Anatomy Of Arm

 

Dear friends, today i am going to share with you an article on anatomy  of arm. This article includes the bones, muscles, fascia, intermuscular septum, nerves and blodd supply of arm. So Enjoy this article.

Anatomy Of Arm

Contents Of Topic

1. Bone

2. Muscles

3. Fascia:

a. Superficial

b. Deep

i. Medial Intermuscular Septum

ii. Lateral Intermuscular Septum

4. Nerves

5. Blood vessels 

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1. Muscle Of Arm:

Muscle groups:

There are two groups of muscles of arm:

a. Flexor compartment:

i. Biceps brachii

ii. Brachialis

iii. Coracobrachialis

b. Extensor compartment:

i. Triceps Brachii

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2. Fascia Of Arm:

Fasciae are of two types:

a. Superficial fascia:

 Loose areolar tissue &

 Variable amount of fat

b. Deep fascia:

Brachial fascia:

Consists of:

Dense C/T

Two thickenings:

 Lateral Septa 

 Medial Septa

Forms compartments of arm

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Medial Intermuscular Septum:

 Along medial supracondylar line 

 Behind coracobrachialis insertion  

 Fades out b/w muscle & long head of triceps

 Gives origin to medial fibres of brachialis & medial head of triceps

 Pierced by ulnar N & ulnar collateral artery

Lateral intermuscular septum

 Extends along lateral supra-condylar line

 Fades out behind insertion of deltoid.

 Posteriorly medial head of triceps arises from it

 Pierced by radial nerve and profunda brachii artery

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Arm:

Region b/w elbow & shoulder joints

Medial & lateral im septum divides arm into 2 compartments

a. Flexor (anterior) & 

b. Extensor (posterior)

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a. Anterior compartment (Flexor):

Contains 3 muscles

i. Biceps brachii

ii. Brachialis

iii. Coracobrachialis

All are innervated by musculocutaneous nerve

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i. Biceps Brachii Muscle:

Origin:

 Long head supraglenoid tubercle

 Short head coracoid process 

Insertion:

 Radial tuberosity (bicepital aponeurosis)

Action:

 Supinator

 Flex arm at elbow & shoulder

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ii. Coracobrachialis:

 Deep to biceps

Orgin:

 Coracoid

Insertion:

 Medial shaft of humerus

 At level of deltoid tubercle

Action:

 Flex arm at shoulder

 Adduct shoulder

Nerve Supply:

 Musculocutaneous (c5,c6,c7)

iii. Brachialis:

 Deep to biceps

 Forms base of cubital fossa

Orgin:

 Medial & lateral surface of humerus

Insertion:

 Tuberosity of ulna

N/s:

 Musculocutaneous (c5, c6)

Action:

 Main flexor at elbow

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Posterior compartment of arm:

Triceps brachii:

 3 heads

 Medial head lies deep to other two

i. Long head:

Orgin:

 Ifraglenoid tubercle

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ii. Lateral head:

Orgin:

 Superior to radial groove

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iii. Medial head:

Orgin:

 Inferior to radial groove

Insertion:

 Olecranon

N/s:

 Radial  (C6, C7, C8, Mainly C7). 

Action:

 Extend arm at elbow