6 - Forearm

Look at side 61 for the comparison of flexor and extensor tendon insertions

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The ________________ has four tendons that extend from the wrist out to the body of the middle phalanges. It does NOT flex the Distal Interphalangeal Joint.

Flexor Digitorum Superficialis

What does FDS stand for?

Flexor Digitorum Superficialis

The flexor carpi radialis inserts into the ____________ and functions to ____________

Flexor carpi radialis inserts into the 2nd metacarpal and functions to abduct and flex the wrist

This muscle inserts into the Pisiform, is entirely innervated by the ulnar nerve, and adducts the hand.

Flexor carpi ulnaris

The median nerve innervates all the muscles in the arm except ________________, which are innervated by the ulnar nerve

Flexor digitorum profundus (1/2 of it) and flexor carpi ulnaris

The __________ inserts at the base of the distal phalanges whereas the ____________ inserts at the base of the middle phalanges.

Flexor digitorum profundus ; flexor digitorum superficialis

_____________ is the only muscle that flexes the interphalangeal joint of the thumb and inserts at the base of the distal phalanx of the thumb.

Flexor pollicis longus

Origin, insertion, and function of the pronator teres

Origin: Medial Epicondyle & Ulnar Head Insertion: Lateral Surface of Radius Function: STRONG pronator

Where does the supinator originate and insert?

Originate: Lateral Epicondyle of the humerus Insert: Lateral, anterior/posterior surface of radius

The ____________ bridges the radial and ulnar artery together on the palmar side. It allows blood flow between the two

Palmar carpal arch

The branches between the radial and ulnar artery in the wrist are called ________________

Palmar carpal branch and dorsal carpal branch

The _____________ attaches to the flexor retinaculum and the palmar aponeurosis. Functions to flex wrist

Palmaris Longus

The muscles in the posterior compartment function as __________________

Posterior compartment - extensors and supinators

The muscles in the posterior compartment all originate from the _________________, thus are _____________

Posterior compartment muscles originate from the lateral epicondylar ridge and lateral epicondyle. They are extensors and supinators

The posterior cutaneous nerve supplies ___________

Posterior cutaneous nerve supplies the posterior forearm skin

This artery penetrates through the interosseous membrane then runs posterior to the interosseous membrane.

Posterior interosseous artery

The deep branch of the radial nerve ultimately becomes the ____________________

Posterior interosseous nerve

The _____________ pronates the forearm at the radioulnar joints with help from pronator teres.

Pronator quadratus

The ______________ helps the interosseous membrane hold the radius and ulna together.

Pronator quadratus

A patient comes to you diagnosed with Pronator syndrome. What does Pronator syndrome entail?

Pronator syndrome is a medial nerve injury when it is compressed between the two heads.

The flexor digitorum superficialis flexes the ___________ joints.

Proximal interphalangeal joints

The brachial artery reaches the head of the radius in the lower cubital fossa and ________________

When the brachial artery reaches the head of the radius, it branches into an ulnar (larger) and radial (smaller) artery.

The extensor digiti minimi functions to ________________

assist in the extension of the interphalangeal joints, extending to the pinkie

What three muscles are on the lateral side of the posterior forearm?

1. Brachioradialis 2. Extensor Carpi Radialis Longus 3. Extensor Carpi Radialis Brevis

What three tendons make up the anatomical snuff box?

1. Extensor pollicis longus 2. Extensor pollicis brevis 3. Abductor pollicis longus

What are the three muscles of the deep group of the anterior forearm?

1. Flexor Digitorum Profundus (FDP) 2. Flexor Pollicis Longus 3. Pronator quadratus

What are the five muscles of the superficial group of the anterior forearm?

1. Pronator Teres 2. Flexor Carpi Radialis 3. Palmaris Longus 4. Flexor Carpi Ulnaris 5. Flexor Digitorum Superficialis (FDS)

There are _____ anterior forearm muscles that are arranged into two groups and 4 layers.

8

Where is the Guyon's canal / Ulnar canal?

