Wrist Anatomy: Bony and Soft Tissue Structures

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Questions and Answers

Which bony structure is located at the base of the 2nd MCP and can be identified by following the flexor carpi radialis tendon?

Hook of the Hamate

Pisiform

Capitate (correct)

Tubercle of the Scaphoid

Which bony landmark is activated through flexion and ulnar deviation of the hand?

Tubercle of the Scaphoid

Lunate

Capitate

Pisiform (correct)

What anatomical feature can be palpated just radial to the flexor carpi radialis tendon?

Ulnar Artery

Flexor Digitorum Superficialis

Median Nerve

Radial Artery (correct)

Which soft tissue structure can be located by alternating finger flexion and extension?

Flexor Digitorum Superficialis Signup and view all the answers

Which structure goes between the pisiform and the hook of the hamate into Guyon's tunnel?

Ulnar Nerve Signup and view all the answers

Which carpal bone can be better appreciated during radial deviation of the wrist?

Tubercle of the Scaphoid Signup and view all the answers

What action would best assist in identifying the palmaris longus?

Placing the thumb and 5th finger together while flexing the wrist Signup and view all the answers

Which tendon can be followed distally to its insertion on the pisiform bone?

Flexor Carpi Ulnaris Signup and view all the answers

Which of the following is NOT a bony landmark of the wrist?

Scaphoid Signup and view all the answers

What are the primary movements allowed at the radiocarpal joint?

Flexion/extension and ulnar/radial deviation Signup and view all the answers

Which intrinsic muscle is NOT part of the thenar eminence?

Flexor Pollicis Longus Signup and view all the answers

In relation to DeQuervain's Syndrome, which dorsal compartment is primarily affected?

Compartment 1 Signup and view all the answers

What classification best describes the midcarpal joint?

Compound joint with 2 degrees of freedom Signup and view all the answers

Which of the following statements accurately describes the axis of motion for the distal radio-ulnar joint?

Longitudinal axis from the radial head distally through the ulnar head Signup and view all the answers

In the context of wrist anatomy, the capitate bone is located in which row of the carpal bones?

Distal row Signup and view all the answers

Which of the following accurately describes the movements available at the distal radio-ulnar joint?

Pronation and supination Signup and view all the answers

Which structures are primarily involved in the first dorsal compartment of the wrist?

Extensor Pollicis Brevis and Abductor Pollicis Longus Signup and view all the answers

What is the significance of Lister's tubercle in relation to the dorsal compartments?

It creates a leverage point for the Extensor Pollicis Longus. Signup and view all the answers

Which tendon can be palpated when performing an ulnar deviation with the thumb extended?

Extensor Pollicis Longus Signup and view all the answers

In the context of DeQuervain's Syndrome, which combination of tendons is affected?

Abductor Pollicis Longus and Extensor Pollicis Brevis Signup and view all the answers

Which structure can be found in the second dorsal compartment of the wrist?

Extensor Carpi Radialis Longus Signup and view all the answers

How can the Extensor Digiti Minimi be identified?

By rolling the finger of the head of the ulna while extending the little finger. Signup and view all the answers

Where is the Extensor Carpi Ulnaris located in relation to the bones of the wrist?

Ulnar side; just volar to the head of the ulna. Signup and view all the answers

Which of the following actions will best activate the Extensor Indicis?

Extension of the index finger. Signup and view all the answers

What role does the anatomical snuffbox play in wrist anatomy?

It helps in identifying bony landmarks during palpation. Signup and view all the answers

What is the main function of the Extensor Pollicis Brevis?

To assist in abduction of the thumb. Signup and view all the answers

Study Notes

Radial Aspect of Wrist: Bony Landmarks

The base of metacarpal 1 can be palpated by following the first metacarpal down from the thumb.
The radius can be palpated along its radial edge.
The scaphoid can be felt by extending the thumb and asking for ulnar deviation, which will fill in the proximal part of the anatomical snuff box.

