L37 Palm Flashcards
Abductor pollicis brevis
PA: Flexor retinaculum, scaphoid, trapezium
DA: Lateral side, base of proximal phalanx
Inn: Recurrent branch of median nerve
Action: Abduction CMC (MP), assists opposition
Opponens pollicis
PA: Flexor retinaculum, scaphoid,
trapezium
DA: Lateral side 1st metacarpal
Inn: Recurrent br. median nerve
Action: Opposition CMC
Flexor pollicis brevis (two heads)
PA: Flexor retinaculum, scaphoid,
trapezium
DA: Lateral side base of proximal
phalanx
Inn: Superficial head: Recurrent
br. median nerve
Deep head: Deep br. ulnar
nerve
Action: Flexion CMC (MP)
Adductor pollicis
PA: Transverse head: Shaft 3rd
metacarpal
Oblique head: Bases 2nd & 3rd metacarpals, carpal bones
DA: Medial side base of proximal
phalanx
Inn: Deep br. ulnar nerve
Action: Adduction CMC (MP)
Abductor digiti minimi
PA: Pisiform
DA: Medial side base proximal
phalanx
Inn: Deep branch ulnar nerve
Action: Abduction (MP)
Flexor digiti minimi
PA: Hook of hamate, flexor
retinaculum
DA: Medial side base proximal
phalanx
Inn: Deep branch ulnar nerve
Action: Flexion (MP)
Opponens digiti minimi
PA: Hook of hamate, flexor
retinaculum
DA: Medial border of 5th
metacarpal
Inn: Deep branch ulnar nerve
Action: Brings 5th digit into
opposition with
thumb
Palmar interossei (3)
PA: Palmar surfaces digits 2, 4, 5
DA: Bases of proximal phalanges
& lateral bands of extensor
expansion, digits 2, 4, 5
Inn: Deep branch ulnar nerve
Actions:
(1) Adduction digits 2, 4, 5
toward axis
(2) Assist lumbrical action
Dorsal interossei (4)
PA: Adjacent sides of two metacarpals
DA: Bases of proximal phalanges &
lateral bands of extensor expansion,
digits 2, 3, 4
Inn: Deep branch ulnar nerve
Actions:
(1) Abduction digits 2, 3, 4
away from axis
(2) Assist lumbrical action
What is a typical position for hand casts or splits?
Wrist neutral or with slight extension (resting position)
What are the 8 carpel bones?
Proximal row (lateral to medial):
- scaphoid
- lunate
- triquestrum
- pisiform
Distal row (lateral to medial):
- trapezium
- trapezoid
- capitate
- hamate
What bones make up the wrist joint?
radius, scaphoid, lunate, & triquetrum
not the ulna!
What is the area between metacarpals called and what is contained there?
web space, filled with muscles and other soft tissue
What is the significance of the palmar aponeurosis?
- Tendon of palmaris longus (PL)
- Continuous with fibrous tendon
sheaths of long flexor tendons - Fibrous septa dividing palm into
compartments
What compartment is Palmer brevis in and what are its features (PA, DA etc)
Not in one of the 5 compartments!
PA: Medial side of palmar aponeurosis
DA: Skin on medial border of hand
Act: Wrinkles skin of hand, deepens
hollow of palm aiding in palmar
grip, protects ulnar a/n
Inn: Ulnar nerve
What is the palmar carpal ligament and what does it do?
(thickening of antebrachial
fascia, holds flexor tendons in
place across the wrist )
What is Dupuytren’s contracture?
Progressive, shortening, thickening,
and fibrosis of the palmar fascia
& aponeurosis (cause unknown)
What are the 5 compartments of the palm?
What is in the central compartment?
- Superficial palmar arch & brs
- Median nerve & brs
- Long flexor tendons (FDS & FDP)
- Lumbricals
(5. Midpalmar space: deep to flexor tendons)
Lumbricals:
What are their positions relative to the different joints?
PA: Tendons of flexor digitorum profundus
DA: Lateral bands of extensor
expansion digits 2-5
Inn: 1 & 2 (lateral): Median n
3 & 4 (medial): Deep br. ulnar n
Actions: MP flexion, PIP & DIP extension
MP joints: Lumbricals are located
anterior to the axis of motion, results in flexion
PIP & DIP joints: Lateral bands are
located posterior to the axis
of motion, results in extension
What is the importance of lumbricals (and interossei)
Flexion of MP jts coupled with Extension of PIP/DIP jts.
Prevents hand from only being able to do full flexion or extension.
What’s in the thenar compartment?
What are the key concepts?
Contents:
- Recurrent n (br. median n)
- Thenar muscles
(3. Thenar space or cleft)
Key concepts:
1. Associated with pollex
(thumb, pollicis)
2. Mm innervated by recurrent
br. of median nerve (with one
exception)
What are the thenar muscles?
- Abductor pollicis brevis
- Opponens pollicis
- Flexor pollicis brevis (2 heads)
Abductor pollicis brevis
PA: Flexor retinaculum, scaphoid, trapezium
DA: Lateral side, base of proximal phalanx
Inn: Recurrent br. median nerve
Action: Abduction CMC (MP) (assists opposition)
Opponens pollicis
PA: Flexor retinaculum, scaphoid,
trapezium
DA: Lateral side 1st metacarpal
Inn: Recurrent br. median nerve
Action: Opposition CMC
Flexor pollicis brevis (2 heads)
- *PA**: Flexor retinaculum, scaphoid, trapezium
- *DA**: Lateral side base of proximal phalanx
- *Inn: Superficial head:** Recurrent br. median nerve
- *Deep head:** Deep br. ulnar nerve
- *Action**: Flexion CMC (MP)
Which digits have continuations of synovial portions of flexor tendon sheaths (bursa)?