Between the pisiform and the hook of the hamate

A patient comes to you with a "wrist drop". What nerve did they injure?

A wrist drop is known to occur with a radial nerve injury in the forearm

The two arteries in the forearm, ulnar and radial, run in the _____________ compartment of the forearm.

Anterior compartment

The muscles in the anterior compartment all originate from the_________________, thus are ______________

Anterior compartment muscles originate from the medial epicondyle and are flexors / pronators.

This artery runs anterior to the interosseous membrane and enters the posterior aspect of the wrist

Anterior interosseous artery

The __________________ travels in the forearm alongside the anterior interosseous artery, suppllying the lateral half of the flexor digitorum profundus, flexor pollicis longus, pronator quadratus, and the wrist joint.

Anterior interosseous nerve

Is the flexor digitorum profundus innervated by the median nerve or ulnar nerve?

Both -- The index & middle finger are innervated by the median nerve while the ring and pinkie fingers are innervated by the ulnar nerve.

The _______________ flexes the elbow joint and is a part of the posterior forearm muscles

Brachioradialis

Name the function of the brachioradialis muscle

Brachioradialis flexes the elbow joint and supinates the forearm

These two muscles originate from the lateral supracondylar ridge

Brachioradialis, extensor carpi radialis longus

A patient has elbow tendonitis, also known as tennis elbow. What is the cause and what are the symptoms of this tendonitis?

Cause: repetitive forceful flexion and extension of wrist, which inflames the periosteum of the lateral epicondyle Symptoms: Pain at lateral epicondyle which radiates down the posterior forearm. Pain at rest or when opening a door or lifting a cup

The _____________ is a major branch of the ulnar artery which immediately branches into the anterior and posterior interosseous arteries

Common interosseous artery

______________________ is when the ulnar nerve is compressed by the flexor carpi ulnaris. Same symptoms of an ulnar nerve injury may occur (claw hand)

Cubital tunnel syndrome

The _________ group of the anterior forearm muscles do not cross over the elbow joint.

Deep group do not cross over the elbow joint

The ____________ bridges the radial and ulnar artery together on the dorsal side. Allows anastomoses between the two.

Dorsal carpal arch

The ________________ extends and abducts the wrist and steady the wrist when clenching a fist. This muscle also inserts onto the 3rd metacarpal

Extensor carpi radialis brevis

The ________________ extends and abducts the wrist and steady the wrist when clenching a fist. This muscle also inserts onto the 2nd metacarpal

Extensor carpi radialis longus

The _______________ enters the hand in its own synovial sheath and own compartment deep to the extensor retinaculum

Extensor carpi ulnaris

What three muscles serve the digits?

Extensor digitorum, extensor carpi ulnaris, extensor digiti minimi

The biggest extensor muscle in the posterior forearm is the _________

Extensor digitorum, it is the extensor for the four medial digits

_____________ is the special extensor connective tissue attaching the extensor tendon to the phalanges

Extensor expansion

Which muscle extends the index finger at the PIP and DIP independently?

Extensor indicies

What is the deep muscle serving the index finger?

Extensor indicis

The proximal portion of the extensor expansion is called the ______________, which is tendon fibers connecting to the palmar ligament

Hood

The median nerve travels __________ to the flexor digitorum superficialis and _____________ to the flexor digitorum profundus.

Inferior to the flexor digitorum superficialis, superior to the flexor digitorum profundus.

There are six tendon sheaths for forearm extensors. What is the clinical significance for these tendon sheath compartments?

Inflammation tends to spread within each of these tendon sheath compartments. To aid in the inflammation, the medication should be injected into the proper compartment.

The _____________ are the connections between adjacent tendons

Intertendinous connections

The median nerve originates from _________________ of the brachial plexus.

Lateral and medial cords

Extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris all originate from the ______________

Lateral epicondyle

The radial recurrent artery returns back to the ______________ for additional blood supply

Lateral epicondyle

Where do all of the superficial anterior forearm muscles originate from?

Medial epicondyle

What two nerves innervate the flexors of the forearm?

