Hand Script Flashcards
Cutaneous innervation of the hand is derived from which nerves?
Median nerve
Ulnar nerve
Superficial branch of the radial nerve
A quick test of the integrity of the___________nerve is to ascertain whether the patient can sense a probe lightly applied to the palmar surface of the index finger.
median
A quick test of the integrity of the ___________nerve is to ascertain whether the patient can sense a probe lightly applied to the palmar surface of the little finger.
ulnar
A quick test of the integrity of the superficial branch of the _____________ nerve is to ascertain whether the patient can sense a probe lightly applied to the dorsal (posterior) surface of the skin fold between the bases of the thumb and index finger.
radial
The intrinsic hand muscle ____________ is the sole prime mover of opposition of the thumb.
opponens pollicis
The posterior forearm muscles ____________ and _____________ are the prime movers of reposition of the thumb.
abductor pollicis longus; extensor pollicis longus
Each lumbrical originates within the palm from one or two tendons of ____________.
flexor digitorum profundus.
Insertion point for lumbricals
Extensor expansion
Each lumbrical can _________ its finger at the metacarpophalangeal joint and ________ its finger at the interphalangeal joints.
flex; extend
. The 1st and 2nd lumbricals are innervated by the _________ nerve, and the 3rd and 4th lumbricals are innervated by the _________nerve.
median; deep branch of the ulnar
Origin and insertion of dorsal interosseous muscles
Origin: Each dorsal interosseous had two heads of origin; the heads originate from the contiguous surfaces of two adjacent metacarpals.
Insertion: The two heads have a common tendon of insertion which passes anterior to the side of a finger’s metcarpophalangeal joint before inserting onto the same side of the finger’s extensor expansion.
Action of dorsal interosseous muscles
Abduct finger
Flex finger at its metacarpophalangeal joint
Extend the finger at its interphalangeal joints
The dorsal interossei are all innervated by the ________________
Deep branch of the ulnar nerve
How many dorsal interosseous muscles do we have?
4
How many palmar interosseous muscles do we have?
3
Each palmar interosseous originates from the _____________ of a finger.
metacarpal
Where do palmar interossei insert?
The tendon of insertion passes anterior to the side of a finger’s metacarpophalangeal joint before inserting onto the same side of the finger’s extensor expansion.
The palmar interossei are all innervated by the _____________.
deep branch of the ulnar nerve.
What are the three thenar muscles?
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
The muscles of the thenar eminence are all innervated by the __________ nerve.
median
Which specific branch of the median nerve innervates the muscles of the thenar eminence?
The recurrent branch of the median nerve
The recurrent branch arises from the median nerve distal to the ___________.
Carpal tunnel
Action and innervation of the adductor pollicis brevis
Action: Adduct thumb and flex thumb
Innervation: Deep branch of the ulnar nerve
What are three muscles of the hypothenar eminence?
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi
Palmaris brevis originates from the _____________ and inserts onto the ___________ on the medial border of the palm. Palmaris brevis can wrinkle the skin covering the hypothenar eminence. Palmaris brevis is innervated by the superficial branch of the ulnar nerve.
flexor retinaculum
______is the spinal nerve which provides most of the nerve fibers that control abduction and adduction of the fingers at their metacarpophalangeal joints.
T1
Paralysis of the intrinsic hand muscles innervated by the deep branch of the ulnar nerve is said to produce a ___________
claw hand.
Paralysis of the muscles of the thenar eminence is said to produce an____________
ape hand.
Klumpke’s palsy
partial palsy of the lower roots of the brachial plexus
Symptoms include intrinsic minus hand deformity, paralysis of intrinsic hand muscles, and C8/T1 Dermatome distribution numbness.
Combination of claw hand and ape hand
What is the mechanism of injury for Klumpe’s palsy? What is an example of instance in which this injury is sustained?
The mechanism of injury which most commonly produces Klumpke’s palsy is excessive traction on the lower parts of the brachial plexus. Instances in which such an injury is sustained include accidents in which a person falling from a significant height grasps at some object to break the fall and in the process hyperabducts the arm.
What is special about C8/T1 nerve fibers?
C8 and T1 are the only spinal nerves that provide innervation for not only the intrinsic hand muscles innervated by the deep branch of the ulnar nerve but also the intrinsic hand muscles innervated by the median nerve.
. ________ spinal nerve provides most of the sensory innervation to the skin of the thumb, __________ spinal nerve provides most of the sensory innervation to the skin of the index, middle, and ringers, and ________ spinal nerves provides most of the sensory innervation to the skin of the little finger.
C6; C7; C8
Neuropraxia
a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due to blockage of nerve conduction, usually lasting an average of six to eight weeks before full recovery
Axonotmesis
An injury to the peripheral nerve of one of the extremities of the body. The axons and their myelin sheath are damaged in this kind of injury, but the endoneurium, perineurium and epineurium remain intact.
Two main blood supplies of the hand
Deep palmar arch
Superficial palmar arch
Where can the superficial palmar arch be found in relation to tendons of the hand? What about the deep palmar arch?
Anterior to tendons of the flexor digitorum profundus and flexor digitorum superficialis
Posterior to the tendons of the flexor digitorum profundus and flexor digitorum superficialis
The superficial palmar arch is a direct continuation of the ____________ artery.
Ulnar
The _________ artery gives off a deep branch immediately distal to the flexor retinaculum, and then curves laterally through the palm as the superficial palmar arch.
ulnar
What are the major branches of the superficial palmar artery?
The digital arteries that supply the fingers
The deep palmar arch is the direct continuation of the __________ artery in the hand.
radial
Princeps pollicis, which is a major artery of the thumb, typically arises from the _________ artery in the hand.
radial
Allen test
a physical test which can determine whether the ulnar and radial arteries are each a chief source of blood supply to a patient’s hand.
Steps of the Allen test
- The patient is asked to make a tight fist. The making of a tight fist increases external pressure upon the capillary beds within the skin of the palm and thereby empties them of much of their blood content.
- The examiner applies pressure to both the ulnar and radial arteries at their palpation sites in the anterior forearm (This significantly blocks blood flow into the palmar arches)
- The patient is asked to unclench the fist, exposing he blanched pallor of the palmar surface
- The examiner releases the pressure on one artery and ascertains whether color is restored to the palmar surface with 2 to 4 seconds.
*The return of color indicates that the artery is a chief source of blood supply to the hand
