Shoulder And Arm - Bones And Muscles Flashcards
Which end of the clavicle is medial? Which end is lateral? What is one main tubercle that can be identified?
Medial: Sternal end
Lateral: Acromial end
Conoid tubercle
What are the bones of the shoulder and arm?
- Scapula
- Sternum: Manubrium, Body, Xiphoid
- Clavicle
- Humerus
Describe a fracture of the clavicle
Common during weight bearing activities
Usually occurs between lateral 1/3 and medial 2/3
As a result of fracture, the medial 2/3 is pulled upwards while the lateral 1/3 is pulled downwards
What are the three borders of the scapula? What are the three angles of the scapula?
Superior, medial and lateral borders
Superior, inferior and lateral angles
What are the main structures on the anterior side of the scapula?
- Coracoid process
- Glenoid cavity
- Subscapular fossa
What are the main structures on the posterior surface of the scapula?
- Acromion
- Supraspinous fossa
- Spine
- Infraspinous fossa
What are the main structures on the humerus?
Head, anatomical neck, surgical neck, greater/lesser tubercle, intertubercular groove, deltoid tuberosity, coronoid fossa, radial fossa, lateral/medial epicondyle, trochlea, capitulum, olecranon fossa, nutrient foramen
Where do fractures commonly occur on the humerus and which structures are endangered?
- Surgical neck: Axillary nerve, Circumflex artery
- Midshaft: Radial nerve, profunda brachii
- Supracondylar: Median nerve, brachial artery
- Medial epicondyle (evulsion fractures): Ulnar nerve endangered
What are the fascial compartments of the arm?
- Deep cervical
- Clavipectoral
- Pectoral
- Axillary
What are the upper limb muscles that originate from the spine? What actions do they carry out? What nerves supply them?
Superficial:
- Trapezius
- Latissimus dorsi
Deeper:
- Levator scapulae
- Rhomboid major
- Rhomboid minor
What is the triangle of auscultation? What are its borders?
It is the space where the stethoscope can be placed to listen to lung action.
It is bordered by:
What are the four pectoral muscles? What are their actions? What nerves supply them?
- Pectoralis major
- Pectoralis minor
- Subclavius
- Serratus anterior
What happens during paralysis of serratus anterior?
Winging of the scapula.
What are the intrinsic shoulder muscles?
- Deltoid
- Teres Major
- Teres minor
- Supraspinatus
- Infraspinatus
- Subscapularis
Describe the deltoid muscle.
- Originates on clavicle and spine of scapula
- Inserts onto the deltoid tuberosity of the humerus
- Abduction at the shoulder
- It is a shunt muscle - tendency of inferior displacement of the head of humerus and deltoid pulls it back into place
- Oriented horizontally
- Assisted by supraspinatus, which pulls HOH into glenoid socket
- It is a site for intramuscular injection
- Axillary nerve is deep to it - if injection too deep, it can pierce the nerve or it can be damaged due to fracture of the humerus.
Describe Teres major.
*
What are the rotator cuff muscles?
- Stabilise shoulder by forming a tight cuff around the GH joint
- Act as dynamic ligaments
- Fixator muscles
- Subscapularis, Supraspinatus, Infraspinatus, Teres minor.
Describe some rotator cuff injuries.
- Impingement of supraspinatus
- Frozen shoulder - “adhesive capsulitis”
- Inflammation of bursal space (bursitis) passes into shoulder cavity.
What are the muscles of the anterior compartment of the arm?
- Biceps brachii: Flexion from elbow. Biceps acts on supinator
- Chorachobrachialis - Inserts into shaft of humerus.
- Brachialis - Starts mid-shaft of humerus. Inserts onto ulna
All supplied by musculocutaneous nerve - passes between 2 heads of coracobrachialis.
What are some forms of biceps injury?
- Tendinitis
- Dislocation
- Rupture of long head “Popeye syndrome”
What muscles are in the posterior compartment of the arm?
- Triceps brachii: 3 heads - 2 at shaft, 1 at scapula. Long head goes to olecranon
- Anconeus - stops pinching during complete extension
Both supplied by radial nerve - passes through medial and lateral heads of TB
- Susceptible to injury in mid-shaft fractures of humerus.
What are the four posterior apertures and what structures are transmitted through them?
- Subscapular notch
- Quadrangular space
- Triangular space
- Triangular interval
