Forearm Script Flashcards
Carpal bone (List)
Scaphoid, Lunate, Triquetrum, Pisiform
Trapezium, Trapezoid, Capitate, and Hamate
The heads of the 2nd to 5th metacarpals form the ___________
Knuckles
During flexion of the hand, more flexion occurs at which joint?
. During flexion of the hand, more movement occurs at the midcarpal joint than at the wrist joint.
Components of a metacarpal
Head, shaft, and base
How is the wrist joint formed?
The wrist joint is a synovial joint, in whcih the scaphoid, lunate, and triquetum articulate with the distal end of the radius and the articular disc of the distal radioulnar joint
*The articular disc is subject to degeneration and thinning as we age
What is the mudcarpal joint?
Synovial joint in which the carpals of the distal row articulate with the scaphoid, lunate, triquetrum
4 movements provide for by wrist and midcarpal joints
Flexion
Extension
Abduction
Adduction
During extension of the hand does more movement occur at the wrist joint or the midcarpal joint?
Wrist joint
Whereas the __________ joint provides almost all the carpal movements responsible for abduction of the hand, the _________ joint provides almost all the carpal movements responsible for adduction of the hand.
midcarpal;wrist
Which finger is the only finger thatn can be abducted in two directions?
Middle finger
Which joint is involved in extension, flexion, abduction, and adduction of the thumb?
Metacarpophalangeal joint
Carpometacarpal joint
Direct or indirect pressure to the anatomical snuffbox can be used to determine whether or not which bone is fractured?
Schaphoid
Fracture of the ___________is one of the most common wrist injuries to occur in individuals of all ages.
scaphoid
Why is it so important to treat scaphoid fractures in a timely manner?
Because they are at risk of avascular necrosis the more proximal fragment of the bone.
As the median nerve extends into the forearm, it gives rise to a major branch called the _____________. The median nerve and its anterior interosseous branch innervate all the anterior forearm muscles except ___________and the medial half of _____________
anterior interosseous nerve; flexor carpi ulnaris; flexor digitorum profundus
In the forearm, the ___________ innervates flexor carpi ulnaris and the medial half of flexor digitorum profundus.
ulnar nerve
As the radial nerve extends through the distal arm, it innervates three posterior forearm muscles: __________, __________, and ____________.
anconeus, brachioradialis and extensor carpi radialis longus.
As the radial nerve then extends into the forearm, it divides into two branches: the__________ and the ____________.
superficial radial nerve; deep radial nerve
The deep radial nerve innervates which muscles?
Extensor carpi radialis brevis
Supinator
The deep radial nerve pierces supinator as it innervates the muscle; upon exiting supinator, the name of the deep radial nerve changes to the _____________
posterior interosseous nerve
Which two muscles of the anterior forearm pronate the forearm?
Pronator teres
Pronator quadratus
Pronator quadratus is innervated by the_______________, and pronator teres is innervated by the _____________.
anterior interosseous nerve; median nerve
Aside from pronation, what additional action can the pronator teres do?
Flex the forearm
Which three anterior forearm muscles move the hand at the wrist and midcarpal joints?
Flexor carpi radialis
Palmaris Longus
Flexor carpi ulnaris
Flexor carpi radialis can _________and _______ the hand; it is innervated by the ___________. Flexor carpi ulnaris can _______ and _______the hand; it is innervated by the __________. Palmaris longus can ________ the hand; it is innervated by the __________.
flex ; abduct; median nerve
flex; adduct; ulnar nerve
flex; median nerve.
Where does the palmaris longus muscle insert?
Flexor retinaculum (in wrist)
Palmar aponeurosis (in hand)
The flexor reticulum is attached medially to the ________and ________ and laterally to the _________ and _________.
hamate; pisiform
scaphoid; trapezium
Which anterior forearm muscles flex the thumb?
Flexor pollicis longus
Which anterior forearm muscles flex the fingers?
Flexor digitorum profundus
Flexor digitorum superficialis
The flexor pollicis longus is innervated by the ___________.
Anterior interosseous nerve
Innervation of the flexor digitorum profundus
Ulnar nerve (medial part)
Anterior interosseous nerve (lateral part)
The flexor digitorum superficialis is innervated by the__________
median nerve
The __________ forms the roof of the carpal tunnel.
