Shoulder & Pectoral Region Flashcards
What are the three kinds of fascia?
- Pectoral Fascia
- Axillary Fascia
- Clavipectoral Fascia
Pectoral Fascia
SUPERIORLY attaches to clavicle and sternum
- continuous inferiorly with the fascia of the anterior abdominal wall
- covers pectoralis major m.
- deep to platisma m.
Clavipectoral fascia
- deep to pectoralis major
- descends from clavicle
- encloses subclavius m. and pectoralis minor m.
- inferior to pectoralis minor becomes suspensory ligament of the axilla
- pulls the skin of the axilla superiorly with shoulder abduction
axillary fascia
- continuation of pectoral fascia laterally
- forms the floor of the axilla
- very fatty and filled with lymph nodes and veins
- need fat to protect the nerves and arteries that pass through there to upper extremity
- in the deep armpit region
what does the pectoral fascia cover?
pectoralis major
what does clavipectoral fascia enclose?
- subclavius m.
- pectoralis minor m.
the axillary fascia is continuous of pectoral fascia in which direction?
laterally
what is located on C4/C5?
clavicle
What is located on T4?
nipples
what is located on T10?
umbilicus
-belly button
pectoralis major
large, fan-shaped muscle covering most of anterior thoracic wall
- pulling on humerus gives medial rotation
- allows for adduction and flexion
innervated by: medial and lateral pectoral nerve
pectoralis minor
origin: 3rd to 5th ribs
insertion: caracoid process of the scapula
-landmark for axillary structures (axillary a.)
- function: pulls the scapula medially, forward, and downward
- aids in respiration
innervated by: medial pectoral nerve
serratus anterior
“boxers/swimmers” muscles
- sawtoothed muscle helps stabilize scapula
- lateral surfaces of upper 8-9 ribs
- hugs the rib cage and goes around to posterior border and inserts at medial border of scapula from underneath side
what is the serratus anterior innervated by?
long thoracic nerve
what happens if the long thoracic nerve is injured or torn?
winging of scapula
what are the functions of the serratus anterior?
when contracts it will pull the scapula forward
- helps keep medial border of scapula down and attached to chest
what is the serratus anterior attached to?
the ribs
what is the deltoid attached to?
humerus
what is the trapezius insertion?
- lateral 1/3 of clavicle
- medial side of acromion
- upper crest and tubercle of scapular spine
supraspinatus initiates abduction up to how many degrees?
0-15 degrees
what degrees can the deltoid abduct?
15-90 degrees
what muscle completes the abduction of the humerus? how many degrees?
trapezius
180 degrees
where is the axillary nerve located?
brachial plexus
what muscles allow for the greater movement of the shoulder?
rotator cuff muscles
what 4 muscles make up the rotator cuffs?
[S i t S]
supraspinatus
infraspinatus
teres minor
subscapularis
what muscle is most frequently torn in rotator cuff injuries?
supraspinatus
T or F. Supraspinatus rotates the humerus
FALSE.
it does not rotate humerus
-it INITIATES abduction of the arm
if you remove the deltoid what muscles will be seen?
rotator cuff muscles
what is the roll of the rotator cuff muscles?
hold humerus into joint
-give great flexibility
-easier to dislocate & injure
teres major
adducts and medially rotates arm
-similiar function to latissimus dorsi (smaller)
latissimus dorsi
extends, adducts, and medially rotates humerus at shoulder
levator scapulae
elevates scapula medially, inferiorly rotates glenoid cavity
rhomboids
fix scapula to thoracic wall; retract and rotate scapula to depress glenoid cavity
-drop shoulder
how many parts is the subclavian artery broken down into?
3
1st part of subclavian artery
VIT
Vertebral artery
Internal thoracic artery
Thyrocervical trunk
-inferior thyroid A.
-transverse cervical A.
-suprascapular A.
2nd part of subclavian artery
costocervical trunk
3rd part of subclavian artery
dorsal scapular artery
what muscle lays on top of subclavian artery?
anterior scalene muscle
branches of the axillary a. are related to what muscle?
pectoralis minor
1st part of axillary artery
Superior thoracic artery
2nd part of axillary artery
thoracoacromial artery
lateral thoracic artery
where does the lateral thoracic artery run to?
runs down to lateral portion of chest to supply blood to breast
3rd part of axillary artery
- subscapular (cicumflex scapular & thoracodorsal)
- anterior cicumflex humeral a.
- posterior circumflex humeral a.
why is there a suprascapular notch?
ligament converts notch to a “foramen” because will have a superior transverse scapular ligament
-above the spine of the scapula
what are the boundaries of the triangular space?
- (s) teres minor
- (i) teres major
- (L) long head of triceps
what passes through the triangular space?
circumflex scapular artery
what are the boundaries of the quadrangular space?
- (s) teres minor
- (i) teres major
- (m) long head of triceps
- (L) humerus
what passes through the quadrangular space?
axillary nerve
posterior humeral circumflex artery (wraps around humerus)
what are the boundaries of the triangular interval?
- (s) teres major
- (m) long head of triceps
- (L) lateral head of triceps
what passes through the triangular interval?
radial nerve
profunda brachii artery
where does the posterior circumflex humeral artery go to?
deltoid muscle
axilla
pyramid-shaped space
- inferior to glenohumeral joint
- superior to axillary fascia
-serves as a protected passageway for the neurovascular structures from the neck to the upper limb
axillary A.
brachial plexus
axillary V.
why do you want to keep the axilla space open & protected?
to prevent pinched nerves
what % is tubuloalveorlar glands in the breast?
95%
how many lactiferous ducts per lobe and sinus?
1
what % of tumors originate in the duct?
80%
suspensory ligaments (of Cooper)
attach lobes to skin & divide glandular tissue into lobes
where are the lactiferous ducts located?
at surface of nipple
what are the lymph nodes of the breast?
[C.L.A.S.P]
Central nodes Humeral (lateral) nodes Apical nodes (below clavicle) Subscapular (posterior) nodes Pectoral (anterior) nodes
what artery mainly supplies the breast? what cavity does it come from?
lateral thoracic artery
-axillary artery
internal thoracic artery (internal mammary)
-subclavian artery
- runs internal portion of chest
- perforating branches that will go through ribs & supply to breast
about what % of breast tissue drains medially?
20%
where does most of the breast tissue drain to?
laterally
what vein is located underneath the clavicle by the apical nodes?
subclavian vein
