Palmar surface of the hand: deep structures. Topographic anatomy of the fingers Video lesson of the topographic anatomy of the phalanx of the finger

brush area

The area of ​​the wrist joint or the area of ​​the wrist regio articulationis radiocarpea, s. regio carpi

Guyon's canal syndrome

De Quervain's disease

Layered structure of the back of the wrist

Layered structure of the palmar region

The middle bed includes:

Features of the blood supply to the hand

The lateral bed corresponds to the elevation of the thumb (thenar) and includes:

"Danger zone" of the palm (Kanavel zone),

medial bed

The layered structure of the fingers

Interdigital (commissural) phlegmon

Phlegmon of the tenar region

PHLEGMON OF THE HYPOTHENAR REGION

CROSS (U-SHAPED) PHEGMON BRUSH

BRUSH AREA (REGIO MANUS)

The hand includes the distal part of the limb, located to the periphery of the line connecting the tops of the styloid processes of the bones of the forearm. On the skin, this line almost coincides with the proximal (upper) carpal fold, below which there are two more folds; middle and distal (lower).

The proximal part of the hand area is distinguished under the name "wrist area" (regio carpi), distal to which is the metacarpus area (regio metacarpi), and even more distally - fingers (digiti).

On the hand, the palmar surface is distinguished - palma manus (vola manus - BNA) and the back - dorsum manus.

outdoor landmarks

In the area of ​​\u200b\u200bthe wrist, on the ulnar side, in front, you can easily feel the pisiform bone, as well as the tendon of the ulnar flexor of the hand that is attached to it. Below the pisiform bone, the hook of the hamate bone (hamulus ossis hamati) is palpated. On the radial side of the palmar surface, right along the tendon line of the turbid flexor of the hand, the tubercle of the navicular bone is palpated. On the back side, on the ulnar side, a triangular bone is well defined, located distally from the ulna.

Distally from the tip of the styloid process of the radius - when the thumb is abducted - a triangular-shaped depression called the "anatomical snuffbox" is determined. Along the bottom of this recess, formed by the scaphoid and large polygonal bones, passes (from the palmar surface to the back) a.radialis.

The metacarpal (metacarpal) bones can be palpated from the back side along their entire length.

The lateral sections of the palm look like elevations formed by the muscles of the thumb (thenar) and little finger (hypothenar). The middle section has the appearance of a cavity and contains the tendons of the flexors of the fingers (with worm-like muscles) and the interosseous muscles.

On the back of the hand, the dorsal metacarpal veins are visible, forming the venous plexus, as well as the extensor tendons of the fingers; sometimes the transverse ligaments connecting the tendons of this muscle are also visible. When the thumb and forefinger are brought together, on the back of the hand between I and II) the metacarpal bone becomes visible elevation formed by the I dorsal interosseous muscle.

palm (palma manus)

The skin (with the exception of the wrist area) is characterized by density and low mobility due to the fact that it is firmly connected with the palmar aponeurosis; it is rich in sweat glands and devoid of hair. All layers of the skin of the palm are significantly spilled, and the epithelium of the stratum corneum forms several dozen rows of cells.

The subcutaneous tissue is permeated with dense fibrous, vertically arranged bundles that connect the skin with the aponeurosis. As a result, the fiber is, as it were, enclosed in fibrous nests, from which, when the skin is cut, it protrudes in the form of separate fat lobules. Small veins pass through the fiber, as well as palmar branches of the median and ulnar nerves that innervate the skin in the wrist area, thenar and hypothenar, and branches of the common palmar digital nerves.

Deeper than the skin and subcutaneous tissue in the area of ​​the wrist and thenar is its own fascia. In the area of ​​the wrist, it thickens, as a result of which it acquires the character of a ligament, which was formerly called lig.carpi volare (BNA). The tendon of the long palmar muscle, which runs approximately along the midline of the forearm, is closely connected with it.

Under the skin of the hypothenar, the small palmar muscle is superficially located, deeper than which is its own fascia, covering the rest of the muscles of the eminence of the thumb.

