Cubital Fossa and Forearm Flashcards
Boundaries of the Cubital Fossa
- Superior (base)- imaginary line between medial and lateral epicondyles of humerus
- Medially- pronator teres
- Laterally- brachioradialis
- Inferiorly (apex)- meeting of brachioradialis and pronator teres
- Posteriorly (floor)- brachialis superiorly and supinator muscle inferiorly
- Anteriorly (roof)- skin, superficial and deep fasciae and bicipital aponeurosis
List the superficial content of the cubital fossa
o Median cubital vein
o Medial cutaneous nerve of forearm
o Upper lateral cutaneous nerve of forearm
list the deep content of the cubital fossa
o Median nerve
o Biceps brachii tendon
o Radial nerve deep to brachialis
o Terminal end of brachial artery
o Radial and ulnar arteries
o Radial recurrent artery
one function of the bicipital aponeurosis
Bicipital aponeurosis separates
superficial and deep structures
of the cubital fossa
Vein associated with IV and venipuncture injections
median cubital vein
Vein that runs diagonally from cephalic vein of forearm to basilic vein of arm
medial cubital vein
which vein is fixed by a communicating perforating vein (pierces the bicipital aponeurosis as it becomes
superficial)
median cubital vein
bone that articulates with 2 carpal bones of the wrist: lunate medially and scaphoid laterally
radius
bone that articulates proximally with the humerus at the capitulum and medially with the ulna on both proximal
and distal ends
radius
List the 9 landmarks of the radius
radial head, radial neck, radial tuberosity, shaft, interosseus border, anterior oblique line, ulnar notch, styloid process, suprastyloid crest
Describe the radial head landmark of the radius
- Radial head
* Round articular structure on the proximal end of the radius
* Cupped proximal surface (articular fovea or facet) articulates with the capitulum of the humerus
* The articular circumference articulates with the ulna
describe the radial neck landmark of the radius
- Radial neck
* Slender segment of the radius between the head and the radial tuberosity
describe the radial tuberosity landmark of the radius
- Radial (bicipital) tuberosity
* Blunt variably shaped structure on the anteromedial side of the proximal radius
* Marks the insertion of the biceps brachii
Describe the landmark of the radius: shaft
Long, thin section between the radial tuberosity and the expanded distal end
* Divided into 3 surfaces- anterior, posterior and lateral
Describe the landmark of the radius: interosseus border
- Sharp medial edge of the radial shaft
- Serves as attachment site for interosseus membrane which divides forearm into anterior and
posterior compartments
Describe the landmark of the radius: anterior oblique line
Gives origin to the extrinsic muscles of the hand
Describe the landmark of the radius: ulnar notch
Concave articular hollow surface on the medial corner of the distal radius, articulating with distal
ulna
Describe the landmark of the radius: styloid process
Sharp projection on the lateral side of the distal radius
Describe the landmark of the radius: Suprastyloid crest
Runs obliquely over the styloid process on the anterior surface
* Serves as attachment for brachioradialis
Describe the landmark of the ulna: olecranon
- Olecranon
* Most proximal part of the bone
* Massive blunt process
* Triceps brachii inserts onto the tuberosity of this process
Describe the landmark of the ulna: trochlear notch
- Trochlear notch
* Articulates with the trochlea of the distal humerus
* Rotary motion is restricted at the ulnar part of the elbow which limits its ability to rotate along its long
axis
Describe the landmark of the ulna: coronoid process
- Anterior beak-shaped projection at the base of the trochlear notch
Describe the landmark of the ulna: ulnar tuberosity
- Roughened depression immediately inferior to the coronoid process
- Marks the insertion of the brachialis muscle
Describe the landmark of the ulna: radial notch
- Small articular surface for the radius
- Located along the lateral margin of the coronoid process
Describe the landmark of the ulna: shaft
- Long segment between the brachial tuberosity and the distal end of the ulna
- Divided into 3 surfaces by the 3 borders- interosseus, anterior (medial), posterior
Describe the landmark of the ulna: interosseus border
- Sharpest border of the ulna
- Lies opposite to radius
- Between the anterior and posterior surfaces
Describe the landmark of the ulna: ulnar head
- Enlarged distal end of the bone
Describe the landmark of the ulna: ulnar styloid process:
- Sharp distalmost projection of the ulna
- On the posteromedial aspect of the bone
- Provides attachment to the ulnar collateral ligament of the wrist
- Separated from the remainder of the head by a deep groove, the fovea
Describe the landmark of the ulna: articular circumference
- Distal, lateral, round articulation that conforms to the ulnar notch of the radius (in the same way that
the radial head conforms to the radial notch of the proximal ulna)
Type of joint in the elbow joint
hinge type synovial joint
What movements does the elbow joint allow
o Flexion by brachialis and biceps brachii
o Extension by triceps brachii assisted by anconeus
The elbow joint has 2 articulations. Describe the articulations?
