Human Anatomy Vol 1

Origin of short head of biceps

brachii from coracoid process

Origin of long head

of biceps brachii

from supraglenoid

tubercle

Glenoid cavity

Muscle belly

Biceps tendon

inserted into

radial tuberosity

Bicipital

aponeurosrs

Fig. 8.3: The biceps brachii muscle in extended elbow

Bicipital

aponeurosrs

Radial

tuberosity

Fig" 8.4: The precise mode of insertion of the biceps brachii
muscle

It is a branch of the lateral cord of the brachial plexus,
arising at the lower border of the pectoralis minor (see
Fig. a.La) in the axilla.

[ue

The root value of musculocutaneous nerve is ventral
rami of C5-C7 segments of spinal cord.

ABM

Humerus

Origin from front of

shaft of humerus and

from medial and lateral

intermuscular septa

lnsertion into front of

coronoid process and

tuberosity of ulna

Fig. 8.5: The origin and insertion of the brachialis muscle

Oligin, Course ond Terminolion

Musculocutaneous nerve arises from the lateral cord

of brachial plexus in the lower part of the axilla. It

accompanies the third part of the axillary artery. It then

enters the front of arm, where it pierces coracobrachialis

muscle.

Then it runs downwards and laterally between

biceps brachii and brachialis muscles to reach the lateral

side of the tendon of biceps brachii. It terminates by

continuing as the lateral cutaneous nerve of forearm

2 cm above the bend of the elbow (Fig. 8.6).

Relollons

In the louer part of the axilla: It accompanies the third

part of the axillary artery and has the following relations.

Ant eriorly : Pectoralis major.

P osteriorly : Subscapularis.

Medially: Axillary artery and lateral root of the median

nerve (see Fig. 4.9).

Laterally: Coracobrachialis (see Fig. a.9).

Musculocutaneous nerve leaves the axilla, and enters

the front of the arm by piercing the coracobrachialis

(Fig.8.6).

In the arm: It runs downward and laterally between

the biceps brachii and brachialis to reach the lateral side

of the tendon of the biceps. It ends by piercing the fascia

2 cm above the bend of the forearm.

Muscular: It supplies the following muscles of the front

of the arm.

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