forearm, hand and wrist Flashcards
how many bones are in the skeleton
206
appendicular skeleton
- supports body weight
- 126 bones
- essential for mobility
- allows for complex movement
- ensures stability
axial skeleton
- forms central axis of body
- 80 bones
- main support structure
- allow for movement, protection of organs, posture and balance
carpal bones (from radius to ulnar)
- scaphoid
- lunate
- triquetrum
- pisiform
- trapezium
- trapezoid
- capitate
- hamate
- s,l,t,p are proximal
- t,t,c,h are distal
what are CMC joints
connect the carpals to the metacarpals
how many phalanges are there
14
ossification of carpal bones
- capitate. 1-3 months
- hamate. 2-4 months
- triquetrum. 2-3 years
- lunate 2-4 years
- scaphoid 4-6 years
- trapezium 4-6 years
- trapezoid. 4-6 years
- pisiform 8-12 years
what are the arteries in the hand and wrist supplied by
- oxygenated blood by the radial and ulnar artery which are branch’s of the brachial arteries
- form a series of interconnected arterial arches in the hand and supply blood to fingers, palms and wrist
radial artery
- supplies lateral hand and forms deep palmer arch
- lateral to the forearm
- gives rise to the palmar metacarpal arteries which gives blood to the metacarpals and contribute to the digital arteries (in fingers)
ulnar artery
- supplies medial hand including middle and ring finger
- forms superficial palmer arch - beneath skin
- gives rise to the common palmar digital arteries and further divide into proper palmar digital arteries
what do both arteries contribute to
- dorsal carpal arch to the back of the hand
what are veins in hand and wrist responsible for
draining blood from this region and returning it to the heart
- venous system consists of superficial and deep veins paired with the corresponding arteries
what do the superficial veins do’
- drain the skin and superficial tissues of hand and wrist
- located at the surface of the skin
cephalic vein
- superficial
- runs along lateral side of forearm and arm
- corresponds to radial artery
basilic vein
- superficial
- runs down the medial side of the forearm and the arm
- corresponds to ulnar artery
basilic and cephalic vein
join to form dorsal venous plexus which drains the dorsal aspect of the hands and fingers
- connects to b and c veins
ulnar and radial veins
- deep
- accompany the arteries & not as visible
- draining deeper structure of the hand and wrist
- ulnar = medial
- radial = lateral
- join to form the palmar venous arch drains blood from palm and fingers
nerves of hand
- crucial for sensory and motor functions, enabling movement and sensation in upper limb
- primary nerves involved are branches of the brachial plexus
(median, ulnar and radial)
D - superficial branch of radial nerve innervates the lateral dorsum of the hand, thumb, index, middle and half of ring
D - dorsal cutaneous branch of the ulnar nerve innervates half of ring and little
P - median nerve innervates the palmer surface of the thumb, index, middle and lateral half of ring finger.
