Chest, Axilla, and Brachial Plexus Flashcards
(43 cards)
Pectoralis Major attachments?
- proximal:
- clavicular head: medial half of clavicle
- sternocostal head: sternum, upper 6 costal cartilages, aponeurosis of external oblique - distal:
- crest of greater tubercle humerus
Pectoralis major innervation?
- medial pectoral nerve
- lateral pectoral nerve
Pectoralis major functions?
- clavicular head
- adduct, flex, and medial rotate humerus - sternocostal head
- extend humerus - raises body when arms fixed
- climbing
pec minor attachments?
- proximal:
- 2nd to 5th ribs (3 heads) - distal:
- coracoid process of scapula
pec minor innervation?
medial pectoral nerve
pec minor function?
- draws scapula inferior and anterior against thoracic wall, stabilizer
- depresses shoulder
subclavius attachments?
- 1st ribs
- middle third of clavicle
subclavius innervation?
nerve to subclavius
subclavius function?
- anchors and depresses lateral part clavicle
- stabilizes clavicle
Serratus anterior attachments?
- proximal:
- 1st to 8th ribs - distal:
- medial border of scapula
serratus anterior innervation?
long thoracic nerve
serratus anterior function?
- holds scapula against thoracic wall
- rotates scapula
- long thoracic nerve (superficial) damage causes winged scapula
components of the breasts?
- adipose tissue
- glands
- where milk is produced - ducts
- transfer milk from glands to nipple - suspensory ligaments
- strong connective tissue that originate deep and radiate out to give structure and support to breast
- clinically important in breast exam, puts pressure on ligaments, can identify breast cancer - retromammary space
- easy to remove breast
- used for breast implants
Importance of lymphatics in breasts?
- more than 75% of lymph from breast drains into axillary nodes, particularly the pectoral (anterior) nodes
- good place to check for breast cancer
- cervical
- parasternal
- abdominal
Contents of the Axilla?
- axillary blood vessels
- axillary artery
- axillary vein - brachial plexus
- cords
- branches - axillary sheath encases the arteries, veins, and nerves
- biceps brachii
- coracobrachialis
- axillary lymph nodes
main blood supply of the axilla?
-axillary artery which is a continuation of the subclavian artery
What are the boundaries of the axillary artery?
- proximal: lateral border of 1st rib
- distal: teres major
What are the three sections of the axillary artery?
- 1sr rib to pec minor
- contains superior thoracic artery
- supplies blood to first two intercostal spaces - behind pec minor
- thoracoacromial artery (clavicular, acromial, deltoid, pectoral), supplies blood to deltoid, subclavius, acromion, pec major and minor
- lateral thoracic artery, supplies blood to serratus anterior - between pec minor and teres major
- anterior circumflex humeral artery
- posterior circumflex humeral artery
- subscapular artery (very short, turns into thoracodorsal artery to supply lats)
What are the roots of the brachial plexus?
anterior rami of spinal nerves C5, C6, C7, C8, T1
What are the trunks of the brachial plexus?
- superior
- middle
- inferior
- turn into anterior and posterior divisions
What are the cords of the brachial plexus?
- lateral
- posterior
- medial
what are the major terminal branches of the brachial plexus?
- musculocutaneous
- axillary
- radial
- median
- ulnar
What does musculocutaneous nerve innervate?
- coracobrachialis (pierces this muscle)
- biceps brachii
- brachialis
- turns into lateral antebrachial cutaneous nerve to innervate skin of lateral forearm
what does axillary nerve innervate?
- teres minor
- deltoid
- small cutaneous portion that innervates skin of inferior portion of deltoid