The central part of the palm region, between thenar and hypothenar, is occupied by the palmar aponeurosis (aponeurosis palmaris). It has a triangular shape with the apex facing the wrist area and the base facing the fingers. The palmar aponeurosis consists of superficial longitudinal fibers (a continuation of the tendon of the long palmar muscle.) And deep transverse

In the distal part of the hand, the longitudinal and transverse fibers of the palmar aponeurosis limit three so-called commissural openings through which digital vessels and nerves pass into the subcutaneous fat layer. Corresponding to the commissural openings, the subcutaneous tissue of the palm forms fat "pillows", which are visible in the form of protrusions between the heads of the II-V metacarpal bones with fingers extended. These fat accumulations are limited by connective tissue strands that connect the skin of the palm here with the longitudinal fibers of the palmar aponeurosis; the areas of the palm occupied by adipose tissue are called commissural spaces. Fiber surrounding the digital neurovascular bundles connects the subcutaneous tissue of the commissural spaces with the middle cellular space of the palm.

In the commissural space on the basis of suppuration of the callus, phlegmon (commissural phlegmon) can develop. Pus with this phlegmon can spread through the tissue that accompanies the digital vessels and nerves into the middle cellular space of the palm, resulting in subaponeurgic phlegmon of the palm.

The palmar aponeurosis, with septa extending from it, and the palmar fascia form three chambers, commonly referred to as fascial lodges. There are two lateral beds (lateral and medial) and one middle.

Middle bed proximally passes into the carpal canal, while the lateral and medial beds are relatively closed receptacles and, under normal conditions, communicate only with the middle bed along the vessels and nerves.

On the borders with thenar and hypothenar, intermuscular septa depart from the palmar aponeurosis: lateral and medial. The lateral septum consists of two parts: vertical and horizontal. vertical; part of the septum is located medially from the main mass of thenar muscles, and the horizontal part goes in front of the adductor muscle of the thumb, attaching to the III metacarpal bone. In the hypothenar region, the septum limits the hypothenar bed from the outside, goes deep and is attached to the fifth metacarpal bone.

Lateral bed of the palm(thenar bed) contains the muscles of the elevation of the thumb, starting from the transverse ligament and bones of the wrist: m.abductor pollicis brevis lies most superficially, m.opponens pollicis (laterally) and m.flaxor pollicis brevis (medially) lie deeper. The adductor muscle of the thumb, starting with two heads from the II-III grazing bones, belongs, like the interosseous muscles, to the layers located deep in the middle part of the palm. Through the lateral bed, between the two heads of the short flexor of the thumb, the tendon of the long flexor of the thumb passes, surrounded by the synovial sheath. Branches of the median nerve and radial artery also pass through the thenar bed.

Medial palm(hypothenar bed) contains the muscles of the elevation of the thumb: mm.abductor, flexor and opponens digiti minimi (quinti - BNA), of which the abductor lies at the ulnar edge of the palm. On top of these muscles, outside the medial bed, is the fourth muscle of the elevation of the thumb mentioned above - m.palmaris brevis. In the hypothenar bed are branches of the ulnar nerve and ulnar artery.

Middle palm rest contains the tendons of the superficial and deep flexors of the fingers, surrounded by a synovial sheath, three worm-like muscles and vessels and nerves surrounded by fiber; superficial palmar arterial arch with its branches, branches of the median and ulnar nerves. Deeper than the middle bed, the interosseous muscles, the deep branch of the ulnar nerve and the deep palmar arterial blow are recognized.

In the proximal part of the palm under the aponeurosis lies the retaining ligament of the flexors associated with it (retinaculum flexorum), formerly called the transverse ligament of the wrist (lig.carpi transversum - BNA). It is thrown in the form of a bridge over the gutter, which is formed from the side of the palm of the carpal bones, covered with deep ligaments. Thanks to this, the carpal tunnel (canalis carpi) is obtained, in which 9 flexor tendons of the fingers and the median nerve pass. Lateral to the carpal tunnel is another channel (canalis carpi radialis), formed by sheets of the transverse ligament and a large polygonal bone; it contains the tendon of the radial flexor of the hand, surrounded by the synovial sheath.

