topic 26: Dorsum of the hand. The anatomical snuffbox (foveola radialis).

Question 1

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muscles & movemnts :

Answer 1

Tendons and Muscles:

*Extensor tendons: Pass over the dorsum of the hand and are responsible for extending the fingers and thumb.
*Dorsal interosseous muscles: Found between the metacarpal bones and are involved in finger abduction.
*Extensor indicis proprius: Extends the index finger.
*Extensor digiti minimi: Extends the little finger.
*Extensor pollicis longus and brevis: Extend the thumb.

Movements:

-Extension: The main action of the extensor muscles is to extend the wrist, fingers, and thumb, allowing for movements such as opening the hand and straightening the fingers.
-Abduction: The dorsal interosseous muscles contribute to finger abduction, which involves spreading the fingers apart from each other.
-Thumb Extension: The extensor pollicis longus and brevis extend the thumb, enabling movements such as pointing and hitchhiking.

Question 2

innervation

Answer 2

1.Ulnar nerve: -dorsal cutaneous branch for skin and deep branch for dorsal interossei muscle
2.Radial n: superficial branch for skin
3.Median nerve : proper palmar digital nerve

Question 3

vessels

Answer 3

Blood Vessels and Nerves:

Dorsal venous network: Drains blood from the dorsum of the hand and fingers.
Radial and ulnar arteries: Provide blood supply to the hand.
Radial and ulnar nerves: Innervate the dorsal aspect of the hand and fingers, providing sensory and motor function.
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Question 4

anatomical snuff box

Answer 4

depression on the lateral aspect of the dorsum of the hand, near the base of the thumb.

Boundaries:
Proximally: Extensor pollicis longus and brevis tendons.
Distally: Extensor pollicis brevis and abductor pollicis longus tendons.
Floor: Scaphoid and trapezium bones.
Roof: Skin and superficial fascia.

Contents:
Radial artery: Runs through the anatomical snuffbox, supplying blood to the hand and fingers.
Radial nerve branches: Provide sensory innervation to the dorsum of the hand.

Clinical Significance:
Palpation of the anatomical snuffbox is used to locate the radial pulse for assessment of arterial blood flow.
The snuffbox is a common site for injuries, including fractures of the scaphoid bone, due to its superficial location and lack of protective soft tissue.