Muscle Anatomy and Innervation Quiz: Upper Extremity

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Questions and Answers

Which nerve innervates the Palmaris Longus muscle?

Radial nerve

Median nerve (correct)

Musculocutaneous nerve

Ulnar nerve

What action is primarily associated with the Flexor Carpi Ulnaris muscle?

Wrist flexion and ulnar deviation (correct)

Wrist extension and radial deviation

Finger flexion and wrist flexion

Shoulder abduction and wrist flexion

From which area does the Flexor Digitorum Superficialis originate?

Base of the 5th metacarpal

Posterior border of the radius

Lateral epicondyle

Medial epicondyle, coronoid process of ulna and upper radius (correct)

What is the common origin for wrist flexor muscles like the Palmaris Longus?

Medial epicondyle (common flexor origin) Signup and view all the answers

Which muscle has an absent presence in approximately 10% of the population?

Palmaris Longus Signup and view all the answers

What is the primary function of the Extensor Carpi Radialis Brevis?

Wrist extension Signup and view all the answers

Which nerve is responsible for the innervation of the Extensor Digitorum?

Deep branch of radial nerve Signup and view all the answers

Which action does the Extensor Digitorum facilitate?

Extension of all joints of the digits Signup and view all the answers

Which anatomical location does the Extensor Carpi Radialis Brevis originate from?

Lateral epicondyle (common extensor tendon) Signup and view all the answers

What is indicated by the term 'extensor hood mechanism' in relation to the Extensor Digitorum?

A shared support structure for multiple tendons in the hand Signup and view all the answers

What is the primary role of the subscapularis muscle?

Shoulder internal rotation Signup and view all the answers

Which muscle stabilizes the glenohumeral joint during shoulder abduction?

Supraspinatus Signup and view all the answers

Which group of fibers of the deltoid muscle is responsible for shoulder flexion?

Anterior fibers Signup and view all the answers

What does the posterior fibers of the deltoid muscle primarily assist with?

Shoulder extension and horizontal abduction Signup and view all the answers

From where does the supraspinatus muscle originate?

Supraspinous fossa of scapula Signup and view all the answers

Which nerve is associated with the subscapularis muscle?

Upper subscapular nerve Signup and view all the answers

What is the function of the rotator cuff muscles?

Shoulder stabilization Signup and view all the answers

What could potentially affect the function of the glenohumeral joint?

Imbalance of the rotator cuff muscles Signup and view all the answers

What structure allows the profundus tendon to pass through under the flexor retinaculum?

Synovial sheath Signup and view all the answers

Which finger tendons are positioned above those of the index and little fingers?

Middle and ring fingers Signup and view all the answers

What is the function of the dorsal interossei?

Abduction at the MCP Signup and view all the answers

Which nerve provides innervation to the Flexor Pollicis Longus?

Median nerve Signup and view all the answers

What is the primary action of the Flexor Pollicis Longus at the IP joint?

Flexes the distal phalanx of the thumb Signup and view all the answers

Where does the 1st interossei arise from?

Ulnar side of the 2nd metacarpal Signup and view all the answers

Which nerve innervates the interossei muscles?

Ulnar nerve Signup and view all the answers

Which statement is true regarding the Flexor Digitorum?

It has dual innervation. Signup and view all the answers

What is a main action performed by the abductor pollicis brevis?

Abducts the thumb Signup and view all the answers

At which joint does the Flexor Pollicis Longus also flex the proximal phalanx of the thumb?

MCP joint Signup and view all the answers

Which interossei is responsible for movement on the ulnar side of the middle finger?

3rd interossei Signup and view all the answers

What is the primary function of the Flexor Digitorum?

Flexes the distal phalanx of the fingers Signup and view all the answers

Where does the Flexor Pollicis Longus originate?

Middle radius Signup and view all the answers

What muscle has two heads that contribute to its function?

Flexor pollicis brevis Signup and view all the answers

The proximal phalanx and extensor tendon are associated with which muscle group?

