List the structures that are communicated through the axilla.
1) axillary artery
2) axillary vein
3) brachial plexus
4) axillary lymphnodes
Describe the borders of the axillary inlet.
Completely defined by bone. The perimeter is defined by:
lateral border of the 1st rib
posterior surface of the clavicle
superior margin of the scapula up to the coracoid process
Derive the path of the posterior circumflex humeral artery from the deltoid muscle back to the arch of the aorta on the right side of the body, including all parts of each artery and all relevant landmark along the way.
brachiocephalic trunk comes off of the aortic arch, divides into common carotid and subclavian ~ at the right sternoclavicular joint. Climbs superiorly and laterally, reaching its apex in the 2nd part of the artery:
1st part of subclavian: runs from the division of BCT to medial margin of anterior scalene muscle
2nd part of subclavian: posterior to anterior scalene muscle
3rd part of subclavian: lateral margin of anterior scalene to lateral margin of the 1st rib
Subclavian artery passes between first rib and clavicle and is renamed axillary artery
1st part of axillary: lateral margin of the 1st rib to superior margin of pec minor
2nd part of axillary: posterior to pec minor
3rd part of axillary: inferior margin of pec minor to inferior margin of teres major
posterior circumflex humeral: third artery off of the 3rd part of axllary
travels through the quadrangular space accompanied by the axillary nerve
Enters the deep surface of the deltoid muscle
Trace the primary blood supply of latissimus dorsi back to the arch of the aorta on the left side of the body. It is not necessary to list all parts of each artery, but do Indicate which part of the relevant artery the primary blood supply branches from.
True or false (if false, provide the correct information): the superior thoracic artery is a branch of the 2nd part of the subclavian artery
FALSE. it is from the 1st part of the axillary artery
True or false (provide the correct information if false): in ~65% of people the lateral thoracic artery arises from the 2nd part of the axillary artery.
True or false (provide the correct information if false): Musculocutaneous nerve receives fibers from all five of the spinal levels of the brachial plexus
FALSE: it receives fibers from C5-C7 only
True or false (provide the correct information if flase): all of the nerves of the brachial plexus come off of or are terminal branches of the lateral, posterior or medial cords.
Essential information: FALSE. All but four of the nerves of the brachial plexus come off of or are continuations of the posterior, lateral or medial cords.
Additional contextual information:
FALSE. All but four of the nerves of the brachial plexus come off of or are continuations of the posterior, lateral or medial cords (dorsal scapular, suprascapular, long thoracic, nerve to subclavius are the exceptions).
Provide the spinal levels for all of the nerves that branch or continue from the posterior cord.
1) axillary: C5, C6
2) superior subscapular: C5, C6
3) Thoracodorsal: C6, C7, C8
4) Lower subscapular: C5, C6
5) Radial: C5, C6, C7, C8, T1
True or false (provide the correct information if false): the anterior compartment of the arm is exclusively innervated by fibers from the anterior divisions.
FALSE: brachialis receives contribution from radial C7.
Which divisions make up the lateral cord of the brachial plexus?
The anterior divisions of the superior and middle trunks.
Describe the innervation of pectoralis minor (include the name of the nerve(s), the spinal levels and primary levels if present).
Essential information: Pectoralis minor is innervated by both the medial pectoral nerve (directly) and the lateral pectoral nerve (indirectly) because lateral pectoral sends a nerve loop down to medial pectoral. It receives fibers from C8 and T1 from medial pectoral and fibers from C5, C6 and C7 from lateral pectoral. The primary levels are C7 & C8.
Additional contextual information: Pectoralis minor is innervated by both the medial pectoral nerve (directly) and the lateral pectoral nerve (indirectly) because lateral pectoral sends a nerve loop down to medial pectoral. It receives fibers from C8 and T1 from medial pectoral and fibers from C5, C6 and C7 from lateral pectoral. The primary levels are C7 & C8, one from medial pectoral nerve and one from lateral pectoral nerve.
List the muscles in the posterior compartment of the arm innervated by the musculocutaneous nerve.
Musculocutaneous does not innervate the posterior compartment of the arm.
True or false (if false, provide the correct information): muscles in the back that are innervated by the brachial plexus are innervated by posterior rami.
FALSE, for a long list of reasons:
1) posterior rami never participate in somatic plexuses
2) muscles in the superficial back are innervated by anterior rami
3) the brachial plexus does not contain posterior rami
Which nerves of the brachial plexus PASS THROUGH the arm but do not provide motor innervation until they reach the forearm?
Ulnar and median nerves.
True or false (if false provide the correct information): the ulnar nerve supplies the medial portion of flexor digitorum superficialis.
FALSE. The ulnar nerve supplies the medial portion of the flexor digitorum profundus muscles.
The following statement/s is/are true:
Describe the innervation of the manual lumbrical muscles.
the 1st and 2nd lumbircals (2 lateral lumbircals) are innervated by the median nerve. The 3rd and 4th lumbricals (2 medial lumbircals) are innervated by the ulnar nerve
Describe the anatomy and function of the coracoclavicular ligament.
Two part ligament running between the coracord process and the lateral end of the clavicle:
The trapezoid part runs from trapezoid line on the lateral clavicle down to the superior surface of the coracoid process
The conoid part runs from the conoid tubercle on the lateral clavicle down to the root of the coracoid process.
Functions to transmit a portion of the mass of the upper limb onto the clavicle and to suspend scapula from clavicle.
Describe the movements of the relevant bones and joints of the upper limb during shoulder protraction as succinctly as possible
-anterior movement of the clavicle at the acromialclavicular joint
-posterior movement of the clavicle at the sternoclavicular joint
-anterior movement of the scapula
List three structures or complexes that support the glenohumeral joint:
1) the bony arch created by the coracoid process, the acromion process and the coracoacromial ligament
2) the tendons of the rotator cuff muscles
3) the glenohumeral ligaments (superior, middle and inferior)
4) the coracohumeral ligament
5) the transverse humeral ligament
6) the LH of triceps brachii
Describe the movements of the relevant bones and joints of the upper limb during flexion of the arm at the glenohumeral joint as succinctly as possible
-anteriomedial movement of the humerus in the glenohumeral joint
-scapular protraction, involving
1) posterior movement of the clavicle at the sternoclavicular joint
2) anterior movement of the clavicle at the acromioclavicular joint
3) anterior movement of the scapula
Trace the nerve innervating rhomboid major back to its spinal levels. Indicate primary spinal levels, if present