Vessels and nerves

On the radial side of the region, over the muscles of the elevation of the thumb or through the thickness of these muscles, the branch a.radialis - r.palmaris superficialis passes. It participates in the formation of the superficial palmar arch, while the radial artery itself passes under the tendons of the dorsal muscles of the thumb, through the "anatomical snuffbox", to the back of the hand.

In the carpal tunnel, as already mentioned, the median nerve passes along with the flexor tendons. Here it is located between the tendon of the long flexor of the thumb, running laterally from the median nerve, and the tendons of both flexors of the fingers, passing medially from the nerve. Already in the carpal tunnel, the median nerve divides into branches that go to the fingers.

On the ulnar side of the wrist area are vasa ulnaria and n.ulnaris. This neurovascular bundle goes in a special canal (canalis carpi ulnaris, s.spatium interaponeuroticum), located at the pisiform bone. The canal is a continuation of the ulnar groove of the forearm and is formed due to the fact that between the lig.carpi volare (this was the name of the thickened part of the fascia of the wrist) and the retinaculum flexorum there is a gap: the artery and nerve pass here immediately outside the pisiform bone, and the nerve lies medially from the artery.

Superficial palmar arch

Directly under the palmar aponeurosis, in the fiber layer, is located superficial palmar arch, arcus palmaris (volaris - BNA) superficialis. The main part of the palmar arch is often formed by a.ulnaris, anastomosing with r.palmaris superficialis a.radialis. The ulnar artery appears in the palm after it has passed through the canalis carpi ulnaris. The superficial branch of the radial artery merges with the superficial branch of the ulnar artery distal to the retaining flexor ligament. The palmar arch formed in this case lies with its convex part at the level of the middle third of the III metacarpal bone.

Three large arteries aa. digitales palmares communes arise from the palmar arch, which, at the level of the heads of the metacarpal bones, emerge from under the palmar aponeurosis through the commissural openings and, having taken in the metacarpal arteries arising from the deep incense arch, divide into their own digital arteries, supplying the reversed to the other side II, W, IV and V fingers. The ulnar edge of the little finger receives a branch from the ulnar artery (before it forms an arc), the thumb and the radial edge of the index finger usually receives supply from the branch of the terminal section of the radial artery (a.princeps policis).

Immediately under the palmar arch are the branches of the median nerve (laterally) and the superficial branch of the ulnar nerve (medially): here, according to the arteries, there are nn.digitales palmares communes, dividing into nn.digitales palmares proprii; they also exit through the commissural openings and go to the fingers. It is generally accepted that the median nerve gives sensory branches to the 1st, 2nd, 3rd fingers and the radial side of the 4th finger, the ulnar nerve - to the 5th finger and the ulnar side of the 4th finger.

However, as the study of differences in the structure of the median and ulnar nerves has shown, only the skin of the thumb is innervated by one median nerve, just as only the skin of the ulnar side of the little finger is innervated by one ulnar nerve. The remaining zones of skin innervation of the fingers should be considered zones of mixed innervation.

The deep branch of the ulnar nerve is predominantly motor. It separates from the common nerve trunk at the base of the hypothenar, and then goes into the depth, between the mm.flexor and abductor digiti minimi, together with the deep branch of the ulnar artery involved in the formation of the deep palmar arch.

The deep branch of the ulnar nerve and the median nerve innervate the muscles of the palm as follows. The deep branch of the ulnar nerve innervates the muscles of the eminence of the fifth finger, all the interosseous muscles, the adductor thumb, and the deep head of the flexor pollicis brevis. The median nerve innervates part of the muscles of the eminence of the thumb (abductor brevis, superficial head of the flexor brevis, opposing muscle) and the lumbrical muscles. However, some of these muscles have a double innervation.

