The video discusses the palmaris longus muscle, a vestigial muscle found in some humans. It explains that around 15% of people lack this muscle in one or both arms. The muscle is considered vestigial because it was likely used by human ancestors for climbing or walking on forearms, but it has no significant function in modern humans. The absence of this muscle does not affect grip strength, and it is often removed during reconstructive surgeries.

What is the palmaris longus muscle, and how can you identify it?

• A muscle in the arm, identified by touching the thumb and pinky together

• A muscle in the neck, identified by turning the head

• A muscle in the back, identified by bending forward

• A muscle in the leg, identified by flexing the knee

Approximately what percentage of people lack the palmaris longus muscle?

• 5%

• 10%

• 15%

• 20%

Why is the palmaris longus muscle considered vestigial?

• It helps in running faster

• It is used for modern activities like typing

• It is essential for swimming

• It was useful for ancestors in climbing or walking on forearms

What is a characteristic of vestigial muscles?

• They are essential for survival

• They do not cause disadvantages or consequences

• They cause significant disadvantages

• They are only found in animals

Why is the palmaris longus muscle often used in reconstructive surgery?

• It is easily accessible and dispensable

• It is the largest muscle in the arm

• It is the strongest muscle in the body

• It is the most flexible muscle