Axilla, Brachial Plexus and Posterior Shoulder Flashcards Preview

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Flashcards in Axilla, Brachial Plexus and Posterior Shoulder Deck (40)
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3 anterior axio-appendicular muscles?

Pectoralis major, pectoralis minor, serratus anterior


Two major muscles of climbing?

Pectoralis major and latissimus dorsi


Proximal and distal attachments of the pectoralis major? Actions?

Has two heads- clavicular (medial half of clavicle) and and sternocostal (goes to superior six costal cartilages)

Distal attachment is to anterior humerus

Actions: horizontal adduction of humerus (looks like the shoulder exercises) and slight flexion and extension of shoulder from the clavicular head.


Proximal and distal attachments of pectoralis minor? Actions?

Proximal: 3rd-5th ribs near the costal cartilages
Distal: Coracoid process of scapula (process at the front)
Actions: pulls scapula forward on the rib cage stabilising it


Serratus anterior proximal and distal attachments? Actions?

Proximal: External surfaces of the 1st-8th ribs
Distal: anterior surface of the scapula
Actions: protracts scapula (pulls scapula out -----> abduction, and holds it against thoracic wall; rotates scapula)


Innervation of serratus anterior?

Long thoracic nerve


Innervation of pectoralis major?

Medial and lateral pectoral nerve


Innervation of pectoralis minor?

Medial pectoral nerve


Posterior axio appendicular muscles?

Trapezius, latissimus dorsi, rhomboid minor and major


Trapezius proximal and distal attachments? Actions?

Proximal: C7-12 spinous processes
Distal: acromion and spine of scapula
Action: upper fibres elevate the scapula, middle fibres adduct the scapula and lower fibres lower the scapula


Innervation of trapezius?

Spinal accessory nerve


Latissimus Dorsi proximal and distal attachments? Actions?

Proximal: T7-12 spinous processes, iliac crest and inferior 3/4 ribs
Distal: Humerus
Action: extends, adducts and medial rotates humerus


Latissimus dorsi innervation?

Thoracodorsal nerve


Rhomboid major and minor proximal and distal attachments? Actions?

Proximal: spinous processes
Distal: posterior scapula
Actions: retract scapula (pull scapula in----> adduction)


Innervation of rhomboid major and minor?

Dorsal scapular nerve


Levator scapulae proximal and distal attachments? Actions?

Proximal: transerve processes of cervical vertebrae
Distal: superior to route of scapula spine in medial border
Actions: elevate scapula


The axillary vein is a continuation of the _________1___________. It becomes the axillary vein at the lower border of____2____muscle.

1) brachial vein (deep vein of the arm)
2) teres major


Teres major contributes to the posterior wall of the axilla; its ______ border corresponds to the inferior extent of the axilla.



The brachial plexus supplies the upper limb and is formed from a very specific intertwining of the ....

anterior rami of spinal nerves C5 – T1


Proximal to distal what does the brachial plexus consist of?

Named Nerves


Describe the trunks of the brachial plexus?

Combinations of roots, which give rise to divisions.
- Superior = combined anterior rami of C5 & C6 spinal nerves
- Middle = anterior ramus of C7 spinal nerve
- Inferior = combined anterior rami of C8 & T1 spinal nerves


Describes divisions of the brachial plexus?

Each trunk divides to give anterior and posterior divisions, which combine to give cords.


Describe cords of the brachial plexus?

The cords are named according to their relationship to axillary artery.
- Medial = a direct continuation of the anterior division of the inferior trunk
- Lateral = formed from the anterior divisions of the superior and middle trunks
- Posterior = formed from the posterior divisions of all three trunks


Describe the named nerves of the brachial plexus?

The cords combine to give the named nerves of the brachial plexus. - The ulnar nerve continues directly from the medial cord
- The musculocutaneous nerve continues directly from the lateral cord
- The posterior cord divides into the axillary nerve and radial nerve
- The medial and lateral cords both contribute the formation of the median nerve


Describe the location of the brachial plexus

The roots and trunks lie mainly between the anterior and middle scalene muscles in the root of the neck.
The divisions lie immediately posterior to the subclavian vessels in the root of the neck (deep to the clavicle).
The cords lie around the axillary artery, which is distal to the first rib.


Describe what the musculocutaneous nerve supplies?

The musculocutaneous nerve can be seen entering to supply the coracobrachialis muscle.
It also supplies the other muscles of the anterior compartment of the arm: biceps brachii and brachialis muscles.


Describe the axillary nerve and what it supplies?

Supplies the shoulder joint, teres minor and deltoid muscles as well as skin of the superolateral arm


When is the radial nerve vulnerable to injury? Why?

Mid shaft humeral fracture- the nerve wraps around the posterior aspect of the mid humerus


What does the radial nerve supply?

All muscles of the posterior compartments of arm and forearm, lots of skin


What does the ulnar nerve supply?

Flexor carpi ulnaris, and ulnar half of the flexor digitorium profundus, most intrinsic muscles of hand.