Upper limb anatomy

Shoulder

The shoulder is where the upper limb attaches to the trunk. Its most important part is the glenohumeral joint; formed by the humerus, scapula and clavicle. The humerus anatomy is a must-know before any discussion on the glenohumeral joint, and you can learn everything about it in our learning materials.

The shoulder joint is reinforced with two groups of muscles, superficial and deep. Superficial muscles include the deltoid and the trapezius, whereas the deep group contains the supraspinatus, infraspinatus, teres minor and subscapularis (rotator cuff) muscles.

To easily remember the rotator cuff muscles, use the mnemonic given below!

Rotator cuff SITS on the shoulder

• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis

Find out everything about shoulder anatomy through our fun and engaging educational content. Also, we have prepared a special quiz for you to solidify your knowledge about the upper limb anatomy. Take the upper extremity anatomy quiz and learn more about the bones, joints, muscles and vessels of the upper extremity!

Arm

The arm is the area between the shoulder and the elbow. Depending on whether you’re a gym lover or not, it may be more or less important to you. But anatomically, all parts of the arm are a must-know. There is only one bone within the arm, and that is the humerus. It is the pillar on which all the other soft tissue structures rely.

Muscles of the arm always crop up in exams! Get your knowledge up to scratch now using our quizzes, diagrams and worksheets.

The muscles are grouped into anterior and posterior compartments by the septa that attach to the humerus. The anterior compartment contains the coracobrachialis, brachialis and biceps brachii muscles. While the posterior compartment contains only one muscle, the triceps brachii.

Last but not least, is the neurovascular compartment. Every single structure of the arm is innervated by the brachial plexus, a network of nerves that originate from the C5-T1 spinal nerves. Arterial blood comes from the brachial artery, which arborizes on its way down the arm giving many branches for the supply of the structures of the arm.Learn more about the nerves of the upper limb with Kenhub.
 

Elbow

The elbow is another “bridge” within the upper limb that attaches the arm and the forearm. Three bones participate in the elbow joint: the humerus, the radius and the ulna. They are shaped and attached in such a way that allows the unique forearm movement of pronation and supination. In order to understand these movements, you can find everything you need to know about elbow anatomy through these learning materials:

The anterior of the elbow is called the cubital fossa, in which, besides the joint, are found important nerves and vessels intended for the supply of both the forearm and hand. 

Forearm

Here comes the part that most students consider the hardest. The twenty muscles, and two bones (radius and ulna), of the forearm. When in anatomical position (supination), the radius is found laterally while the ulna is medially in the forearm. This is why while studying the forearm anatomy, you'll often encounter with terms radial, meaning lateral, and ulnar referring to the medial part of the forearm. 

Radius and ulna articulate with each other by proximal and distal radioulnar joints and also contribute to the elbow and wrist joints. Thanks to the common sense of Mother Nature while designing these two bones, we can perform movements uniquely seen in the forearm such as supination and pronation.

Learn more about those two bones in the following study unit.

The muscles of the forearm are grouped into anterior and posterior compartments, with the anterior compartment containing mostly flexors, and the posterior, extensors. Both the anterior and posterior compartments can be further divided into superficial and deep layers. 

We know that reading about twenty muscles, two compartments and four layers can be monotonous, so we have designed these study units with video tutorial and integrated quizzes to make this topic more interesting, and your life easier!

Arterial supply of the forearm is through the branches of the radial and ulnar arteries, whereas innervation comes from the radial, ulnar and median nerves.

Test your knowledge on the anatomy of the upper limb with this quiz.

Hand

The hand is probably the finest product of human evolution from the aspect of our body mechanics. The hand anatomy enables us various movements, with the spectrum ranging from rough movements, such as smashing a mosquito, to the finest movements like playing the guitar, drawing, or writing calligraphically.

To understand how this works, let’s start with the basic parts of the hand, which are:

• the wrist (carpus)
• the metacarpus
• the digits

The bony background of the hand is very interesting. The carpus contains 8 bones, the metacarpus are comprised of 5, and the digits have 14 bones. The bones within the carpus are small, irregularly shaped, and have such curious names that you may like to choose one for your instagram account: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate and hamate bones.

Metacarpal bones, on the other hand, are easier to remember since they are named metacarpal I to V, with metacarpal I being the ‘root’ for the thumb and metacarpal V for the pinky finger. Finally the digits are supported with three consecutively attached bones called the proximal, middle and distal phalanges, all specifically named by adding I-V at the end. 

When it comes to the muscles, they are called the intrinsic muscles of the hand. Meaning they both originate and insert within the hand. This is in contrast to the ‘extrinsic’ forearm muscles that originate from the forearm, and insert into the hand. The intrinsic muscles of the hand are the: palmaris brevis, interossei (palmar and dorsal), adductor pollicis, thenar, hypothenar and lumbrical muscles. You can learn everything about them with our learning materials and test yourself with the integrated quiz.

As far as the neurovasculature is concerned, both arteries and nerves are continuations from the neurovascular elements of the forearm. To master this topic, check out our study unit:

Related articles

Articles within this topic:

• Arm and shoulder anatomy
• Elbow and forearm
• Hand anatomy
• Neurovasculature of the upper limb