2.4.3. Anatomy Lab - Wednesday - Lab Palm Hand Neuro Flashcards
What does the thenar compartment refer to, and what structures does it contain?
The thenar compartment is the lateral compartment of the palmar surface of the hand
It contains the abductor pollicis brevis (laterally), the flexor pollicis brevis (medially), and the opponens pollicis (deeply)
What does the hypothenar compartment refer to, and what structures does it contain?
The hypothenar compartment is the medial compartment of the palmar surface of the hand
It contains the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti
What is the “carpal tunnel”?
The relatively tight passageway beneath the flexor retinaculum (aka transverse carpal ligament) through which the median nerve and the tendons to the fingers and thumb are transmitted
Name the bones of the wrist (8)
Scaphoid
Lunate
Triquetrum
Pisiform
Trapezium
Trapezoid
Capitate
Hamate
What is the most commonly fractured bone in the wrist?
The scaphoid
What bones does the scaphoid interface with? (3)
Radius, trapezium, and trapezoid
Which phalange (proximal, middle or distant) is absent in the thumb?
The middle
List the wrist bones in the proximal row from lateral to medial (radial to ulnar)
Scaphoid
Lunate
Triquetrum
Pisiform
List the wrist bones in the distal row from lateral to medial (radial to ulnar)
Trapezium
Trapezoid
Capitate
Hamate
What is unique about the scaphoid’s blood supply?
What can sometimes happen to the blood supply after a fracture?
It enters the bone from the distal pole of the scaphoid on its dorsal side.
The proximal pole may suffer a loss of blood flow and undergo aseptic (sterile) necrosis - aka avascular necrosis
What does “reduction” of a fracture refer to?
An attempt to “set” the fracture or to re-establish its normal anatomical shape.
What does the lunate articulate with?
the radius
What does the triquetrum articulate with?
proximally with the articular disc of the distal radio-ulnar joint
What does the trapezium articulate with?
The first and second metacarpals
What does the trapezoid articulate with?
The second metacarpal
What does the capitate articulate with?
the third metacarpal distally
What does the hamate articulate with?
the fourth and fifth metacarpals
Which wrist bone is the largest?
the capitate
What is the palmar aponeurosis?
A thick aponeurotic (tendon) layer overlying the central compartment of the palm; the palmaris longus inserts into it
What is unique about the origins and insertions of the intrinsic muscles of the hand?
They all originate and insert entirely within the hand
List the intrinsic muscles of the hand (9)
1) Abductor pollicis brevis
2) Flexor pollicis brevis
3) Opponens pollicis
4) Abductor digiti minimi
5) Flexor digiti minimi brevis
6) Opponens digiti
7) Adductor pollis
8) Lumbricals (for the index, middle, ring, and small fingers)
9) Interosseous (dorsal and palmar)
Abductor pollicis brevis:
Origin
Insertion
Innervation
Action
Origin: flexor retinaculum, tubercles of scaphoid and trapezium
Insertion: lateral side of the base of the proximal phalanx of thumb
Innervation: recurrent branch of the median nerve (C8, T1)
Action: Abducts thumb; helps oppose it
Opponens pollicis:
Origin
Insertion
Innervation
Action
Origin: flexor retinaculum, tubercles of scaphoid and trapezium
Insertion: lateral side of the first metacarpal
Innervation: recurrent branch of the median nerve (C8, T1)
Action: to oppose thumb; it draws 1st metacarpal medially to center of the palm and rotates it medially
Flexor pollicis brevis:
Origin
Insertion
Innervations (2)
Action
Origin: flexor retinaculum and tubercles of scaphoid and trapezium
Insertion: lateral side of base of proximal phalanx of thumb
Innervations: 1) Superficial head is innervated by the recurrent branch of the median nerve (C8, T1); 2) Deep head is innervated by the deep branch of the ulnar nerve (C8, T1)
Action: flexes thumb
Abductor digiti minimi:
Origin
Insertion
Innervations
Action
Origin: Pisiform
Insertion: medial side of base of proximal phalanx of 5th digit
Innervations: Deep branch of ulnar nerve (C8, T1)
Action: abducts 5th digit; assists in flexion of its proximal phalanx