Muscles of the Hand Quiz – Palm, Deep Layer and Back

All 11 muscles on the diagram

Show the list

Thumb side 4

Abductor pollicis brevis It moves the thumb away from the palm. With the other thenar muscles it makes the rounded mound at the base of the thumb.
Flexor pollicis brevis It bends the thumb. It forms the inner side of the mound at the base of the thumb.
Opponens pollicis It moves the thumb across the palm to touch the other fingers. It lies under the two surface muscles of the thumb.
Adductor pollicis It pulls the thumb back toward the palm. Its two heads begin on the third metacarpal and the wrist bones.

Little-finger side 4

Abductor digiti minimi It moves the little finger away from the other fingers. It is the surface muscle of the little-finger side.
Flexor digiti minimi brevis It bends the little finger. It lies beside the abductor digiti minimi.
Palmaris brevis A thin muscle just under the skin. It pulls on the skin at the edge of the palm and deepens the hollow of the hand for a grip.
Opponens digiti minimi It moves the little finger across the palm toward the thumb. It lies under the other two little-finger muscles.

Middle of the hand 3

Lumbricals They bend the fingers at the knuckles. They also straighten the finger joints beyond them. Each begins on a tendon, not on a bone.
Palmar interossei They pull the fingers toward the middle finger. One lies under the adductor pollicis.
Dorsal interossei There are four. They spread the fingers away from the middle finger.

How this list was compiled: Every name and action checked on 2026-09-30 against OpenStax Anatomy and Physiology 2e, section 11.5 Muscles of the Pectoral Girdle and Upper Limbs (Intrinsic Muscles of the Hand and its table), https://openstax.org/books/anatomy-and-physiology-2e/pages/11-5-muscles-of-the-pectoral-girdle-and-upper-limbs, and against Wikipedia, text only: Muscles of the hand, Thenar eminence, Hypothenar eminence, Adductor pollicis muscle, Lumbricals of the hand, Palmar interossei muscles, Dorsal interossei of the hand, Palmaris brevis muscle, https://en.wikipedia.org/wiki/Muscles_of_the_hand. Third source, and the second for the palmaris brevis, which the textbook does not name: TeachMeAnatomy, The Muscles of the Hand, https://teachmeanatomy.info/upper-limb/muscles/hand/. All wording is our own. Licence: own work

The drawing: Drawn for this site on 2026-10-05 in our own curves. The bones follow the measures this site took for its hand-bones drawing from Gray's Anatomy of the Human Body, 20th US edition (1918), fig. 219, drawn by Henry Vandyke Carter (https://commons.wikimedia.org/wiki/File:Gray219.png), and from the plate of the left wrist in Johannes Sobotta's Atlas and Text-book of Human Anatomy (1909) (https://commons.wikimedia.org/wiki/File:Sobo_1909_127.png); the outline of the hand follows Gray's fig. 1237 (https://commons.wikimedia.org/wiki/File:Gray1237.png), and the place of each muscle follows Gray's figs. 427, 428 and 429 (https://commons.wikimedia.org/wiki/File:Gray427.png, https://commons.wikimedia.org/wiki/File:Gray428.png, https://commons.wikimedia.org/wiki/File:Gray429.png). All are in the public domain (Wikimedia Commons), mirrored here to a right hand. Licence: own work

How it works

This muscles of the hand quiz asks the intrinsic muscles, the ones that begin and end inside the hand. Three drawings of a right hand show the surface of the palm, its deep layer and the back.

Read the full guide

Read the name in three parts

Pollicis means of the thumb and digiti minimi means of the little finger. Abductor, flexor, opponens and adductor say what the muscle does: move away, bend, bring across the palm, pull back in. Brevis means short.

Three groups by place

The thenar muscles make the mound at the base of the thumb, and the hypothenar muscles the smaller mound below the little finger. Between them lie the lumbricals beside the long tendons, and the interossei between the metacarpal bones: the palmar set on the palm side, the dorsal set on the back.

Dorsal interossei abduct and palmar interossei adduct, measured from the middle finger.
The opponens muscles lie under the other two of their group, along the outer metacarpal on each side.

Questions and answers

What are the intrinsic muscles of the hand?

The muscles that both begin and end within the hand: the thenar muscles of the thumb, the hypothenar muscles of the little finger, and the lumbricals and interossei between them. They give the fingers their fine, precise movements.

What are the thenar muscles?

The abductor pollicis brevis, the flexor pollicis brevis and the opponens pollicis, which form the rounded mound at the base of the thumb. Some textbooks also count the adductor pollicis. All of them move the thumb.

What do the lumbricals do?

They bend the fingers at the knuckles while straightening the two joints beyond them. There are four, one for each finger, and each begins on a long flexor tendon in the palm, not on a bone.

What is the difference between the palmar and dorsal interossei?

Both lie between the metacarpal bones. The palmar interossei are on the palm side and pull the fingers toward the middle finger. The four dorsal interossei are on the back of the hand and spread the fingers apart.