inferior ulnar collateral artery &
posterior ulnar recurrent artery.
2-Musculocutaneous Nerve
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Origin : lateral cord of brachial
plexus in axilla.
Course : It descends downward
and laterally,piercing
coracobrachialis muscle, and then
passes between biceps & brachialis.
It appears at lateral margin of
biceps tendon, piercing deep fascia
above elbow, where it descends as
lateral cut. N. of forearm on the
lateral aspect of forearm.
Branches :
1-muscular (biceps,
coracobrachialis, +brachialis).
.2-Cutaneous: lateral cutaneous
nerve of forearm to supply skin of
front & lateral sides of forearm
down to the root of thumb.
3-articular : to elbow joint.
3-Median Nerve
origin : medial & lateral Cords
of brachial plexus in axilla.
 Course : above,it descends on
lateral side of brachial artery.
-At the middle of arm, it
crosses the brachial artery.
Then it descends on the medial
side of the artery.
- At the elbow ,it is crossed by
the biciptal aponeurosis.
 Has No branches in the upper
arm.
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Structures passing through
post.compartment : 1-Ulnar Nerve
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Origin : medial cord of brachial plexus
in axilla.
Course : above, it is covered posteriorly
by medial head of triceps.
-it descends medial to the brachial
artery as far as the middle of the arm,
where the insertion of
coracobrachialis, it pierces medial facial
septum , accompanied by superior
ulnar collateral artery to descend in the
post. compartment of arm, passing
behind medial epicondyle to enter
forearm bet. 2 heads of flexor carpi
ulnaris.
It has No branches in the arm.
Only, it has articular to elbow joint.
2- Profunda brachii artery
3-Radial Nerve
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Origin : post.cord of brachial plexus
in the axilla.
 Course : -on leaving axilla, it passes
immediately into post. compartment of
arm where it descends in spiral groove
of humerus , accompanied by
profunda brachii artery, deep to lateral
head of triceps.
-Then,it pierces lateral facial septum
above elbow to enter anterior
compartment of arm,between brachialis
(medially) and brachioradialis &
extensor carpi radialis longus (laterally).
-At the front of lateral
epicondyle, it terminates into
superficial & deep branches.
N.B: deep branch is called post. Interosseous N.,passes through supinator muscle to reach
back of forearm./ and superficial branch is the continuation of radial N.,descends as small
N.in front of forearm to reach dorsum of hand (to supply lateral part of dorsum of hand
+ proximal parts of lateral 31/2 fingers ).
Branches of the Radial nerve
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In the axilla :
1-post.cut.N.of arm.
2-branches to long head of triceps.
In the Spiral groove :
1-branches to lateral & medial heads
of triceps.
2-branch to anconeus.
3-lateral cut. N. of arm.
4-post. Cut.n.of forearm.
In anterior compartment of arm
above elbow,
( in deep groove bet. brachialis &
brachioradialis):
1-Muscular : brachialis (lateral ½),
brachioradialis, &
extensor carpi radialis longus.
2-Articular : elbow joint.
In front of lateral
epicondyle of humerus, it
divides into two terminal
branches :
1-superficial branch.
2-deep branch
(posterior interosseous N.).