anatomy of muscles of the arm, blood vessels, and nerves of anterior and posterior compartments of the arm

1. Anatomy Department
The ARM
ALAZHAR UNIVERSITY
Faculty of Medicine for Girls
Year 1-Semester II
Academic year: 2020 / 2021
Module Name: Musculoskeletal and skin
Course code: IMP 07- 10212
Credit hours: 8 crh

2. OBJECTIVES:
1- Understanding
anatomy of the muscles
of front and back of the
upper arm.
2- Understanding
anatomy of the blood
supply of the upper arm
3- Know anatomy of the
nerves present in the
upper arm
At the end of the lecture, students should be able to:

4. 1. Extension: The upper arm extends from the shoulder to the elbow.
2. Layers: it has the following layers:
1. Skin.
2. Superficial fascia: it contains basilic and
cephalic veins and also fat.
3. Deep fascia.
-Two fascial septa, on the medial and the lateral
sides, called medial and lateral intermuscular
septa extend from the deep fascia and attach to
the medial and lateral supracondylar ridges of
the humerus, respectively.
- These 2 fascial septa divide the arm into an
anterior and a posterior fascial compartments

5. Contents of The Anterior
Compartment of The Arm
1. Muscles:
1) Biceps brachii Muscle.
2) Coracobrachialis Muscle.
3) Brachialis Muscle.
2. Blood Vessels:
1) Brachial artery.
2) Basilic vein.
3. Nerves:
1) Musculocutaneous nerve.
2) Other nerves pass through the anterior
compartment:
a) Median nerve.
b) Ulnar nerve.
c) Radial nerve.

6. Cutaneous Nerves of the Upper Arm
A) Lateral side of the upper arm:
1. The supraclavicular nerves (C3, C4):
they are branches from cervical plexus .They
supply the skin on the upper 1/2 of the
deltoid.
2. The upper lateral cutaneous nerve of the
arm (C5, C6):
-It is a branch of axillary nerve.
-It supplies the skin on the lower 1/2 of the
deltoid.
3. The lower lateral cutaneous nerve of the
arm (C5, C6):
- It is a branch of the radial nerve,
- It supplies the skin of the lateral side of the
arm below the deltoid.

7. B) Medial side of the upper arm:
1. The intercostobrachial nerve (T2):
-It is a lateral cutaneous branch of the 2nd intercostal
nerve.
- It supplies the skin of the upper part of the medial
side of the arm close to axilla.
2. The medial cutaneous nerve of the arm (C8& T1):
- It is a branch of the medial cord of the brachial
plexus.
- It supplies the skin of the medial side of the arm
below the axilla.
C) Back of the upper arm:
The posterior cutaneous nerve of the arm (C5, 6, 7,
8):
- It is a branch of the radial nerve.
- It supplies the skin on the posterior surface of the
arm from deltoid tuberosity to the elbow.

8. 1. Biceps Brachii Muscle:
• Origin: by 2 heads
1) Long head: from the supraglenoid tubercle
of the scapula inside the capsule of the shoulder
joint.
2) Short head: from the tip of coracoid process
of the scapula.
The 2 heads fuse to form a spindle –shaped
muscle.
• Insertion: into:
1) The radial tuberosity .
2) The deep fascia of the upper part of the
medial side of the forearm by the bicipital
aponeurosis.
A) Muscles of Anterior Compartment of the Arm

9. • Nerve Supply: Musculocutaneous
nerve.
• Action:
1) Flexion of the forearm at the elbow joint.
2) Powerful supination of the forearm at
the radio-ulnar joints
3) The long head steadies the head
of the humerus in the glenoid cavity.

10. 2) Coracobrachialis Muscle:
• Origin: From the tip of coracoid process
of the scapula by a common tendon
with short head of biceps.
• Insertion: Into the middle of the medial
border of the shaft of the humerus.
• Nerve Supply: Musculocutaneous
nerve.
• Action:
1-Flexion of the upper arm at the
shoulder joint.
2-Weak adduction of the upper arm at
shoulder joint.

11. 3) Brachialis Muscle:
• Origin: From the anterior surface of the lower
half of the shaft of the humerus.
• Insertion: Into the anterior surface of the
coronoid process of the ulna.
• Nerve Supply:
1) Musculocutaneous nerve.
2) The lateral part is supplied by the radial
nerve.
• Action: Strong flexion of the forearm at the
elbow joint.

