BM 1041:03 Lecture Notes - Lecture 25: Extensor Carpi Ulnaris Muscle, Extensor Digitorum Muscle, Radial Nerve
23 May 2018
School
Department
Course
Professor
Describe the anatomy of the wrist. Explain and demonstrate the
movements of the wrist joint and name and identify the muscles
responsible for these movements. Name the function, attachments
and nerve supply of these muscles. Identify and name the main
ligaments of the wrist and their attachments.
Extension and/or abduction/adduction of hand at wrist
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Extension of 4 medial digits
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Extension or abduction of thumb
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Supination forearm
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Movements
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Radial nerve - KNOW BRANCHES
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Innervation
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Superficial and deep layers
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Posterior compartment forearm
Extension of wrist and digits
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Screen clipping taken: 9/05/2018 9:41 AM
Superficial layer
L2 - forearm: posterior
Wednesday, 9 May 2018
9:35 AM
wk 11 Page 1
Screen clipping taken: 9/05/2018 9:47 AM
7 muscles
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Origin: supraepicondylar ridge and lateral epicondyle of humerus
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Insertion: All except brachioradialis and anconeus, extend as tendons into hand
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Brachioradialis
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Screen clipping taken: 9/05/2018 9:50 AM
Tendon inserts onto adjacent dorsal surfaces of the bases of metacarpals II and III
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Extends and abducts wrist
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Extensor carpi radialis longus
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Tendon inserts onto adjacent dorsal surfaces of the bases of metacarpals II and III
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Lies deep to radialis longus
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Extends and abducts wrist
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Innervated by deep branch of radial nerve
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Extensor carpi radialis brevis
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Forms 4 tendons, which pass into a finger
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In fingers, each tendon inserts via aponeurosis (extensor hood) into the base of
the dorsal surfaces of the middle and distal phalanges
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Major extensor of 4 medial digits
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Innervated by posterior interosseous nerve (continuation of deep branch of radial
nerve)
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Extensor digitorum
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Accessory extensor of little finger
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Medial to extensor digitorum in forearm
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Inserts with tendon of extensor digitorum into extensor hood of little finger
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Innervated by posterior interosseous nerve
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Extensor digit minimi
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Extensor carpi ulnaris
wk 11 Page 2
Medial to extensor digiti minimi
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Tendon inserts into medial side of base of metacarpal V
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Extends and adducts wrist
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Innervated by posterior interosseous nerve
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Extensor carpi ulnaris
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Anconeus
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Extensors of wrist and digits
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Supinators
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Thumb abductor
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movements
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Screen clipping taken: 9/05/2018 9:51 AM
Screen clipping taken: 9/05/2018 10:08 AM
All except supinator originate from posterior surfaces of radius, ulna and interosseous
membrane and pass into thumb and fingers
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All innervated by posterior interosseous nerve (radial nerve)
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Humeral head - originates from lateral epicondyle
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Ulnar head (deeper) - originates from supinator crest on posteriolateral
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2 heads at its origin
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Supinator
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5 muscles
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Deep layers
wk 11 Page 3
Document Summary
Explain and demonstrate the movements of the wrist joint and name and identify the muscles responsible for these movements. Identify and name the main ligaments of the wrist and their attachments. Screen clipping taken: 9/05/2018 9:41 am wk 11 page 1. Origin: supraepicondylar ridge and lateral epicondyle of humerus. Insertion: all except brachioradialis and anconeus, extend as tendons into hand. Tendon inserts onto adjacent dorsal surfaces of the bases of metacarpals ii and iii. Forms 4 tendons, which pass into a finger. In fingers, each tendon inserts via aponeurosis (extensor hood) into the base of the dorsal surfaces of the middle and distal phalanges. Innervated by posterior interosseous nerve (continuation of deep branch of radial nerve) Inserts with tendon of extensor digitorum into extensor hood of little finger. Tendon inserts into medial side of base of metacarpal v. All except supinator originate from posterior surfaces of radius, ulna and interosseous membrane and pass into thumb and fingers.
