What are the 2 posterior compartment muscles that do not pass the wrist joint?
Supinator and brachioradialis do not pass the wrist joint. *Brachioradialis flexes forearm at the elbow*
Where does the radial nerve split and where does each branch go?
Radial nerve splits at cubital fossa. Superficial radial nerve pierces the brachioradialis and the deep radial nerve pierces the supinator muscle.
Where does the superficial radial nerve reappear after piercing the brachioradialis?
Superficial radial nerve reappears in the anatomical snuffbox.
Which muscles start at ulnar and insert onto the thumb?
Adductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus
What are the medial and lateral borders of the anatomical snuffbox?
APL and EPB form the lateral border of anatomical snuffbox. EPL forms the medial border of the anatomical snuffbox.
What are the bones of the proximal row of carpal bones? Which bones articulate with the radius?
Scaphoid, Lunate, Triquitrium, Pisiform. Scaphoid and Lunate articulate with radius.
What sits between the triquitrium+pisiform and the ulna?
A triangular cartilaginous disk.
What are the bones of the distal row of carpal bones?
Trapezium, Trapezoid, Capitate, and Hamate.
Where does the blood supply of the scaphoid pass before supplying it?
Scaphoid contains a proximal and distal end. between these ends is a ridge through which the blood supply for the scaphoid passes through (the distal half)
What complications can happen from a FOOSH to the hand?
Scaphoid can get fractured
What is the design fault with blood supply of the scaphoid?
Proximal pole of the scaphoid can get necrotic as a result of fracture.
What causes handlebar neuropathy?
Hook of hamate and pisiform meet up with a ligament through which the ulnar nerve goes through. Entrapment of this nerve causes handlebar neuropathy. intrinsic muscles of the hand innervated by this nerve get compromised.
How many phallanges are there in each finger?
Thumb has only 2 phalanges while the rest have 3.
How are the hand's compartments formed?
Palmar aponeurosis sends out extensions to the 5th metacarpal and the 3rd metacarpal. This creates fascial compartments (the thenar and hypothenar compartments and central compartment)
What are the 2 thenar compartments?
Superficial thenar compartment (Abd PB and FPB) Deep thenar compartment. (adductor pollicis here)
Where is the palmaris brevis muscle found?
Fibers from the palmar aponeurosis to the skin are called palmaris brevis.
What causes dupuytren's contracture?
Palmar fascia can get thick and shrink and forms a contracture and this causes ring and little fingers to contract. This is known as dupuytren's contracture. This is relieved surgically.
Where does the flexor retinaculum attach?
trapezium and scaphoid on lateral side and hamate and pisiform on the medial side
What are the boundaries of the carpal tunnel?
Roof: Flexor retinaculum Floor: carpal bones Proximal end marked by wrist crease.
What structures lie superficial to the flexor retinaculum?
PL tendon Ulnar artery, ulnar nerve superficial branch of radial artery. palmar cutaneous branch of median nerve.
What passes through the flexor retinaculum?
FDS (x4 tendons) FDP (x4 tendons) FPL Median Nerve:(recurrant thenar branch and lateral+medial branches) FCR (within the roof of the carpal tunnel) Synovial sheaths
Which FDS tendons pass more superficially and which pass more deeply?
Superficially: 3,4 Deep: 2,5
Where do the FDP tendons pass through the carpal tunnel?
The FDP tendons pass more deeply to FDS tendons.
Where in the carpal tunnel to FPL and FCR pass?
FPL passes through carpal tunnel deep to median nerve and FCR superficial to median nerve within flexor retinaculum.
Where does the extensor retinaculum attach?
Extensor retinaculum attaches to radius laterally and triquetrium, pisiform and FCU medially.
What are the contents of the extensor retinaculum?
6 tunnels 9 tendons Synovial sheaths.
What are the boundaries of the anatomical snuffbox?
Anteriorly: tendons of APL and EPB. Posteriorly: tendon of EPL Roof: skin, subcutaneous tissue, cephalic vein, radial nerve. Floor: scaphoid and trapezium
What can be found in the anatomical snuffbox?
What are the muscles of the first hand layer?
Thenar muscles: Abductor pollicis brevis Flexor pollicis brevis Hypothenar muscles: Abductor digiti minimi Flexor digiti minimi
Where do the first layer of hand muscles originate from?
Where do the first layer of hand muscles insert?
Base of proximal phallanx
Where do the second layer of hand muscles originate from?
Flexor digitorum profundus tendons
What are the second layer muscles called?
Where do the second layer muscles insert?
Extensor expansions of digits 1 - 4
What is the function of the lumbricals?
Lumbricals flex the MCP joints while extending the IP joints.
What are the muscles of the 3rd layer of the hand?
Thenar muscles: Opponens Pollicis Adductor Pollicis Hypothenar muscles: opponens digiti minimi
What is the origin of adductor pollicis? Where does it insert?
One oblique head originates at the flexor retinaculum Transverse head starts at 3rd metacarpal It inserts at medial side of proximal phallanx.
What branches does the median nerve form in the hand and what do they innervate?
Recurrent branch of the median nerve supplies muscles of the thenar compartment. Specifically; the abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis. OAF. An earlier branch supplies the 1st and 2nd lumbricals . Lateral branch supplies the 5th lumbrical.
What intrinsic muscles of the hand are innervated by the ulnar nerve?
All the non "1'+2' LOAF" muscles are innervated by the ulnar nerve.
Where do the 4th layer of hand muscles originate from?
The shafts of the Metacarpals
What are the muscles of the 4th layer?
The interossei: 3 palmar (adduct; known as pAd) 4 dorsal (abduct; aka dAb)
Where do muscles of the 4th layer insert?
Onto the lateral side of the digit onto the extensor expansion.
What is the axis of the hand that interossei move fingers relative to?
The middle finger is the axis of the hand with no interossei attachments.
Which muscle is partially supplied by the ulnar nerve?
Muscle supplied partially by ulnar nerve are the 2 medial heads of the flexor digitorum profundus.