Anatomy of the hand Flashcards
What forms the roof of the carpal tunnel?
Flexor retinaculum
What structures lie deep to the flexor retinaculum?
-Flexor digitorum superficialis and profundus muscle tendons
- Flexor pollicis longus muscle tendons
- Median nerve
What structure passes through the flexor retinaculum?
Tendon of the flexor carpi radialis muscle
What is the name of the triangular fascial layer on the palm, and what is its function?
Palmar aponeurosis
-Protects structures of the palm
-It is the point of insertion for the palmaris longus muscle.
Describe the lumbricals in terms of their origin, insertion, innervation and action
Origin: tendons of the flexor digitorum profundus muscle
Insertion: Lateral sides of the extensor hoods
Innervation:
- Lateral two lumbricals by the median nerve
- Medial two lumbricals by the ulnar nerve
Action:
Flexion at the metacarpophalangeal joints
- Extends the dorsal interphalangeal joints
Describe the abductor pollicis brevis muscle in terms of its origin, insertion, innervation and action
Origin:
Tubercle of the trapezium and scaphoid
- Adjacent flexor retinaculum
Insertion:
Proximal phalanx and extensor hood of thumb
Innervation:
- Recurrent branch of the median nerve
Action:
Abduction of the thumb at the metacarpophalangeal joint
Describe the opponens pollicis muscle in terms of its origin, insertion, innervation and action
Origin
- Tubercle of the trapezium and the flexor retinaculum
Insertion
- Lateral margin and palmar surface of the 1st metacarpal
Innervation
- Recurrent branch of the median nerve
Action
Medially rotates the thumb
Describe the adductor pollicis muscle in terms of its origin, insertion, innervation and action
Origin
Oblique head: Capitate and Bases of 2nd and 3rd metacarpals
Transverse head: Anterior surface of the shaft of the 3rd metacarpal
Insertion:
Base of the proximal phalanx of the thumb
Extensor hood of the thumb
Innervation
- Deep branch of the ulnar nerve
Action
Adducts the thumb
Describe the abductor digiti minimi muscle in terms of its origin, insertion, innervation and action
Origin
- Pisiform and the pisohamate ligament
- Tendon of the flexor carpi ulnaris muscle
Insertion
- Proximal phalanx of the little finger
Action
- Abducts little finger at metacarpophalangeal joint
Innervation by the Deep branch of the ulnar nerve
Describe the flexor digiti minimi muscle in terms of its origin, insertion, innervation and action
Origin
- Hook of the hamate and the flexor retinaculum
Insertion
- Proximal phalanx of the little finger
Action
- Flexes little finger at the metacarpophalangeal joint
Innervation
- Deep branch of the ulnar nerve
Describe the opponens digiti minimi muscle in terms of its origin, insertion, innervation and action
Origin
- Hook of the hamate and the flexor retinaculum
Insertion
- Medial aspect of the 5th metacarpal
Action
- Laterally rotates of the 5th metacarpal
Innervation
- Deep branch of the ulnar nerve
How many interosseous muscle does the hand have? how are they positioned?
There are 7 interosseous muscles.
-3 on the palmer side (2nd, 4th and 5th fingers), 4 on the dorsal side (2nd, 3rd and 4th fingers)
Describe the palmer interosseous muscles in terms of their origin, insertion, innervation and action
- Origin
- Sides of the metacarpals
- Insertion
- Extensor hoods of the index, ring and little fingers
- Proximal phalanx of the index, ring and little fingers
- Action
- Adduction of the index, ring and little fingers
- Extension at the dorsal interphalangeal joints
- Innervation
- Deep branch of the ulnar nerve
What is the name of the structure that lies over the tendons of the posterior compartment?
Extensor retinaculum
Which muscle tendons are found in compartment 1?
Abductor pollicis longus muscle
- Extensor pollicis brevis muscle
Which muscle tendons are found in compartment 2?
Extensor carpi radialis longus muscle
Extensor carpi radialis brevis muscle
Which muscle tendons are found in compartment 3?
- Extensor pollicis longus muscle
Which muscle tendons are found in compartment 4?
- Extensor digitorum muscle
- Extensor indicis muscle
Which muscle tendons are found in compartment 5?
- Extensor digiti minimi muscle
Which muscle tendons are found in compartment 6?
Extensor carpi ulnaris muscle
Describe the dorsal interosseous muscles in terms of its origin, insertion, innervation and action
- Origin
- Adjacent metacarpals
- Insertion
- Extensor hoods of the index, ring and middle fingers
- Proximal phalanx of the index, ring and middle fingers
Action - Abduction of the index, ring and middle fingers
- Extension at the dorsal interphalangeal joints
- Innervation
- Deep branch of the ulnar nerve
What is an extensor hood?
