Lecture 4: Breast, Pectoral Region, & Axilla Flashcards
What type of tissue is the breast comprised of? [2]
Glandular & Adipose
What are the ligaments in breast? They go to the skin.
Suspensory Ligaments
75% of lymphatic drainage goes to the ______________________ in the breast.
axillary lymph node.
In the axillary lymph nodes, which node drains most of the breast?
Pectoral
What are the 5 axillary lymph nodes (that account for 75% of drainage)?
Pectoral, subscapular, humeral, central, apical
The remaining 25% of lymphatic drainage of the breast goes to which lymph nodes?
Parasternal
What do lymph nodes do?
Monitor fluid left behind by circulation
Why is it important to understand the path of lymph?
Infections and cancers often follow this path
What muscles move the upper limb? [3]
Pectoralis Major
Pectoralis Minor
Serratus Anterior
What is the action of the pec. major?
Flexes, ADDucts, & medially rotates arm (shoulder)
What is the innervation of the pec. major?
Medial and lateral pectoral nn.
What is the action of the pectoralis minor?
Protracts & depresses scapula
What is the innervation of the pectoralis minor?
Medial pectoral n.
What is the action of the serratus anterior?
Protracts & depresses scapula
What is the innervation of the serratus anterior?
Long thoracic n.
Define intercostal space
The space between 2 ribs
How many intercostal spaces are there on ONE side of the body? (both sides = X2)
11 spaces
Intercostal muscles are the muscles of…
Respiration
List the intercostal muscles from SUPERFICIAL to DEEP
- External intercostals
- Internal intercostals
- Innermost intercostals + Tranversus Thoracis
What is the fiber direction of the external intercostal muscles?
Inferiomedially (hands in pocket)
What muscles go from the posterior rib to the beginning of the costal cartilage?
External intercostal muscles
What is the fiber direction of the internal intercostal muscles?
Inferolaterlaterally (Clutch your pearls)
What muscle goes from sternum to angles of rib?
Internal intercostal muscles
What muscle is found deep to internal intercostals?
Innermost intercostal muscles
Where are the innermost intercostal muscles located?
Lateral sides of the thoracic wall
How do we tell the innermost intercostal muscles apart from the internal intercostals?
Nerves and vessels run between the internal and innermost intercostal muscles. `
What do you find in the intercostal space?
VAN (vein, artery, nerve)
Where do the main vessels & nerve branches run in the intercostal space?
Costal groove (inferior rib)
Where do collateral branches of VAN run in the intercostal space?
Superior to the next rib.
What are the 3 parts of the sternum?
Manubrium
Body
Xiphoid process
What is the sternal angle?
The horizontal junction between manubrium and body. It is at the level of the 2nd rib (use to help count ribs)
What is the “pyramidal” space at the junction of the arm and thorax?
Axilla (armpit)
What is the apex, medial wall, lateral wall, and base of the axilla?
Apex: clavicle, scapula, 1st rib
Medial: Thoracic cage + serratus anterior
Lateral: humerus and muscles
Base: skin and fascia
What is within the neurovascular bundle of the axilla?
Axillary Artery
Axillary Vein
Brachial Plexus
Subclavian artery –> (1) —> Brachial artery
1: Axillary artery
When does the subclavian artery become the axillary artery?
Lateral 1st rib
When does the axillary artery become the brachial artery?
Inferior teres major
What muscle divides the axillary artery into 3 parts?
Pectoralis major
What is the first branch of the axillary artery?
Superior (supreme) thoracic artery
What is the second branch of the axillary artery?
Thoracoacromial Artery
Lateral Thoracic artery
What is the third branch of the axillary artery?
Subscapular A
Anterior Humeral Circumflex A
Posterior Humeral Circumflex A
What does subscapular A branch into?
Circumflex Scaupular A
Thoracodosral A
What does the subscapular A. anastomose with?
Suprascapular and dorsal scapular A.
What is the path of axillary lymph nodes? [5]
- Subscapular
- Pectoral
- Lateral
- Central
- Apical
What are the roots of the brachial plexus?
C5-T1
The brachial plexus divides into ________ & __________ divisions.
Anterior & Posterior
The anterior and posterior divisions of the brachial plexus are both from __________ rami.
Anterior
What is the composition or “breakdown” of the brachial plexus?
Roots (rami) - 5
Trunks - 3
Divisions - 2
Cords - 3
Branches (terminal)
“Randy Travis Drinks Cold Beer”
Where are the brachial plexus roots found?
Between anterior and middle scalenes
What nerves come of the roots of the brachial plexus ?
Long thoracic and dorsal scapular nerves
What are the trunks of the brachial plexus?
Superior, Middle, and Inferior
What roots make up the superior trunk of the brachial plexus?
C5 & C6
What roots make up the middle trunk of the brachial plexus?
C7
What roots make up the inferior trunk of the brachial plexus?
C8-T1
What nerve comes off the trunks of brachial plexus?
Suprascapular n.
What are the divisions of the brachial plexus?
Anterior and Posterior
What is the lateral cord of the brachial plexus?
Anterior divisions of superior and middle trunks
What is the medial cord of the brachial plexus?
The anterior division of the inferior trunk
What is the posterior cord of the brachial plexus?
ALL posterior divisions.
What branches come off the lateral cord of the brachial plexus?
Lateral pectoral n.
What branches come off the posterior cord of the brachial plexus?
Upper subscapular
Thoracodorsal (middle subscapular)
Lower subscapular
What branches come off the medial cord of the brachial plexus?
Medial pectoral n.
Medial cutaneous n. of arm
Medial cutaneous n. of forearm
What are the terminal branches of the brachial plexus?
Axillary N
Musculocutaneous N
Radial N
Median N
Ulnar N
What does the axillary nerve innervate?
Deltoid
Teres Minor
Skin on upper lateral arm
What does the median nerve innervate?
Most anterior forearm (flexor) muscles
Skin and a few muscles of the hand
What does the musculocutaneous nerve innervate?
Anterior arm (flexor) muscles
Skin on lateral forearm
What does the radial nerve innervate?
Posterior arm muscles
Posterior forearm muscles
Skin on lateral arm
Skin on posterior arm
Skin on posteriore forearm
Skin on part of hand
What does the ulnar nerve innervate?
Most hand muscles
1 & 1/2 muscles in forarm
Skin on part of hand
