Pectoral And Axillary Regions Flashcards
What is the difference in pectoral region surface anatomy between males and females?
Pec major m. forms contour in males, whereas this is formed by breast in females
Nipple is usually located in 4th intercostal space along midclavicular line in males, while in females the location varies significantly after puberty
What skeletal muscle of facial expression extends from the mandible to the upper thorax, just inferior to the clavicle?
Platysma m.
What are the 2 cutaneous nerves associated with the pectoral region?
Supraclavicular nn. C3-C4 from the cervical plexus
Intercostal nn. T1-T7
What cutanous nerves of the pectoral region supply the skin associated with intercostal spaces?
Intercostal nn. T1-T7
What cutaneous nerves of the pectoral region innervate the skin of the 1st and 2nd intercostal spaces?
Supraclavicular nn. C3-C4 from cervical plexus
The female breast is located vertically from ribs _____-____ and horizontally from ________ to __________
2-6
Sternum to midaxillary line
The female breast is completely contained within ______ _____ and is located anterior to the ________ ________ muscle
Superficial fascia
Pectoralis major m.
The _________ space lies between the breast and pec major muscle in females
Retromammary
Female nipples contain 15-20 openings to _______ _______, each of which drains milk from 1 mammary gland
Lactiferous ducts
Pigmented skin around the nipple is called the
Areola
Female breasts are mad eup of 15-20 ________ glands, ________ CT, and condensations of fascia that form ________ _______ and septa which separate lobules from one another
Mammary; fatty; suspensory ligaments
What are the 3 arteries that typically supply the female breast?
Lateral thoracic a.
Intercostal a.
Internal thoracic a. (Perforating branches in intercostal spaces 3-6)
What 2 veins supply the female breast?
Internal thoracic v.
Axillary v.
Where do most lymphatic vessels converge in the breast tissue?
On subareolar lymph plexus beneath the skin of the areola
Most lymphatic vessels converge on subareolar lymph plexus beneath the skin of the areola. From here, several major lymph vessels transport to various locations.
75% of lymph vessels travel to the ______ nodes
Pectoral nodes
Most lymphatic vessels converge on subareolar lymph plexus beneath the skin of the areola. From here, several major lymph vessels transport to various locations.
75% of lymph vessels travel to the pectoral nodes, which drain to ______ nodes
Axillary
Most lymphatic vessels converge on subareolar lymph plexus beneath the skin of the areola. From here, several major lymph vessels transport to various locations.
75% of lymph vessels travel to the pectoral nodes which drain to axillary nodes
25% of lymph vessels travel to what 4 groups of nodes?
Infraclavicular
Parasternal
Contralateral
Abdominal
Most lymphatic vessels converge on subareolar lymph plexus beneath the skin of the areola. From here, several major lymph vessels transport to various locations.
75% of lymph vessels travel to the pectoral nodes which drain to axillary nodes
25% of lymph vessels travel to infraclavicular, parasternal, contralateral, and abdominal nodes. What is the significance of these nodes if a patient presents with cancer in the right breast?
It can spread to the liver
_____________ nodes on one side are connected to contralateral nodes by lymphatic vessels which cross anterior midline
Parasternal
Origin of the clavicular part of pectoralis major m.
Medial 1/2 of clavicle
Origin of sternal part of pectoralis major m.
Manubrium and body of sternum
Origin of costal part of pectoralis major m.
Costal cartliages 1-6
Insertion of pectoralis major m.
Tendon of insertion has 2 laminae:
Anterior - from clavicular and upper sternocostal parts
Posterior - from lower sternocostal part - insert highest on humerus, as they pass laterally, they twist to attain a more superior position relative to fibers of anterior lamina
Bilaminar tendon crosses the intertubercular groove of the humerus to insert on the crest of the greater tubercle
What 2 nerves innervate pectoralis major m.?
Lateral pectoral n. (C3-7) - supplies most of upper portion
Medial pectoral n. (C8-T1) - supplies lower portion after passing through or around pectoralis minor m.
Actions of pectoralis major m.
Adduction and medial rotation of humerus
Origin of pectoralis minor
Ribs 2-5 or 3-6
Insertion of pectoralis minor m.
Coracoid process of scapula
Innervation of pectoralis minor m.
Medial pectoral n.
Action of pectoralis minor m.
Depressor and downward rotator of scapula
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the anterior wall?
Clavicle
Pectoralis major m.
Pectoralis minor m.
