15. Muscles of Forearm Flashcards
Identify
- Pronator teres muscle
- Pronator quadratus muscle
Identify 2. O & I
- Pronator quadratus muscle
Origin (proximal): arises from the medial aspect of the anterior surface of the distal one-fourth of the ulna.
Insertion (distal): The distal fourth of the lateral border and anterior surface of the shaft of the radius.
Identify 1. O & I
- Pronator teres muscle
Origin (proximal): The pronator teres has 2 heads.
- The humeral head arises immediately above the medial epicondyle from the common flexor tendon, intermuscular septum, and antebrachial fascia.
- The ulnar head arises from the medial side of the coronoid process of the ulna.
Insertion (distal): The pronator teres inserts about midway along the lateral surface of the radius.
Identify 1. Action
- Pronator teres muscle
Action: The pronator teres rotates the radius on the ulna (pronation) and helps flex the forearm at the elbow.
Identify 1. Innervation
- Pronator teres muscle
→ the median nerve (pronator teres—C6 and C7)
Identify 2. O & I
- Pronator quadratus muscle
Origin (proximal): arises from the medial aspect of the anterior surface of the distal one-fourth of the ulna.
Insertion (distal): The distal fourth of the lateral border and anterior surface of the shaft of the radius.
Identify 2. Action
- Pronator quadratus muscle
The pronator quadratus pronates the hand.
→ It is assisted by the pronator teres when additional power is required.
Identify 2. Innervation
- Pronator quadratus muscle
→ the median nerve (pronator teres—C6 and C7; pronator quadratus—C8 and T1).
Origin (proximal): The pronator teres has 2 heads.
- The humeral head arises immediately above ____ from the common flexor tendon, intermuscular septum, and antebrachial fascia.
- The ulnar head arises from the medial side of ____
- the medial epicondyle
- the coronoid process of the ulna.
Which muscle is the deepest muscle of forearm?
The pronator quadratus
Origin (proximal): The pronator teres has 2 heads.
- The humeral head arises immediately above ____ from the common flexor tendon, intermuscular septum, and antebrachial fascia.
- The ulnar head arises from the medial side of ____
- the medial epicondyle
- the coronoid process of the ulna.
Identify
- Flexor carpi radialis muscle
- Head of radius
- Lateral epicondyle of humerus
- Tendon of flexor carpi ulnaris muscle
The role of The radial extensors?
The radial extensors help the flexor carpi radialis abduct the wrist.
Identify 1. O & I
- Flexor carpi radialis muscle
- Head of radius
- Lateral epicondyle of humerus
- Tendon of flexor carpi ulnaris muscle
Identify 1. Action
- Flexor carpi radialis muscle
Action: Flexes the hand at the wrist joint and aids in wrist abduction.
Identify 1. Innervation
- Flexor carpi radialis muscle
Innervation: Median nerve (C6 and C7).
Identify 1 - 2
- Palmaris longus muscle
- Radius
Identify 1. Action
- Palmaris longus muscle
Action: Flexes the hand at the wrist and tightens the palmar aponeurosis.
Identify 3 - 5
- Palmar aponeurosis (cut)
- Hook of hamate
- Pisiform bone
Identify 6
- Ulna
Identify 1. O & I
- Palmaris longus muscle
Origin (proximal): arises from the medial epicondyle of the humerus by the common flexor tendon and the antebrachial (forearm) fascia.
Insertion (distal): Inserts into the anterior aspect of the distal flexor retinaculum and into the palmar aponeurosis.
Identify 1. Innervation
- Palmaris longus muscle
Median nerve (C6 and C7).
____ (which nerve?) lies just lateral to the tendon of the palmaris longus muscle before entering the carpal tunnel.
The median nerve
The median nerve lies just lateral to the tendon of ____ (which muscle?) before entering the carpal tunnel.
Palmaris longus muscle
The median nerve lies just lateral to the tendon of the palmaris longus muscle before entering ____ (space?)
the carpal tunnel
Identify
- Flexor carpi ulnaris muscle
- Tendon of flexor carpi radialis muscle
- Medial epicondyle of humerus
- Common flexor tendon
- 5th metacarpa
Identify 1. O & I
- Flexor carpi ulnaris muscle
- Tendon of flexor carpi radialis muscle
- Medial epicondyle of humerus
- Common flexor tendon
- 5th metacarpa
The role of The ulnar extensor?
