The forearm and cubital fossa Flashcards
Articulations between the ulna and radius? (2)
Proximal radioulnar joint- radius articulates with radial notch of ulna=pivot join. Allows pronation and supination (radius crossover ulna in pronation)
Distal radioulnar joint: Near wrist between ulnar head and ulnar notch of radius
What membrane lies between the radius and ulna?
Features of membrane (2)
Interosseous membrane- thick and fibrous
Supination- what is it how is this achieved?
Palm up. Supinator(post forearm m) and biceps brachii (ant forearm m) contact and the elbow is flexed
Pronation- what is it how is this achieved?
Palm Down- Pronator teres and pronator quadrates contract (ant arm muscles)
Cubital fossa- what is it
triangular depression anterior to elbow joint contains superficial veins used for IV connotations and blood samples
Superior border of cubital fossa
imaginary border between lateral and medial epicondyles
Floor of cubital fossa
Brachialis
lateral border of cubital fossa
Brachioradialis
Medial border of cubital fossa
Pronator teres
Superficial muscles of anterior arm
Pronator teres, flexor carpi radialis, palmaris longus and flexor carpi ulnaris
Intermediate muscles of anterior arm
Flexor Digitorum Superficialis
Deep muscles of anterior arm
Flexor digitorum profundus, flexor pollicus longus, Pronator quadratus
Action of most of the muscles in the anterior forearm
Flexors of the wrist, fingers and thumb
Origin of the superficial flexors
Medial epicondyle of humerus
PT, FCU,FCR,PL which order are they in from the most lateral
PT, FCR, PL, FCU
Pronator teres- attachment, action and innervation
Laterally to mid shaft of radius, pronates forearm, Median N
Flexor carpi radialis- attachment, action and innervation
Base of metacarpal 2&3. Flexion and abduction at wrist, Median N
Palmaris longus - attachment, action and innervation
Absent in 15% population, inserts onto the flexor retinaculum (palmar aponeurosis(which band of CT in wrist)) Flexion of wrist. Median N
Flexor carpi ulnaris - attachment, action and innervation
Attaches onto the pisiform carpal bone. Flexion and abduction at wrist. Ulnar N
what muscles are vulnerable when the palmar spect of the hand is injured
Muscles of the anterior arm
Flexor digitorum superficialis- origin, attachment, action and innervation
from medial epicondyle and radius. Gives rise to 4 tendons that travel under flexor retinaculum through carpal tunnel and attach to middle phalanges of the 4 fingers.
Flexes metacarpopharengeal joints and proximal interpharengeal joints of 4 fingers and flexes the wrist.
Innervation: Median N (by 2nd finger
Ulnar NV bundle lies medial to FDS and radial NV bundle lies lateral
Flexor digitorum profundus- origin, attachment, action and innervation
From ulna and Interosseous membrane. Gives rise to 4 tendons that travel under flexor retinaculum through carpal tunnel and attach to distal phalanges of the 4 fingers.
Only m that flexes distal interpharengeal joints of 4 fingers. Also flexes the wrist.
Medial 1.5 (4th and 5th finger)- Ulnar N the rest by anterior interosseous N (deep branch of median N)
Flexor pollicus longus- origin, attachment, action and innervation
Lateral to FDP. Originates from ant radius and Interosseous membrane. Inserts onto distal phalanx of thumb. Flexes thumb
anterior interosseous N (deep branch of median N)
Pronator quadratus- origin, attachment, action and innervation
From ant radius and inserts onto ant ulna.
Pronates the forearm
Anterior interosseous N (deep branch of median N)