13. 1) Brachial Artery

14. 1. Ascending branch (deltoid branch)
2. Anterior descending branch (radial
collateral)
3. Posterior descending branch (middle
collateral)
4. Muscular branches: to triceps.
5. Nutrient: to the humerus.
Branches of Profunda brachii artery
(largest branch):
https://www.youtube.com/watch?v=Fk_UxqjTg14

15. Anastomosis around the Elbow
Brachial artery
Ulnar artery
Anastomosis around
medial epicondyle
Radial artery
Anastomosis around
lateral epicondyle

16. Anastomosis around the medial epicondyle
Behind of the medial epicondyle:
Superior ulnar
collateral artery
(from brachial
artery
Posterior branch
of inferior ulnar
collateral artery
(from brachial
artery)
Posterior ulnar
recurrent artery
(from ulnar
artery).
In Front of the medial
epicondyle:
Anterior branch of
inferior ulnar
collateral artery
from brachial
artery.
Anterior ulnar
recurrent artery
from ulnar artery.

18. Anastomosis around the lateral epicondyle
Behind of the lateral epicondyle
Middle collateral artery
(posterior descending)
artery branch of
profunda brachii artery
Interosseous recurrent
artery branch of the
posterior interosseous
artery (ulnar artery).
In Front of the lateral epicondyle
Radial collateral artery
(anterior descending)
branch of profunda
brachii artery
Radial recurrent
artery branch
of radial artery.

20. NERVES OF ANTERIOR COMPARTMENT OF THE
ARM
1) Musculocutaneous Nerve (C5, 6 and 7)
- Type: mixed nerve.
- Origin: in the axilla from lateral cord of the
brachial plexus.
- Course: - It runs downward piercing the
coracobrachialis muscle then passes between the
biceps and brachialis muscles.
- End: it pierces the deep fascia just above the
elbow joint to become the lateral cutaneous nerve
of the forearm.
- Branches: 1) Muscular branches.
2) Articular branches.
3) Cutaneous branches:

21. Injury to Musculocutaneous Nerve
1. Site: ……….
2. Weapon: ……………
3. Results:
Motor Sensory

22. - Type: mixed nerve.
- Origin: in the axilla by 2 roots
lateral root from lateral cord of the brachial plexus.
Medial root from medial cord of the brachial plexus.
- Course: It runs downward from the axilla arm cubital fossa forearm hand.
- End: it passes deep to the flexor retinaculum to reach the palm of the hand
2) Median Nerve (C5, 6, 7, 8 and T1)
- Branches:
1) in the axilla: no branches.
2) In the arm: no branches.
3) In the cubital fossa :
A) Muscular branches: to supply muscles
of forearm
B) Articular branches: to supply elbow and
superior radioulnar joints.

23. - Type: mixed nerve.
- Origin: in the axilla from the medial cord of the brachial plexus.
- Course: It runs downward from the axilla arm behind the elbow forearm
hand.
- End: it passes superficial to the flexor retinaculum to reach the palm of the hand
3) Ulnar Nerve (C8 and T1)
- Branches:
1) in the axilla: no branches. 2) In the arm: no branches.

24. ‫مصري‬
!!!

25. THE POSTERIOR COMPARTMENT OF
THE ARM

26. • Contents:
A) Muscles:
1) Triceps brachii muscle.
2) Subanconeus muscle
(articularis cubiti).
B) Blood Vessels:
1) Profunda Brachii artery
2) Superior and inferior ulnar
collateral arteries.
C) Nerves:
1) Radial nerve
2) Ulnar nerve

27. A) MUSCLES OF POSTERIOR
COMPARTMENT OF THE ARM
1) Triceps brachii Muscle
• Origin: by 3 heads:
- Long head: from infra-glenoid tubercle of
scapula.
- Lateral head: from back of the humerus
along upper lip of the spiral groove (oblique
ridge).
- Medial head: from:
1- Back of the humerus below the spiral
groove.
2- Back of the medial and lateral intermuscular
septa.
N.B. The 3 heads fuse together, the medial
head lies deep to the lateral head (laterally) and
long head medially.
Left upper limb

