Upper Limb (part 4) Flashcards
What bones form the radial-carpal joint?
Radius, Scaphoid, and Lunate bones
Which bones make up the Proximal row of Carpal bones? (4)
From Lateral to Medial:
-Scaphoid
-Lunate
-Triquetrium
-Pisiform
Which bones make up the distal row of carpal bones? (4)
These bones articulate with the metacarpal bones to form the carpal-metacarpal joints.
From Lateral to Medial:
-Trapezium
-Trapezoid
-Capitate
-Hamate
A large mound of muscle proximal to the thumb
Thenar Eminence
A large mound of muscle proximal to the little finger
Hypothenar Eminence
Found between the Thenar and Hypothenar Eminences
Intermediate Compartment
A triangular shaped structure that begins in the intermediate compartment.
-Has slips of connective tissue that feed into the digits and cover the proximal portions of the digits
-Improves our grasp by creating artificial friction with the skin when you pick up something
Palmar Aponeurosis
A band of tissue running between the two eminences
-Proximal to the Palmar Aponeurosis
Flexor Retinaculum
Joins the lateral, distal carpal bones (Trapezium & Trapezoid) with the medial, distal carpal bones (Capitate & Hamate) to form the Carpal Concavity.
Flexor Retinaculum
Formed by the Carpal bones attaching to the Flexor Retinaculum to make an oval space.
Carpal Tunnel
What structures run through the Carpal Tunnel? (4)
-MEDIAN NERVE
-Tendons of the Flexor Digitorum Superficialis m., Flexor Digitorum Profundus m., and Flexor Pollicis Longus m.
What causes Carpal Tunnel Syndrome?
Compromised Median Nerve due to buildup of pressure, usually due to fluid retention (edema, arthrtitis)
What structures do NOT go through the Carpal Tunnel? (5)
-Palmar Cutaneous Branch of the Median Nerve (branches off before tunnel, runs over it)
-Ulnar Nerve and Ulnar Artery (pass anterior to the tunnel)
-Flexor Carpi Radialis m. (runs through split in the tunnel fibers)
-Palmaris Longus m. (passes over the tunnel)
Nerve that branches off of the Median Nerve just before it gets to the Flexor Retinaculum. Runs over the tunnel, so not affected by CTS.
-Supplies General Sensation to the Thenar Eminence (lateral palm)
Palmar Cutaneous Nerve
Will CTS cause changes in sensation to the skin over the Thenar Eminence (lateral palm)?
NO: the Palmar Cutaneous Nerve branches off before the tunnel.
After the Median Nerve passes through the Carpal tunnel, it gives off this branch in the palm of the hand.
Supplies motor innervation to the muscles of the Thenar Eminence.
-Abductor Pollicis Brevis m.
-Flexor Pollicis Brevis m.
-Opponens Pollicis m.
Recurrent Branch of the Median Nerve
Which 3 muscles are innervated by the Recurrent Branch of the Median Nerve? (Muscles of the Thenar Eminence)
-Abductor Pollicis Brevis m. (abducts thumb)
-Flexor Pollicis Brevis m. (flexes thumb)
-Opponens Pollicis m. (thumb and little finger form a circle)
Found on the dorsal hand and more proximal.
-Connects the radius and the ulna.
-Crosses tendons coming from above and inserts them into the digits of the hand.
-Shifts the tendons down when dorsiflexing the wrist
-Has Compartments 1-6, with 1 starting on thumb side
Extensor Retinaculum
What are the contents of Compartment 1?
Abductor Pollicis Longus m. and Extensor Pollicis Brevis m.
Injury affecting Compartment 1 - occurs with overuse of thumb leading to tendon rubbing back and forth too much, causing pain, swelling, and tendonitis of these tendons
DeQuervain’s Tenosynovitis
What are the contents of Compartment 2?
Extensor Carpi Radialis Longus m. and Extensor Carpi Radialis Brevis m.
What are the contents of Compartment 3?
Extensor Pollicis Longus m.
What are the contents of Compartment 4?
Extensor Digitorum m. and Extensor Indicis m.
What are the contents of Compartment 5?
Extensor Digiti Minimi m.
What are the contents of Compartment 6?
Extensor Carpi Ulnaris m.
What is the purpose of the 6 compartments?
The Extensor Retinaculum crosses over these to hold them in place while you’re dorsiflexing your wrist and fingers.
Which nerve supplies sensation to:
-Dorsal, lateral side of hand
-Dorsal side of thumb
Superficial Radial Nerve