Last update:

Triceps Brachii Muscle: Lateral Head

image descriptionTriceps Brachii Muscle: Lateral Head

The lateral head of the Triceps brachii, one of three heads of the muscle, originates from the humerus, superior to the radial groove to insert on the olecranon process.

A posterior view of the upper arm and shoulder showing the bony elements and the associated muscles. The visible, labelled muscles are as follows: Trapezius, Deltoid, Teres Minor, Teres Major, Triceps Brachii: Long Head, Triceps Brachii: Lateral Head (highlighted in green), Latissimus Dorsi, Triceps Brachii: Medial Head.
A posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible, labelled muscles are as follows: Infraspinatus, Teres Minor, Teres Major, Triceps Brachii: Long Head, Triceps Brachii: Lateral Head (highlighted in green), Latissimus Dorsi, Triceps Brachii: Medial Head.
A posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible, labelled muscles are as follows: Teres Major, Triceps Brachii: Long Head, Triceps Brachii: Lateral Head (highlighted in green), Latissimus Dorsi, Triceps Brachii: Medial Head.
A posterior view of the upper arm and shoulder showing the lateral head of the triceps brachii muscie.
1
2
3
4

image descriptionTriceps Brachii Muscle Lateral Head Attachments: Origin and Insertion

Origin (proximal attachment)
a. Proximal portion of posterior humerus, superior to radial groove.

Insertion (distal attachment)
a. Posterior olecranon process of ulna.

A posterior view of the upper arm and shoulder showing the bony elements and the associated muscles. The visible, labelled muscles are as follows: Trapezius, Deltoid, Teres Minor, Teres Major, Triceps Brachii: Long Head, Triceps Brachii: Lateral Head (highlighted in green), Latissimus Dorsi, Triceps Brachii: Medial Head.
A posterior view of the upper arm and shoulder showing the lateral head of the triceps brachii muscie.
A posterior view of the upper arm and shoulder showing the bony elements and the attachment of the Triceps Brachii Lateral Head. Origin at the proximal portion of posterior humerus, superior to radial groove is marked by a red oval. The insertion at the posterior olecranon process of ulna is marked by a blue oval. Transparent Triceps Brachii Lateral Head connects the two attachment sites.
1
2
3

Actions of the Triceps Brachii Muscle Lateral Head:

a.  image descriptionExtends the forearm the at elbow.

Learn the muscles of the arm faster with this step-by-step muscles of the arm and shoulder study guide. 

Nerve to the Triceps Brachii muscle Lateral Head and its spinal segment:

a. Radial nerve (C7, C8).

An Overview of the Posterior Arm muscles

A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the associated soft structures. The visible structures are labelled 1-8 and the answers in the box below are concealed.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are labelled 1-8 The answers in the box below are as follows 1.Trapezius 2. Deltoid 3. Teres Minor 4. Teres Major 5. Triceps Brachii: Long Head 6. Triceps Brachii: Lateral Head 7. Latissimus Dorsi 8. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are labelled 1-9. The answers in the box below are as follows 1.Supraspinatus 2. Deltoid 3. Infraspinatus 4. Teres Minor 5.. Teres Major 6. Triceps Brachii: Long Head 7. Triceps Brachii: Lateral Head 8. Latissimus Dorsi 9. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-8. The answers in the box below are as follows 1. Supraspinatus 2. Infraspinatus 3. Teres Minor 4. Teres Major 5. Triceps Brachii: Long Head 6. Triceps Brachii: Lateral Head 7. Latissimus Dorsi 8. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-7. The answers in the box below are as follows: 1. Infraspinatus 2. Teres Minor 3. Teres Major 4. Triceps Brachii: Long Head 5. Triceps Brachii: Lateral Head 6. Latissimus Dorsi 7. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-7. The answers in the box below are as follows 1. Infraspinatus 2. Teres Minor 3. Teres Major 4. Triceps Brachii: Long Head 5. Triceps Brachii: Lateral Head 6. Latissimus Dorsi 7. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-6. The answers in the box below are as follows 1. Teres Minor 2. Teres Major 3. Triceps Brachii: Long Head 4. Triceps Brachii: Lateral Head 5. Latissimus Dorsi 6. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures of the forearm are numbered 1-5. The answers in the box below are as follows 1. Teres Major 2. Triceps Brachii: Long Head 3. Triceps Brachii: Lateral Head 4. Latissimus Dorsi 5. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-4. The answers in the box below are as follows 1. Triceps Brachii: Long Head 2. Triceps Brachii: Lateral Head 3. Latissimus Dorsi 4. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-3. The answers in the box below are as follows 1. Triceps Brachii: Long Head 2. Triceps Brachii: Lateral Head 3. Triceps Brachii: Medial Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the deeper muscles. The visible structures are numbered 1-2. The answers in the box below are as follows 1. Triceps Brachii: Long Head 2. Triceps Brachii: Lateral Head.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the isolated Triceps Brachii Lateral Head labelled 1.
A test yourself image of the posterior view of the upper arm and shoulder showing the bony elements and the attachment of the Triceps Brachii Lateral Head. Origin at the proximal portion of posterior humerus, superior to radial groove is marked by a red oval. The insertion at the posterior olecranon process of ulna is marked by a blue oval. Transparent Triceps Brachii Lateral Head connects the two attachment sites.
Test yourself while observing the Triceps Brachii muscle Lateral Head
1
2
3
4
5
6
7
8
9
10
11
12
13
Related Articles
Featured image Featured image showing two views of the posterior upper arm and shoulder. The image on the left shows the bony elements and the muscles of the posterior upper arm and shoulder, the image on the right shows isolated Triceps Brachii Medial head.
Triceps Brachii Muscle: Medial Head

The medial head of the Triceps brachii arises from inferior two-thirds of the humerus to insert, along with the other two heads of the triceps, on the olecranon of the ulna.
Featured image showing two views of the posterior upper arm and shoulder. The image on the left shows the bony elements and the muscles of the posterior upper arm and shoulder, the image on the left shows isolated Triceps Brachii Long head.
Triceps Brachii Muscle: Long Head

The long head of the Triceps brachii is one of three heads that make up the muscle. It descends between teres minor and major, dividing the wedge-shaped interval between them and the humerus into triangular and quadrangular spaces.

Feature image showing posterior view of muscles of posterior arm and back and triceps brachii.
Triceps Brachii Muscle – Long Head

An interactive tutorial featuring the (origin, insertion, innervation, and actions) of Triceps Brachii, Long Head usingGBS iconic illustrations and animations.