Immediately upon exiting the carpal tunnel into the middle palmar bed, the median nerve gives a branch to the lateral side to the muscles of the eminence of the thumb. The place where this branch departs from the median nerve is designated in surgery as the "forbidden zone" due to the fact that incisions made within this zone may be accompanied by damage to the motor branch of the median nerve to the muscles of the thumb and dysfunction of the latter. Topographically, the "forbidden zone" roughly corresponds to the proximal half of the thenar area.

Deep palmar arch

Arcus palmaris profundus lies on the interosseous muscles, under the flexor tendons, being separated from the latter by fiber and a plate of deep palmar fascia. In relation to the superficial deep arch lies more proximally. The deep arc is formed mainly by the radial artery, which passes from the rear through the first intermetacarpal space and anastomoses with the deep palmar branch of the ulnar artery. Aa.metacarpeae palmares depart from the arc, which anastomose with the dorsal arteries of the same name and flow into aa.digitales palmares communes.

Synovial sheaths of the palm

The flexor tendons of the fingers have synovial sheaths. On the I and V fingers, the synovial sheaths of the flexor tendons continue into the palm, and only in rare cases the digital section of these sheaths is separated from the palmar septum. The palmar sections of the vaginas of the I and V fingers are called synovial sacs or bags. Thus, two bags differ: radial and ulnar. The radial contains one tendon (long flexor of the thumb); the elbow, in addition to the two flexors of the little finger, also contains the proximal part of the tendons of the flexors of the II, III and IV fingers; in total, therefore, there are eight tendons: four tendons of the superficial and four tendons of the deep flexor of the fingers.

In the proximal part of the hand, both bags, radial and ulnar, are located in the carpal tunnel, under the retinaculum flexorum; between them passes the median nerve.

The proximal blind ends of both synovial sacs reach the area of ​​the forearm, located on the square pronator, in the tissue of the Pirogov space; their proximal border is 2 cm superior to the tip of the styloid process of the radius.

Cellular spaces of the palm

Cellular spaces of the palm Each fascial bed of the palm has its own cellular space: in the thenar muscle bed - the lateral palmar space, in the hypothenar mouse bed - the medial palmar space, in the middle: the bed - the middle palmar cellular space. In practice, the most important are two spaces - lateral and middle.

Lateral cellular space, known in the surgical clinic as the thenar fissure, stretches from the III metacarpal bone to the first interdigital membrane, more precisely to the tendon of the long flexor of the thumb, surrounded by the radial synovial bag. The tenar space is located on the anterior surface of the transverse head of the adductor thumb muscle, lateral to the middle cellular space of the palm, and is separated from the latter by a lateral intermuscular septum. The horizontal part of this partition covers the thenar gap in front.

Medial cellular space, otherwise - the gap of the hypothenar, is located within the medial fascial bed. This gap is tightly delimited from the middle cellular space.

Middle palmar cellular space from the sides it is limited by intermuscular septa, in front - by the palmar aponeurosis, behind - by the deep palmar (interosseous) fascia. This space consists of two slits: superficial and deep. The superficial (subaponeurotic) gap is located between the palmar aponeurosis and the tendons of the flexors of the fingers, the deep (subtendonous) gap is between the tendons and the deep palmar fascia. In the subaponeurotic fissure are the superficial palmar arterial arch and branches of the median and ulnar nerves. Along the course of the vessels and nerves, the fiber of this gap communicates through the commissural openings with the subcutaneous tissue in the region of the heads of the metacarpal bones. The dry tissue gap of the palm leads distally to the back surface of the III, IV and V fingers through the channels of the worm-like muscles: this is how in practical surgery connective tissue gaps are noted, in which the worm-shaped muscles pass, surrounded by fiber. Through these channels, pus from the middle cellular space of the palm can reach the back surface of the fingers. The tendinous fissure of the palm can communicate through the carpal tunnel with the deep cellular space of Pirogov on the forearm.

The suppurative process in the synovial sheaths of the fingers is referred to as "purulent tendovaginitis of the finger", and purulent inflammation of the palmar synovial sacs is referred to as "purulent tendobursitis of the palm". palm spaces.

