Upper Limb Anatomy Book Pdf

[Darth Gupta]

Everwondered what the differences are between us humans and animals regarding the upper limb? One of them is certainly our ability to high five each other when we ace our anatomy exam. Of course, there are many more functions and movements that our upper extremity offers to us, and this is all due to its perfect anatomy that is designed to allow a large degree of mobility.

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.

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!

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.

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.

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!

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.

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.

There are a large number of muscles in the upper limb, these are involved in allowing us to move and perform important tasks such as gripping with our hands or raising our arms, they also provide extra stability around the shoulder joint.

There are 4 main groups of bones in the upper limb, the bones of the shoulder girdle, upper arm, forearm, and the bones of the hand. These provide skeletal support as well as being the site of origin and attachment for the many muscles to act as leverage points. The joints of the upper limb are found between some of these bones and the muscles crossing them allow us to orient these joints.

The nerves of the upper limb arise from a complex arrangement of nerve fibers known as the brachial plexus; These nerves give sensation to our upper limb, as well as innervating the muscles, allowing us to move them at will.

The anatomical areas found on the upper limb can serve as key landmarks to help us find important anatomical structures such as finding one of the superficial veins: The median cubital vein (a common site site for venepuncture) in the antecubital fossa of the arm. This vein, as well as the deep veins, act as counterparts to the arteries supplying the arm by bringing deoxygenated blood back to the heart.

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The upper extremity or arm is a functional unit of the upper body. It consists of three sections, the upper arm, forearm, and hand. It extends from the shoulder joint to the fingers and contains 30 bones. It also consists of many nerves, blood vessels (arteries and veins), and muscles. The nerves of the arm are supplied by one of the two major nerve plexus of the human body, the brachial plexus.

The upper extremity begins at the shoulder joint. This joint is commonly referred to as a ball-and-socket joint, although it is more correctly described as a ball-and-saucer joint. In contrast to the hip, the other ball-and-socket joint of the body, the socket is much shallower. This allows for less restriction of movement at the joint but compromises stability in the process. The elbow joint is referred to by many as a hinge joint. This is partially true but does not explain the ability to pronate and supinate the forearm at the elbow joint. The articulation of the radial head and the radial notch on the ulna allows for this motion. This creates what is called a "pivot" joint, allowing the movement of one bone on another. The wrist joint can be classified as an ellipsoidal or condyloid joint. There are also joints of the carpal bones, which are referred to as intercarpal joints. Even though they are synovial joints, they do not allow much movement. The interphalangeal joints are basic hinge joints.[1][2][3]

During the third week of development, the trilaminar embryonic disc is formed. Three layers, the endoderm, mesoderm, and ectoderm, are differentiated. The notochord is formed from mesoderm, and the overlying ectoderm becomes the neural plate. During the fourth week, the upper and lower limb buds begin to form. Muscle, bone, blood vessels, and lymphatics are all formed from the mesoderm, while the peripheral nerves are differentiated neural crest cells.

Thirty bones in total make up the structure of the upper extremity. They act as a framework for the muscle, blood vessels, nerves and lymphatics to work upon. There is one bone in the upper arm region, the humerus. The forearm contains two bones, the radius and the ulna. When picturing the upper extremity in a standard anatomical position with the palm of the hand facing forward, the radius is located laterally and the ulna medially. However, because the forearm allows rotation around a central axis, the terms radial and ulnar provide a better description when describing direction or location in the forearm, wrist, and hand. The wrist and hand contain 27 bones. There are eight carpal bones, organized into a proximal and distal row. The proximal bones, from radial (thumb side) to ulnar are the scaphoid (navicular), lunate, triquetrum, and pisiform. From radial to ulnar, the distal row consists of the trapezium, trapezoid, capitate, and hamate. There are five metacarpal bones, each associated with a group of phalanges. There are also 14 phalanx bones. Fingers two to five have a proximal, intermediate, and distal phalanx, while the thumb has only a proximal and distal phalanx. Although many bony injuries can result, the most clinically significant are injuries to the humerus and scaphoid bones. Injuries at the neck of the humerus can result in axillary nerve injury. Midshaft fractures will damage the radial nerve, and supracondylar fractures can damage the median nerve (a common mnemonic is "ARM"). Another common clinical pathology is an injury to the scaphoid. Not only is it the most commonly injured carpal bone, but it also is a common site of avascular necrosis due to its retrograde blood supply. This commonly occurs in fall on an outstretched hand (FOOSH) injuries.

The arterial supply of the upper extremity starts with the subclavian artery. The subclavian has a complicated course through the axilla, changing names twice before it gets to the upper arm. As it passes the one rib, it becomes the axillary artery. In the axilla, it passes deep to the pectoralis minor muscle toward the humerus. It gives off the anterior and posterior circumflex humeral arteries, before coursing posteriorly around the humeral head, giving rise to its largest branch, the subscapular artery. As it passes the teres minor, it becomes the brachial artery. At this point, it gives off the profundal brachii, which supplies the deep structures of the arm. It then travels along the humerus in the radial groove, along with the radial nerve. As it passes into the elbow, near the median nerve, it courses deep to the brachialis and splits into 2 branches, the radial (lateral branch) and ulnar (medial branch). The radial artery courses down the arm and supplies the deep palmar arch, while the ulnar artery supplies the superficial palmar arch. Due to its many anastomosing arteries, there are not many clinical correlates to the arterial injury of the upper extremity.

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