Wk 7 Lec 3 Hand Muscles

Intrinsic muscles of the hand are... Extrinsic muscles are located where? what do they move?

..Intrinsic muscles of the hand are many small muscles within the hand. They allow for manual dexterity (precise movements) Extrinsic muscles are located in the forearm but move the fingers/hands.

Dorsal Interossei. Move fingers away from midline, or away from the axis. Abductors. how many dorsal interossei?

4 Dorsal interosseii. 2 insert into third finger.

What do Interossei do?

Abduct and Adduct the fingers.

The hand is the part of the upper extremity ______ to the wrist.

Distal to the wrist.

Palmaris Brevis What does it NOT do? There are small transverse bands located over the hypothenar muscles.

Does NOT move the little finger. ____________ Palmaris brevis. -helps deepen palm and provide gripping action. -originates off palmar apanorosis. -inserts into skin of medial side of hand. -intervated by ulnar nerve. -helps to build up hypothenar eminence and deepen the palm and help with gripping.

Palmer Interossei They bring the fingers closer together, Adductors, toward the midline/axis. PAD. how many palmar interossei?

3 palmer interosseii ____________ One of the groups of the interossei muscles. Palmer interossei. Adductors of the finger = bringing them closer to midline/axis. -black line is pointing down axis. green arrows are bring it inwards, palmar interosei have 3 components. 1st) originates off ulnar side of the 2nd metacarpal . 2nd) off radial side of 4th metacarpal. 3rd) off radial side of 5th metacarpal. these muscles will then insert into the proximal phalanx of the digit of origin. for example, first inserts into proximal phalanx of index finger. second into proximal phalanx of ring finger. third goes into prox phalanx of little finger. all are intervated by ulnar nerve. as they contract, they will pull the fingers in towards that axis, "adduction" since the interossei have fibers which extend into extensor expansion hood on the dorsal aspect of each of the digits, they also aid in flexion of metacarpal phalangial joint and extension of interphalangial joints. they will aid in the motion created by the lumbericles, as well.

Lumbricles How many lumbricle muscles? Attaches to what? Passes to insert into the expansion hood on the dorsum of the digitis. Which are median and which are ulnar nerve?

4 lumbricle muscles. 1-4 from lateral to medial. Attach to the tendons of the flexor digitorum longus muscle. Passes to insert into the expansion hood on the dorsum of the digitis. 1 and 2 are the MEDIAN nerve. 3 and 4 are the ULNAR nerve. __________ lumbricles. -4 in number. -numbered L to M. closest to thumb is 1. little finger is 4. -originate of tendons of flexor digitorum profondous. -insert onto radial side (thumb side) of the extensor expansion hood of fingers 2, 3, 4, and 5. -they create this bye bye action by flexing the metacarpal phalangial joint and extending the interphalangial joint. -they are originating off the radial side (thumb side) of tendons of flexor digitorum profoundous. -they hook around and insert on radial/thumb side onto the dorsal aspect of the extensorhoods of digits 2-5. -two lateral muscles (closest to thumb) are intervated by median nerve. -3 and 4 (by little finger ) are intervated by ulnar nerve. -flex metacarpal phalangial joint and extend interphalangial joint for bye bye motion.

Hypothenar Muscles --> Form the hypothenar eminence of the medial side of the palm. Which 3? Plamaris brevis IS NOT PART OF THE HYPOTHENAR COMPARTMENT.it doesn't move the little finger.

Abductor digiti Minimi Flexor Digiti Minimi Brevis Opponens Digiti Minimi _____________ hypothenar enimence. -formed by muscles on medial side of palm. there are 3. they all have "digit minimi". little digit or little finger. -responsible for movement of little finger. Palmaris brevis = no! why? ______

What do Lumbricles do?

Flex the MPJ (metacarpophalangeal joint) and extend the IPJ (interphalangeal joint) "bye-bye muscles"

Abductor Digiti Minimi It is the most ____ muscle in the hypothenar eminence. Forms rounded contour on medial side of the hand. Action to little finger? Which nerve?

It is the most medial. it's action is to Abducts little finger. Ulnar nerve. ______________________ First muscle that forms hypothenar eminence. Abductor digiti minimi. -helps form convex contour of medial side of hand. -originates of pisiform bone. -inserts into ulnar side of base of the proximal phalanx of the fifth digit. -intervated by ulnar nerve. -abducts little finger. -action: aids in flexion.

