Axillary Region Flashcards
The brachial plexus runs through this structure that leads to the posterior triangle of the neck. What is this structure bounded by?
Cervicoaxillary canal
Clavical anteriorily
Scapula Posterally
1st rib medially
What nerve is the lateral branch of the 2nd intercostal nerve (T2) that supples the chest wall and continues to the arm
Intercostobrachial nerve
What artery begins at the lateral border of the first rib (and is a continuation of the subclavian artery)?
How many branches are there off of this artery?
Axillary Artery
6 Branches
The first artery that branches off the axillary artery in region 1
The superior thoracic artery
The second and third arteries branching off the axillary artery in region 2 (covered by the pectoralis minor
Thoracoacromial Artery (trunk)
Lateral thoracic artery (supplies lateral breast)
The fourth, fifth, and sixth arteries branching off the axillary artery in region 3
Subscapular Artery (divides into the circumflex scapular (anastomoses with supra scapular) artery and throacodorsal artery (to latissimus)
Posterior Circumflex Humeral Artery (quadrilateral space, then anastomises with anterior circumflex humeral artery)
Anterior Circumflex Humeral Artery
The posterior triangle of the neck is formed by the?
Trapezeus posteriorly
Sternocleidomastoid medially
Clavical inferiorly
The brachial plexus is formed by what nerves?
What part of the nerves form the Roots of the brachial plexus?
C5 -C8 and T1
The ventral roots (rami) form the Roots of the brachial plexus
The five segments of the brachial plexus
Roots - Trunks - Divisions - Cords - Branches (Nerves)
The trunks of the brachial plexus
Superior C5-C6
Middle C7
Inferior C8-T1
The divisions of the Brachial plexus
Anterior and posterior divisions sections of the Divisions are the same as the Trunks
Superior C5-C6
Middle C7
Inferior C8-T1
The cords of the brachial plexus
Lateral is C5, C6, C7
Posterior C5-T1
Medial C8 and T1
What are the major (clinically important) nerve branches out of the brachial plexus?
Musculocutaneous NErve Median Nerve Axillary Nerve Radial Nerve Ulnar Nerve
The lateral chord gives rise to which nerves?
Lateral pectoral nerve (pec major)
Musculocutaneous nerve
Lateral root joins with the medial root and gives rise to the median nerve
The Posterior cord gives rise to which nerves?
Axillary (deltoid, teres minor)
Radial
Thoracodorsal Nerve (latissimus)
Upper and lower sub scapular nerves (subscapularis, trees major)
The Medial Cord gives rise to which nerves?
The medial root joins with the lateral root and gives rise to the median nerve
Medial Pectoral nerve (pec major and minor)
Medial brachial cutaneous nerve
Medial antebrachal cutaneous nerve
Long thoracic nerve is from what region of the brachial plexus? What muscle does it innervate? What is clinically important about this nerve?
The Roots of C4, C6, and C7 (ventral rami)
Serratus Anterior
Winged Scapula
An injury causing an increase in angle between the neck and the shoulder (resulting from fall, car crash, delivery of baby, etc) could injure which spinal roots? What muscle do the innervate?
What is the clinical presentation?
What is this called?
C5 and C6
Lateral rotators (teres minor, infraspinatus) Abductors of arm (supraspinatus, deltoid)
Arm will be medially rotated and adducted Waiters Tip (loose lateral rotation of arm)
Upper brachial plexus injury (Erb-Duchenne Palsy)
An injury causing upper limb to be pulled superiorly (baby during delivery, or person hanging form cliff) causes what injury?
Lower brachial plexus injury (Klumpke paralysis)
Injury to C8-T1
Ulnar Nerve
Median Nerve
Causes Atrophy of intrinsic (short) muscles of hand
Claw Hand - Paralysis of hand
The nerves that supply sensory information of the medial portions of upper extremity
Medial cutaneous nerve of arm
Medial cutaneous nerve of forearm
Mucle located on inner (anterior) surface of scapula and is part of the rotator cuff
Innervated by?
Subscapularis
Innervated by upper and lower sub scapular nerves (posterior cord of brachial plexus)
An injury causing an increase in angle between the neck and the shoulder (resulting from fall, car crash, delivery of baby, etc) could injure which spinal roots? What muscle do the innervate?
What is the clinical presentation?
What is this called?
C5 and C6
Lateral rotators (teres minor, infraspinatus) Abductors of arm (supraspinatus, deltoid)
Arm will be medially rotated and adducted Waiters Tip (loose lateral rotation of arm)
Upper brachial plexus injury (Erb-Duchenne Palsy)
An injury causing upper limb to be pulled superiorly (baby during delivery, or person hanging form cliff) causes what injury?
Lower brachial plexus injury (Klumpke paralysis)
Injury to C8-T1
Ulnar Nerve
Median Nerve
Causes Atrophy of intrinsic (short) muscles of hand
Claw Hand - Paralysis of hand
The nerves that supply sensory information of the medial portions of upper extremity
Medial cutaneous nerve of arm
Medial cutaneous nerve of forearm
Mucle located on inner (anterior) surface of scapula and is part of the rotator cuff
Innervated by?
Subscapularis
Innervated by upper and lower sub scapular nerves (posterior cord of brachial plexus)
What cord mainly supplies extensors?
Exception?
Posterior Cord
Except for brachioradialis
Glenohumoral joing dislocation
Usually occurs in inferior direction (slightly anterior) do to a sudden blow when fully abducted or to excessive lateral rotation of the upper extremity.
