Axilla and Arm Flashcards
What are the attachments of the Anconeus muscle?
From lateral epicondyle of the humerus to the lateral surface of the olecranon process of the ulna
What are the attachments of the Short Head of the Biceps Brachii muscle?
From the coracoid process of the scapula to the radial tuberosity and deep antebrachial fascia (through the bicipital aponeurosis)
What are the attachments of the Long Head of the Biceps Brachii muscle?
From the supraglenoid tubercle of the scapula to the radial tuberosity and deep antebrachial fascia (through the bicipital aponeurosis)
What are the attachments of the Brachialis muscle?
From the distal anterior shaft of the humerus & lateral & medial intermuscular septa to the coronoid process & ulnar tuberosity
What are the attachments of the Coracobrachialis muscle?
From the coracoid process of the scapula to the proximal medial shaft of the humerus
What are the attachments of the Long Head of the Triceps Brachii muscle?
From the infraglenoid tubercle of the scapula to the olecranon process of the ulna
What are the attachments of the Lateral Head of the Triceps Brachii muscle?
From the proximal posterolateral shaft of the humerus to the olecranon process of the ulna
What are the attachments of the Medial Head of the Triceps Brachii muscle?
From the distal posteromedial shaft of the humerus to the olecranon process of the ulna
What are the actions of the Anconeus muscle?
Extension of the elbow
What are the actions of the Biceps Brachii muscles?
Flexion of the shoulder & elbow & supination of the forearm (Short head and long head have same actions)
What are the actions of the Brachialis muscle?
Flexion of the elbow
What are the actions of the Coracobrachialis muscle?
Flexion & adduction of the shoulder
What are the actions of the Long Head of Triceps Brachii?
Extension of the shoulder & elbow
What are the actions of the Lateral Head of the Triceps Brachii?
Extension of the elbow
What are the actions of the Medial Head of Triceps Brachii?
Extension of the elbow
What innervates the Anconeus muscle?
Radial nerve
What innervates the Biceps Brachii muscles?
Musculocutaneous nerve
What innervates the Brachialis muscle?
Musculocutaneous nerve & small branch from radial nerve
What innervates the Coracobrachialis muscle?
Musculocutaneous nerve
What innervates the Triceps Brachii muscles?
Radial nerve
What are the spinal roots of the Aconeus muscle?
C7-8
What are the spinal roots of the Biceps Brachii muscles?
C5-6
What are the spinal roots of the Brachialis muscle?
C5-6
What are the spinal roots of the Coracobrachialis muscle?
C6-7
What are the spinal roots of the Triceps Brachii muscles?
C6 - T1
What are the boundaries of the axilla?
Apex: 1st rib, clavicle Base: skin of the armpit Anterior: pectoralis minor and major muscles Posterior: scapula, subscapular muscle Medial: serratus anterior muscle Lateral: humerus
What are the contents of the axilla?
Axillary a., Axillary v., Axillary lymph nodes, 3 cords of the brachial plexus
What are the location and contents of the triangular space?
Boundaries: Teres minor and major muscles and the long head of triceps brachii
Contents: Circumflex scapular a.
What are the location and contents of the triceps hiatus?
Boundaries: Medial and Lateral head of triceps brachii and Teres major m.
Contents: Radial n. and Profunda brachii a.
Predict what neurovascular structures would be injured based on bone fracture located at the surgical neck of the humerus, radial groove of the humerus?
Primarily the radial nerve because it runs through the groove along with deep brachial artery
Posterior circumflex humeral artery, anterior circumflex humeral artery, and the Axillary nerve
Apply the convention for naming spinal nerves as they exit the vertebral column to the radial nerve.
The radial n. arises from the posterior cord of the brachial plexus. The posterior cord is the union of the posterior divisions of all the trunks, so we have information from the upper trunk (C5, C6), the middle trunk (C7), and the lower trunk (C8, T1).
Apply the convention for naming spinal nerves as they exit the vertebral column to the axillary nerve.
The axillary n. arises from the posterior cord of the brachial plexus. The posterior cord is the union of the posterior divisions of all the trunks, but only information from the upper trunk (C5, C6) is present.
Apply the convention for naming spinal nerves as they exit the vertebral column for the musculocutaneous nerve.
The musculocutaneous nerve arises from the lateral cord of the brachial plexus. The lateral cord is the union of the upper trunk (C5, C6) and the middle trunk (C7). So information is present from the C5-C7 roots.
Apply the convention for naming spinal nerves as they exit the vertebral column for the median nerve.
The median nerve arises from the lateral root and medial root of the median nerve. These roots arise from the lateral cord and the medial cord. The lateral cord is the union of the upper trunk (C5, C6)and middle trunk (C7). The medial cord contains information from the lower trunk (C8, T1). The information present in the median nerve comes from C5-T1.
Apply the convention for naming spinal nerves as they exit the vertebral column for the ulnar nerve.
