Fingers, N459 Notes, Anatomy, Upper Limb, Wrist and Hand

Sagittal Section Finger:

1. Synovial and fibrous sheath for the flexor tendons
2. Articulate cartilage and articular cavity
3. Extensor mechanism consists of the Lateral Band and the Central Tendon
4. Synovial membrane over the joint (not the synovial Sheath for the flexor tendons)

Cross Section through distal phalynx

1. I can see 9 fine nerves - how many can you see?
2. Fine tissue and AREOLAR TISSUE in anterior enclosed space

Arteries and Nerves

1. Dorsal digital artery and Nerve - Proximal 2/3
2. Palmar digital artery and nerve with nutrient branch to epiphysis and metaphysis
3. Dorsal branches of palmar digital arteries and nerves to dorsum of middle and terminal palanges Distal 1/3

Location of Areolar Tissue, 

also referred to as "loose connective tissue".

It may be found in tissue sections from almost every part of the body. It surrounds blood vessels and nerves and penetrates with them even into the small spaces of muscles, tendons, and other tissues. It may likewise be present in the mediastinal extremities. Nearly every epithelium rests on a layer of areolar tissue, whose blood vessels provide the epithelium with nutrition, waste removal, and a ready supply of infection-fighting leukocytes in times of need. Because the abundance of open, fluid-filled space, leukocytes can move about freely in areolar tissue and can easily find and destroy pathogens.

The areolar tissue is found beneath the dermis layer and is also underneath the epithelial tissue of all the body systems that have external openings.

It is also a component of the lamina propria of the digestive and respiratory tracts, the mucous membranes of reproductiveand urinary systems, the stroma of glands, and the hypodermis of the skin.

Extensor Tendon at Wrist, N458, Anatomy, Upper Limb, Wrist and Hand

6 Compartment

1. Compartment 1:
1. Extensor Pollicis Brevis
2. Abductor Pollicis Longus
2. Compartment 2
1. Extensor Carpi Radialis Longus
2. Extensor Carpi Radialis Brevis
3. Compartment 3
1. Extensor Pollicis Longus
4. Compartment 4
1. Extensor Indicis
2. Extensor Digitorum 
5. Compartment 5
1. Extensor Digiti minimi
6. Compartment 6
1. Extensor Carpi Ulnaris

Dorsal Interosseous Muscles

Intertendinous connections

Transverse Fibers of Extensor Expansions (Hoods)

Wrist and Hand: Deep Dorsal Dissection, N457, Anatomy, Upper Limb, Wrist and Hand

Wrist and Hand: Deep Dorsal Dissection, N457, Anatomy, Upper Limb, Wrist and Hand

1. Nerves
1. Superficial branch of radial nerve
1. Dorsal Digital Branches of Superficial Branch of Radial nerve to 1st, 2nd, 3rd and Radial half of the 4th fingers
2. Dorsal Branch of Ulnar Nerve
1. Dorsal Digital Branches of dorsal Branch of Ulnar Nerve
3. Antebrachial Cutaneous Nerve
1. Lateral Antebrachial Cutaneous Nerve
2. Medial Antebrachial Cutaneous Nerve
3. Posterior Antebrachial Cutaneous Nerve 
4. Dorsal branches of Palmar digital branches of Ulnar Nerve and Palmar Digital arteries to dorsum of middle and distal phalanges of 5th and Ulnar half of 4th fingers
5. Dorsal branches of Palmar digital branches of Median Nerve and Palmar Digital arteries to dorsum of middle and distal phalanges of 2nd, 3rd and Radial half of 4th fingers
2. Extensor Retinaculum
3. Thumb
1. Abductor Pollicis Longus
2. Extensor Pollicis Longus and 
3. Extensor Pollicis Brevis
4. Extensor Carpi Ulnaris Tendon
5. Extensor Carpi Radialis
1. Extensor Carpi Radialis Longus Tendon
2. Extensor Carpi Radialis Brevis Tendon

Wrist and Hand: Superficial Dorsal Dissection, N456, Anatomy, Upper Limb, Wrist and Hand

Wrist and Hand: Superficial Dorsal Dissection, N456, Anatomy, Upper Limb, Wrist and Hand:
Posterior (Dorsal) View
Nerves:

1. Superficial branch of radial nerve
2. Posterior Antebrachial Cutaneous Nerve
3. Dorsal branch of the Ulna Nerve
4. Dorsal digital nerves and veing

Communicating branches between the radial and the Ulna Nerves

Vessels

1. Cephalic Vein
2. Basilic Vein

Wrist and Hand: Superficial Radial Dissection, N455, Anatomy, Upper Limb, Wrist and Hand

Wrist and Hand: Superficial Radial Dissection, N455, Anatomy, Upper Limb, Wrist and Hand

Lateral (Radial) View

Nerves:

1. Superficial branch of the Radial Nerve with its medial and lateral branches 
1. Lateral branches to the Lateral Thumb
2. Medial branch to the medical aspect of the thumb - Dorsal Digital branches of the radial nerve

Muscles and tendons

1. Abductor Pollicis longus tendon
2. Insertion of extensor Pollicis Brevius Tendon
3. Insertion of extensor pollicis Longus tendon
1. 1st Dorsal Interosseous Muscle
2. Extensor Carpi Radialis longus tendon
3. Extensor Carpi radialis Brevis tendon

Arteries

1. Radial Artery in the Anatomical Snuffbox with its dorsal carpal branch

Anatomical Snuffbox:

• Radial Nerve (dorsal digital branch)
• Cephalic Vein branches
• Radial Artery and branches
• Scaphoid  bone

Anatomical snuff box
anatomical snuff box
The mucous sheaths of the tendons on the back of the wrist. (Anatomical snuff box not labeled, but visible at right.)
Artery	radial artery
Vein	cephalic vein
Nerve	radial nerve

Pathology

The radius and scaphoid articulate deep to the snuffbox to form the basis of the wrist joint. In the event of a fall onto an outstretched hand, this is the area through which the brunt of the force will focus. This results in these two bones being the most often fractured of the wrist. In a case where there is localized tenderness within the snuffbox, knowledge of wrist anatomy leads to the speedy conclusion that the fracture is likely to be of the scaphoid. This is understandable as the scaphoid is a small, oddly shaped bone whose purpose is to facilitate mobility rather than confer stability to the wrist joint. In the event of inordinate application of force over the wrist, this small scaphoid is clearly likely to be the weak link. Interestingly, scaphoid fracture is one of the most frequent causes of medico-legal issues.

Anatomical peculiarity

An interesting anatomical anomaly in the vascular supply to the scaphoid is the area to which the blood supply is first delivered. Blood enters the scaphoid distally. Consequently, in the event of a fracture the proximal segment of the scaphoid will be devoid of a vascular supply, and will—if action is not taken—avascularly necrose within a sufferer's snuffbox. Due to the small size of the scaphoid and its shape, it is difficult to determine, early on, whether or not the scaphoid is indeed fractured with an x-ray. Further complications include; carpal instability (ligament disruption) and fracture-dislocations.