The Hand Flashcards
Week 9
Name the carpal bones
(So Long to Pinky Here Comes The Thumb
Scaphaoid
Lunate
Triqyetrum
pisiform
Hamate Capitate
Trapaezoid
Trapezium
In the anterior view, where does the pisiform bone lie?
Anterior to the triquetum
Is the anterior hand palmar or dorsal?
palmar
Name the 5 joints of the hand and their functional type
interphalangeal joint (Hinge)
Metapophalangeal joint (Condyloid)
Carpometacarpal joint (plane)
Intercarapl joints (plane)
1st CMS
(saddle)
Which joints of the hand can do circumduction?
1st Carpometacarpal joint and metacarpophalangeal joint
What join forms the knuckles?
Metacarpophalangeal Joint
What differentiates intrinsic vs extrinsic muscles of the hand?
Intrinsic
Entirely within the hand
Extrinsic
Originate from forearm.
Name the 5 intrinsic muscles (inc groups) of the hand
Thenar, Hypothenar, lumbricals, interosseu and Adbsuctor pollic
What muscle does the abductor pollicis brevis contract simultaneously with
abductor pollicis longus
Where does the thenar group muscles originate?
tubercule of trapezium and flexor retinaculum
What movement does the thenar group muscles allow for and what are they all innervated by?
movement
-exert all actions at metacarpophalangeal joint
innervation
recurrent branch of median nerve
What muscles make up the thenar group?
Adb Pollicis Brevis
Flexor Pollicis Brevis
Opponens Pollicis
what muscles make up the hypothenar group?
Abd digiti minimi
flexor digiti minimi brevis
opponnens digiti minimi
What are all the Hypothenar group muscles innervated by?
deep branch of ulnar nerve
Which two Hypothenar group muscles have the same Origin. (what is this origin)
FDM and ODM = Hook of hamate and flexor retinaculum
O/I of lumbricals
Tendons of FDP –> extensor hood of index, middle, ring and little fingers
Movement of Lumbricals (and how)
Flexion at MCP joint and Extension at IP joint
=lumbricals insert on the palmar side of extensor hood, only continues to dorsal surface if finger therefore acts posteriorly to IP joint
Innervation of the lumbricals
1st and 2nd = median nerve
3rd and 4th = deep branches of ulnar nerve
Name the two interossei muscles
Palmar interossei
Dorsal inerossei
O/I and movement of palmar interossei
Side of metacarpals –> extensor hood of index, ring and little fingers
Adduction of index, middle and ring at MCP joint
O/I and movement of dorsal interossei
Adj side of metacarpals –> extensor hood and base of proximal phalanges of index, ring and middle fingers
Adduction of index, ring and little fingers at MCP joints
What are the interossei muscles innervated by?
Deep branch of ulnar
O/I of Abductor Pollicis Longus
Metacarpal II, capitate and bases of metacarpal II-III –> extensor hood and base of proximal phalanx of thumb
Movement and innervation of Adbuctor pollicis
Thumb abduction
Deep branch of ulnar
What is the extensor Hood?
tendons of long extensors (Ext D and Ext PL) flattened and expanded over the metacarpophalangeal joints
What is the clinical significance of tendon sheaths?
affects the spread of infections
How is the power grip created?
Extended wrist
IP and MCP joints flexed using extrinsic flexors
What movements create the Precision grip?
Extended wrist, flexion of digits, opposition of CMC joint and use of short intrinsic muscles.
What finger muscles are involved in flexion?
Intrinsic Muscle
Lumbricals
Interossei
FDMB
Extrinsic
FDS
FDP
What finger movements are involved in extension?
Intrinsic
Lumbricals
Interossei
Extrinsic
ED
EI
EDM
What finger movements are involved in Abduction?
Dorsal Interossei
ADM
What finger muscles are involved in adduction?
palmar interossei
What finger movements are involved in opposition of the little finger?
Opponens Digiti Minimi
What muscles allow for flexion and extension respectively of teh thumb?
Flexion
FPB
FBL
Extension
EPB
EPL
What muscles allow for Abduction and Adduction of the thumb respectively
Abduction
Abd PB
Abd PL
Adduction
Add P
Where does the Ulnar Nerve innervate (sensory) (hand)
Palmar
-medial 1 ½
-medial palm
Dorsal
-medial dorsum
-medial 1 5/6
Where does the Median nerve innervate (sensory) (hand)
Palmar
-lateral palm
Later 3 ½ dig
Dorsal
-tips of lateral 3 ½ digits
What does the radial nerve innervate for the hand (sensory)
Palmar
-lateral thenar eminence
Dorsal
-lateral dorsum
-lateral 3 ½ digits without tips
Path of ulnar artery
Ulnar artery –> superficial palmar arch –> common palmar digital arteries –> proper palmar digital arteries
path of radial artery
Radial artery –> deep palmar arch –> palmar metacarpal arteries
What is the Phalanx?
Singular word for phalanges
What plane does flexion and extension of the MCP joints of digits 2-5 occur in?
saggital
What plane does flexion of the thumb occur in and why?
coronal
1st CMC joint is rotated 90 degrees
What is the Flexor Retinaculum and its role?
= thick connective tissue ligament that runs between the scaphoid and pisiform
= anterior boundary of carpal tunnel
= holds tendons that run through the carpal tunnel in place and prevents them form bowing out.
Where does the:
a- radial artery
b- ulnar artery
enter the hand?
a- via anatomical snuffbox and through 2 heads of 1st dorsal interosseous and adductor pollicis
b- anterior to flexor retinaculum and through Gaylon’s canal
Describe the Ulnar Claw
Caused by: Ulnar Nerve damage
This nerve supplies: Hypothenar, adductor pollicis, medial lumbricals and palmar interossei
impact= loss/impaired sensation to the medial side of hand and wrist (little finger and 1/2ring finger)
Compare the damage caused if the ulnar nerve was damaged above the elbow joint versus below.
Below =
FDP is not affected by a wrist ulnar lesion = Distal IP are flexed
Above=
LESS clawing of 4th and 5th IP as the distal IP joints not flexed (FDP is affected)
radial deviation (due to loss of carpi ulnaris)
functional hand loss = similar
Functional issues of ulnar claw
Difficulty making a fist due to hyperextension of the metacarpophalangeal joints.
Impaired movement of the little finger and weakness in the hypothenar muscles.
Weakness in finger abduction and adduction affecting both dorsal and palmar interossei.
What are the borders of the anatomical snuffbox?
brevis sandwich
Extensor pollicis longus –> brevis –> abductor longus tendon
What artery runs through the anatomical snuffbox?
Radial artery
What are the bones on the floor of the snuffbox?
scaphoid and trapezium
What nerve is affected in carpal tunnel and how is its damage caused?
Median nerve compression
Overuse, swelling of tendons and tend sheaths
(if swollen, nowhere for pressure to be released so it pushes on structures within the tunnel)
Boundaries of the Carpal Tunnel
Roof = flexor retinaculum
Floor = carpal bones
Medial = lat surface of hamate
lateral= medial surface of trapezium
What are the contents of the Carpal Tunnel?
9 tendons:
-4 tendons of FDP
- 4 tendons of FDS
- flexor pollicis longus tendon
Functional issues associated with Carpal tunnel
Loss of cutaneous innervation for the palm of the hand which weakens the grip of the hand.
Loss of sensory feedback for hand = loss of feedback on how tight to hold objects.
thenar group weakness
If there was damage to the radial artery at the wrist, would there be a wrist drop?
No