What 2 muscles form the anterior axillary fold?
Pectoralis major m.
Pectoralis minor m.
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the posterior wall?
Scapula
Subscapularis m.
Teres majorm.
Latissimus dorsi m.
What muscles form the posterior axillary folds?
Teres major m.
Latissimus dorsi m.
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the medial wall?
Ribs
Intercostal mm.
Serratus anterior m.
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the lateral wall?
Intertubercular sulcus of humerus (contains tendon of long head of biceps brachii)
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the base?
Skin
Superficial fascia of armpit
The boundaries of the axillary region are made up of an anterior wall, posterior wall, medial wall, lateral wall, base, and apex.
What structures make up the anterior, posterior, and medial aspects of the apex?
Anterior - clavicle
Posterior - scapula
Medial - first rib
What are the overall contents of the axillary region?
Cords of brachial plexus
Axillary a.
Axillary v.
Axillary lymph nodes
Muscle tendons
The axillary a. Is a continuation of what major a.?
Subclavian a.
Where does the axillary a. begin and end?
Begins at lateral border of first rib at apex of axilla
Ends at lower border of teres major m.
The axillary artery has 3 parts. The first part is between the first rib and medial border of pec minor m. Does this part have any branches?
Yes, only branch is the supreme thoracic a.
The axillary artery has 3 parts. The first part is between the first rib and medial border and has one branch - the supreme thoracic a. The second part is deep to pec minor and has 2 branches - what are they?
Thoracoacromial trunk
Lateral thoracic a.
The axillary artery has 3 parts. The first part is between the first rib and medial border and has one branch - the supreme thoracic a.
The second part is deep to pec minor and has 2 branches - the lateral thoracic a. and the thoracoacromial trunk.
The third part is lateral to the lateral border of pectoralis minor m. And has 3 branches, what are they?
Subscapular a.
Anterior humeral circumflex a.
Posterior humeral circumflex a.
The axillary v. is a continuation of what vein of the arm?
Basilic v.
Where does the axillary vein begin and terminate?
Begins at lower border of teres major m.
Terminates at lateral border of first rib where it becomes continuous with subclavian v.
[tributaries correspond to branches of axillary a.]
Axillary LNs vary in number between 12-36 and there is no sharp distinction between groups. What are the 4 groups of axillary LNs?
Apical (infraclavicular)
Central nodes
Lateral nodes
Subscapular nodes
Which of the following receive lymph from the upper extremity, but not the shoulder; and send lymph to central nodes?
A. Apical nodes
B. Infraclavicular nodes
C. Lateral nodes
D. Subscapular nodes
C. Lateral nodes [on distal part of axillary v.]
Which of the following receive lymph from breast and anterior thoracic wall and send lymph to apical and central nodes?
A. Infraclavicular nodes
B. Lateral nodes
C. Subscapular nodes
D. A and C
C. Subscapular nodes
Which of the following are located posterior to the pectoralis minor m., receive lymph from 3 other lymph node groups, and send lymph to apical nodes?
A. Infraclavicular nodes
B. Central nodes on axillary v.
C. Lateral nodes on distal axillary v.
D. Subscapular nodes
B. Central nodes on axillary v.
Which of the following receive lymph from ALL other axillary nodes, give rise to subclavian lymph trunk, and connect with the supraclavicular nodes in the neck?
A. Apical (infraclavicular nodes)
B. Central nodes
C. Lateral nodes
D. Subscapular nodes
A. Apical (infraclavicular nodes)
Which subgroup of axillary LNs are located medially on proximal part of axillary v. close to the apex?
Apical (infraclavicular nodes)
Where are subscapular nodes located?
Next to subscapular a. and v.
Where are central nodes of the axillary region located?
Posterior to pectoralis minor m.
Lateral nodes on the distal part of the axillary vein receive lymph from the upper extremity, except for which area?
The shoulder
What muscle tendons are contained in the axillary region?
Coracobrachialis t.
Biceps brachii tt. (Long and short heads)
Collateral circulation around the scapula is extensive. Where might the axillary a. be ligated?
Between the thyrocervical trunk and the subscapular a.
This reverses direction of blood flow in subscapular a. So that arterial blood reaches the distal portion of the axillary a.
Ligation to the axillary a. distal to the subscapular a. is medical malpractice due to locations of axillary artery anastomosis.
The subscapular a. receives blood via anastomes with what 3 aa.?
Suprascapular a.
Transverse cervical a.
Intercostal aa.