The ulnar extensor helps the flexor carpi ulnaris adduct the hand at the wrist.
Identify 1. Action
- Flexor carpi ulnaris muscle
Action: Flexes and adducts the hand at the wrist.
Identify 1. Innervation
- Flexor carpi ulnaris muscle
Innervation: Ulnar nerve (C7 and C8).
___ (nerve?) runs between the heads of Flexor carpi ulnaris muscle as it courses toward the wrist.
The 2 heads of Flexor carpi ulnaris muscle join just below ___
the ulnar nerve
Origin (proximal): Flexor carpi ulnaris muscle has 2 heads.
- The humeral head arises from ___ by the common flexor tendon.
- The ulnar head arises from ____ and ____
- the medial epicondyle of the humerus
- the medial margin of the olecranon; posterior border of the ulna.
Identify
Flexor digitorum superficialis muscle
Flexor pollicis longus muscle
Flexor digitorum profundus tendons
Identify 1. O & I
- Flexor digitorum superficialis muscle
Origin (proximal): Flexor digitorum superficialis muscle arises by 2 heads
- The humeroulnar head arises from the medial epicondyle of the humerus, the ulnar collateral ligament, and the coronoid process of the ulna.
- The radial head arises from the superior half of the anterior aspect of the radius.
Insertion (distal): Four tendons of insertion of the flexor digitorum superficialis attach to the bodies of the middle phalanges of the medial 4 digits (index finger to little finger).
Identify 1. Action
- Flexor digitorum superficialis muscle
Action:
- This muscle acts primarily as a flexor of the proximal interphalangeal joints.
- contributes to flexion of all the joints it crosses, including the elbow, wrist, and metacarpophalangeal joints.
Identify 1. Innervation
Flexor digitorum superficialis muscle
Innervation: Median nerve (C7, C8, and T1).
Comment: Opposite the bases of the 1st phalanges, each tendon of Flexor digitorum superficialis muscle divides to allow the corresponding tendon of the deep flexor (___ muscle) to reach each finger.
Flexor digitorum superficialis muscle
Flexor pollicis longus muscle
Flexor digitorum profundus tendons
Identify
- Flexor digitorum profundus muscle
- Flexor digitorum superficialis tendons (cut away)
- Flexor digitorum profundus tendons
Identify 1. O & I
- Flexor digitorum profundus muscle
Origin (proximal): arises from the proximal three-fourths of the medial and anterior aspects of the ulna and from the interosseous membrane.
Insertion (distal): Four tendons of the flexor digitorum profundus attach to the bases of the distal phalanges of the medial 4 digits (index finger to little finger).
Identify 1. Action
- Flexor digitorum profundus muscle
Action:
- The primary action of the flexor digitorum profundus muscle is flexion of the distal interphalangeal joints.
- Some flexion at the proximal interphalangeal joints, the metacarpophalangeal joints, and the wrist (because its tendons cross those joints.)
Flexor digitorum profundus muscle also produces some flexion at the proximal interphalangeal joints, the metacarpophalangeal joints, and the wrist
→ WHY?
because its tendons cross those joints.
Identify 1. Innervation
- Flexor digitorum profundus muscle
Innervation:
Proximal to the wrist, the flexor digitorum profundus muscle divides into 2 parts.
- The medial part is innervated by the ulnar nerve (C8 and T1).
- The lateral portion of the muscle is innervated by the anterior interosseous branch of the median nerve (C8 and T1).
Flexor digitorum profundus muscle
Innervation:
Proximal to the wrist, the flexor digitorum profundus muscle divides into 2 parts.
- The medial part is innervated by the ____.
- The lateral portion of the muscle is innervated by ___
- ulnar nerve (C8 and T1)
- the anterior interosseous branch of the median nerve (C8 and T1).
Identify
Flexor pollicis longus muscle
Interosseous membrane
Flexor digitorum profundus muscle
Identify 1. O & I
- Flexor pollicis longus muscle
Origin (proximal): Flexor pollicis longus muscle arises from anterior aspect of the radius and adjacent interosseous membrane.
Insertion (distal): Flexor pollicis longus muscle inserts on the base of the distal phalanx of the thumb.