Interossei Signup and view all the answers

Which muscle acts to flex the thumb?

Flexor pollicis brevis and longus Signup and view all the answers

What nerve primarily innervates the Opponens Pollicis muscle?

Median nerve Signup and view all the answers

Which muscle is responsible for the opposition of the thumb?

Opponens Pollicis Signup and view all the answers

Which muscle of the hypothenar eminence is responsible for abducting the little finger?

Abductor Digiti Minimi Signup and view all the answers

What joint movement is facilitated by the Flexor Digiti Minimi Brevis?

Flexion of MCP joint Signup and view all the answers

Which bone is the origin for the Abductor Digiti Minimi muscle?

Pisiform bone Signup and view all the answers

What is the function of the Opponens Digiti Minimi muscle?

Opposes the little finger Signup and view all the answers

Which structure is involved in the innervation of the Flexor Digiti Minimi Brevis?

Deep branch of ulnar nerve Signup and view all the answers

The deep head of the Opponens Pollicis muscle is associated with which bone?

Trapezium Signup and view all the answers

Study Notes

Upper Extremity Muscles

Trapezius: Originates at the medial part of the superior nuchal line, ligamentum nuchae, and thoracic spinous processes. Inserts onto the lateral part of the clavicle, acromion, and spine of the scapula. Innervated by the spinal accessory nerve (CN XI). Acts as a whole to rotate the scapula upward, or individually, for upward rotation (upper trap), retraction (middle trap), or depression and upward rotation (lower trap).
Latissimus Dorsi: Originates from spinous processes of T7-T12, lumbar aponeurosis, crest of ilium, and lower three or four ribs. Inserts onto the floor of the bicipital groove of the humerus. Innervated by the thoracodorsal nerve. Actions include shoulder extension, internal rotation, adduction, and can contribute to scapular depression and retraction.
Levator Scapulae: Originates from transverse processes of C1-C4. Inserts onto the superior angle and medial border of the scapula. Innervated by the dorsal scapular nerve. Elevates the scapula and performs downward rotation.
Rhomboid Minor: Originates from spinous processes of C7 and T1. Inserts onto the vertebral border of the scapula at the base of the spine. Innervated by the dorsal scapular nerve. Elevates and downwardly rotates the scapula.
Rhomboid Major: Originates from spinous processes of T2-T5. Inserts onto the vertebral border of the scapula below the rhomboid minor. Innervated by the dorsal scapular nerve. Elevates and downwardly rotates the scapula.
Serratus Posterior Superior: Originates from spinous processes of C7-T2. Inserts onto the upper ribs. Innervated by the intercostal nerves. Acts to elevate the ribs in inspiration.
Serratus Posterior Inferior: Originates from spinous processes of T11-L2. Inserts onto the lower ribs. Innervated by the intercostal nerves. Depresses the ribs in exhalation.
Deltoid: Originates from the lateral third of the clavicle, acromion, and spine of the scapula. Inserts onto the deltoid tuberosity of the humerus. Innervated by the axillary nerve. Acts as a whole to stabilizes the glenohumeral joint or individually, the anterior fibers for flexion and horizontal adduction, middle fibers for abduction, and posterior fibers for extension and horizontal abduction.
Subscapularis: Originates from the subscapular fossa. Inserts onto the lesser tubercle of the humerus. Innervated by the upper and lower subscapular nerves. Stabilizes the glenohumeral joint and rotates the humerus internally.
Supraspinatus: Originates from the supraspinous fossa. Inserts onto the superior facet of the greater tubercle of the humerus. Innervated by the suprascapular nerve. Primarily abducts the humerus.
Infraspinatus: Originates from the infraspinous fossa. Inserts onto the middle facet of the greater tubercle of the humerus. Innervated by the suprascapular nerve. Primarily rotates the humerus externally.
Teres Minor: Originates from the lateral border of the scapula above teres major. Inserts onto the lower facet of the greater tubercle of the humerus. Innervated by the axillary nerve. Primarily externally rotates the humerus.
Teres Major: Originates from the lower lateral border of the scapula, as far as the inferior angle. Inserts onto the medial lip of the bicipital groove, inferior to the insertion of the latissimus dorsi. Innervated by the lower subscapular nerve. Primarily adducts, internally rotates, and extends the humerus.