P - ulnar nerve digital branch innervates little, medial half of ring on the palmar surface
what is the hand primarily innervates by
median and ulnar nerve in the palmar aspect
radial and ulnar nerve in dorsal aspect
medial nerve location
runs near the radial artery until reaches carpal tunnel
ulnar nerve location and radial nerve location
U = runs alongside the ulnar artery
R = runs alongside radial artery in forearm but in the hand the superficial branch runs along the lateral side
extensor tendons
- allow you to straighten your wrist and finger
- pass thru compartment in the wrist known as extensor retinaculum
- helps maintain smooth movement at wrist
major tendons
extensor digitorum- extends index, middle, little and ring
extensor indicis- extend index (isolated)
extensor digiti minimi- extend little (isolated)
extensor pollicis brevis- extend thumb at metacarpophalangeal joint
extensor pollicis longus- thumb (interphalangeal joint)
abductor pollicis longus- extend thumb and abduction at some extent
flexor tendons
- responsible for flexing the fingers and thumbs and originate from muscle in forearm, travel thru wrist into hand
- flexor digitorum superficialis (flexes the middle phalanges of the medial four digits at the proximal interphalangeal joints)
- flexor pollicis longus (flexes the thumb- interphalangeal and metacarpophalangeal joint)
- flexor carpi radialis (flexes wrist and ABDucts the wrist)
- flexor carpi ulnaris (flexes wrist and ADDucts the wrist)
- flexor digitorum profundus (flex index, middle, ring and little)
- palmaris longus (flex wrist)
muscles of hand
- intrinsic= originate within the hand and provide fine motor control
- extrinsic= originate in forearm and control broader movement of hand and fingers
intrinsic muscles - thumb
the inner muscles e.g. thumbs
- located at base of the thumb and resp for movements
- abductor pollicis brevis= abducts thumb
- opponens pollicis= opposes thumb
- adductor pollicis= adducts thumb
- flexor pollicis brevis= flexes thumb
- flexor, abductor and opponens are thenar muscles (thumb muscle)
intrinsic muscles - little finger
- opponens digiti minimi ( opposes the little)
- flexor digiti minimi brevis (flexes little)
- abductor digiti minimi (abducts the little)
- all HYPOTHENAR MUSCLES
central muscles
primarily resp for movement of fingers
- lumbrical (flex mcp while extending the PIP and DIP joints)
extrinsic muscles
originate in forearm, tendon extend into hand and resp for powerful movements of fingers
- flexor muscles flex
- extensor muscles extend
- flexor digitorum profundus and flexor digitorum superficialis are resp for flexing ( grasping stuff)
- extensor digitorum communis extend the fingers at the mcp, pip and dip joint
- when edc contracts, all 4 fingers extend which allow for opening the hand after flexion
- extensor pollicis longus- resp for thumb extension
interossei muscles
- dorsal interossei muscles go in between intermetacarpal spaces
- 4DAB= 4 muscles in each hand, dorsal side of hand, abductor muscles
- palmar interossei muscle adducts the fingers
articulation
- ulnar articulates w humerus
- radius articles with carpals
- in between called inter osseous space - fibrous CT - connects 2 bone together and provide stability
what does radius articulate to
capitulum of humerus= flex and exten of arm
radial notch of ulna= articulates there to form the proximal radio ulnar joint= rotation of arm (pivot)
head of radius
- rounded proximal end of the bone
- crucial 4 movement and stability of elbow joint and proximal radioulnar joint
- disc shapes and smooth rounded surface that’s concave
- articulates w capitulum of the humerus = elbow joint = allow 4 flexion and extension of arm
neck of radius
- narrow cylindrical region that connects head to shaft
- provide support 4 head of radius
- acts as attachment point for muscles
radial tuberosity
- roughened oval prominence
- faces towards ulna
- located on anterior medial aspect, distal to head and neck
- serves as p.o.a for bicep brachii via bicep tendon = key 4 elbow flexion and forearm supination
anterior border
- sharp elognated ridge
- runs longitudinally along anterior surface of radius and extends from radial tuberosity to the distal end of the radius
- provides p.o.a for multiple muscles
posterior border
- prominent ridge located on the posterior side of the radius
- forms distinct ridge that runs parallel to anterior border, on opposite sides of the
- p.o.a for extensor muscles
groove for extensor carpi radialis longus
- on lateral side of radius
- proximal to styloid process
- provide path for the tendon of muscle as it travels down the forearm
- insertion point and helps to protect the tendon
groove for extensor digitorum and extensor indicis
- found on distal end of radius
- protects tendons
styloid process
- prominent bony projection
- located on distal end of radius