Identify 1. Action
- Flexor pollicis longus muscle
Action:
- The primary action of the flexor pollicis longus muscle is flexion of the distal phalanx of the thumb.
- The muscle also can flex the proximal phalanx because its tendon crosses that joint.
Identify 1. Innervation
- Flexor pollicis longus muscle
Innervation: Median nerve (anterior interosseous branch) (C7, C8, and T1).
Identify
- Supinator muscle
- Pronator teres muscle
- Ulna
- Pronator quadratus muscle
- Radius
- Lateral epicondyle of humerus
Identify 1. O & I
- Supinator muscle
Origin (proximal): Supinator muscle arises from the lateral epicondyle of the humerus
Insertion (distal): Inserts into the lateral, posterior, and anterior surfaces of the proximal third of the radius.
Identify 1. Action
- Supinator muscle
Action: The supinator rotates the radius to supinate the forearm and hand. Supination occurs whether the forearm is flexed or extended.
Identify 1. Innervation
- Supinator muscle
Innervation: Deep branch of the radial nerve (C5 and C6).
The most powerful supinator of the forearm is (1)_____ which acts primarily when the forearm is flexed.
In contrast, the (2)___ can supinate a forearm that is flexed or extended.
- the biceps brachii
- supinator
____ (ARTERY?) passes through the supinator, serving as its major blood supply.
The posterior interosseous artery
Identify 1. O & I
1. Brachioradialis muscle
Origin (proximal): the lateral supracondylar ridge of the distal humerus and intermuscular septum.
Insertion (distal): lateral aspect of the distal radius just proximal to the styloid process.
Identify 1. Action?
1. Brachioradialis muscle
Action: Brachioradialis muscle is an accessory flexor of the forearm at the elbow.
Identify 1. Innervation?
1. Brachioradialis muscle
Innervation: Radial nerve (C5 and C6), before it divides into its superficial and deep branches.
Is the brachioradialis extensor or supinator?
It is not an extensor or supinator.
→ It is a weak flexor of the forearm at the elbow and is most efficient as a flexor when the forearm is in midpronation.
Identify 2 - 3
- Radial artery
- Median nerve
Identify 4 - 5
- Ulnar artery
- Ulnar nerve
Identify 6
Palmaris longus muscle
Identify 7
- Flexor digitorum superficialis muscle
Identify 8 - 9
- Flexor carpi radialis muscle
- Pronator teres muscle
Identify 1. O & I
- Extensor carpi radialis longus muscle
Origin (proximal): Extensor carpi radialis longus muscle arises from lateral supracondylar ridge of the humerus.
Insertion (distal): Attaches to the base of the 2nd metacarpal.
Identify 1. Action
- Extensor carpi radialis longus muscle
Action: Extends and abducts the hand at the wrist joint.
Identify 1. Innervation
- Extensor carpi radialis longus muscle
Innervation: Radial nerve (C6 and C7).
The extensor carpi radialis longus muscle arises just distal to (1)____ (muscle?)
Its belly ends in the proximal third of the forearm.
Its flat tendon continues distally along the lateral border of the radius beneath (2) ____ (2 muscles?)
- the brachioradialis muscle.
- the abductor pollicis longus and extensor pollicis brevis muscles.
Identify 2 - 3
- Tendon of extensor carpi radialis longus muscle
- Tendon of extensor carpi radialis brevis muscle
Identify 4 - 5
- Abductor pollicis longus muscle
- Extensor pollicis brevis muscle
Identify 1. O & I
- Extensor carpi radialis brevis muscle
Origin (proximal): Extensor carpi radialis brevis muscle arises from lateral epicondyle of the humerus.
Insertion (distal): Extensor carpi radialis brevis muscle inserts on the base of the 3rd metacarpal bone.
Identify 1. Innervation
- Extensor carpi radialis brevis muscle
Innervation: Radial nerve (deep branch) (C7 and C8).
The extensor carpi radialis brevis muscle is shorter and thicker than (1)___ (MUSCLE?), which partially covers it.
Occasionally, both muscles form a single belly that gives rise to 2 tendons. This muscle is important for a power grip (a power grip requires wrist extension).
the extensor carpi radialis longus
Which movement of wrist that is required for a power grip?
wrist extension
Identify 1. Action
- Extensor carpi radialis brevis muscle
Action: Extends and abducts the hand at the wrist joint.