- Articulation:
1. Humeroulnar
o Trochlear of humerus and trochlear notch of ulna
2. Humeroradial
o Capitulum of humerus and head of radius
Describe the radial collateral ligament
o Fan-like
o Extends from lateral epicondyle of humerus and blends distally with the anular ligament of the
radius
Describe the anular ligament
o Encircles and holds the head of the radius in the radial notch of the ulna
o Forms the proximal radio-ulnar joint which allows the pronation and supination of the forearm
describe the ulnar collateral ligament
Ulnar collateral ligament
o Triangular
o Extends from the medial epicondyle of the humerus to the coronoid process and olecranon of
the ulna
o Consists of 3 bands:
1. The strongest anterior cord-like band
2. The weakest posterior fan-like band
3. The slender oblique band deepens the socket for the trochlear of the humerus
What is the blood supply of the elbow joint
Anastomosis around elbow joint:
* Inferior ulnar collateral artery anastomoses with anterior ulnar recurrent artery
* Superior ulnar collateral artery anastomoses with posterior ulnar recurrent artery
* Middle collateral branch of profunda brachii a. anastomoses with recurrent interosseus a.
* Radial collateral branch of profunda brachii artery anastomoses with radial recurrent artery
innervation of the elbow joints
Musculocutaneous, radial and ulnar nerves
Describe the bursae in the elbow joint
o Bursae:
1. Intratendinous olecranon bursa- in the tendon of triceps brachii
2. Subtendinous olecranon bursa- between olecranon and triceps tendon
3. Subcutaneous olecranon bursa- in subcutaneous tissue over olecranon
4. Bicipitoradial bursa- separates biceps tendon from the anterior part of the radial tuberosity and
reduces abrasion
Type of joint of the proximal radio-ulnar joint
Pivot type synovial joint
Articulation of the proximal radio-ulnar joint
Articulation: head of radius and radial notch of ulna
Describe the ligament of the proximal radio-ulnar joint
- Anular ligament:
o Attached to ulna anterior and posterior to radial notch
o Creates a ring that completely encircles the head of the radius
o Synovial membrane continues distally as sacciform recess of proximal radio-ulnar joint on the
neck of the radius
(Anular ligament allows the radius to rotate
within the anular ligament
without binding, stretching or
tearing the synovial membrane)
Blood supply of the proximal radio-ulnar joint
Blood supply:
o Radial portion of the peri-articular arterial anastomosis of elbow joint
o Radial and middle collateral arteries anastomose with the radial and
recurrent interosseus arteries
List the movements of the proximal radio-ulnar joint
- Supination
- Pronation
Muscles involved with supination at the proximal radio-ulnar joint
o When there is no resistance, supinator acts
o With resistance, biceps brachii acts with assistance from extensor pollicis longus and extensor
carpi radialis longus
Muscles involved with pronation at the proximal radio-ulnar joint
o Primarily pronator quadratus
o Secondarily pronator teres
o When forearm is in mid-pronated position (palm facing thigh), flexor carpi radialis, palmaris
longus and brachioradialis act
nerves that allow for supination at the proximal radio-ulnar joint
musculocutaneous and radial nn.
