Week 11 Content Flashcards
What makes up the apex of the axilla?
AKA the inlet of the axilla
clavicle, superior border of scapula, first rib
What make up the medial, posterior, lateral, and anterior walls of the axilla?
medial- serratus anterior
posterior- subscapularis, teres major, latissimus dorsi
lateral- humerus, coracobrachialis long head of biceps
anterior- pectoralis major and minor
Where does the long thoracic nerve originate?
from roots of C5, C6, C7 before the formation of the superior, middle, and inferior trunks of the brachial plexus
Long thoracic nerve passes posterior to which muscle?
middle scalene (hides it)
If the long thoracic nerve is damaged, what happens to movement of the arm?
innervates the SA, which assists the scapula in raising the arm by keeping it next to the thoracic wall (pulling the scapula medially and inferiorly). therefore, damage to the nerve causes the SA to elevate away from the thoracic wall, resulting in:
- trouble raising the arm to the level of the shoulder
- winging of the scapula when the arm is pushed forward
What nerves form the brachial plexus?
ventral primary rami of spinal nerves C5-T1
What is the order of organization of sections of the brachial plexus?
roots (ventral rami) trunks divisions cords terminal branches (peripheral nerves)
How many nerves branch from the divisions of the brachial plexus?
none. branches only come off of the roots, trunks, and cords
Name the muscles supplied by the musculocutaneous nerve.
coracbrachialis
biceps brachii
greater part of the brachialis
What are the terminal branches of the lateral, posterior, and medial cords?
lateral cord- musculocutaneous n. and some of median n.
posterior cord- radial n.
medial cord- ulnar n. and some of median n.
Which muscle divides the axillary artery into 3 parts? Describe the parts and the branches of each.
pec minor
part 1- medial (superior) to pec minor; has 1 branch (superior thoracic a.)
part 2- posterior to pec minor; has 2 branches (thoraco-acromial a. and lateral thoracic a.)
part 3- lateral (inferior) to pec minor; has 3 branches (subscapular a., anterior circumflex humeral a., posterior circumflex humeral a.)
How do the pronator muscles of the forearm accomplish pronation?
when they contract, the radius rotates at the elbow and the distal radius crosses over the ulna. they are assisted by the anconeus muscle posteriorly
Name the contents of the carpal tunnel.
flexor digitorum superficialis tendons flexor digitorum profundus tendons flexor pollicis longus tendon flexor carpi radialis tendon median n.
Name the contents of the cubital fossa from lateral to medial.
TAN
Tendon of biceps brachii
Artery (brachial a. and accompanying vein)
Nerve (medial n.)
What is the clinical importance of the cubital fossa?
like other flexion surfaces of large joints (groin, popliteal fossa, armpit, anterior neck), it is an area where blood vessels and nerves pass relatively superficially, and with an increased amount of lymph nodes.
the area just superficial to the cubital fossa is often used for venous access (phlebotomy) in procedures such as injections, obtaining samples for blood tests, or the insertion of a peripherally inserted central catheter (PICC line)
What is the historical significance of the cubital fossa?
when blood-letting was practiced, the bicipital aponeurosis was known as the “grade of God” tendon because it protected the more important contents of the fossa (the brachial artery and the median n.)
Describe the fascial compartments of the brachium.
arm is enclosed in a sheath of fascia known as the brachial fascia, which is continuous with the fascia of the axilla and the fascia of the forearm
brachial fascia gives rise to the medial and lateral intermuscular septa that divide the arm into anterior and posterior compartments
Describe OINA for biceps brachii.
O- supraglenoid tubercle of scapula (long head) and coracoid process of scapula (short head)
I- tuberosity of the radius and bicipital aponeurosis
N- musculocutaneous n.
A- forearm flexion and supination
Describe OINA for coracobrachialis.
O- coracoid process of the scapula
I- middle third of the medial side of the humerus
N- musculocutaneous n.
A- shoulder/arm flexion and adduction
Describe OINA for brachialis.
O- distal half of anterior surface of humerus
I- coronoid process and tuberosity of the ulna
N- musculocutaneous n.
A- forearm flexion
Describe OINA for triceps brachii.
O- infraglenoid tubercle (long head), posterior humerus inferior to spiral groove (medial head), posterior humerus superior to the spiral groove (lateral head)
I- olecranon process of the ulna
N- radial n.
A- forearm extension
Describe OINA for anconeus.
not considered part of the posterior compartment
O- lateral epicondyle of humerus
I- lateral surface of the olecranon process and posterior surface of the ulna
N- radial n.
A- forearm extension
Describe the location of the musculocutaneous nerve and what it supplies.
arises from the lateral cord of the brachial plexus and supplies the muscles of the anterior brachium