Axilla Flashcards
Osteology of pectoral region
Acromioclavicular joint:
Joint type: ?
What does it connect:
Plane-type synovial joint connects clavicle + scapula
Sternoclavicular joint:
Joint type: ?
What does it connect:
Saddle-type synovial joint functions as a
ball & socket (scapula movement); connects clavicle + thorax
Identify this muscle
Pectoralis Major
Pectoralis Major
Origin:
Insertion:
Action:
Innervation
Origin: medial surface of clavicle + sternum + ribs
Insertion: lateral lip on intertubercular sulcus
Innervation: lateral (C5-C7) + medial pectoral nerve (C8-T1)
Action: adduction, medial rotation of humerus, flexes humerus, extension from a flexed position
Identify this muscle:
Pectoralis Minor
Pectoralis Minor
Origin:
Insertion:
Action:
Innervation
Origin: ribs 3-5
Insertion: coracoid process
Innervation: medial pectoral nerve (C8-T1)
Action: stabilizes scapula by drawing it inferiorly and against thoracic wall
Identify this muscle
subclavius
Subclavius
Origin:
Insertion:
Action:
Innervation
Origin: junction of the 1st rib and the costal cartilage
Insertion: inferior, middle clavicle
Innervation: Nerve to subclavius (C5-C6)
Action: anchors and depresses the clavicle
Identify this muscle
Serratus anterior
Boundaries of the Axilla:
Base
Skin, subq tissue, axillary fascia
Boundaries of the Axilla:
Apex
Space between 1st rib + clavicle; cervico-axillary canal
Boundaries of the Axilla:
Anterior
Pectoralis major, pectoralis minor, pectoral and clavipectoral fascia
Boundaries of the Axilla: Posterior
Superiorly via the scapula and subscapularis
Inferiorly via teres major and latissimus dorsi
Boundaries of the Axilla: Lateral
Intertubercular groove of the humerus
Boundaries of the Axilla: Medial
Thoracic wall + serratus anterior
What is located within the axillary sheath?
axillary arteries & branches, axillary vein and tributaries; brachial plexus
What is located OUTSIDE of the axillary sheath
axillary lymph nodes, lymphatic vessels, axillary fat
Fascia of the Pectoral Region: Deltoid Fascia
Descends from clavicle, acromion, and scapular spine; Continuous w. the pectoral fascia anteriorly, infraspinous fascia inferiorly.
Fascia of the Pectoral Region: Axillary Fascia
Continuation of the pectoral fascia; Forms floor of the axilla.
Fascia of the Pectoral Region: Pectoral Fascia
Descends from the clavicle + sternum, investing the pectoralis major. Becomes the axillary fascia laterally
Fascia of the Pectoral Region: Claviopectoral Fascia
Descends from clavicle, encloses the subclavius and pectoralis minor; continuous w. axillary fascia.
Cephalic vein location:
subq vein of the (lateral/medial) aspect of the upper limb; Travels thru the deltopectoral groove & feeds INTO the _____ vein
Superficial, subq vein of the lateral aspect of the upper limb; Travels thru the deltopectoral groove & feeds into the axillary vein
Axillary Vein: formed by the ____ and ____ veins and becomes the _____ vein at the lateral border of the ____ rib.
formed by the brachial and basilic veins and becomes the subclavian vein at the lateral border of the 1st rib
Basilic Vein Location: travels along the _____ aspect of the arm
travels along the medial aspect of the arm
1st part of the axillary artery (Hint: located between the first rib and medial border of pectorals minor
- Superior thoracic artery
2nd part of the axillary artery (Hint: lies posterior to pectoralis minor)
- Thoracoacromial artery: Clavicular, Acromial, Deltoid, Pectoral
- Lateral Thoracic Artery
3rd part of the axillary artery (Hint: from the lateral border of pectorals minor to inferior border of teres major)
- Subscalpular –> Circumflex scapular artery + Thoracodorsal artery
- Anterior circumflex humeral artery
- Posterior circumflex humeral artery
Axillary artery becomes the brachial artery.. when?
after the inferior border of teres major
Subclavian artery branches (Hint: VIT C & D)
- Vertebral Artery
- Internal Thoracic Artery
- Thyrocervical Trunk –> transverse cervical artery + supra scapular
- Costocervical Artery
- Dorsal Scapular Artery
Serratus anterior
Origin:
Insertion:
Innervation:
Action:
Origin: lateral parts of the 1st - 8th ribs
Insertion: anterior surface of the medial border of scapula
Innervation Long thoracic nerve (C5-C7)
Action: protraction and superior rotation of scapula
Cause of clavicle fracture:
direct fall on the shoulder; indirect due to the transmission of force from arm and forearm to shoulder during a fall on an outstretched hand
Presentation of clavicle of fracture:
Medial fragment is elevated d/t SCM;
Lateral fragment is depressed d/t weight of arm and adducted and pulled medially d/t pectoralis major.