Identify 1
- Extensor digitorum muscle
Origin (proximal): Extensor digitorum muscle arises from lateral epicondyle of the humerus.
Insertion (distal): Extensor digitorum muscles insert as extensor expansions of the medial 4 digits (index finger to little finger).
Identify 1. O & I
- Extensor digitorum muscle
Origin (proximal): Extensor digitorum muscle arises from lateral epicondyle of the humerus.
Insertion (distal): Extensor digitorum muscles insert as extensor expansions of the medial 4 digits (index finger to little finger).
Identify 1
- Extensor digitorum muscle
Action:
- extension at the metacarpophalangeal and interphalangeal joints.
- also participates in wrist extension when the fingers are extended.
Identify 1. Nerve?
- Extensor digitorum muscle
Innervation: Radial nerve (posterior interosseous branch) (C7 and C8).
The tendons of the extensor digitorum pass through (1)___ and to the extensor expansions of the medial 4 digits.
Occasionally, this muscle has only 3 tendons instead of 4. Often, (2)___ is attached to the extensor digitorum.
- the extensor retinaculum
- the extensor digiti minimi
Identify 2 - 4
- Abductor pollicis longus muscle
- Extensor pollicis brevis muscle
- Extensor pollicis longus tendon
Identify 1. O & I
- Extensor digiti minimi muscle
Origin (proximal): Extensor digiti minimi muscle arises from lateral epicondyle of the humerus.
Insertion (distal): Extensor digiti minimi muscle inserts as an extensor expansion of the 5th digit.
Identify 1. Action
- Extensor digiti minimi muscle
Action:
- Extends the 5th digit at the metacarpophalangeal and interphalangeal joints.
- also participates in wrist extension when the fingers are extended.
Identify 2- 4
- Common extensor tendon
- Lateral epicondyle of humerus
- Ulna
Identify 5 - 6
- Extensor digiti minimi tendon
- Extensor indicis tendon
Identify 1
- Extensor carpi ulnaris muscle
Origin (proximal): Extensor carpi ulnaris muscle has 2 heads. One head arises from the lateral epicondyle of the humerus, and the other arises from the posterior border of the ulna.
Insertion (distal): Attaches to the medial side of the base of the 5th metacarpal.
Identify 2 - 4
- Abductor pollicis longus tendon
- Extensor pollicis brevis tendon
- Extensor pollicis longus tendon
Identify 1. O & I
- Extensor carpi ulnaris muscle
Origin (proximal): Extensor carpi ulnaris muscle has 2 heads. One head arises from the lateral epicondyle of the humerus, and the other arises from the posterior border of the ulna.
Insertion (distal): Attaches to the medial side of the base of the 5th metacarpal.
Identify 1. Action
- Extensor carpi ulnaris muscle
Action: Extends and adducts the hand at the wrist joint.
Identify 1. Innervation
- Extensor carpi ulnaris muscle
Innervation: Radial nerve (posterior interosseous branch (C7 and C8).
- Extensor carpi ulnaris muscle
Origin (proximal): Extensor carpi ulnaris muscle has 2 heads.
- One head arises from ____, and the other arises from ___
- The lateral epicondyle of the humerus
- the posterior border of the ulna.
3 muscles necessary for a power grip
- the extensor carpi radialis longus and brevis muscles
- the extensor carpi ulnaris
Identify 1 - 2
- Abductor pollicis longus muscle
- Extensor pollicis brevis muscle
Identify 1. O & I
- Abductor pollicis longus muscle
Origin (proximal): Abductor pollicis longus muscle arises from posterior aspect of the ulna, radius, and interosseous membrane.
Insertion (distal): Attaches to the base of the 1st metacarpal bone.
Identify 1. Action?
- Abductor pollicis longus muscle
Action:
- Abducts, extends, and laterally rotates the thumb at the carpometacarpal joint.
- It also may contribute to abduction of the wrist.
Identify 1. Innervation
- Abductor pollicis longus muscle
Innervation: Radial nerve (posterior interosseous branch) (C7 and C8).
