Exam 3: Axilla

Question 1

Axilla

Answer 1

• pyramidal shaped space between arm & thorax providing passage for vessels & nerves to reach upper limb
• neurovascular structures are ensheathed in fascial sleeve–> axillary sheath

Question 2

Axillary Artery

Answer 2

• continues from subclavian after 1st rib
• 1st part- between lat. border of 1st rib & med. border of pec minor
  
  • enclosed by axillary sheath
  • has 1 branch (sup. thoracic a.)
• 2nd part- post. to pec minor
  
  • has 2 branches (thoracoacromial a & lat. thoracic a)
• 3rd part- between lat. border of pec minor & inf. border of t. major
  
  • 3 branches (subscapular, ant. circumflex humeral, post. circumflex humeral a)

Question 3

Superior Thoracic Artery

Answer 3

• small
• supplies muscles in 1st & 2nd rib intercostal spaces & serratus ant.
• anastomoses w/ intercostal a.

Question 4

Thoracoacromial Artery

Answer 4

• short wide trunk
• deep to clavicular head of pec minor
• divides into 4:
  
  • acromial
  • deltoid
  • pectoral
  • clavicular

Question 5

Lateral Thoracic Artery

Answer 5

• supplies pec muscles, axillary lymph nodes & breast

* important source of blood to lat. part of mammary gland in women

Question 6

Subscapular Artery

Answer 6

• largest of axillary a.
• divides into circumflex scapular & thoracodorsal a
• supplies subscapularis, t. major, serratus ant. & latissimus dorsi

Question 7

Circumflex Humeral Artery

Answer 7

• ant. & post. circumflex anastomses w/ each other

* supplies shoulder muscles such as debt, t. major & minor, long head of triceps

Question 8

Compression of Axillary Artery

Answer 8

• needed when heavy bleeding of arm
• 2 locations:
  
  • 3rd part: palpate inf part of lat. wall of axilla against hum.
  • beginning of a.- downward pressure in angle between clavicle & attachment of the sternocleidomastoid m. against 1st rib

Question 9

Axillary Vein

Answer 9

• lies on med. side of axillary a
• has more abundant tributaries than branches of axillary n.
• has more anastomoses
• has more variations

Question 10

Receiving Bypass

Answer 10

• receives directly or indirectly from thracoepigastric v. –> collects blood from superficial v. of inguinal region
• blood used to return to heart through IVC, now go through SVC
  
  • collateral route for venous return when IVC is obstructed

Question 11

Axillary Lymph Nodes

Answer 11

• apical
• central
• humeral (lateral)
• pectoral (anterior)
• subscapular (posterior)

*bottom 3 drain into central, then drain into apical, then drain into subclavian lymphatic trunk

Question 12

Enlargement of Nodes

Answer 12

• results from infections of upper limb or cancer shoulder& thoracic region
• humeral group - 1st involved
• enlargement of apical may obstruct cephalic v.