List all the anastomosis in the upper limb. With mnemonics and easy explanation according to MS1 level
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Loading Image
Loading Image
I now have all the information I need from the textbooks and diagrams. Let me compose a comprehensive, MS1-level answer.
Anastomoses of the Upper Limb
An anastomosis is a connection between two arteries (or veins) that allows blood to "bypass" a blocked or ligated vessel. Think of it as a road network - if the main highway is blocked, side roads still get you to your destination. These are clinically important for collateral circulation.
There are 4 main anastomoses in the upper limb:
1. Scapular Anastomosis (Scapular Arcade)
Location: Around the scapula (shoulder blade)
The Big Idea: Connects branches coming down from the neck/subclavian artery with branches coming up from the axillary artery.
| Artery (From Above) | Artery (From Below) |
|---|---|
| Suprascapular a. (from thyrocervical trunk of subclavian) | Circumflex scapular a. (from subscapular a. of axillary) |
| Dorsal scapular a. (from transverse cervical a.) | Same |
Clinical importance: If the axillary artery is ligated or blocked, blood can still reach the arm via this anastomosis. The anastomosis forms an arcade on the posterior surface of the scapula.
Mnemonic: "Supra-Dorsal MEETS Circumflex"
Suprascapular + Dorsal scapular MEET Circumflex scapular = Scapular Arcade
2. Cubital Anastomosis (Arterial Anastomosis Around the Elbow)
Location: Around the elbow joint (cubital fossa area)
The Big Idea: Branches coming down from the brachial artery and profunda brachii meet branches coming up (recurrent) from the radial and ulnar arteries.
Think of it as a ring of vessels around the elbow made of descending branches from above and ascending (recurrent) branches from below.
Branches forming it:
Coming from ABOVE (descending):
| Artery | Source |
|---|---|
| Radial collateral a. | Profunda brachii |
| Middle collateral a. (medial collateral a.) | Profunda brachii |
| Superior ulnar collateral a. | Brachial artery |
| Inferior ulnar collateral a. | Brachial artery |
Coming from BELOW (ascending/recurrent):
| Artery | Source |
|---|---|
| Radial recurrent a. | Radial artery |
| Anterior ulnar recurrent a. | Ulnar artery |
| Posterior ulnar recurrent a. | Ulnar artery |
| Recurrent interosseous a. | Posterior interosseous a. |
Mnemonic: "2 Profs, 2 Brachials + 3 Recurrents + 1 Interosseous"
A simpler way to remember all 8 vessels: "SRIM + RAUPI"
Superior ulnar collateral, Radial collateral, Inferior ulnar collateral, Middle (medial) collateral (these come from ABOVE) Radial recurrent, Anterior ulnar recurrent, Ulnar posterior recurrent, Posterior Interosseous recurrent (these come from BELOW)
Clinical importance:
- The brachial artery can be safely ligated distal to the origin of the profunda brachii because the cubital anastomosis provides collateral flow to the forearm.
- This is also why the radial artery can be harvested as a graft (e.g., for CABG) - the ulnar artery can supply the hand via the anastomosis.
3. Palmar Arches (Anastomosis in the Hand)
There are two palmar arches - both are anastomoses between the radial and ulnar arteries.
A) Superficial Palmar Arch
- Formed mainly by: Ulnar artery (terminal branch) + superficial palmar branch of radial artery
- Location: Superficial to the long flexor tendons, under the palmar aponeurosis
- Level: Projects across the palm at the level of the distal border of the thumb
- Gives rise to: 3 common palmar digital arteries → proper digital arteries
Memory trick: "Ulnar is Superficial" - the Ulnar (letter further right in the alphabet) supplies the Superficial arch.
B) Deep Palmar Arch
- Formed mainly by: Radial artery (terminal branch enters through 1st dorsal interosseous space) + deep palmar branch of ulnar artery
- Location: Deep to the long flexor tendons, on the bases of metacarpals
- Gives rise to: 3-4 palmar metacarpal arteries
Memory trick: "Radial goes Deep" - the Radial (letters earlier in the alphabet) supplies the Deep arch.
