Axilla And Brachial Plexus Flashcards
What runs from neck to first rib?
Subclavian artery.
What is base of axilla?
Skin of the armpit and superficial fascia which overlies the deep or Axillary fascia.
Describe anterior wall of axilla?
Pec major and it’s investing fascia (pectoral fascia) and pectoralis minor (clavipectoral fascia)
What is in the deltopectoral triangle?
Cephalic vein and thoracoacromial trunk (artery)
What makes up the medial wall of the axilla?
Serratus anterior and the ribs.
What forms lateral wall of axilla?
Bicipital groove of humerus.
What is the apex of the axilla?
Upper border of scap, clavicle, and first rib.
What does brachial plexus do?
Provides inner action to the upper limb.
Somatic afferents of brachial plexus?
Exteroceptive: pain, temp, pressure, touch, vibration (cutaneous innervations).
Proprioceptive: joint and position sense.
Autonomics of brachial plexus function?
Sympathetics to the upper limb that innervate sweat glands and smooth muscle of arteries and hair follicles.
Brachial plexus sends motor to voluntary muscles via what?
Somatic efferents.
What rami does brachial plexus consist of?
Ventral primary rami from C5 thru T1 as well as a small contribution from C4
What roots form upper trunk of brachial plexus?
C5/6
What roots from brachial plexus form middle trunk?
C7
What roots of brachial plexus form lower trunk?
C8 and T1
What nerves come off upper trunk of brachial plexus?
Dorsal scapular nerve.
Suprascapular nerve.
Nerve to subclavius.
What nerve stems from C5 past T1?
Long thoracic nerve.
Dorsal scapular nerve?
C4/5
Long thoracic nerve?
C5/6/7
Nerve to subclavius?
C5/6 and sometimes C4
Suprascapular nerve?
C5//6 and sometimes C4
What cords arise from divisions of brachial plexus?
Lateral cord, posterior cord, medial cord
What nerve roots does lateral cord consist of?
C5/6/7
What nerve roots stem from posterior cord?
C5/6/7/8/T1
What nerve roots stem from medial cord of brachial plexus?
C8/T1
What nerve is derived from lateral cord?
Lateral pectoral nerve.
What nerves derive from medial cord?
Medial pectoral nerve
Medial brachial cutaneous nerve
Medial antebrachial cutaneous nerve
What nerves are derived from posterior cord?
Upper subscapular nerve.
Thoracodorsal nerve.
Lower subscapular nerve.
Upper subscapular nerve and lower subscapular nerve roots?
C5/6
Thoracodorsal nerve roots?
C6/7/8
Muscolocutenaous nerve roots?
C5/6/7
Ulnar nerve roots?
C7/C8/T1
What are the 5 terminal branches of the brachial plexus that are formed from the cords?
Musculocuteanous nerve.
Median nerve.
Ulnar nerve.
Axillary nerve.
Radial nerve.
What 2 terminal branches does posterior cord give rise to?
Axillary nerve and radial nerve.
Radial nerve roots?
C5/6/7/8/T1
Axillary nerve roots?
C5/6
Median nerve roots?
C6/7/8/T1
What are general upper trunk brachial plexus injuries referred to as?
Erb palsy
Duchenne-Erb palsy
Upper radicular syndrome “waiter’s tip position”
How are upper trunk brachial plexus injuries produced?
By increasing angle between neck and shoulder.
Examples: thrown from motorcycle, hitting a tackle dummy wrong, carrying a heavy backpack for long periods of time
What happens when an action increases the angle between the neck and shoulder?
A pull, tear, or stretch occurs of C5/6 and nerve roots of upper trunk
