radiocarpal joint
-carpal bones involved
scaphoid
lunate
triquetrum articulates via a fibrocartilaginous disc
how does the ulna articulate at the wrist joint?
does not articulate with the carpal bones
has a fibrocartilaginous disk to the radius
distal radioulnar joint
- how are the radius and ulna attached
- how do they articulate at this joint?
attached the entire extent of the forearm by an interosseus membrane
distal radioulnar joint has an articular joint with the ulnar notch of the radius “rolling” on the ulna
radiocarpal ligament names
radial and ulnar collateral ligaments
ligaments of the MCP, PIP and DIP joints
radial and ulnar collateral ligaments
where is the longitudinal axis in the hand
through the 3rd finger
thumb actions
radial abduction/adduction palmar abduction/adduction opposition MP flexion/extension IP flexion/extension
finger MCP actions
flexion/extension
abduction/adduction
rotation
finger PIP and DIP actions
flexion/extension
finger rotation is technically_____, since the MCP has ____ degrees of freedom
technically circumduction, a movement that outlines a cone
MCP has only 2 degrees of freedom
thumb radial abduction/adduction
- what is another name?
- where does this motion occur
- what plane is it in?
flexion/extension of thumb occurs at CMC joint in frontal (coronal) plane
palmar abduction/adduction
- what is another name
- where does this motion occur
- what plane is it in
abduction/adduction
occurs at CMC
in sagittal plane
fascia of wrist and hand
- continuation of
- fascial thickenings occur where and are named _____
continuation of antebrachial fascia (deep fascia of forearm) thickenings -near distal end of forearm -flexor retinaculum (anterior) -extensor retinaculum (posterior)
flexor and extensor retinaculi of wrist
-function
fulcrums for the tendons of the forearm flexors and extensors
flexor retinuaculum of wrist
- function (apart from acting as a pulley)
- some texts say ____ performs this function
closes off the carpal groove (sulcus) for the formation of the carpal tunnel
some texts say a transverse carpal ligament performs this function
flexor retinaculum of wrist vs. transverse carpal ligament
flexor retinaculum
-made of superficial collagen fibers running transversely as part of antebrachial fascia
transverse carpal ligament
-attached to
–carpal bones
–tubercles of the scaphoid and trapezium (radially)
–pisiform and hook of the hamate (ulnar side)
we will consider them to be the same in this class
deep fascia of the palm
- thin over…
- thickened along…
thin -thenar eminence -hypothenar eminence dthick -middle of palm as palmar aponeurosis
what marks the lateral and medial boundaries of the central compartment of the palm
-central compartment is separated from…
lateral and medial septa mark the boundaries
separates from the thenar (lateral) and hypothenar (medial) eminences
central compartment of palm
- palmar extension of…
- carries…
- this fascial space is continuous with…
palmar extension of carpal tunnel
carries
-tendons of the superficial and deep digital flexor muscles
continuous with the fascial plane separating the superficial and deep muscles of the anterior compartment of the forearm
if the central compartment of the palm is penetrated (such as by puncture wounds from a drill bit), what can happen?
