Wednesday, April 29, 2015

Scalenus Anterior Muscles

Posted by Pulasthi Senaratna

Scalenus Anterior Muscles

Scalenus Anterior Muscles

The scalenus anterior is an impt muscle of the lower part of the neck

because of its relations with the impt structures in that region

Origin

from the ant tubercles of the tnvs processes of CV3, 4, 5 & 6

Insertion

The fibres are inserted into

1. scalene tubercle on inner border of 1st rib

2. ridge on upper surface of 1st rib

Innervation

from ventral rami of C4, 5 & 6

Action

1. assists elevating 1st rib

2. when acting from below, it laterally flexes & rotates cervical part of vertebral column

Relations

Anteriorly

Posteriorly

Medially

Laterally

1. prevertebral layer of deep cervical fascia

2. phrenic n

3. supf cervical & suprascapular art

4. IJV & subclavian vein

1. subclavian art

2. brachial plexus

3. cervical dome of pleura

1. vertebral art & v

2. inf thyroid art

3. thyrocervical trunk

4. symp trunk

5. on the left side, thoracic duct

1. roots of brachial plexus

2. subclavian art

3. roots of phrenic n