2.11 pectoral region, axilla and brachial plexus

Question 1

list structures and discuss references to costal cartilages

Answer 1

1. jugular/suprasternal notch
2. sternal angle
   
   1. at the junction of teh manubrium and body of sternum, which indicates the level of the second costal cartilages
3. xiphisternal junction
4. xyphoid process of the sternum
5. seventh costal catilages
   
   1. most inferior ones to articulate with the sternum

Question 2

discuss the surface anatomy regions blocked

Answer 2

nipple- level of fourth intercostal space

anterior axillary fold-formed mainly by the pectoralis major muscle

Question 3

Discuss the nerves ofthe pectoral region. what are the cutaneous nerves of the chest derived from? indicate structures on the picture

Answer 3

cutaneous nerves of thorax

1. cutaneous nerves of the chest are branches of intercostal nerves formed by the anterior rami of spinal nerve
   
   1. lateral cutaneous branches of intercostal nerves
   2. anterior cutaneous branches of intercostal nerves

Question 4

define structures and explain

Answer 4

pectoral region for female: breast

1. structures-superficial compartment deep compartment
   
   1. superficial compartment
      
      1. suspensory ligaments
         
         1. well developed connective tissue stroma surrounds the ducts and lobules of mammargy gland.
         2. these are continuous with the dermis of the skin and support the breast
      2. mammary glands
         
         1. modified seat glands in the superficial fascia anterior to the pectoral muscles and the anterior thoracic wall
         2. consist of ducts and associated secretory lobyles. They converge to form 15-20 lactiferous ducts
            
            1. which openindependtly to the nipple
      3. axillary tail
         
         1. mammary glands that extend along the inferolateral edge of the pectoralis major muscle to the axillary fossa
   2. deep compartment
      
      1. retromammary space
         
         1. layer of loose connective tissue, over the pectoralis major, sepatates the breast from the deep fascia and proveds some degree of movement over underlying structures

Question 5

discuss the lymph pathway in breast tissue. What pathology is a concern here?

Answer 5

1. 75% of breast lymph drains into the axillary ymph nodes
2. in breast cancer
   
   1. carnicoma from the medial quadrants may metastasize to parasternal nodes
      
      1. ​these are along the internal thoracic arty or to opposite breast
   2. tumor goeth and spead depend on the eact cellular site of origin.

Question 6

describe the pectoral fascia

Answer 6

pectoral muscles

1. enclosed in fascia
   
   1. pectoralis major
      
      1. facia is attached to the clavicle and sternum, continues with fascia of abdomen
   2. pectoralis minor and subclaviud
      
      1. clavipectoral fascia encloses pectoralis and subclavius and attaches to the clavicla above and to the floor of the axilla below

Question 7

define this structure, borders, function, and contents

Answer 7

the axilla

1. structure
   
   1. pyramidal-shaped region at the junction of the upper extremity. generated from surrounding structures
   2. borders
      
      1. apex-enterance
         
         1. convergenxe of the clavicle, scapula and the first rib
      2. base-floor
         
         1. axillary fascia open leterally into arm, skin of armpit
      3. anterior wall
         
         1. pec major/min
         2. fascia
      4. posterior wall
         
         1. scapula
         2. muscles
            
            1. subscapularis
            2. teres major
            3. latismus dorsi
            4. long head of triceps brachi
      5. medial wall
         
         1. seratus anterior
         2. thoracic cavity
      6. lateral wall
         
         1. intertubercular sulcus
         2. tendon of long head of the biceps brachii treaverses the intertubercular groove
2. function
   
   1. all major structures passing into and out of the upper limb pass through the axilla.
3. contents
   
   1. axillary artery/vein
   2. axillary lymph nodes
   3. brachial plexus
   4. axillary sheath-fascia enclosing the major nerves and blood vessels

Question 8

define the main artery that continues into the arm. Define, structure, functin and regions (include major artery branches

Answer 8

axillary artery

1. structure
   
   1. continuation of the subclavian artery into the axilla
2. function
   
   1. deliver blood
3. regions
   
   1. first
      
      1. medial to the pectoralis minor
         
         1. one arterial branch
            
            1. superior thoracic artery
   2. second part
      
      1. posterior to the pectoralis minor
         
         1. two arterial branches
            
            1. thoracoacromial
            2. lateral thoracic artery
   3. thrid part
      
      1. lateral to pectoralis minor
         
         1. three artery branches
            
            1. subscapular artery
            2. anterior circumflex humeral
            3. posterior circumflex humeral

Question 9

discuss the 3 major veins in the arm,axillary shoulder region. How are they orientated?