uncontrolled infection can spread into the forearm
what other areas on the palm can be potential spaces for harboring infections
thenar eminence
hypothenar eminence
adductor pollicis muscle
dorsal surface of the hand surface markings
tendons of extensor digitorum (best seen with digits extended and abducted)
veins
-part of the dorsal venous plexus of the hand
-a number can be seen to enter the cephalic vein on the lateral side of the wrist
palmar surface of the hand surface markings
transverse and longitudinal fissures
-within thick skin of palm
digital flexion creases
-mark the levels of the MCP joint (proximal digital crease), PIP (middle digital crease), and DIP (distal digital crease)
nerves of the hand
nerves of the forearm
median
ulnar
radial
which muscles in the hand do the median and ulnar nerves control
short muscles of the hand
what muscles of the hand does the radial nerve control
entirely sensory over the dorsolateral part of the hand and thumb
median nerve
-enters hand via ____ and with _____
enters hand via carpal tunnel with... tendons of -flexor digitorum superficialis -flexor digitorum profundus -flexor pollicis longus
median nerve recurrent branch
- location
- function
location
-seen on the surface of the thenar eminence
-moved deep and proximally to be seen branching just distal to the flexor retinaculum
function
-motor nerve to thenar eminence muscles (except adductor pollicis)
median nerve motor function
motor innervation to lumbricals 1 and 2
median nerve sensory innervation
radial 1/2 of palm
dorsal surface of thumb
lateral 2 1/2 digits (1/2 digit is variable and evident with dissection of the digital branches in the palmar side of the hand)
sensory component extends onto the distal end of the dorsal side of digits 2 through half of four
ulnar nerve
- enters hand…
- function
enters hand lateral to pisiform along with ulnar artery -superficial to wrist at this point function -nerve of fine movement of the hand -sensory and motor component
ulnar nerve sensory information
-done by…
superficial branch to palmar surface of ulnar digit and a half
dorsal cutaneous branch that innervates the dorsal surface of ulnar digit and a half
-palmar branch that innervates ulnar half of palm
ulnar nerve motor innervation
-done by…
deep branch (also sensory to joint) that innervates
-hypothenar muscles
-lumbricals 3 and 4
-adductor pollicis
-dorsal and palmar interosseus
all these small muscles give us fine motor control of digits (not the muscles of the forearm)
radial nerve
- motor component to short muscles of the hand
- how does it control hand movement
no motor component to the short muscles of the hand
controls hand movement due to innervation of muscles of the extensor compartment
radial nerve sensory innervation
-done by…
superficial branch of the radial nerve
-covers the radial 1/2 of the dorsum of the hand and thumb extending only up the proximal 1/2 of digits 2-4
arteries/arterial structures of the hand
radial artery
ulnar artery
superficial palmar arterial arch
deep palmar arterial arch
radial artery superficial palmar branch
- where does it split off
- anastomoses with…
branch from radial artery before it enters the extensor compartment through the anatomical snuff box
anastomoses with
-superficial palmar arterial arch of ulnar artery
radial artery after superficial palmar branch branches off
- where does it go?
- enters _____ as the _____
goes through the snuff box and curves around the dorsal side of the thumb
enters the palm deep as the deep palmar arterial arch
anastomoses with the ulnar artery
deep palmar arterial arch (end of radial artery)
-branches
princeps pollicis artery
radialis indicis artery
digital arteries
ulnar artery
-branches
deep palmar branch
superficial palmar branch
deep palmar branch of ulnar artery
-anastomoses with…
deep palmar artery of radius
superficial palmar artery of ulnar artery
-forms _____ with _____
forms superficial palmar arch with superficial palmar arch of radius
superficial palmar arterial arch
- formed primarily by…
- where is it formed
- deep to the___
formed primarily by the superficial branch of the ulnar artery
crosses the palm about midway across the metatarsals
deep to palmar aponeurosis
deep palmar arterial arch
- formed primarily by…
- location
formed primarily by the deep branch of the radial artery
located near the proximal ends of the metatarsals close to the carpal tunnel
carpal tunnel syndrome
-etiology
swelling decreases the space in the carpal tunnel and increases the pressure on the median nerve and tendons fo the forearm flexors
what can limit space in the carpal tunnel lead to carpal tunnel syndrome
irritation
infections
abnormal growth of the flexor retinaculum
genetics
sensory components of carpal tunnel syndrome
pain to anesthesia over the sensory map of the hand
motor components of carpal tunnel syndrome
weakenss of the thenar muscles
atrophy of the thenar muscles
with carpal tunnel syndrome, weakness and pain may occur due to pressure on the synovial sheaths of the…
flexor digitorum superficialis
flexor digitorum profundus
ulnar nerve damage
-sensory components
anesthesia or hypoesthesia over ulnar nerve sensory map of hand
ulnar nerve damage
-motor components
loss of fine motor control due to loss of
-lumbricals 3 and 4
-all interossei
thumb only has weak adduction due to loss of adductor pollicis
wrist drop
-evidence of…
radial nerve damage
where can the radial nerve be damaged to lead to wrist drop?
as high as the arm as the radial nerve travels around the posterior side of the humerus
traveling over the lateral epicondyle
wrist drop
-muscles affected
loss of
- extensor digitorum (posterior interosseus; branch of radial enrve)
- extensor carpi ulnaris
- extensor carpi radialis longus
- extensor carpi radialis brevis
what other actions will be affected if wrist drop is present due to radial nerve damage
finger extension
thumb extension
thumb abduction