Additional Upper Extremity Muscles and Actions (Page 2-8)

Coracobrachialis: Short head, coracoid process. Long head, supraglenoid tubercle (blends with labrum). Functions in flexion, adduction, and internal rotation of the shoulder.
Biceps Brachii: Short head, coracoid process. Long head, supraglenoid tubercle. Flexes and supinates the forearm, flexes the shoulder.
Brachialis: Lower, anterior humerus. Flexes the elbow.
Triceps Brachii: Long head, infraglenoid tubercle. Extends the elbow.
Anconeus: Lateral epicondyle, posterior humerus. Extends the elbow.
Pectoralis Major: Clavicular, sternal. Flexes, adducts, internally rotates shoulder.
Pectoralis Minor: Ribs 2-5. Draws scapula forward and downward.
Subclavius: First rib. Stabilizes and depresses the clavicle.
Pronator Teres: Medial epicondyle (common flexor origin) and coronoid process of ulna. Pronates and flexes the forearm.
Flexor Carpi Radialis: Medial epicondyle (common flexor origin). Flexes and radially deviates wrist.
Palmaris Longus: Medial epicondyle (common flexor origin). Flexes and radially deviates wrist, tenses the palmar fascia.
Flexor Carpi Ulnaris: Medial epicondyle (common flexor origin), proximal ulna. Flexes and ulnarly deviates wrist.
Flexor Digitorum Superficialis: Upper 3/4 ulna, interosseous membrane. Flexes proximal phalanges and wrist.
Flexor Digitorum Profundus: Upper 3/4 ulna, interosseous membrane, extends wrist.. Flexes distal interphalanges.
Pronator Quadratus: Distal ulna. Pronates forearm.
Palmaris Brevis: Hypothenar fascia. Flexes the metacarpophalangeal (MCP) joint of the thumb.
Lumbricals: Flexes the MCP joint and extends the IP joints of fingers.
Adductor Pollicis: Flexor retinaculum, trapezium/trapezoid. Abducts and adducts thumb.
Abductor Pollicis Brevis: flexor retinaculum, trapezium. Abducts thumb.
Opponens Pollicis: flexor retinaculum, trapezium. Opposes thumb.
Abductor Digiti Minimi: pisiform bone. Abducts the little finger.
Opponens Digiti Minimi: pisiform bone. Opposes the little finger.
Brachioradialis: Upper lateral supracondylar ridge of humerus, lateral radius above styloid process. Flexes the elbow and supinates or pronates forearm.
Extensor Carpi Radialis Longus: Lateral epicondyle of humerus. Extends and radially deviates the wrist.
Extensor Carpi Radialis Brevis: Lateral epicondyle, radius. Extends and radially deviates the wrist.
Extensor Digitorum: Lateral epicondyle, radius. Extends the digits.
Extensor Digiti Minimi: Lateral epicondyle, radius. Extends the little finger.
Extensor Carpi Ulnaris: Lateral epicondyle, radius. Extends and ulnarly deviates the wrist.
Supinator: Lateral epicondyle, ulna and radius. Supinates the forearm.
Abductor Pollicis Longus: Posterior ulna, proximal radius. Abducts the thumb.
Extensor Pollicis Longus: Posterior ulna, proximal radius. Extends the thumb.
Extensor Pollicis Brevis: Posterior ulna. Abducts and extends the thumb.
Extensor Indicis: Posterior distal ulna. Extends the index finger.

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Test your knowledge on muscle anatomy and innervation with this quiz. Questions cover various muscles including the Palmaris Longus, Flexor Carpi Ulnaris, and Extensor Digitorum, focusing on their origins, functions, and neural connections. Perfect for students studying human anatomy.