SNORT Tutorial Sreekanth Malladi (modifying original by N. Youngworth)
Dr. SREEKANTH THOTA DEPARTMENT OF ANATOMY UPPER LIMB Hand.
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Transcript of Dr. SREEKANTH THOTA DEPARTMENT OF ANATOMY UPPER LIMB Hand.
WINDSOR UNIVERSITYSCHOOL OF MEDICINE
St.Kitts
Dr. SREEKANTH THOTA
DEPARTMENT OF ANATOMY
UPPER LIMB
Hand
The hand is the region of the upper limb distal to the wrist joint.
It is subdivided into three parts:
1. Wrist 2.Metacarpus 3.Digits (five fingers
including the thumb). The hand has an anterior
surface (palm) and a dorsal surface (dorsum of hand).
HAND
The carpal tunnel is formed anteriorly at the wrist by a deep arch formed by the carpal bones and the flexor retinaculum.
Carpal tunnel and structures at the wrist
The base of the carpal arch is formed medially by the pisiform and the hook of the hamate and laterally by the tubercles of the scaphoid and trapezium.
Carpal arch
flexor retinaculum is a thick connective tissue ligament that bridges the space between the medial and lateral sides of the base of the arch and converts the carpal arch into the carpal tunnel.
Flexor retinaculum
Four tendons of the flexor digitorum profundus
Four tendons of the flexor digitorum superficialis
One tendon of the flexor pollicis longus
Median nerve
Structure and relations
Carpal tunnel syndrome is an entrapment syndrome caused by pressure on the median nerve within the carpal tunnel.
Carpal tunnel syndrome
8
Carpal Tunnel syndrome
Common in computer professionals.
Due to constant dorsiflexion of wrist while typing the keyboard
The palmar aponeurosis is a triangular-shaped condensation of deep fascia that covers the palm and is anchored to the skin in distal regions.
The apex of the triangle is continuous with the palmaris longus tendon.
Palmar aponeurosis
Dupuytren contracture is a disease of the palmar fascia resulting in progressive shortening, thickening, and fibrosis of the palmar fascia and aponeurosis.
Dupuytren Contracture of Palmar Fascia
1. Hypothenar compartment
2. Thenar compartment 3. Central compartment 4. Adductor
compartment 5.Interosseous
compartment
Compartments of palm
The intrinsic muscles of the hand are located in five compartments
All of the intrinsic muscles of the hand are innervated by the deep branch of the ulnar nerve except for the three thenar and two lateral lumbrical muscles, which are innervated by the median nerve.
Muscles
Muscles of the HandThenar Muscles
Abductor Pollicis Brevis Abducts thumb
Opponens Pollicis To oppose thumb
Flexor Pollicis Brevis Flexes thumb
Muscles of the HandHypothenar Muscles
Abductor Digit Minimi Abducts digit 5
Flexor Digiti Minimi Brevis Flexes proximal phalanx of digit 5
Opponens Digiti Minimi bringing digit 5 into opposition with the thumb
Palmaris brevis
Action:Improves grip
Thenar and hypothenar Muscles
Adductor pollicis
Action:Adducts thumb towards middle digit
Movements of thumb
Extension: extensor pollicis longus, extensor pollicis brevis
Flexion: flexor pollicis longus and flexor pollicis brevis
Abduction: abductor pollicis longus and abductor pollicis brevis.
Adduction: adductor pollicis Opposition: opponens pollicis.
Movements of thumb
Muscles of the Hand Short Muscles Lumbricals
1 and 2Flex digits at metacarpo-phalangeal joints and extends interphalangeal joints
Lumbricals3 and 4
Flex digits at metacarpo-phalangeal joints and extends interphalangeal joints
Dorsal interossei1-4
Abducts digits from axial line and act with lumbricals to flex metacarpo-phalangeal joints and extends interphalangeal joints
Palmar interossei1-3
Adducts toward axial line & assist lumbriaclas in flexing the same joints as above
Lumbrical muscles
Dorsal interossei
Action of Dorsal Interossei :
DAB : Abduction
Little finger and thumb have no Dorsal interossei muscle
Palmar interossei
Action of Palmar interossei :
PAD :Adduction
Middle finger and thumb have no palmar interossei muscle
Blood supply to the hand is by the radial and ulnar arteries, which form two interconnected vascular arches (superficial and deep) in the palm.