Flexor retinaculum
Which major structures pass through the carpal tunnel?
The median nerve
Tendons of the flexor pollicis longus
Tendons of the flexor digitorum superficialis
Tendons of the flexor digitorum profundus
A ___________ is an elongated bursa wrapped around a tendon.
synovial sheath
What is the radial bursa?
a collection of synovial fluid around the Tendon of the Flexor Pollicis Longus muscle, the primary flexor of the thumb. It is primarily to keep the muscle tendon lubricated during it’s movements and reduce friction.
______ is the spinal nerve which provides most of the nerve fivers that control flexion of the thumb and fingers at their interphalangeal joint.
C8
*C8 provides most of the nerve fibers to the prime movers (flexor pollicis longus, flexor digitorum superfiacialis, and flexor profundus)
What is compartment syndrome? Which compartments are most sensitive to comparment syndrom?
Any condition tht leads to compression of blood vessels, nerves, and muscles in muscle compartments of the limbs.
The anterior and posterior muscle compartments of the forearm and the anterior, lateral, deep posterior, and superficial posterior muscle compartments of the leg are the limb compartments most sensitive to compartment syndrome.
Which type of fracture is common in children that fall on an outstreched hand? What are the risk factors?
A supracondylar fracture of the humerus
Risk factors
- Swelling
- Ischemic necrosis (if swelling goes untreated)
Volkmann’s ischemic contracture
permanent flexion contracture of the hand at the wrist, resulting in a claw-like deformity of the hand and fingers. Passive extension of fingers is restricted and painful.
Anconeus can _________ the forearm; it is innervated by the _________.
extend; radial nerve.
Brachioradialis’ major action is _________ of the forearm. It is innervated by the________.
flexion; radial nerve
Innervation of supinator
deep radial nerve
Upon existing the posterior surface of the supinator, the name of the deep radial nerve changes to the ____________
Posterior interosseous nerve
Supinator is innervated by only __ and _______ nerve fibers.
C5; C6
What are the three posterior forearm muscles that move the hand at the wrist and the midcarpal joints?
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
Action of the extensor carpi radialis longus. Innervation?
Extend and abduct the hand
Radial nerve
Action of the extensor carpi brevis. Innervation?
Extend and abduct the hand
Deep radial nerve
Action of the extensor carpi ulnaris. Innervation?
Posterior interosseous nerve
Wrist drop
medical condition in which the wrist and the fingers cannot extend at the metacarpophalangeal joints.
Results from pressure of radial nerve in axilla
Which posterior forearm muscles extend the thumb?
Abductor pollicis longus
Externsor pollicis brevis
Extensor pollicis longus
The three mosterior forearm muscles which extend the thumb are all innervated by the _______________.
Posterior interoseous nerve
The anatomical snuffbox is a highly clinically relevant surface anatomy feature because it is used to help diagnose a fractured ___________.
scaphoid.
* The most commonly fractured carpal
The extensor digiti minimi and extensor digitorum are innervated by the ___________.
Posterior interosseous nerve
Which joints do the extensor digiti minimi and extensor digitorum extend the fingers at?
Metacarpophalangeal
Interphalangeal
What is the extensor expansion?
the special connective attachments by which theextensor tendons insert into the phalanges
Action and innervation the extensor indicis
Action: Extend the index finder at its metacarpophalangeal and interphalangeal joints
Innervation: Posterior interosseous nerve
Extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum, and extensor digiti minimi all originate from the ___________ of the humerus via a common tendon of origin called the ___________
lateral epicondyle; common extensor tendon.
Lateral epicondylitis
due to excessive use of the muscles of the back of the forearm
chronic tendinosis
Deneration of the common extensor tendon
The ulnar artery and ulnar nerve both extend from the forearm into the hand by passing superficial to the _____________
flexor retinaculum.
Upon entering the hand, the ulnar nerve divides into two terminal branches: a _______________ and a _____________.
superficial ulnar nerve; deep ulnar nerve
The ____________ is the most commonly dislocated carpal.
lunate
Which type of dislocation is most common?
Anterior dislocation
Which nerve fiber provides most of the sensory innervation to the skin on the medial side of the forearm?
C6
Which nerve fiber provides most of the sensory inenrvation to the skin on the medial side of the forearm?
T1
