upper limb 2 - forearm, elbow, hand, wrist

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Questions and Answers

What primary action does the long head of the triceps perform at the shoulder joint?

Rotate the arm medially

Flex the arm

Extend and adduct the arm (correct)

Abduct the arm

Which nerve is NOT a primary supplier to the muscles in the back of the arm and forearm?

Median nerve (correct)

Musculocutaneous nerve (correct)

Radial nerve

Ulnar nerve (correct)

What is the anatomical landmark where the axillary artery becomes the brachial artery?

Midpoint of the humerus

Outer border of the first rib

Superior border of the radius

Lower border of teres major (correct)

Which of the following arteries is NOT part of the arterial supply to the elbow joint?

Subclavian artery Signup and view all the answers

Which of the following correctly describes the boundaries of the cubital fossa?

Medially by pronator teres and the mass of flexor muscles of the forearm, and superiorly by an imaginary line between epicondyles Signup and view all the answers

Which muscle of the anterior compartment of the forearm is innervated by the ulnar nerve?

Flexor digitorum profundus Signup and view all the answers

Which muscle is located in the deep layer of the anterior compartment of the forearm?

Flexor pollicis longus Signup and view all the answers

Identify the muscle that is primarily responsible for pronation of the forearm.

Pronator teres Signup and view all the answers

Which of the following muscles originates from the medial epicondyle?

Flexor carpi radialis Signup and view all the answers

What is the primary nerve that innervates the majority of superficial forearm muscles?

Median nerve Signup and view all the answers

Which muscle is primarily responsible for the flexion of the forearm at the elbow joint?

Brachialis Signup and view all the answers

What is the nerve supply for both the biceps brachii and brachialis muscles?

Musculocutaneous nerve Signup and view all the answers

Which of the following actions is NOT performed by the biceps brachii?

Extension of the forearm Signup and view all the answers

From where does the long head of the triceps brachii originate?

Infraglenoid tubercle of scapula Signup and view all the answers

Which structure does the musculocutaneous nerve pierce?

Coracobrachialis Signup and view all the answers

Which muscle acts as an accessory flexor of the arm at the shoulder joint?

Biceps brachii Signup and view all the answers

What is the insertion point of the brachialis muscle?

Tuberosity of the ulna Signup and view all the answers

Which of the following muscles does NOT belong to the posterior compartment of the arm?

Coracobrachialis Signup and view all the answers

Which nerve innervates the muscles in the posterior extensor compartment of the forearm?

Radial nerve Signup and view all the answers

What is the primary function of the flexor retinaculum in the forearm?

Prevent the bowing of tendons Signup and view all the answers

Which of the following structures is located medial to the tendon of biceps brachii in the cubital fossa?

Brachial artery Signup and view all the answers

What is the common origin point for most flexors of the forearm?

Medial epicondyle Signup and view all the answers

Which bone features the radial tuberosity?

Radius Signup and view all the answers

Which two pronator muscles are found in the anterior flexor compartment of the forearm?

Pronator teres and pronator quadratus Signup and view all the answers

In which region of the ulna is the ulnar notch located?

Distal end Signup and view all the answers

What type of joint is the proximal radio-ulnar joint?

Pivot joint Signup and view all the answers

Which muscle is responsible for the flexion and abduction of the wrist?

Flexor carpi radialis Signup and view all the answers

What is the nerve supply for the Flexor carpi ulnaris?

Ulnar nerve Signup and view all the answers

Which muscle primarily flexes the interphalangeal and metacarpophalangeal joints of the thumb?

Flexor pollicis longus Signup and view all the answers

Which muscle originates from the lateral epicondyle of the humerus and helps in wrist extension?

Extensor carpi ulnaris Signup and view all the answers

What is the primary action of the Brachioradialis?

Flexion of elbow Signup and view all the answers

Which muscles provide the main action of adduction in the hand?

Palmar interossei Signup and view all the answers

Which of the following is correct regarding the innervation of the lumbricals?

Median and ulnar nerves Signup and view all the answers

The action of the Extensor indicis is to:

Extend the index finger Signup and view all the answers

Which muscle's action includes the medial rotation of the thumb?

