MUSCLES-TRICEPS

SUMMARY

1. Long head - arises from the infraglenoid tubercle. 
2. Lateral head - arises from the back of the humerus, extending from the surgical neck to the deltoid insertion. 
3. Medial head - arises from the medial side of the radial groove & lower posterior surface of the humerus & bilateral intermuscular septae. 
4. Insertion - into the olecranon.
5. Nerve supply - radial nerve. Arterial supply - profunda brachii a. (branch of the brachial a.)
6. Action - extensor of the elbow, also assists in extending the shoulder joint. 
7. The radial n. & profunda brachii a.  pass b/w the lateral & medial heads of the triceps. 

Image: Gray, Henry. Anatomy of the Human Body. Philadelphia: Lea & Febiger, 1918; Bartleby.com, 2000. www.bartleby.com/107/ [Accessed 21 Apr. 2019].  

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone.
Gray, H., Carter, H.V. and Davidson, G. (2017). Gray’s anatomy. London: Arcturus.