Below the shoulders and aside from the muscle groups which support them, the biceps brachii and the triceps brachii make up the bulk of your upper arms.
What causes biceps/triceps to feel weak but look big when working out in the gym? - Quora
If you want big arms, what matters more the biceps or the triceps? - Quora
Biceps Vs Triceps: What's The Difference?
Why do biceps and triceps grow slowly? - Quora
What happens when I do biceps and triceps every day? - Quora
If you want big arms, what matters more the biceps or the triceps? - Quora
Muscle Group of the Week: Triceps
What will happen if I train only my biceps and triceps and not any other part? - Quora
If you want big arms, what matters more the biceps or the triceps? - Quora
What are some good methods on making your biceps and triceps pop out more from weightlifting? - Quora