nerves that allow for pronation at the proximal radio-ulnar joint
median nerve
type of joint of the distal radio-ulnar joint
Pivot type synovial joint
Describe the movement that can occur at the distal radio-ulnar joint
- Pronation
o Distal end of the radius rotates anteromedially crossing over the ulnar anteriorly - Supination
o Radius uncrosses from ulna- its distal end rotates posterolaterally to make the bones parallel
Blood supply and innervation of the distal radio-ulnar joint
o Anterior and posterior interosseus arteries
o Anterior and posterior interosseus nerves
type of joint at the wrist joint
Condyloid type synovial joint
what are the 4 ligaments of the wrist joint
palmer radiocarpal ligaments, dorsal radiocarpal ligaments, ulnar collateral ligament, radial collateral ligament
the ligament that :
o Attached to radial styloid process and scaphoid
o Strengthens the joint laterally
radial collateral ligament
ligament that:
o Attached to ulnar styloid process and triquetrum
o Strengthens the joint medially
ulnar collateral ligament
the ligament that:
o Pass from radius to the 2 rows of carpals
o Strong and directed so that the hand follows the radius during supination of the forearm
palmar radiocarpal ligament
the ligament that:
o Take the same direction as palmar radiocarpal ligaments so that the hand follows the radius
during pronation of the forearm
dorsal radiocarpal ligament
blood supply to the wrist joint
Branches of the dorsal and palmar carpal arches
innervation of the wrist joint
From anterior interosseus branch of median n., posterior interosseus branch of radial n. and the
dorsal and deep branches of the ulnar n.
do superficial muscles cross the elbow joint
true
list the superficial muscles of the anterior flexor-pronator compartment
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
what is the intermediate muscle
Flexor digitorum superficialis
list the deep muscles of the anterior flexor-pronator compartment
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
innervation of the pronator teres
median nerve
innervation of the Flexor carpi radialis
median nerve
innervation of the Palmaris longus
median nerve
innervation of the Palmaris longus
ulnar nerve
innervation of the Flexor digitorum superficialis
median nerve
innervation of the Flexor digitorum profundus
lateral half - median nerve
innervation of the Flexor pollicis longus
anterior interosseous n. from median n.
innervation of the pronator quadratus
anterior interosseous n. from median n.
innervation of the brachioradialis
radial nerve
innervation of the extensor carpi radialis longus
radial nerve
innervation of the Extensor carpi radialis brevis
Deep branch of radial n.
innervation of the extensor digitorum
Deep branch of radial n.
innervation of the Extensor digiti minimi
Deep branch of radial n.
innervation of the Extensor carpi ulnaris
Deep branch of radial n.
innervation of the Supinator
Deep branch of radial n.
innervation of the extensor indicis
Posterior interosseus n. from
deep branch of radial n.
innervation of the Abductor pollicis longus
Posterior interosseus n.
innervation of the extensor pollicis longus
Posterior interosseus n.
innervation of the extensor pollicis brevis
Posterior interosseus n.
Pronators of the forearm:
- Pronator teres
- Pronator quadratus
flexors of the wrist:
- Flexor carpi radialis (also abducts wrist)
- Flexor carpi ulnaris (also adducts wrist)
- Palmaris longus
Flexors of the fingers:
- Flexor digitorum superficialis (middle
phalanges) - Flexor digitorum profundus (distal
phalanges)
Flexor of the thumb:
- Flexor pollicis longus
supinator of forearm:
Supinator
extensors of wrist:
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor carpi ulnaris
extensors of the fingers:
- Extensor digitorum (4 fingers)
- Extensor indicis (index finger)
- Extensor digiti minimi (little finger)
Extensors of the thumb
- Extensor pollicis longus
- Extensor pollicis brevis
abductor of the thumb:
- Abductor pollicis longus
distal articulation of the ulna?
Articulates distally with the ulnar notch of the radius and with the articular disc that separates it from
the carpal bones
Proximal articulation of the ulnar
Articulates proximally with the trochlea of the humerus and with the head of the radius
Longest, thinnest bone in the forearm?
ulna
muscles that flex the wrist joint
Flexion- Flexor carpi radialis and flexor carpi ulnaris, with assistance from flexors of the fingers
and thumb, palmaris longus and abductor pollicis longus
muscles that extend the wrist joint
Extension- extensor carpi radialis longus AND brevis, extensor carpi ulnaris, with assistance
from extensors of the fingers and thumb
muscles that abduct the wrist joint
Abduction- abductor pollicis longus, flexor carpi radialis, extensor carpi radialis longus AND
BREVIS (limited to 15° by radial styloid process)
muscles that adduct the wrist joint
Adduction- simultaneous contraction of extensor carpi ulnaris and flexor carpi ulnaris