Week 2 Flashcards
Which type of joint is the elbow?
Hinge synovial joint
3 elbow joints?
Humeroulnar joint
Humeroradial joint
Proximal radioulnar joint
Elbow movements?
Flexion and extension
Pronation and supination
How is the elbow stable?
Trochlea
Olecranon
Both snugly fit their bones
Where are radius and ulna anatomically, what parts of the elbow do they articulate with?
Radius: lateral, articulates with the capitulum
Ulna: medial, articulates with trochlea
Medial/lateral epicondyles function?
Muscle attachment
Which forearm bone is longer?
Ulna
Two proximal processes of ulna?
Olecranon: larger posterior elbow prominence
Coronoid: smaller, anterior
Notch at proximal ulna?
Trochlear notch: articulates with humerus
Distal parts of ulna?
Head: articulates with radius
Styloid process: wrist ligaments
Why is ulna not part of wrist joint?
Articular disc (fibrocartilaginous ligament) prevents articulation with carpal bones
Which side is the radius on?
Thumb
What is at proximal radius?
Head: articulates with capitulum of humerus and radial notch of ulna
Radial tuberosity: medial, biceps attach here
What is at distal radius? What does it articulate with?
Articulates with ulnar head and proximal carpal bones
Styloid process laterally
Ulnar notch medially
What is the humeroulnar joint? Where? Reinforced by? Movements? Which processes limit movement past 180 degrees?
Trochlea of humerus and trochlear notch of ulna
Medial
Reinforced by ulnar collateral ligament
Flexion/extension
Ulnar processes
What is the humeroradial joint? Where? Reinforced by?
Capitulum of humerus, radial head
Lateral
Reinforced by radial collateral ligament
Supination/pronation
Moves passively in flexion/extension
Difference between humeroradial and humeroulnar joint?
Humeroradial joint more circular so can rotate for pronation/supination
Where do biceps brachii heads attach?
Scapula
Long vs short head of biceps brachii?
Long: attaches to tubercle superior to glenoid cavity. Runs superior to humeral head through intertubercular groove, more lateral
Short: attaches to coracoid process of scapula, more medial
Where do biceps brachii muscle bellies lie over? What ligament holds the long head in place?
Coracobrachialis/brachialis
Transverse humeral ligament
Where do both biceps brachii heads converge to?
Coverge to single tendon
Insert on radial tuberosity of radius at medial aspect of radius
What does the biceps brachii give off? What does it allow?
Gives off bicipital aponeurosis: flat sheet of connective tissue
Attaches biceps indirectly to posterior border of ulna
Biceps brachii actions?
Flexion at shoulder and elbow
Supinates radioulnar joint (fixed elbow)
Short head flexes shoulder
Long head holds humerus against glenoid cavity (stabilising function)
Biceps innervation?
Musculocutaneous nerve