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
Flexor digiti minimi brevis:
Origin
Insertion
Innervation
Action
Origin: hook of hamate and flexor retinaculum
Insertion: medial side of base of proximal phalanx of 5th digit
Innervation: Deep branch of ulnar nerve (C8, T1)
Action: Flexes proximal phalanx of 5th digit
Opponens digiti:
Origin
Insertion
Innervation
Action
Origin: Hook of hamate and flexor retinaculum
Insertion: medial border of 5th metacarpal
Innervation: Deep branch of ulnar nerve (C8, T1)
Action: Draws 5th metacarpal anterior and rotates it, bringing 5th digit into opposition with the thumb
Adductor pollicis:
Origin (2)
Insertion
Innervation
Action
Origin: 1) Oblique head originates on the bases of the 2nd and 3rd metacarpals, capitate, and adjacent carpals; 2) Transverse head originates on the anterior surface of the shaft of the 3rd metacarpal
Insertion: Medial side of base of proximal phalanx of thumb
Innervation: Deep branch of ulnar nerve (C8, T1)
Action: Adducts thumb toward lateral border of palm
Which muscle’s main action is palmar adduction of the thumb, allowing for the grasping and manipulation of objects?
Opponens pollicis
Which nerve makes it possible for the hand to perform fine, rapid, coordinated motor movements, such as playing the piano or violin?
The deep motor branch of the ulnar nerve
What type of structure do the lumbricals both originate and insert on?
Tendons
What side of each digit are the lumbricals ALWAYS on?
The radial side of each digit.
Lumbricals for the 1st and 2nd digits (index and middle fingers):
Origin
Insertion
Innervation
Action
Origin: lateral two tendons of flexor digitorum profundus
Insertion: lateral sides of extensor expansions of 2nd-5th digits
Innervation: Median nerve (C8, T1)
Action: Flex metacarpophalangeal joints, extend interphalangeal joints of the 2nd-5th digits
Lumbricals for the 3rd and 4th digits (ring and small finger):
Origin
Insertion
Innervation
Action
Origin: medial three tendons of flexor digitorum profundus
Insertion: lateral sides of extensor expansions of 2nd-5th digits
Innervation: Deep branch of ulnar nerve (C8, T1)
Action: flex metacarpophalangeal joints, extend interphalangeal joints of the 2nd-5th digits
How many dorsal interossei are there?
There are 4
How many palmar interossei are there?
There are 3
Dorsal Interossei:
Origin
Insertion
Innervation
Action
Origin: adjacent sides of two metacarpals
Insertion: bases of proximal phalanges; extensor expansions of 2nd-4th digits
Innervation: Deep branch of ulnar nerve (C8, T1)
Action: Abduct 2nd-4th digits from axial line; assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
The superficial palmar arch is a continuation of which artery?
the ulnar artery
The deep palmar arch is a continuation of which artery?
The radial artery
Which branch of the ulnar nerve is the sensory branch?
What sensation does it provide?
The superficial branch
Supplies sensation to the skin of palmar and distal dorsal aspects of digit 5 and the medial side of digit 4 and proximal portion of the palm
What branch of the ulnar nerve is motor?
What does it innervate?
The deep branch of the ulnar nerve
Innervates hypothenar muscles, lumbricals of digits 4 and 5, ALL interossei, adductor pollicis, deep head of flexor pollicis brevis
The median nerve provides sensation to what part of the hand?
Provides sensation to the skin of the palmar and distal dorsal aspects of lateral 3.5 digits and adjacent palm
What muscles does the motor branch of the median nerve innervate in the hand?
abductor pollicis brevis, opponens pollicis, superficial head of flexor pollicis brevis
What sensation is provided by the common palmar digital nerve?
Provides sensation to skin of the palmar surfaces of the adjacent sides of two digits
What is the motor function of the common palmar digital nerve?
Sympathetic motor to the skin; motor nerve to the 1st & 2nd lumbrical muscles
What is the sensory function of the proper palmar digital nerve (2)?
Median: provides sensation to the palmar skin and nail bed of digits 1-3 and the lateral side of 4th digit
Ulnar: provides sensation to the palmar and dorsal skin on medial side of the 4th digit and all of the 5th digit
What is the motor function of the proper palmar digital nerve?
Provides sympathetic motor to the skin
Demonstrate (without hurting yourself):
Forearm supination and pronation
Ulnar deviation and radial deviation
Wrist extension and flexion
Finger abduction and adduction
Finger hyper-extension, extension and flexion
Demonstrate:
Thumb extension and flexion
Opposing thumb to finger
Palmar abduction
Radial abduction
Anteposition (opposition) and retroposition
Identify:
Palmar aponeurosis
Identify the following:
- Abductor pollicis brevis
- Flexor pollicis brevis
- Flexor retinaculum (cut)
- Carpal tunnel (beneath the flexor retinaculum
Identify the following:
- Abductor pollicis brevis (cut and reflected)
- Opponens pollicis
- Superficial palmar arterial arch
Identify the following:
- Adductor pollicis
- Opponens pollicis
- Abductor digiti minimi (cut)
Identify the following:
- Abductor digiti minimi
- Flexor digiti minimi brevis
Identify the following:
- Abductor digiti minimi (cut and reflected)
- Flexor digiti minimi brevis (cut and reflected)
- Opponens digiti minimi
Identify the following:
- Lumbricals (index and middle fingers)
- Adductor pollicis
Identify the following:
- Common palmar digital artery
- Proper palmar digital artery
- Common palmar digital nerve
- Proper palmar digital nerve
*Note the distal bifurcation of the common digital artery versus the proximal bifurcation of the common digital nerve. This characteristic is surgically significant in the safe separation of webbed fingers.
Identify the following:
- Ulnar artery (to superficial arch)
- Deep arterial arch (radial artery)
Note: Remember USA: Ulnar artery = Superficial arch = furthest Away. This means that the Ulnar Artery is the main contributor to the superficial arch, which is located furtherly distal than the deep arch
Identify the following:
- Median nerve
- Princeps pollicis artery
Identify the following:
- Proximal phalanx
- Middle phalanx
- Distal phalanx
- Metacarpal bone
- Carpal bones
Identify the following:
- Trapezium
- Trapezoid
- Capitate
- Hamate
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
What position is the arm in when it becomes most vulnerable to glenohumeral (shoulder) dislocation?
When the arm is pulled upward and backward in should abduction and external rotation (think of a baseball pitcher’s or football quarterback’s throwing position)
Which is more common: a posterior shoulder dislocation or an anterior shoulder dislocation?
When does the more uncommon one generally occur?
Anterior dislocation is more common
Posterior dislocation is seen mainly with seizures (or severe trauma)
What nerve can be injured by a fracture of the humerus at the mid-shaft?
The radial nerve
