The humerus Flashcards
What is the humerus?
Where does it articulate?
Long bone of the upper limb. It extends from the shoulder to the elbow.
The proximal aspect of the humerus articulates with the glenoid of the scapula,forming the glenohumeral joint.
Distally at the elbow the humerus articulates with the head of the radius and the trochlear notch of the ulnar
What anatomical landmarks occur at the proximal end of the humerus
Head, anatomical neck, surgical neck, greater and lesser tubercle, intertubercular sulcus
Where does the greater tuberosity lie?
What attaches to it?
Laterally on the humerus
supraspinatus, infraspinatus, teres major (rotator cuff muscles)
Where is the lesser tuberosity
What attaches to it?
Much smaller, medially located structure
Subscapularis
Where does the long head of the biceps brachii sit on the humerus
In the intertubercular sulcus
Where does the anatomical neck of the humerus lie?
Where does the surgical neck of the humerus lie?
Under the head of the humerus, above the tuberosities.
Below the head and the tuberosities,
Why is the surgical neck relevant?
If you fall on an outstretched hand/get a direct blow it can fracture and cause damage to axillary nerve causing deltoid and teres minor palsy as weoll as badge patch palsy
Where do the deltoid muscles attach to the humerus
On the shaft,on the lateral side on an area known as the deltoid tuberosity.
What sits in the radial or spiral groove?
The radial nerve and profunda brachii
What muscles attach to the anterior aspect of the humeral shaft?
corachobrachialis, deltoid, brachialis, brachioradialis
What muscles attach to the posterior aspect of the humeral shaft?
Medial and lateral heads of the triceps
What occurs during a mid shaft humeral fracture
Risks damage to the radial nerve and profunda brachi artery
The radial nerve innervates the extensors of the wrist leading to wrist drop
Where does the ulnar bone attach?
Where does the radius attatch?
The trochlea
The capitulum
What three depressions accommodate the forarm bones during flexion and extension?
Coronoid- posterior medial
radial-posterior lateral
olecranon- anterior
What occurs during a supracondylar fracture?
Fracture of the distal humerus above elbow joint, cna lead to damage of brachial causing volkamns contractures
Can also damage the anterior iterossus nerves. Weakness can be tested by getting patient to make an okay sign.
