2.2.5. Anterior Shoulder Flashcards
What are four functions of the thoracic wall(cage)
Protect vital organs Resist negative internal pressure generated by elastic recoil of the lungs Provide attachment for upper limbs Provide anchoring attachment of many muscles that move and maintain limbs
What are the landmarks of the sternum
Jugular notch
Angle of Louis(aka sternal angle
Gladiolus
Manubrium
xiphoid process
What anatomical levels does the sternal angle mark?
The second pair of coastal cartilages.
What is the infrasternal angle?
The angle formed by the cartilage of the false ribs and the inferior angle of the xiphoid process
What is the difference between the true and false ribs
What ribs have a coastal groove? What is the function of the coastal groove?
Which rib has the scalene turbucle?
Rib 1. The scalene turbucle is the attachment point for the anterior scaleneus muscule.
What is poland syndrome
Unilateral absence of both pectorali muscles, often associated with other ipsilateral limb deformities.
What is pectus excavatum
condition of a caved in chest due to rib overgrowth. contrast with pectus carinatum undergrowth of the ribs causing the chest to bow outward.
Pec major Origin, Insertion, Innervation, Blood supply, Main action (OIIBM)
Origin: Sternal half of clavicle, sternum to 7th rib, aponeurosis of EO
Insertion: lateral lip of intertubercular sulcus of humerus
Innervation: Medial and lateral pectoral nerves
Blood supply: pectoral branche of thoraco-acromial artery
Main action: flexes and adducts arm, rotates medially
Pec Minor O.I.I.B.M.
Origin: Upper margin of rib 3-5
Insertion: coracoid process of scapula
Innervation: Medial pectoral nerves
Blood supply: pectoral branche of thoraco-acromial artery
Main action: lowers the lateral angle of scapula, protracts scapula
Serratus A. OIIBM
Origin: lateral surface of 8-9 ribs
Insertion: coastal surface, medial border of scapula
Innervation: Long thoracic
Blood supply: Lateral thoracic a.
Main action: protracts scapula/holds it against thoracic wall
- Medial pectoral nerve***
- Lateral pectoral nerve
- Pec. minor
** Medial pectoral nerve is LATERAL to the lateral pectoral nerve. easy to distinguish because the medial nerve goes through pec minor and also innervates pec major, where the lateral pec nerve BYPASSES mec pinor.
What is winged scapula? Which NERVE injury causes this problem and what disability does the patient have? Why is the long thoracic nerve exceptional?
- Paralysis of Serratus anterior by injuring the long thoracic nerve is one cause of a winged scapula.
- The upper limb may not be able to be abducted above horizontal position because the serratus anterior is unable to rotate the glenoid cavity superiorly to allow complete ABduction of the limb.
- long thoracic nerve is exceptional in that it is superficial to the serratus anterior