Identify 1 - 2
- Abductor pollicis longus muscle
- Extensor pollicis brevis muscle
Identify 3 - 4
- Extensor pollicis longus tendon
- 1st dorsal interosseous muscle
Identify 5 - 7
- Extensor indicis tendon
- Extensor digitorum tendons
- Abductor digiti minimi muscle
Identify 8 - 9
- Extensor digiti minimi muscle
- Extensor carpi ulnaris muscle
When the thumb is abducted, the tendon of (1)____ (muscle?) becomes prominent and forms the lateral boundary of the (2)____ (space?)
- the abductor pollicis longus
- “anatomical snuffbox.”
Identify 1 - 2
- Extensor pollicis brevis muscle
- Abductor pollicis longus muscle
Identify 1. O & I
- Extensor pollicis brevis muscle
Origin (proximal): Extensor pollicis brevis muscle arises from the posterior surface of the radius and the interosseous membrane.
Insertion (distal): Attaches to the base of the proximal phalanx of the thumb.
Identify 1. Action
- Extensor pollicis brevis muscle
Action:
- Extends the proximal phalanx of the thumb at the metacarpophalangeal joint.
- By its continued action, it also can extend the 1st metacarpal bone at the carpometacarpal joint.
Identify 1. Innervation
- Extensor pollicis brevis muscle
Innervation: Radial nerve (posterior interosseous branch) (C7 and C8).
The extensor pollicis brevis muscle, a short extensor of the thumb, courses with (1)____ (muscle?).
→ The tendons of the 2 muscles form part of the lateral boundary of (2)____ (space?)
- the abductor pollicis longus muscle
- the “anatomical snuffbox.”
Identify 3 - 4
- Radius
- Supinator muscle
Identify 5 - 6
- Anconeus muscle
- Ulna
Identify 7
- Extensor indicis muscle
Identify 8 - 9
- Extensor retinaculum
- Radial artery (in anatomical snuff box)
Identify 1 - 2
- Extensor pollicis longus muscle
- Extensor carpi ulnaris muscle (retracted)
Identify 1. O & I
- Extensor pollicis longus muscle
Origin (proximal): Extensor pollicis longus muscle arises from posterior surface of the middle third of the ulna and the interosseous membrane.
Insertion (distal): Attaches to the base of the distal phalanx of the thumb.
Identify 1. Action
- Extensor pollicis longus muscle
Action:
- Extends the distal phalanx of the thumb at the metacarpophalangeal and interphalangeal joints.
- contribute to abduction of the thumb. (Because it runs in an oblique fashion)
Identify 1. Innervation
- Extensor pollicis longus muscle
Innervation: Radial nerve (posterior interosseous branch) (C7 and C8).
Which artery can be found at the “anatomical snuffbox?”
The radial artery
Which bone lies in the floor of the snuffbox?
- scaphoid and trapezium carpal bone
Identify 3 - 5
- Lateral epicondyle of humerus
- Extensor carpi radialis longus muscle
- Extensor carpi radialis brevis muscle
Identify 6
- Interosseous membrane
The anatomical snuffbox is bounded
- laterally by ___
- medially by ____.
- ____ lies in the floor of the snuffbox
- the tendons of the abductor pollicis longus and extensor pollicis brevis muscles
- the extensor pollicis longus tendon
- The scaphoid carpal bone
Identify 1. Action
- Extensor indicis muscle
Action: Extends all the joints of the index finger. It can help other extensors extend the wrist.
Identify 1. Innervation
- Extensor indicis muscle
Innervation: Radial nerve (posterior interosseous branch) (C7 and C8).
The extensor indicis muscle, a narrow, elongated muscle, lies medial and parallel to ___ (MUSCLE?).
It permits the index finger to extend independently of the other fingers.
the extensor pollicis longus muscle
Identify 1 - 2
- Pronator teres muscle
- Supinator muscle
Identify 3 - 5
- Flexor carpi radialis muscle
- Flexor pollicis longus muscle
- Extensor digitorum muscle
Identify 6
- Pronator quadratus muscle
Identify 7 - 9
- Flexor digitorum profundus muscle
- Flexor carpi ulnaris muscle
- Flexor digitorum superficialis muscle
Muscles of the anterior, or flexor, compartment of the forearm are innervated largely by ____
Only the flexor carpi ulnaris and the medial half of the flexor digitorum profundus are innervated ____
- the median nerve and its branches.
- by the ulnar nerve and its branches.
Muscles of the posterior compartment of the forearm are innervated by ___
the radial nerve and its branches.
