008 Anatomy of the arm, elbow and cubital fossa Flashcards
describe the anatomical features on the posterior side of the humerus (proximal half)
- head (round at top)
- anatomical neck where head attaches to rest of humerus
- greater tubercle between anatomical neck and surgical neck
- surgical neck under greater tubercle
- triceps attachment beneath surgical neck
- radial groove for radial nerve and profunda brachii
- then deltoid tuberosity for deltoid attachment (lateral)
- then coracobrachialis attachment medial and halfway down humerus
describe the anatomical features of the anterior side of the humerus (proximal half)
- greater tubercle lateral
- lesser tubercle medial
- bicipital groove/intertubercular sulcus = between lesser and greater tubercle and is the attachment of the bicep tendon
- deltoid tuberosity is lateral halfway down
- attachment for coracobrachialis is medial half way down
describe the anatomical features of the anterior side of the distal part of the humerus
- lateral supraepicondylar ridge
- medial supraepicondylar ridge
- radial fossa = lateral, slot for radius when arm bent
- coronoid fossa = medial, slot for ulna when arm bent
- lateral epicondyle (more distal)
- medial epicondyle (more distal
- capitulum = articular surface for radius
- trochlea = articular surface for ulna
describe the anatomical features of the posterior side of the distal part of the humerus
- posterior part of the trochlea = attaches to ulna
- olecranon fossa ( for the olecranon of the ulna)
describe what happens if you fracture the humerus above the deltoid insertion
- rotator cuff muscles will pull upper part of arm inwards and deltoid pulls lower part of arm downwards
describe what happens if you fracture the humerus below the deltoid insertion
- more common
- deltoid pulls upper part of arm outwards
describe the anatomical features of the anterior proximal half view of the radius
- radius = lateral = side of thumb
- head of radius = attaches to capitulum of humerus
- neck of radius, beneath head
- radial tuberosity (medial), where the bicep brachii muscle inserts
- oblique line below radial tuberosity
describe the anatomical features of the proximal half of the ulna
- ulna = medial = pinky
- olecranon = posterior/back of ulna head, behind trochlea notch, where tricep brachii muscle attaches
- olecranon = tip of elbow
- trochlea notch = where ulna meets the humerus
- coronoid process, bony part sticking out beneath trochlea notch
- radial notch, lateral = where radius slots into ulna
- ulnar tuberosity = bump below coronoid process = attachment for brachialis muscle
what are the 4 movements at the elbow?
- flexion, extension
- pronation, supination
what is the bony part of the elbow called?
- olecranon
what attaches to the radial tuberosity of the radius?
bicep brachii
what attaches to the ulnar tuberosity on the ulna?
brachialis muscle
describe the membranes/fat areas on the elbow joint
- 2 fat pads on top of the radius and ulna fossa in the humerus
- synovial membrane on top of the bones in the elbow joint, strong and fibrous, strengthening the joint
- sacciform recess = excess of synovial membrane/ capsule around elbow, below annular ligament
what is the sacciform recess?
- excess synovial membrane/capsule below the annular ligament
what are the 3 ligaments on the elbow joint?
- radial collateral ligament
- ulnar collateral ligament
- annular ligament
what is the origin and insertion of radial collateral ligament?
- from lateral epicondyle to annular ligament of radius
what is the origin and insertion of ulnar collateral ligament?
- from medial epicondyle to coronoid process and olecranon
what is the location and function of the annular ligament?
- loops around the head of the radius
- allows radius to pivot and rotate against ulna without unarticulating
in this image what is the yellow, blue and red bone?
yellow = humerus
red = radius
blue = ulna
what do the 2 arrows point to in this image?
- capitulum (left)
- trochlea (right)
what is the clinical significance of the annular ligament in children?
- ‘pulled elbow/nursemaid’s elbow
- in children the annular ligament is not funnel-shaped, it has straight verticle sides, so it doesn’t lock in the radius
- so if you pull a child arm upwards, the radius can pop out of the ligament and dislocate
what is a supracondylar fracture and what are the different types?
- fracture of the humerus just above the epicondyles
- type 1 = fracture but aligned still with the rest of humerus/elbow
- type 2 = fractured and misaligned but 1 end still connected
- type 3 = complete clean break, bones completely seperated
what is epicondylitis?
- repetitive strain on the elbow causing inflammation of the lateral epicondyle ( tennis elbow) or medial epicondyle (golfers elbow)
- strain from flexor and extensor muscles
what are the 3 muscles of the anterior arm?
- biceps
- coracobrachialis
- brachialis
what is the origin of the coracobrachialis muscle?
- corocoid process of the scapula
what is the insertion of the coracobrachialis muscle?
- medial aspect of the humerus
what is the innervation of the coracobrachialis muscle?
- musculocutaneous nerve (C5-7)
what is the action of the coracobrachialis muscle?
- flexes and adducts arm at shoulder
what is the origin of the biceps brachii muscle?g
- long head = supraglenoid tubercle of scapula
- short head = coracoid process of scapula
what is the insertion of the biceps brachii?
- radial tuberosity (both heads)
what is the innervation of the biceps brachii?
- musculocutaneous nerve (C5-7)
what is the action of the biceps brachii?
- flexion of arm and forearm, and powerful supination
what is the origin of the brachialis?
- anterior of humerus
what is the insertion of the brachialis?
- ulnar tuberosity and anterior surface of coronoid process of ulna
what is the innervation of the brachialis?
- musculocutaneous nerve (C5-6) and radial nerve (C7)
what is the action of the brachialis muscle?
powerful flexor of forearm
what is the origin of the long head of the tricep?
- infraglenoid tubercle of the scapula
what is the origin of the lateral head of the tricep?
- posterior surface of humerus, superior to radial groove
what is the origin of the medial head of tricep?
- inferior to the radial groove
what is the insertion of the tricep heads?
- all olecranon of ulna
what is the innervation of the triceps?
- radial nerve (C6,7,8)