28. - Insertion: by a common tendon into the upper surface of olecranon process of the
ulna.
N.B. A small slip from medial head is inserted into back of the capsule of the elbow joint
(articularis cubiti or subanconeus).
Nerve supply: radial nerve.
- Action:
1- Powerfull extension of the
elbow joint.
2- The long head extends
the arm at the shoulder joint
and supports the lower part
of the capsule of the
shoulder joint on raising the
arm.
3- Subanconeus pulls the
capsule of the elbow during
its extension, preventing its
crushing

29. 2) Articularis cubiti (subanconeus)
- origin:
It consists of the few deep fibres of
the lower part of triceps
- Insertion:
into the posterior part of the
capsule of the elbow joint.
- Nerve supply: radial nerve.
- Action:
- Articularis cubiti pulls the capsule
of the elbow during its extension,
preventing its crushing.
•

30. B) BLOOD VESSELS
OF THE POSTERIOR
COMPARTMENT OF
THE ARM
1) Profunda Brachii artery
2) Superior and inferior
ulnar collateral arteries.

31. (C) NERVES OF POSTERIOR
COMPARTMENT OF THE
ARM

32. - Type: mixed nerve.
- Origin: in the axilla as the larger of
the 2 terminal branches of the posterior
cord of the brachial plexus.
- Course: A) In the axilla: It runs
behind 3rd part of axillary artery in
front of posterior wall of axilla;
subscapularis, teres major and
latissimus dorsi.
1) Radial Nerve (C5, 6, 7, 8 and T1)

33. B) In the arm:
- It runs posterior to brachial
artery, in front of long head
of triceps.
- It turns backwards with
profunda brachii artery
between the long and lateral
heads of triceps to enter the
spiral groove.
- In the spiral groove, it
passes downwards and
laterally in contact with the
humerus deep to the lateral
head of triceps.

34. - At the lateral end of the spiral groove, it pierces the
lateral intermuscular septum from behind forwards
accompanied by radial collateral artery to enter the
anterior compartment of the upper arm.
- In the anterior compartment of the arm, It descends
between brachialis muscle medially and
brachioradialis muscle laterally.
- In front of lateral
epicondyle, it divides
into posterior
interosseous nerve
(motor) and superficial
radial nerve (sensory).

35. • Branches:
A) In the axilla:
1) Muscular branches to supply long and medial heads of
triceps muscle
2) Cutaneous branches: Posterior cutaneous nerve of
the arm to supply skin on back of the arm from deltoid
tuberosity to the elbow.
B) In the Spiral groove
1) Muscular branches to supply
- Medial and lateral heads of triceps muscle.
- Anconeus muscle.
2) Cutaneous branches:
1-Lower lateral cutaneous nerve of the arm to supply skin
on lateral side of the arm from deltoid tuberosity to the
elbow.
2- the Posterior cutaneous nerve of the forearm to supply
skin on back of forearm till the wrist.

36. C) In the lower 1/3 of the
arm:
1) Muscular branches: to
supply:
- Lateral part of brachialis.
- Brachioradialis.
-Extensor carpi radialis
longus.
2) Articular branches: to
supply the elbow joint.

37. MUSCLES OF THE UPPER ARM

38. 3) Which of the following is the action of the triceps brachii muscle?
A. Powerful extension of the elbow joint.
B. Powerful supination of the forearm.
C. Powerful flexion of the elbow.
D. Abduction of the arm.
4) Which of the following nerves supplies the triceps brachii muscle?
A. Ulnar.
B. Radial.
C. Musculocutaneous.
D. Median.
1) Which of the following is a branch of the brachial artery?
A. Profunda brachii artery.
B. Deltoid branch.
C. Radial collateral.
D. middle collateral.
2) Which of the following muscles are supplied by the musculocutaneous nerve?
A. Triceps and anconeus.
B. Biceps brachii and brachialis.
C. Coracobrachialis and deltoid.
D. Biceps and triceps.

39. 6) Which of the following nerves supplies the medial side of the arm?
A. Musculocutaneous.
B. Posterior cutaneous nerve of the arm.
C. Medial cutaneous nerve of the arm.
D. Ulnar.
7) Which of the following is the origin of biceps brachii muscle?
A. Supra-glenoid tubercle of the scapula.
B. The radial tuberosity.
C. The deep fascia of the upper part of the forearm.
D. Anterior surface of the humerus.
Short Answer questions:
1) Mention origin, insertion, nerve supply and action of biceps brachii muscle.
2) Mention origin, insertion, nerve supply and action of brachialis muscle.
3) List 4 branches of brachial artery.

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