Brachium Flashcards
shoulder movements
forward flexion (sagittal plane)
extension (post sagittal plane)
abduction (coronal plane or scapular plane)
adduction
horizontla abduction (horizontal plane starting at 90* flexion)
horizontal adduction
int & ext rotation (medial and lateral rotation)
each of four articulation adds to shoulder motion: glenohumeral, screamioclavicular, sternoclavicular, and scapulothoracic
pectoralis major attachments
clavicular head: from the anterior surface of medial half of the clavicle
sternocostal head: anterior surface of sternum and first 6 costal cartilage and from aponeurosis of external oblique
distal attachment: lateral lip of intertubercular groove of humerus
pectorals major action
clavicular head: flex and adduct humerus across middle
sternal head: adduct and internal rotate humerus if arm is in a flexed and abducted position
reverse action: elevates thorax, accessory muscle in respiration
pectorals major innervation
medial pectoral n.: C8, T1
lateral pectoral n: C5,6,7
aponeurosis
collagen fibers organized in a certain direction
distal attachment of pectorals major
lateral lip intertubercular groove of humerus
pectoralis minor location
from anterior surface exterior surface of ribs 3-5
pectoralis minor attachment
distal attachment to upper surface of coracoid process
pectoralis minor actions
stabilizes scapula by drawing it inferiorly and anteriorly against the thoracic wall, depresses the tip of the shoulder
pectoralis minor innervations
medial pectoralis n.: C8, T1
and lateral pectoralis n.: C5,6,7
subclavius muscle location
from junction of 1st rib and its costal cartilage to inferior surface of middle 1/3 of clavicle
subclavius action
depresses and anchors the clavicle
subclavius innervation
nerve to subclavius (C5,6)
axillary artery location
continuation of subclavian artery (changes at lateral border of 1st rib)
axillary artery portions
1st portion: supreme thoracic artery
-tucked really high up between rib 1 and 2
2nd portion : two branches
- thoracoacromial trunk (4 branches: acromial, clavicular, pectoral, deltoid artery)
- lateral thoracic artery (feeds pectoral muscles)
3rd portion: three branches
- subscapular artery (circumflex scapular and thoracodorsal artery)
- anterior humeral circumflex artery
- posterior humeral circumflex artery
brachial artery location
begins at inferior border of teres major (continuation of axillary artery)
branches of brachial artery
- profunda brachii artery
- travels with radial nerve in radial groove and divides into:
- –radial collateral artery (anastomosis with radial recurrent artery) and
- –middle collateral artery (anastomosis with posterior interosseous recurrent artery) - superior ulnar collateral artery (anastomosis with posterior ulnar recurrent artery)
- inferior ulnar collateral artery (anastomosis with anterior ulnar recurrent artery)
humerus positioning
articulates with glenoid cavity superiorly and radius/ulna inferiorly
head faces medial, slightly posterior, and superiorly at 135*
greater tubercle-laterally
lesser tubercle- anteriorly
intertubercular groove houses biceps brachia tendon
scapula location
connects to sternum via the clavicle
articulates with head of humerus at gleaned fossa
anatomically located between ribs 2 and 7
scapula parts
body
spine: posterior and ends at accordion process laterally
coracoid process: anterior, is a muscles attachment
glenoid cavity: faces slightly anterior and lateral
2 surfaces: costal (ribs side) and dorsal
scapular borders
superior
medial
lateral
scapula angles
superior
inferior
lateral
dorsal surface of scapula
suprasinous fossa (located on costal surface)
infraspinous fossa
spinoglenoid notch
spine and root of the spine
facet
small smooth area of bone usually for articulation
sternum
comprised of manubrium, body, and xiphoid process
manubrium of sternum
jugular notch at TV3
clavicular notch
articulates with 1st and 2nd costal cartilage and clavicle
sternal angle
located at TV4-5
junction of manubrium with body
body of sternum articulations
ribs 2-7
brachial plexus
found in neck and axilla, deep to pectorals major and minor
descends posterior to concavity of medial 2/3 of clavicle
junior of ventral rami C5,6,7,8, T1
accompanies axillary artery and vein
upper trunk
ventral rami C5,6
middle trunk
ventral ramus C7
lower trunk
ventral rami C8 and T1
trunks divide into
anterior and posterior divisions (found deep to clavicle)
cords are named
based on location in relation to axillary artery
lateral cord
anterior divisions of upper and middle trunk
posterior cords
posterior divisions of upper, middle, and lower trunks
medial cord
anterior division of lower trunk
dorsal scapular nerve
(C4) C5 ventral ramus
innervated rhomboid major and minor (retractors of scapula)
long thoracic nerve
C5,6,7 ventral rami
innervates serratus anterior (protractor and upward rotator of scapula)
nerve branches off upper trunk
suprascapular nerve (C5,6) innervates supraspinatur and infraspinatus, AC and GH joints nerve to subclavius (C5,6) innervates subclavius muscle
lateral cord branches
lateral pectoral n. (C5,6,7)
musculocutaneous n. (C5,6)
(lat. contribution to) axillary n. (C5,6,7)
medial cord branches
medial pectoral n. (C8,T1) medial brachial cutaneous n. (C8,T1) medial antebrachial cutaneous n. (C8,T1) ulnar n. (C7,8,T1) (med. contribution to) median n. (C8,T1)
posterior cord branches
upper subscapular n. (C5,6) thoracodorsal n. (C6,7,8) lower subscapular n. (C5,6) axillary n. (C5,6) radial n. (C5,6,7,8,T1)