Answer 9

axillary vein-continuation of the basilic vein

1. location
   
   1. basillic vein ends at the inferior borderof teres major and becomes the axillary vain
   2. axillary vein becomes the subclavian vein at the lateral border of the first rib
2. extra
   
   1. the cephalic vein pierces the costocoracoid membrane to enter the ​medial part of the axillary vein

Question 10

describe the vascularture to the scapula. what is the clinically important application of this blood flow, think if somthing pierced and blocked the axillary artery

Answer 10

vessels to scapula

1. suprascapular artery
   
   1. branch from the thryocervical trunk, on the first segment of the subclavian artery
   2. enters scapular region above the suprascapular foramen
   3. supplies blood to
      
      1. 2. subscapular artery
   4. ​branches from the third segment of the axillary artery
   5. gives rise to the circumflex artery
      
      1. _anastomoses with dorsal scapular_ and suprascapular arteries
2. clinical significance
   
   1. ligature of the axillary artery is possible between the TCT and the subscapular artery, because blood flow will reverse in the subscapular and scapular circumflex branches to reach the brachial artery.
   2. damage to axillary artery
      
      1. anterior shoulder dislocation, humerus may cause artery rupture
      2. direct blow to the shoulder girdle may cause damage to the axillary artery
      3. thrombosis from crutches-lead to artery aneurisim

Question 11

what is this structure and primary affector sites

Answer 11

brachial plexus

1. effector
   
   1. motor and sensory
   2. thoracoappendecular muscles
   3. appendicular muscles

Question 12

describe the regions anatomy, names of nerves and where they are going. not includeing terminal branches(on another card)

Answer 12

1. roots
   
   1. the anterior rami of C5-T1
   2. carry
      
      1. postganglionic sympathetic fibers to the periphery
      2. GSE
      3. GSA
   3. enter the posterior triangle of the neck, passing between the anterior scalene and middle scalene muscles. lie superior and posterior to the subclavian artery
   4. branches
      
      1. dorsal scapular nerve(C5)
      2. Long thoracic nerve(C5,6,7)
2. trunks-3
   
   1. superior
      
      1. C5 and C6
   2. middle
      
      1. C7
   3. inferior
      
      1. C8 and T1
      2. lies on the rib 1
   4. branch
      
      1. suprascapularnerveC5-6
         
         1. goes to
            
            1. supraspinatus
            2. infraspinatus
      2. nerve to subclavius
3. divisions
   
   1. each of the three trunks of the brachial plexus divides into an anterior and a posterior division
      
      1. three anterior
      2. three posterior
4. cords
   
   1. three cords of th brachial plexus originate from the divisions and are arrange around the second part of the axillary
   2. lateral,
      
      1. C5 and C7
   3. medial
      
      1. C8 and T1
   4. posterior
      
      1. C5-T1, all feed into
   5. branches
      
      1. lateral pectoral nerve(C5,6,7)
         
         1. pectoralis major
      2. medial pectoral nerve
         
         1. pectoralis major
         2. pectoralis minor
      3. upper subscapular
         
         1. subscapularis
            
            1. (C5-6)
      4. middle subscapular/ thoracodorsal nerve
         
         1. latissmus dorsi (C6-8)
      5. lower subscapuler nerve(C5-6)
         
         1. subscapularis
         2. teres major
5. terminal nerves
   
   1. musculotaneous
   2. median
   3. radial
   4. ulnar
   5. axillary

Question 13

draw and describe the brachial plexus. Include the 5 sections, names of nerves, names of branching nerves and lastly the innervation site for the terminal branches

Answer 13

1. terminal branches
   
   1. musculocutaneous (C5-C7)
      
      1. innervation to
         
         1. anterior arm
      2. becomes lateral cutanrous nerve of forarm
   2. median (C6-T1)
      
      1. innervates
         
         1. anterior compartment of the forearm
            
            1. except
               
               1. flexor carpi ulnaris
               2. part of flexor difitorum profundus
         2. thenar muscles
         3. lateral two lumbricals -in hand
   3. ulnar(C8-T1)
      
      1. innervates
         
         1. forearm muscles
         2. medial hand
   4. radial(C5-T1)
      
      1. innervates
         
         1. posterior aspect of upper extremity
   5. axillary(C5-C6)
      
      1. innervates
         
         1. deltoid
         2. teres minor
         3. long head of triceps