Quick Summary Table:
| Arch | Mainly From | Completed By | Location |
|---|---|---|---|
| Superficial | Ulnar a. | Superficial palmar branch of Radial | Superficial to flexors |
| Deep | Radial a. | Deep palmar branch of Ulnar | Deep to flexors, on metacarpal bases |
Mnemonic: "UR Deep, RU Shallow"
Ulnar Radial = the Ulnar is the main contributor to the superficial arch (with Radial completing it) Radial Ulnar = the Radial is the main contributor to the deep arch (with Ulnar completing it)
Clinical importance:
- The Allen's test checks patency of the superficial palmar arch - compress both radial and ulnar arteries, release one, and see if the hand flushes pink (confirms intact arch).
- Important before inserting radial arterial lines or harvesting the radial artery.
4. Carpal Arches (Wrist Anastomoses)
Two small anastomotic arches at the wrist level:
| Arch | Formed By |
|---|---|
| Palmar (anterior) carpal arch | Palmar carpal branch of radial a. + palmar carpal branch of ulnar a. |
| Dorsal (posterior) carpal arch | Dorsal carpal branch of radial a. + dorsal carpal branch of ulnar a. |
These give rise to the dorsal metacarpal arteries supplying the back of the hand and fingers.
Master Summary Table
| Anastomosis | Location | Connects | Clinical Importance |
|---|---|---|---|
| Scapular arcade | Around scapula | Suprascapular + dorsal scapular (from subclavian) ↔ Circumflex scapular (from axillary) | Collateral if axillary a. ligated |
| Cubital anastomosis | Around elbow | 4 descending branches (brachial/profunda) ↔ 4 recurrent branches (radial/ulnar/interosseous) | Brachial a. can be ligated distal to profunda; radial a. can be harvested |
| Superficial palmar arch | Palm (superficial) | Ulnar a. ↔ radial a. (superficial branch) | Allen's test; ensures hand viability |
| Deep palmar arch | Palm (deep) | Radial a. ↔ ulnar a. (deep branch) | Backup supply to palm |
| Carpal arches | Wrist | Radial ↔ ulnar (palmar and dorsal branches) | Supply dorsal hand; backup at wrist |
The Big Picture Mnemonic: "Shoulder Elbow Wrist Hand"
Scapular arcade → Elbow (cubital) → Wrist (carpal arches) → Hand (palmar arches)
Just go from proximal to distal down the limb - there is an anastomosis at every major region.
Sources: Color Atlas of Human Anatomy Vol. 2 (THIEME), pp. 106-111; General Anatomy and Musculoskeletal System THIEME Atlas, p. 410; Fischer's Mastery of Surgery, p. 6990.
Explain wrist, elbow and shoulder joint.
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Loading Image
Loading Image
Loading Image
Here is a summary of what was covered:
What You Just Learned - 3 Upper Limb Joints at a Glance
Shoulder (Glenohumeral)
- Ball-and-socket; most mobile, least stable
- Head of humerus (ball) + glenoid cavity (socket, deepened by labrum)
- Stabilized by rotator cuff (SITS), not its ligaments
- Most commonly dislocated anteriorly → risk to axillary nerve
Elbow
- 3 joints in 1 capsule - humeroulnar + humeroradial (hinge) + proximal radioulnar (pivot)
- Key ligaments: medial/lateral collateral + annular ligament around radial head
- Fat pad sign = look for a fracture
- Most dangerous complication: brachial artery injury in supracondylar fracture
Wrist (Radiocarpal)
- Condyloid joint - 2 axes only (no rotation here!)
- Radius + TFCC meet SLT (Scaphoid, Lunate, Triquetrum)
- Ulna does NOT directly touch carpals
- Most common fractures: Colles' (distal radius) and scaphoid
This is a shared conversation. Sign in to Orris to start your own chat.