Dorsal Soft Tissue Structures

The dorsal aspect of the wrist and hand has six compartments.
The first compartment includes:
- Abductor pollicis longus
- Extensor pollicis brevis

1st Dorsal Compartment

The abductor pollicis longus makes up the most radial aspect of the compartment and attaches to the base of the first metacarpal.
The extensor pollicis brevis attaches to the proximal aspect of the first phalanx.
Both muscles are involved in DeQuervain's Syndrome.

3rd Dorsal Compartment

The extensor pollicis longus is found in the dorsal leg of the anatomical snuffbox.
The EPL curves around the ulnar aspect of Lister's tubercle to improve functionality.

2nd Dorsal Compartment

The extensor carpi radialis longus and extensor carpi radialis brevis are in the compartment radial to Lister's tubercle.
The tendons can be easily identified by giving slight resistance into extension and radial deviation with a relaxed thumb.
The ECRL attaches to the base of the second metacarpal.
The ECRB attaches to the base of the third and second metacarpals.

4th Dorsal Compartment

The extensor indicis and extensor digitorum tendons reside in the compartment.
The extensor indicis can be palpated by asking for extension of the index finger.
The extensor digitorum tendons can be activated by alternating extension of the fingers.

5th Dorsal Compartment

This compartment is more ulnar and contains the extensor digiti minimi.
The extensor digiti minimi can be palpated by rolling the finger against the head of the ulna while activating little finger extension.

6th Dorsal Compartment

The extensor carpi ulnaris is located palmar to the head of the ulna.
It can be palpated during wrist extension and ulnar deviation and followed to its insertion on the base of the fifth metacarpal.

Palmar Bony Structures

The pisiform can be located in the flexor crease of the wrist on the pinky side by rolling the thumbpad in small circles.
The tubercle of the scaphoid is located on the radial side of the wrist.
The scaphoid tubercle can be palpated by activating the flexor carpi radialis and following the tendon distally, using ulnar and radial deviation to better appreciate the tubercle.

Palmar Soft Tissue Structures

The flexor carpi radialis, radial artery, flexor carpi ulnaris, ulnar artery, ulnar nerve, flexor digitorum superficialis, palmaris longus, and median nerve are soft tissue structures commonly found on the palmar aspect of the wrist.
The flexor carpi radialis can be identified by flexing and radially deviating the wrist.
The radial artery is located just radial to the FCR and also has a pulsation in the anatomical snuffbox.
The flexor carpi ulnaris can be identified by flexing and ulnarly deviating the wrist.
The ulnar artery runs between the pisiform and the hook of the hamate into Guyon's tunnel.
The ulnar nerve has superficial branches that sometimes can be palpated over the hook of hamate.
The flexor digitorum superficialis can be palpated more radially from the ulnar structures.
The palmaris longus can be palpated by placing the thumb and fifth finger together and flexing the wrist.
The median nerve can be found directly beneath the palmaris longus.

Distal Radio-Ulnar Joint

This joint complex is a pivot joint with 1 degree of freedom and 2 directions of motion (pronation/supination).
The longitudinal axis runs from the radial head through the ulnar head.

Radiocarpal Joint

The radiocarpal joint is formed by the radius and radioulnar disc proximally.
Distally, it involves the scaphoid, lunate, and triquetrum.
The joint is classified as an ovoid and complex due to its shape and the number of articulating surfaces.
It has 2 degrees of freedom and 4 directions of motion: flexion/extension and ulnar/radial deviation.

Midcarpal Joint

The midcarpal joint is formed by the scaphoid, lunate, and triquetrum proximally.
Distally, it involves the trapezium, trapezoid, capitate, hamate.
This joint has a reciprocally concave-convex configuration and is classified as a condyloid or modified hinge joint with 2 degrees of freedom and 4 directions of motion: flexion/extension and ulnar/radial deviation.
The joint is considered complex due to the number of articulating surfaces.

Dorsal Bony Structures

While it can be difficult to palpate the individual carpal bones, the borders of the carpus can be clearly identified.
Bony structures include the ulnar styloid process, radial styloid process, base of metacarpals 1-5, and capitate.

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Description

Explore the bony landmarks and soft tissue structures of the wrist, focusing on the radial aspect and dorsal compartments. This quiz covers key muscles involved in DeQuervain's Syndrome and their anatomical significance. Perfect for students of anatomy and physiology.