L4 Anterior Compartment: Arm, Forearm, Hand Flashcards
Elbow joint shape and movement
Hinge shaped synovial joint
Humeral-radial and humeral-ulnar
Capitulum and radial head meet (lateral)
Trochlea and trochlear notch meet (medial)
Transverse axis allows for flexion and tension only
Proximal radio-ulnar joint shape and movement
Between radial notch of ulnar and radial head
Pivot shaped synovial
Vertical axis allows rotation of radius on ulna (pronation/supination)
What major branches make up the anterior compartment of the brachial plexus of the arm? And what are their main actions?
Musculocutaneous n.
Flexion of arm and forearm
Supination of forearm
Median and ulnar n. Pass through arm but DONT innervate anything
(Ulnar nerve gives funny bone response)
What major branches make up the anterior compartment of the brachial plexus of the forearm? And what are their main actions?
Median n. , ulnar n.
Flexion of forearm, WRIST and FINGERS
Pronation of forearm
Distal radio-ulnar joint shape and movement
Pivot shaped synovial joint
Between distal end radius and ulna
Vertical axis allows rotation of radius on ulna (pronation/supination)
Ulna does not touch carpals because of articular disc
Why is adduction of the hand greater than abduction?
Styloid process of the radius limits abduction
Wrist (radiocarpal) joint shape and movement
Conyloid shaped synovial joint
Between radius and lunate and scaphoid of wrist (ulna doesn’t participate)
Transverse axis allows flexion and extension
Anteroposterior axis allows abduction and adduction
Carpometacarpal joints shape and movement
Between carpal and metacarpals
Fingers -plane shaped synovial allow adduction and abduction
Thumb- saddle shaped synovial allows flexion, extension, adduction, abduction, circumduction
What are three ligaments of the elbow?
Radial collateral ligament
Ulnar collateral ligament
Anular ligament
What are parts of the elbow that form the joint ?
Capitulum and radial head
Trochlea and trochlear botch
What compartment is the musculocutaneous nerve in, where does it travel, and what does it innervate/what sensory info does it get?
Anterior
Lateral cord pierces through coracobrachialis travels between biceps brachii and coracobrachialis/brachialis
Terminates at the lateral cutaneous nerve of forearm
Motor innervation of C5 and C6
Sensory info from lateral forearm (C6)
How can you test C5 and C6 spinal cord segments?
Hit inner elbow joint and observe biceps reflex
Brief jerk= good
Prolonged/excessive response =bad
What 3 ligaments hold radius and ulna together?
Anular ligament
articular disc at distal radio-ulnar joint
interosseous membrane- seen between radius and ulna in cross-section of forearm
Metacarpophalangeal joints shape and movements
Condyloid shaped synovial joints
Rotation around transverse axis- flexion and extension
Rotation around anteroposterior axis- abduction, adduction, circumduction
What are the four metacarpal ligaments?
Deep transverse metacarpal ligament
Lateral collateral ligaments
Medial collateral ligaments
Palmar ligament
Interphalangeal joints shape and movement?
Hinge shaped synovial
Rotation around transverse axis-flexion and extension
2 on fingers
Proximal interphalangeal joint (PIP)
Distal interphalangeal joint (DIP)
1 on thumb
Ligaments associated with interphalangeal joints
Palmar
Lateral collateral
Medial collateral
Superficial muscles of anterior compartment of forearm
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi unlaris
Intermediate muscles of anterior compartment of forearm
Flexor digitorum superficialis
Deep muscles of anterior compartment of forearm
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratics
What’s the relationship of the tendons of flexor digitorum superficialis and profundus?
Tendon of FDP goes through tendon of FDS and extends further
What compartment is the median nerve in, where does it travel, and what does it innervate/what sensory info does it get?
Anterior
Leaves cubical fossa by passing btw two heads of pronator teres
Passes deep to flexor retinaculum
(Palmar branch passes superficial to flexor retinaculum)
Innervate MOST muscles of anterior compartment (C7,8)
Sensory info from lateral palm and tip of thumb (C6,7)
Whats the Anterior inteosseus n
Branch of median nerve
Travels distally to median n.
Innervate muscles in the deep layer except FDP
What compartment is the ulnar nerve in, where does it travel, and what does it innervate/what sensory info does it get?
Anterior
Enters forearm by passing posteriorly around medial epicondyle
Travels medially w ulnar a.
Innervate FCU and medial part of FDP (C8,T1)
Sensory info from medial palm, tip of little finger (C8)
What’s the roof of the carpal tunnel called and the four bones on its corners?
Flexor retinaculum
Scaphoid Pisiform Trapezium Hamate(hook)
What’s ulnar/Guyons canal
Canal right above carpal tunnel which contains ulnar a. and ulnar n.
What are joints of the hand/wrist
Carpometacarpal
Metacarpophalangeal (MP)
PIP
DIP
What are the tendons / nerves within carpal tunnel you should know?
Median n
FPL, FCR, FDS, FDP tendons
What compartment are all muscles of the hand part of and what are the 5 compartments?
Anterior
Thenar-pollex
Central-long flexor tendons and lumbricals
Adductor- adductor pollicis
Interosseous - interosseous muscles
Hypothecate - digit V
Muscles of thenar and adductor compartment
Flexor pollicis brevis
Abductor pollicis brevis
Opponens pollicis
Adductor pollicis
Flexor pollicis brevis is separated into two heads what innervates each?
Deep head - deep branch of ulnar n
Superficial head- recurrent branch of median n
Muscles of the hypothenar compartment
Flexor digiti minimi brevis
Abductor digiti minimi
Opponens digiti minimi
What are the muscles of the Interosseous compartment?
3 Palmar interossei
On pinky, ring, pointer
Adduction (fingers to middle finger)
4 dorsal interossei
Little deeper
Abduction (fingers away from middle finger)
What are the muscles of the lumbricals compartment?
4 lumbricals
Originate on tendons of FDP and insert on digits 2-5
Simultaneous flexion of MP joints and extension of IP joints
What muscle innervation and sensory is the median nerve responsible for in the hand?
recurrent branch of median n. innervates thenar muscles (except deep head of FPB) and lateral lumbricals (C8)
C6,7 provide sensory info from thumb, middle and pointer fingers and portion of palm that lines up with them
What muscle innervation and sensory is the ulnar nerve responsible for in the hand?
Deep branch of ulnar n. innervates hypothenar, interossei, medical lumbricals, and deep head of FPB (T1, C8)
Superficial branch of ulnar n. gives sensory info from medial palm, tip of little finger from