- conical and extends downwards from distal end
- situated on lateral side of wrist and serves as p.o.a for ligaments
dorsal tubercle
- small rounded prominence
- serves as a pulley
summary of radius
- long bone
- articulates proximally and distally with the ulna at the proximal and distal radioulnar joints
- PROXIMAL radioulnar joint articulation allows for supination and pronation of the forearm
- articulates distally with the proximal row of carpal bones at radiocarpal joints (scaphoid and lunate)
- articulates proximally at the elbow joint with the capitulum of the humerus at the humeroradial joint
summary of ulna
- long bone
- articulates distally with radius at the distal radioulnar joint
- articulates proximally at the proximal radioulnar joint which allows pronation and supination of the forearm
- articulates proximally at the elbow joint with the trochlea of the humerus at the humeroulnar joint
olecranon
- prominent bony projection proximal end ulna
- bit that sticks out
- fits into olecranon fossa of the humerus
trochlear notch
- large c shaped depression on the proximal end of the ulna
- in between olecranon and radial notch
- articulates with trochlear of the humerus and allows for a hinge like motion (flexion nd extension)
coronoid process
- triangular forward-facing structure just below trochlear notch
- fits into coronoid fossa of humerus when elbow flexed
- prevents ulna from slipping out of place
- p.o.a for muscles n ligs
radial notch
- smooth concave depression on lateral side of coronoid process
- articulates with head of radius to form part of the proximal radioulnar joint
- gives attachment to the annular ligament of the radius
- holds it into the radial notch = allow pronation and supination of forearm
supinator crest
- sharp prominent ridge
- extends downwards towards middle of ulna
- serves as attachment site for the supinator muscle (resp for supination of forearm)
- annular ligament also attaches near
posterior border
- sharp palpable ridge
- extends from olecranon to distal end of ulna
vertical ridge
- extends down the shaft of ulna as muscle attachment point
head
- rounded distal end of ulna
- positioned laterally
- articulates with radius, distal radioulnar joint and triangular fibrocartilage complex (TFCC = stabilises the wrist)
styloid process
- pointy bone projection on the distal ulna
- serves as attachment point for ulnar collateral ligament and TFCC
rotation of lower arm
- lower arm primarily rotates thur the action of the radius and ulna w help of muscles
- radial head fits into radial notch of ulna, prox and dist
- head of ulna articulates with ulnar notch of the radius
- parallel when palm is supinated but when pronated radius crosses over ulna at the wrist
SUPINATE: - supinator muscle and bicep[ brachii contract= radius rotate outwards and uncross from ulna
PRONATE: - pronator teres & quadratus muscles contract pulling the radius over the ulna= rotate hand downwards
main arteries that supply blood to forearm
radial and ulnar
what do radial and ulnar artery do
- Provide necessary blood flow to forerarm, muscle, bone n tissue
- radial artery runs alongside lateral side of the forearm and ulna runs alongside medial
collateral arteries
branches that form connections between major arteries and are essential for maintaining an adequate blood supply
- in case of arterial obstruction
- if blocked, collaterals take on more blood flow
types of collateral arteries
- radial collateral
- ulnar collateral
radial collateral artery
- supplies blood 2 muscle on lateral side of the forearm
- contribute to connections around the elbow joint with radial recurrent artery
ulna collateral artery
- contribute 2 blood supply on medial side of below joint
- connects with ulnar recurrent artery
common interosseous arteries
- travel between ulna nd radius providing collateral circulation
major superficial veins
cephalic and basilic
cephalic
- runs alongside lateral side and drains into the subclavian vein
basilic
- runs down medial side of forearm and drains into the brachial or auxiliary vein
median cubital vein
- found in the cubital fossa at the front of the elbow
- connects cephalic and basilic
superficial anterior muscles
- anterior compartment muscles originate on the humerus, typically on carpals, metacarpal, and phalanges
- function primarily as flexors
names of superficial anterior muscles
- palmaris longus
- flexor carpi radialis
- flexor carpi ulnaris
- flexor digitorum superficialis (largest one)
names of superficial posterior muscles in forearm
- extensor carpi radialis longus
- extensor carpi ulanris
- extensor carpi radialis brevis
- extensor digitorum
names of deep anterior muscles
- flexor digitorum profundus
- flexor pollicis longus
- pronator quadratus
deep posterior muscles
- abductor pollicis longus
- extensor pollicis longus
- extensor indicis
- extensor pollicis brevis