Median nerve and ulnar nerve

Your patient has a median nerve injury near the elbow joint. When you ask the patient to make a fist, what will this patient show and why?

Median nerve injury = Hand of Benediction. The patient shows the hand of benediction when asked to make a fist because the median nerve innervates the thumb, 1st and 2nd fingers. The 3rd and 4th fingers are innervated by the ulnar nerve (via flexor digitorum profundus) so they are not affected.

The ______________ innervates 6.5 muscles in the forearm while the ____________ innervates 1.5 muscles in the forearm.

Median nerve, 6.5 Ulnar nerve, 1.5

_____________ arteries return to the elbow joint for additional blood supply

Recurrent arteries

The __________________, with fibers from C8 and T1, innervates the thenar muscles of the hand.

Recurrent branch of the median nerve

Through the anatomical snuff box, which carpal bones can be palpated?

Scaphoid and trapezium

The superficial group of the anterior forearm muscles all ____________________

Superficial anterior forearm muscles all attach to the medial epicondyle through a common flexor tendon and all cross the elbow joint.

The superficial branch of the radial nerve innervates ___________

Superficial branch of the radial nerve innervates the skin on the dorsal side of the hand and some joints in the hand

On the palmar side, the ______________ is the superficial branch between the radial and ulnar artery.

Superficial palmar arch

What muscle in the posterior forearm functions as a supinator?

Supinator

Which muscle supinates the posterior forearm?

Supinator

Clinically called a "ganglion", the ______________ is a condition in which there is pocket, about the size of a small grape, filled with muscinous fluid on the dorsum of the wrist.

Synovial cyst of the wrist

Tendons enter the hand through the _________________ deep to the ________________________.

Tendons enter the hand through the COMMON SYNOVIAL SHEATH deep to the EXTENSOR RETINACULUM.

A patient comes to you with hand flexion complications. To rule out whether it is a median nerve or ulnar nerve injury, what test can be done?

Test the 1st & 2nd distal interphalangeal joints for median nerve damage, test the 3rd and 4th distal interphalangeal joints for ulnar nerve damage.

The _____________ divides into four tendons that extend from the wrist, posterior to the tendons of FDS, and flexes the distal interphalangeal joints.

The Flexor Digitorum Profundus

The ulnar nerve runs from the groove near the medial epicondyle down to the __________ between the pisiform and hook of the hamate.

The Ulnar Canal / Guyon Canal

What three muscles serve the thumb?

The abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus

The anterior and posterior ulnar recurrent arteries return to the ____________________ for ___________

The anterior and posterior ulnar recurrent arteries return to the medial epicondyle of the humerus for additional blood supply

A patient comes for an evaluation. You ask them to make a fist and they form a "claw hand". What type of injury does this patient have?

Ulnar nerve injury

A patient comes in with numbness and tingling in the medial part of their palm and along the 4th and 5th digits. What type of injury do you suspect?

Ulnar nerve injury

Where is the deep palmar arch and what is it's function?

The deep palmar arch is on the palm side, deep to the superficial palmar arch. It functions to bridge the ulnar artery and radial arteries deep into the hand.

Your patient has carpal tunnel syndrome. Although the nerves in the carpal tunnel are being compressed, the patient still has sensation in the palm region. Why is this?

The patient with carpal tunnel syndrome has palmar sensation because of the palmar cutaneous branch of the median nerve. It runs superficially to the carpal tunnel to innervate the palm.

Your patient with pronator syndrome is complaining of pain and tenderness. Where is this sensation?

The proximal anterior forearm

The flexor digitorum superficialis originates from the medial epicondyle and ______________

The radial and ulnar head

Where is a common place to measure the pulse in the arm?

The radial artery in the distal forearm near the radial styloid process

Why is the claw hand a side effect of an ulnar nerve injury?

The ulnar nerve innervates the 4th and 5th digits. If it is damaged, they will not form a fist.

Where do extra extensors lie on the posterior side of the hand?

The ulnar side of their corresponding ligament

The abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus all serve the ________________

Thumb