Opponens Digiti Minimi Lies deep to the .... Inserts along _____ border of the ______. Action on little finger? Which nerve?

LIes deep to the abductor and flexor. Inserts along medial border of the 5th metacarpal. Helps to bring the little finger to meet the thumb. Ulnar nerve. _____________ 3rd muscle in hypothenar eminence. Opponens digiti minimi. -square shaped. -lies deep to abductor and flexor of little finger. -originates off hook of the hamate and the flexor retinaculum. - inserts into ulnar side of 5th metacarpal. -intervation: ulnar nerve. -action: oppose little finger. to see this, u need to reflect both the flexor digiti minimi brevis AND the abductor digiti minimi brevis. SO! ppponens to little finger and thumb are similarily located. both deep to abductors and flexors.

Interossei Where are they located? Divided into ___ and ____. ^both can be seen from palmer aspect

Located between metacarpals, between bones. Divided into dorsal and palmar.

Opponens Pollicis Located deep to the ____ and _____. Inserts along the lateral border of the ______. Opposes the thumb Which nerve?

Located eep to the Abductor and Flexor. Inserts along lateral border of the 1st metacarpal. Opposes the thumb. --> moves the thumb across the palm to meet the little finger. MEDIAN nerve. _______________ Located eep to the Abductor and Flexor. Inserts along lateral border of the 1st metacarpal. Opposes the thumb. --> moves the thumb across the palm to meet the little finger. MEDIAN nerve.

Flexor Digiti Minimi Brevis Located _____ to the abductor. Action to the little finger? What is the nerve?

Located lateral to the abductor. Flexes the little finger. Ulnar nerve. ___________________ Flexor digiti minimi brevis. -short flexor of little finger. -this muscle flexes the little finger, and it is a short muscle . -can be very small and hard to distinguish from abductor. -more muscular the hands = more distinct the intrinsic muscle. -originates off the hook of the hamate and flexor retinaculum. -inserts into ulnar side of base of proximal phalanx of 5th digit. -insertion is usually fused to that of the adductor digiti minimi. -inervated by ulnar nerve. -action: flexes little finger.

Flexor Pollicis Brevis Located ______ to the abductor. Which nerve?

Located medial to adbuctor. uses median nerve. ________________ short flexor of thumb. -located medial to abductor pollicis brevis. -flexes thumb and aids in opposition. -originates of trapezium and flexor retinaculum. -inserts into base of proximal phalanx of thumb. insertion fuses with abductor pollicis brevis sometimes. -intervated by median nerve. -action: flexes thumb and aids in opposition.

What are the mid palmer muscles?

Mid Palmer muscles are Lumbricles and Interossei.

Abductor Pollicis Brevis Moves thumb forward in the _____ plane. Forms _____ edge of thenar eminence. Which nerve?

Moves thumb foward in the SAGGITAL plane. forms Lateral edge. Uses median nerve. ________________ Abductor Pollicis Brevis. -short abductor of thumb. -this forms lateral edge of Thenar eminence. -abduction: moves thumb foward at a 90 degree angle to palm of hand. saggital plane. test: abduct thumb against resistence. can palpate it. originates of scaphoid and trapezium as well as flexor retinaculum. -inserts into base of proximal phalanx of thumb. -intervated by median nerve. -action: abduction of thumb.

Moving away from the axis is.... moving toward the axis is... ALL are innervated by the...

Moving away = abduction moving toward = Adduction Innervated by ulnar. ALL. ______________ since axis runs through middle fingers, you can't bring THAT finger any closer towards middle. therefor the mdidle finger can't be adducted. moving the middle finger either way is abduction. All interossei are intervated by ulnar nerve.

Carpal Tunnel Syndrome Results from? Median nerve: sensory loss or tingling over lateral 3.5 digits. What happens to the thenar muscles? Relieve symptoms by...

Results from Reduction in size of carpal tunnel Motor loss to the Thenar muscles except adductor. Cannot oppose the thumb. relieve by partial or complete division of the Flexor Retinaculum.

Hand muscles are divided into 3 groups: What are they innervated by?

Thenar --> The Thumb Hypothenar --> the little finger Mid palmar --> Middle of the hand Innervated by the median and Ulnar nerves. _____________________ 1. Thenar muscles. -thenar eminence: lateral side of palm. responsible for opposition of thumb... moving the thumb to touch tip of little finger. -opposition is complex. needs help from many intrinsic muscles. there are 3. Adductor lies medial to rounded muscular area of eminence. so its not part of it.