14 Questions
From where does the long head of the triceps brachii muscle arise?
The long head arises from the infraglenoid tubercle of the scapula.
What is the origin of the lateral head of the triceps brachii muscle?
The lateral head arises from an oblique ridge on the upper part of the posterior surface of the humerus, corresponding to the lateral lip of the radial (spiral) groove.
Where does the medial head of the triceps brachii muscle arise from?
The medial head arises from a large triangular area on the posterior surface of the humerus below the radial groove, as well as from the medial and lateral intermuscular septa.
What is the insertion point of the long and lateral heads of the triceps brachii muscle?
They are inserted into the posterior part of the superior surface of the olecranon process.
How is the medial head of the triceps brachii muscle inserted?
The medial head is inserted partly into the superficial tendon, and partly into the olecranon process.
Where do the thoracic branches of the axillary artery lie in contact with?
Pectoral muscles
What prevents nipping of the capsule during extension of the arm?
A few fibres of the medial head are inserted into the capsule of the elbow joint, preventing nipping of the capsule during arm extension.
What is the course of the circumflex scapular vessels?
They wind round the lateral border of the scapula
Where do the subscapular vessels run along?
Lower border of the subscapularis
What is the course of the axillary nerve and the posterior circumflex humeral vessels?
They pass backwards close to the surgical neck of the humerus
What structures run from the apex to the base along the lateral wall of the axilla?
Axillary artery and the brachial plexus of nerves
Where do the thoracic branches of the axillary artery lie in contact with?
Pectoral muscles
What is the course of the subscapular vessels?
Along the lower border of the subscapularis
Where do the circumflex scapular vessels wind round?
The lateral border of the scapula
Study Notes
Triceps Brachii Muscle
- The long head of the triceps brachii muscle arises from the infraglenoid tubercle of the scapula.
- The lateral head of the triceps brachii muscle originates from the posterior surface of the humerus, above the radial groove.
- The medial head of the triceps brachii muscle arises from the posterior surface of the humerus, below the radial groove.
- The long and lateral heads of the triceps brachii muscle insert into the olecranon of the ulna.
- The medial head of the triceps brachii muscle is inserted into the olecranon of the ulna, blending with the tendon of the lateral head.
Axillary Artery and Vessels
- The thoracic branches of the axillary artery lie in contact with the upper four ribs.
- The intermuscular septum prevents nipping of the capsule during extension of the arm.
- The circumflex scapular vessels course around the lateral border of the scapula.
- The subscapular vessels run along the subscapular fossa.
- The axillary nerve and the posterior circumflex humeral vessels course around the surgical neck of the humerus.
Axillary Structures
- The subscapular vessels and the axillary nerve run from the apex to the base along the lateral wall of the axilla.
- The circumflex scapular vessels wind round the lateral border of the scapula.
This quiz covers the origin of the triceps brachii muscle, including its three heads: long head, lateral head, and medial head. It involves identifying the specific points of origin for each head on the scapula and humerus.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