Arteries of hand
Ulnar artery and superficial palmar arch
Superficial palmar arch: Ulnar artery+ palmar branch of radial artery
Deep palmar arch: Deep palmar branch of ulnar artery+ radial artery
Radial artery and deep palmar arch
To test for adequate anastomoses between the radial and ulnar arteries, compress both the radial and ulnar arteries at the wrist, then release pressure from one or the other, and determine the filling pattern of the hand.
Allen's test
Positive allen test
The hand is supplied by the ulnar, median, and radial nerves.
Nerves
Immediately distal to the pisiform, ulnar nerve divides into a deep branch, which is mainly motor and a superficial branch, which is mainly sensory.
Ulnar nerve
Deep branch: supplies the hypothenar interossei, adductor pollicis, and the two medial lumbricals.
Superficial branch: supply skin on the palmar surface of the little finger and the medial half of the ring finger
The ulnar nerve is most commonly injured at two sites:
1. Elbow 2. wrist Clawing of the hand: Metacarpophalangeal joints of the fingers
are hyperextended and the interphalangeal joints are flexed.
Ulnar nerve injury
Clawing of the hand
Compression of the ulnar nerve may occur at the wrist where it passes between the pisiform and the hook of the hamate.
Ulnar Canal Syndrome (Guyon Tunnel Syndrome)
The median nerve is the most important sensory nerve in the hand because it innervates skin on the thumb, index and middle fingers, and lateral side of the ring finger.
Branches: 1. Recurrent branch: innervates the three
thenar muscles 2. Palmar digital nerves: In addition to skin,
the digital nerves supply the lateral two lumbrical muscles
Median nerve
Refers to a deformity in which thumb movements are limited to flexion and extension of the thumb in the plane of the palm.
Severance of median nerve paralyzes the thenar muscles and the thumb loses much of its usefulness.
Ape hand
The only part of the radial nerve that enters the hand is the superficial branch.
Innervates skin over the dorsolateral aspect of the palm and the dorsal aspects of the lateral three and one-half digits distally to approximately the terminal interphalangeal joints.
Superficial branch of the radial nerve
Superficial branch of the radial nerve
A 21 year old girl is brought to the emergency department with a puncture wound on the palmar side of her left index finger. Preservation of which of the following movements of her index finger will confirm the functional integrity of the flexor digitorum profundus muscle?
A. Flexion of the metacarpophalangeal jointB. AdductionC. AbductionD. Flexion of the distal interphalangeal jointE. Flexion of the proximal interphalangeal
joint
1
A 53-year-old African American man involved in a motor vehicle accident sustains a severe mid-shaft fracture of the right humerus. Vitals are Temp-100.0F, BP-120/88mm/Hg, pulse- 118/min, and RR- 14/min. Examination reveals wrist drop and no ulnar or radial pulses in the right arm. Examination reveals decreased sensation over the dorsal aspect of the lateral 3½ digits. The rest of the physical exam is otherwise unremarkable. What nerve is most likely injured given the findings in this patient?
A.Axillary nerve B.Musculocutaneous nerve C.Median nerve D.Radial nerve E.Ulnar nerve
2.
The figure below represents cutaneous innervation of wrist and hand. The area A in the figure represents which Nerve?
3
1.Superficial branch of radial nerve2.Anterior interosseous nerve3.Palmar branch of median nerve4.Palmar branch of ulnar nerve5.Lateral cutaneous nerve of fore arm