elbow Flashcards
what type of joint is the elbow? what movement is allowed?
- hinge joint
- allows movement in sagittal plane
what are the three main bones of the elbow?
- humerus
- ulna
- radius
what is the humerus?
- bone of the upper arm that goes from the scapula to the elbow joint where it meets the ulna and radius
where are the radius and ulna in an anatomical position?
- radius is more lateral (thumb)
- ulna is more medial (pinky)
what does radius articulate with?
- tubercles of humerus
what articulates with the facet of radial head?
- capitulum
what is next to the capitulum? what does it articulate with?
- next to this is the trochlea of the humerus
- articulates with ulna
what does the humerus contain at the end?
- two epicondyles
- lateral and medial
- medial more prominent
what is the olecranon?
- prominence of the ulna that wraps around two tubercles of humerus
what does olecranon act as?
- attachment site for triceps
what is the radial fossa?
- small, shallowed depression on humerus
- gives space to head of radius to fit when elbow bends
what is the olecranon fossa?
- depression that provides space for ulna to fit in during extension
what is the coronoid fossa?
- depression that fits with coronoid process of ulna during full flexion of elbow
what is the coronoid process?
- triangular shaped bony prominence that extends from proximal end of ulna
what is the radial notch?
- surface that provides attachment for ligaments
- articular surface for the head of the radius
what is the main joint of the elbow?
- radioulnar joint
- articulation between ulna and radius at proximal end
what works together in the elbow and why?
- proximal and distal joints work together to produce pronation and supination
what does radius and ulna form?
- fibrous joint
- limited movement
what is the interosseous membrane?
- long sheet of ligaments that connects ulna & radius to provide stability and flexibility for supination/ pronation
what is the oblique cord?
- angle between ulna and radius
- holds them together during movement
what further prevents bones moving across each other?
- joint capsule
what do ligaments of the elbow do?
- holds the radius and ulna together
what are the five main elbow ligaments?
- annular
- quadrate
- medial collateral
- lateral collateral
- dorsal radioulnar
why is the annular ligament unique?
- starts and ends on the ulna as it wraps around the radius so it’s in place against ulna
what is annular ligament sometimes included in?
- lateral collateral ligaments
what does annular ligament provide?
- stability during spinning movements
what is the quadrate ligament?
- directly connects the radius to the ulna in a straight line
what is the role of the quadrate ligament?
- holds bones together to aid stability and flexibility during movement
what is the medial collateral ligament?
- complex of ligaments
- inside elbow
where does the medial ulnar collateral ligament originate and insert?
- originates at the medial epicondyle
- inserts onto ulnar
what are the three parts of the medial collateral ligament?
- posterior bundle
- transverse ligament
- anterior bundle
how is the posterior bundle shaped and why?
- fan shaped so starts narrow then fans out into ulna
what does the transverse ligament do?
- cuts across elbow joint
what does the anterior bundle connect?
- band that connects humerus to ulna
what is the lateral collateral ligament? where does it originate and insert?
- on the thumb side (radius)
- originates on lateral epicondyle
- inserts onto head of radius
what does the lateral radial collateral ligament provide?
- provides stability for radial movements
what are the two ligaments of the lateral collateral ligament?
- ulnar lateral collateral ligament
- radial lateral collateral ligament
what does the ulnar lateral collateral ligament connect?
- connects humerus to ulna
where does the radial lateral collateral ligament go? and why?
- goes underneath the annular ligament then connects to radius
- to hold radius in place relative to humerus
what does dorsal radioulnar ligament provide?
- stability
what are antagonistic pairs? - give an example in the elbow joint
- cause opposite movements
- biceps causes flexion while triceps causes extension
what are the three elbow flexor muscles?
- biceps brachii
- brachialis
- brachioradialis
where does biceps brachii originate and insert?
- short head originates at tip of coracoid process
- long head originates at supraglenoid tubercle of scapula
- inserts onto radial tuberosity and forearm fascia
where does brachialis originate and insert?
- originates at distal half of anterior surface of humerus
- inserts into coronoid process and tuberosity of ulna
where does brachioradialis originate and insert?
- originates at lateral ridge of distal humerus
- inserts on lateral surface of distal radius
what are the two elbow extensors?
- triceps brachii
- anconeus
where does triceps brachii originate and insert?
- long head= infraglenoid tubercle
- lateral head= humerus above radial groove
- medial head= humerus below radial groove
- inserts into ulna olecranon
where does anconeus originate and insert?
- originates at lateral epicondyle
- inserts onto lateral side of olecranon process