Tendons of the Extensor digitorum and extensor pollicis longus expand over the proximal phalanges to form a hood. This is called the extensor hood.
Which muscles insert on the extensor hood?
- Middle 4 fingers
- Interossei and lumbricals
In the thumb
- The adductor pollicis and abductor pollicis brevis muscles insert
Which muscles are innervated by the deep branch of the ulnar nerve? (5)
-Adductor pollicis muscle
-Abductor digiti minimi
-Flexor digiti minimi
-Opponens digiti minimi
-Interosseus muslces (both palmar and dorsal)
Two median lumbricals
Which muscles are innervated by the recurrent branch of the median nerve? (3)
Abductor pollicis brevis muscle
Flexor pollicis brevis muscle
Opponens pollicis muscle
Two lateral lumbricals
Describe the brachial artery
It is the continuation of the axillary artery.
It spans from the inferior border of the teres major muscle to the cubital fossa.
Not superficial
What branches does the brachial artery gives off?
Muscular branches
- Deep artery of the arm
- Superior and inferior ulnar collateral
- Terminates as the radial and ulnar artery
List the branches of the ulnar artery
Common interosseus
- Anterior and posterior interosseus
Anastomotic branches
- Anterior and posterior ulnar recurrent collateral
List the branches of the radial artery
Muscular branches
- Anastomotic branches
- Radial recurrent artery
Describe the superficial palmar arch
Superficial palmar arch
- Joining of ulnar and radial arteries
- Contribution mainly by the ulnar artery
Describe the deep palmar arch
Deep palmar arch
- Joining of ulnar and radial arteries
- Contribution mainly by the radial artery
Describe the palmar digital arteries that arise from the superficial palmar arch
Superficial palmar arch
- Gives off common palmar digital arteries
- They terminate as proper palmar digital arteries
- Palmar digital artery to medial side of the little finger
Describe the palmar digital arteries that arise from the deep palmar arch
Deep palmar arch
- Gives off palmar metacarpal arteries
- Radialis indicis artery to the index finger
- Princeps pollicis artery to the thumb
Describe the dorsal digital arteries
Dorsal carpal arch is formed by the dorsal branches of
radial and ulnar arteries
- Gives off dorsal metacarpal arteries which terminate
as dorsal digital arteries
Where do the dorsal superficial veins commence?
They commence at the dorsal venous network
What is formed from the dorsal venous network?
Basilic and cephalic veins
Describe the cephalic vein
- Lies laterally
- Lies superficial
- Disappears in deltopectoral triangle
- Drains into subclavian vein
Where do the basilic and cephalic veins join? What joins them?
They join at the cubital fossa.
Median cubital vein joins them
Describe the deep veins
Have same names as arteries
* From digital veins to palmar venous arches
* Radial and ulnar
* Brachial
* Axillary
* Subclavian
* Brachiocephalic vein (With jugulars)
* Superior vena cava
What nerve does the median nerve give off in the cubital fossa?
Anterior interosseus nerve
Which muscles are innervated by the anterior interosseus nerve?
Deep flexors
- Flexor pollicis longus
- Lateral half of Flexor digitorum profundus
- Pronator quadratus
The median nerve enters the palm via the____________________
carpal tunnel
Which muscles of the hand are supplied by the median nerve?
Supplies thenar group and lateral 2 lumbricals
The median nerve gives sensory innervation to ____________________
lateral 3 ½ fingers
The __________ nerve runs over the flexor retinaculum at the wrist
Ulnar
Explain the division of the ulnar nerve and what they innervate
Superficial branch
- Skin on medial 1 ½ fingers on both surfaces
* Deep branch innervates
- Hypothenar
- 2 medial lumbricals
- All interossei
- Adductor pollicis muscle
What is innervated by the deep branch of the radial nerve? (post. interosseus nerve)
- Extensor carpi radialis brevis muscle
- Supinator muscle
- Extensor digitorum muscle
- Extensor digiti minimi muscle
- Extensor carpi ulnaris muscle
- Extensor pollicis longus and brevis muscles
- Extensor indicis muscle
What is innervated by the superficial branch of the radial nerve?
Superficial innervates lateral 3 ½ of dorsum
Intrinsic hand muscles
Thenar
Hypothenar
Lumbricals
Adductor pollicis
Palmar interosseous
Dorsal interosseous
Thenar muscles
AFO
-Abductor pollicis brevis
-Flexor pollicis brevis
-Opponens pollicis
Hypothenar mucsles
AFO
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi
Where do lumbricals arise from?
FDP (flexor digitorum profundus) tendon
Palmar interosseous
PAD
(adduct)
Dorsal interosseous
DAB
(abduct)