What are the implications?
Digits 1 (ulnar bursa) and 5 (radial bursa) have continuous sheaths that allows infection to spread from the digit to the forearm.
What’s in the adductor compartment?
Adductor pollicis:
Transverse head
Oblique head
PA: Transverse head: Shaft 3rd metacarpal
Oblique head: Bases 2nd & 3rd
metacarpals, carpal bones
DA: Medial side base of proximal
phalanx
Inn: Deep br. ulnar nerve
Action: Adduction CMC (MP)
What’s in the hypothenar compartment?
Key concepts?
Key concepts:
1. Associated with digit 5
(digiti minimi)
2. Mm innervated by deep
branch of ulnar n.
Contents:
Hypothenar muscles (3)
1. Abductor digiti minimi
2. Flexor digiti minimi
3. Opponens digit minimi
Hypothenar muscles: (info)
Abductor digiti minimi:
Flexor digiti minimi:
Opponens digiti minimi:
Abductor digiti minimi:
PA: Pisiform
DA: Medial side base proximal phalanx
Inn: Deep branch ulnar nerve
Action: Abduction (MP)
Flexor digiti minimi:
PA: Hook of hamate, flexor retinaculum
DA: Medial side base proximal phalanx
Inn: Deep branch ulnar nerve
Action: Flexion (MP)
Opponens digiti minimi:
PA: Hook of hamate, flexor retinaculum
DA: Medial border of 5th metacarpal
Inn: Deep branch ulnar nerve
Action: Brings 5th digit into
opposition with
thumb
What are the contents and key concepts of the interosseous compartment?
Key concepts:
Mm innervated by deep branch of ulnar n.
Contents:
- Palmar interossei (unipennate)
- Dorsal interossei (bipennate)
Palmar Interossei (PADs)
PA: Palmar surfaces digits 2, 4, 5
DA: Bases of proximal phalanges
& lateral bands of extensor
expansion, digits 2, 4, 5
Inn: Deep branch ulnar nerve
Actions: (1) Adduction digits 2, 4, 5 toward axis
(2) Assist lumbrical action
Dorsal Interossei (DABs)
PA: Adjacent sides of two metacarpals
DA: Bases of proximal phalanges &
lateral bands of extensor expansion,
digits 2, 3, 4
Inn: Deep branch ulnar nerve
Actions: (1) Abduction digits 2, 3, 4
away from axis
(2) Assist lumbrical action
How do DABs, PADs and Lumbricals work together?
- All three mm are
located anterior to the
flexion/extension axis
of the MP joint: Flex
at MP joints - All three mm are
incorporated into the
lateral band portion of
the extensor expansion. - The lateral bands
are located posterior to
the flexion/extension
axes of the PIP & DIP
joints: Extension at
PIP & DIP joints
What makes up the deep palmar arch?
What does it give rise to?
The deep palmar arch is an anastomose of the radial artery and the deep branch of the ulnar artery, located near the bases of metacarpals.
It gives rise to the palmar metacarpal arteries (anastomose with superficial palmar arch near MC heads)
What makes up the superficial palmar arch?
What are the branches of the superficial palmar arch?
The superficial primary arch is the main continuation of ulnar artery (primary role) and is completed by a
branch of the radial artery.
It is the primary artery supply to digits 2-5
It gives rise to the common palmar digital aa which give rise to proper palmar digital aa (sides of adj. digits)
What are the palmar side veins of the hand?
Parallels arterial pattern:
Superficial & deep venous palmar arches
Drain into: Deep veins of
forearm (ulnar & radial vv)
What are the dorsal side veins of the hand?
Dorsal venous
network drains into:
Superficial veins:
Cephalic & Basilic vv.
(dorsal digital vv most distal)
What is contained in the carpal tunnel?
What ligament defines the carpal tunnel?
9 tendons (from FDS, FDF, FPL) and the median n.
The flexor retinaculum (transverse carpal ligament)
Median n in hand:
location, branches, etc
passes through carpal tunnel to enter palm then branches into:
- Recurrent branch: motor to thenar muscles except for deep head of flexor pollicis brevis
-
Common palmar digital nn: in metacarpal area (innervates lateral 2 lumbricals) then branch into proper palmar digital nn (follows artery naming)
Proper digital nn supply sensory innervation to to adjacent sides to lateral 3 & 1/2 digits (4th is half deep branch of ulnar n)
What is the sensory innervation on the palmar surface?
blue = Ulnar n
yellow = median n
pink = radial n
purple and green? not sure
What is the dorsal sensory innervation of the hand?
blue = ulnar n
pink = radial n
yellow = median n
What are some important actions of the median n in the thumb? (from Walters’ chart)
Unique: Pronation:
(pronators teres & quadratus)
Flexion digits 2 & 3
FD superficialis: PIP
FD profundus: DIP
Flexion digit 1
FP longus: IP
Lumbrical Actions
Lumbricals 1 & 2 to
digits 2 & 3
Opposition (thumb)
Opponens pollicis
Ulnar n and the hand:
Where do you test sensory innervation of the ulnar n?
Enters palm under palmar carpal ligament but above the transverse carpal ligament (guyon’s tunnel). Then splits into superficial and deep branches.
- Deep Branch: (motor, described later)
-
Superficial Branch:
Motor branch: palmaris brevis
Sensory branch:
2a. (Proper) palmar digital n to medial side of digit 5
2b. Common palmar digital nerve
2b1. (Proper) palmar digital nerves to digit 4 & 5
Associated with (proper) digital aa
Sensory distribution of the ulnar n is tested in the pinky
What does the ulnar nerve supply?
- Hypothenar muscles (3)
- Medial 2 lumbricals (digits 4 & 5)
- Palmar interossei
- Dorsal interossei
