Anatomy -- Upper Limb 2 Flashcards
Define the axilla and its boundaries
Space between:
- Pectoralis major (anterior)
- Latissimus dorsi/subscapularis/ teres major (posterior)
- Serratus anterior muscles (medial)
Axilla purpose
Pathway from the neck to the upper limb where vessels and nerves funnel
Arteries with some sort of direct relation to the axillary artery
- Subclavian artery
- Brachial artery
- Circumflex humeral artery
- Deep brachial artery
When does the subclavian artery become the axillary artery
Once it passes over the 1st rib
When does the axillary artery become the brachial artery
Once the axillary artery passes the teres major
Purpose of anastomoses in the axillary area
Reroute blood supply to extremities in case of ligature or compression
Describe the relationship of the basilic vein to the axillary/brachial artery
Runs along the artery
Describe the relationship of the cephalic vein to the axillary/brachial artery
Parallel and lateral
Location of axillary lymph nodes
Around the basilic vein
Roots of postfixed brchial plexus
C6 - T2
Roots of normal brachial plexus
C5 - T1
Describe the progression of the nerves from the brachial plexus
Mnemonic = Really Thirsty? Drink Cold Beer.
- Roots (ventral rami of spinal nerves)
- Trunks
- Divisions
- Cords
- [Terminal] Branches
Location of lateral and medial cords
Anterior to axillary artery
NOTE: Terminal branches form a big “M”
Function of lateral and medial cords
Branches innervate anterior compartment of arm/forearm (=flexor muscles)
Roots of lateral cord
C5, 6, 7
Roots of medial cord
C8; T1
Function of posterior cord
Innervation of posterior compartment of arm and forearm (=extensor muscles)
Roots of posterior cord
C5 - 8; T1
Terminal branches of lateral cord and their function(s)
- Musculocutaneous nerve (anterior compartment of arm)
- Median nerve (anterior compartment of forearm and hand)
Terminal branch of medial cord and its function(s)
Ulnar nerve (forearm and hand)
Terminal branches of posterior cord and their function(s)
- Axillary nerve (deltoid muscle)
- Radial nerve (posterior compartment of arm and forearm)
Define Erb-Duchenne palsy and its cause
- Upper BP lesion causing Shy waiter’s tip position (limb hangs by side)
- Due to lateral hyperextension of neck
Muscles affected by upper brachial plexus injury
Proximal
Muscles affeced by lower brachial plexus injury
Distal muscles
Define Dejerine-Klumpke palsy and its cause
- Lower BP lesion causing claw hand (weakness of all intrinsic muscles of hand)
- Hyperabduction of arm (stretch of axilla)
From where does the long thoracic nerve branch?
Brachial plexus from roots C5, 6, 7
How to test for lesion of long thoracic nerve
Ask patient to do push up on the wall (force retraction)
From where does the thoracodorsal nerve branch and what are its roots?
Brachial plexus from C6 - 8
Muscles innervated by axillary nerve
Deltoid muscle
Spinal level of axillary nerve
C5 - 6
Muscles innervated by long thoracic nerve
Serratus anterior muscle
Spinal levels of long thoracic nerve
C5 - 7
Muscles innervated by the musculocutaneous nerves
Anterior compartment of arm
Spinal levels of musculocutaneous nerves
C5 - 7
Muscles innervated by thoraco-dorsal nerve
Latissimus dorsi
Spinal levels of thorca-dorsal nerve
C6 - 8
Muscles innervated by radial nerve
Posterior compartment of arm/forearm
Spinal levels of radial nerve
C5 - T1
Muscles innervated by median nerve
Anterior compartment of forearm and hand
Spinal levels of median nerve
C5 - T1
Muscles innervated by ulnar nerve
Forearm and hand
Spinal levels of ulnar nerve
C8 - T1
Define the quandrangular space
4 sided space bounded by:
- Teres major (inferior)
- Long head of triceps (medial)
- Humerus (lateral)
- Subscapularis muscle (superior)
Define the triangular interval
3 sided space bounded by:
- Teres major (superior)
- Long head of triceps (medial)
- Humerus (lateral)
Through which space does the radial nerve cross?
Triangular interval
Through which space does the axillary nerve cross?
Quadrangular space
Which nerve is involved when the neck of the humerus is fractured?
Axillary nerve
Which nerve is involved when the shaft of the humerus is fractured?
Radial nerve
Which nerve is involved when the medial epicondyle of the humerus is fractured?
Ulnar nerve