Opponens pollicis Signup and view all the answers

What joint do the Flexor digitorum profundus and superficialis primarily act on?

Interphalangeal joints Signup and view all the answers

What is the primary action of the Supinator muscle?

Supination of the forearm Signup and view all the answers

Which muscle is NOT a part of the posterior compartment of the forearm?

Flexor carpi ulnaris Signup and view all the answers

Which muscle is responsible for extending and abducting the wrist?

Extensor carpi radialis longus Signup and view all the answers

Study Notes

Muscles of the Arm

Anterior compartment:
- Biceps brachii: Flexes the forearm at the elbow, supinates the forearm, and flexes the arm at the shoulder.
- Brachialis: Flexes the forearm at the elbow.
- Coracobrachialis: Flexes the arm at the shoulder.
Posterior compartment:
- Triceps brachii: Extends the forearm at the elbow and also extends and adducts the arm at the shoulder (long head).
- Anconeus: Assists in extending the forearm at the elbow.
Nerve supply:
- Musculocutaneous nerve: Supplies biceps brachii, brachialis, and coracobrachialis.
- Radial nerve: Supplies triceps brachii and anconeus.
Arteries:
- Axillary artery: Begins at the outer border of the first rib, continues as the brachial artery.
- Brachial artery: Divides into radial and ulnar arteries below the elbow joint.

Elbow Joint

Hinge joint: Allows flexion and extension at the elbow.
Articular surfaces: Between the humerus, ulna, and radius.
Capsule & ligaments: Stabilize the joint.
Arterial supply: Brachial, profunda brachii, radial, and ulnar arteries.
Nerve supply: Musculocutaneous, radial, and ulnar nerves.

Cubital Fossa

Location: Anterior aspect of the elbow.
Boundaries:
- Superiorly: Line connecting the medial and lateral epicondyles.
- Medially: Pronator teres and flexor muscles of the forearm.
- Laterally: Brachioradialis and extensor muscles.
Contents:
- Tendon of biceps brachii
- Brachial artery
- Median nerve

Muscles of the Forearm

Anterior compartment (Flexors)
- Superficial layer: Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis.
- Deep layer: Pronator quadratus, flexor pollicis longus , and flexor digitorum profundus.
Posterior compartment (Extensors)
- Superficial layer: Brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor carpi ulnaris, extensor digiti minimi, and anconeus.
- Deep layer: Supinator, extensor pollicis longus, extensor pollicis brevis, and extensor indicis.
Nerve supply:
- Median nerve: Supplies most of the anterior compartment muscles.
- Ulnar nerve: Supplies flexor carpi ulnaris and the medial half of flexor digitorum profundus.
- Radial nerve: Supplies all posterior compartment muscles.

Muscles of the Hand

Intrinsic muscles: Located within the hand, responsible for fine motor movements.
- Thenar muscles (thumb): Opponens pollicis, abductor pollicis brevis, flexor pollicis brevis, and adductor pollicis.
- Hypothenar muscles (little finger): Opponens digiti minimi, abductor digiti minimi, and flexor digiti minimi brevis.
- Other intrinsics: Lumbricals and interossei (palmar and dorsal).

Wrist Joint

Synovial joint: Allows flexion, extension, abduction, and adduction.
Articular surfaces: Distal end of radius and scaphoid, lunate, and triquetrum.
Ligaments: Fibrous capsule, dorsal and palmar radio-carpal ligaments, radial and ulnar collateral ligaments.

Radio-ulnar Joints

Proximal radio-ulnar joint: Between the radius and ulna.
Distal radio-ulnar joint: Between the radius and ulna.
Interosseous membrane: Connects the radius and ulna along their shafts.

Applied Anatomy - Subluxation or Pulled Elbow

Also known as nursemaid's elbow, or pulled elbow
Occurs when the radial head is pulled out of the annular ligament, usually in young children.
Commonly happens when a child is abruptly pulled by the hand.

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Description

This quiz covers the anatomy of the muscles in the arm, including the anterior and posterior compartments, along with their functions and nerve supply. It also addresses the structure and function of the elbow joint as a hinge joint. Test your knowledge on these crucial components of human anatomy.