The ulnar nerve arises from the medial cord of the brachial plexus. The medial cord arises from the anterior division of the lower trunk (C8, T1). In this case, the ulnar nerve receives information from C7 via the Ansa Pectoralis so the nerve contains information from C7-T1.
Apply the convention for naming spinal nerves as they exit the vertebral column for medial cutaneous nerves of the brachial and antebrachial.
The medial cutaneous branches of the arm and forearm arise from the medial cord of the brachial plexus. The medial cord is an extension of the anterior division of the lower trunk, so these nerves contain information from C8-T1.
Apply the convention for naming spinal nerves as they exit the vertebral column for the medial pectoral nerve.
The medial pectoral nerve arises from the medial cord of the brachial plexus. The medical cord is an extension of the anterior division of the lower trunk (C8, T1).
Apply the convention for naming spinal nerves as they exit the vertebral column for the long thoracic nerve.
The long thoracic nerve arises from the ventral rami of roots of C5, C6, and C7, so it contains information from C5-7.
Apply the convention for naming spinal nerves as they exit the vertebral column for the lateral pectoral nerve.
The lateral pectoral n. arises from the lateral cord of the brachial plexus. The lateral cord is the union of the anterior root of the middle trunk (C7) and the anterior root of the upper trunk (C5, C6), so the nerve receives its information from C5-C7.
Apply the convention for naming spinal nerves as they exit the vertebral column for the upper and lower subscapular nerves.
The lower and upper subscapular nerves arise from the posterior cord of the brachial plexus. The posterior cord is the union of the 3 posterior divisions of the upper, middle, and lower trunks. In this case, the nerves can only be traced back to the upper trunk, so the nerves only receive information from C5 and C6.
Apply the convention for naming spinal nerves as they exit the vertebral column for the thoracodorsal nerve.
The thoracodorsal nerve arises from the posterior cord of the brachial plexus. The posterior cord is the union of the anterior divisions of all the trunks, however, the nerve only receives information from C6, C7, and C8.
Apply the convention for naming spinal nerves as they exit the vertebral column for the dorsal scapular nerve.
The dorsal scapular nerve arises from the ventral rami root of C5, and the nerve is also in a position to receive information from C4.
Apply the convention for naming spinal nerves as they exit the vertebral column for the suprascapular nerve.
The suprascapular nerve arises from the upper trunk of the brachial plexus and receives information from C4-C6.
Apply the convention for naming spinal nerves as they exit the vertebral column for the subclavian nerve.
The subclavian nerve arises from the upper trunk of the brachial plexus, so it transmits information from C5 and C6.
Describe territories and path of drainage of axillary lymph nodes to the venous system.
The supratrochlear nodes (hand and forearm) drains into the humeral nodes (hand, forearm, medial arm, deep forearm).
The humeral, pectoral (anterior thorax and breast), and subscapular (posterior shoulder, posterior thorax and scapula) nodes drain into the central node.
The central nodes drain into the Apical nodes.
The infraclavicular (shoulder and lateral arm) nodes also drain into the Apical nodes.
The apical drains into the R subclavian trunk > R lymphatic duct > R venous angle or “jugulosubclavian junction” into the venous system > R brachiocephalic vein > Superior Vena Cava > R atrium
What are the 5 axillary lymph nodes?
Humeral, Pectoral, Subscapular, Central, and Apical
What axillary lymph nodes do the infraclavicular lymph nodes drain into?
The apical lymph nodes
What drains into the humeral axillary lymph nodes?
The supratrochlear lymph nodees
What are the territories of the humeral lymph nodes?
Hand, forearm, deep forearm, medial arm
What are the territories of the pectoral lymph nodes?
Anterior thorax and breasts
What are the territories of the subscapular lymph nodes?
posterior thorax, posterior shoulder, scapula
What are the territories of the infraclavicular lymph nodes?
lateral arm and shoulder
what are the territories of the supratrochlear lymph nodes?
hand and forearm
Predict the most common dislocation of the shoulder based on the structure of the joint capsule.
Anterior shoulder dislocation. Happens in the abducted position. The head of the humerus moves anteriorly and inferiorly.
Structure: the inferior joint capsule is the only structure stabilizing the joint, making it vulnerable.
What dermatome is associated with spinal nerve C6?
the skin overlying the Thumb and medial arm, medial forearm
What dermatome is associated with spinal nerve C7?
skin overlying the Index and middle fingers
What dermatome is associated with spinal nerve C8?
Skin overlying the 5th digit
What is a common testing site of the dermatome associated with spinal nerve C8?
The tip of the 5th digit
What areas of the skin are associated with dermatome C5?
Skin overlying the lateral arm and forearm
deltoid tuberosity is common testing site
What areas of the skin are associated with dermatome T1?
skin overlying the medial forearm and arm
Common testing site: aspect of the forearm just below the medial epicondyle
What dermatome is associated with spinal never T2?
Skin overlaying the axillary region
What dermatome is associated with spinal nerve C4?
Skin overlaying the shoulder