If the synovial sacs of the palm are affected by the purulent process, then the further spread of the process can go in three directions: 1) pus from one synovial sac can pass into another synovial sac, resulting in the so-called V-shaped, or cross, phlegmon of the hand. This transition of pus may be due to the presence (in 10% of cases) of communication between the radial and ulnar synovial sac or the fact that pus melts the adjacent walls of both sacs; 2) rupture of the palmar section of the synovial sacs leads to the development of a suppurative process in the cellular spaces of the palm; with lesions of the radial synovial sac - in the thenar cellular space, with lesions of the ulnar synovial sac - in the middle cellular space of the palm; 3) if the rupture of the synovial sacs occurs in their proximal (carpal) section, then purulent streaks form in the Pirogov space of the forearm; may be involved in the purulent process and the wrist joint.

The hand includes the distal part of the limb, located to the periphery of the line connecting the tops of the styloid processes of the bones of the forearm. On the skin, this line almost coincides with the proximal (upper) carpal fold, below which there are two more folds: middle and distal (lower).

The proximal region of the hand is distinguished under the name "wrist region" (regio carpi), distal to which is the metacarpal region (regio metacarpi), and even more distally - fingers (digiti).

On the hand, the palmar surface is distinguished - palma manus and the back - dorsum manus.

PALMA MANUS)

The skin (with the exception of the wrist area) is characterized by density and low mobility due to the fact that it is firmly connected with the palmar aponeurosis; it is rich in sweat glands and devoid of hair. The weight of the layers of the skin of the palm is significantly developed, and the epithelium of the stratum corneum forms several dozen rows of cells.

The subcutaneous tissue is permeated with dense fibrous, vertically arranged bundles that connect the skin with the aponeurosis. As a result, the fiber is, as it were, enclosed in fibrous nests, from which, when the skin is cut, it protrudes in the form of separate fat lobules. Small veins pass through the fiber, as well as palmar branches of the median and ulnar nerves that innervate the skin in the wrist area, thenar and hypothenar, and branches of the common palmar digital nerves.

Deeper than the skin and subcutaneous tissue in the area of ​​the wrist and thenar is its own fascia. In the area of ​​​​the wrist, it thickens, as a result of which it acquires the character of a ligament, which was formerly called lig. carpi volare (BNA). The tendon of the long palmar muscle, which runs approximately along the midline of the forearm, is closely connected with it.

Under the skin of the hypothenar, the small palmar muscle is superficially located, deeper than which is its own fascia, covering the rest of the muscles of the eminence of the thumb.

The central part of the palm region, between thenar and hypothenar, is occupied by the palmar aponeurosis (aponeurosis palmaris). It has a triangular shape with the apex facing the wrist area and the base facing the fingers. The palmar aponeurosis consists of superficial longitudinal fibers (a continuation of the tendon of the long palmar muscle) and deep transverse ones.

Vessels and nerves. On the radial side of the region, a branch a passes over the muscles of the eminence of the thumb or through the thickness of these muscles. radialis - Mr. palmaris superficialis. She participates in the formation of the superficial palmar arch; the radial artery itself passes under the tendons of the dorsal muscles of the thumb, through the "anatomical snuffbox", to the back of the hand.

In the carpal tunnel, as already mentioned, the median nerve passes along with the flexor tendons. Here it is located between the tendon of the long flexor of the thumb, running laterally from the median nerve, and the tendons of both flexors of the fingers, passing medially from the nerve. Already in the carpal tunnel, the median nerve divides into branches that go to the fingers.

On the ulnar side of the wrist area are vasa ulnaria and n. ulnaris. This neurovascular bundle goes in a special canal (canalis carpi ulnaris, s. spatium interaponeuroticum), located at the pisiform bone. The canal is a continuation of the ulnar groove of the forearm and is formed due to the fact that between the lig. carpi volare (the so-called thickened part of the fascia of the wrist) and retinaculum flexorum there remains a gap: the artery and nerve pass here immediately outward from the pisiform bone, and the nerve lies medially from the artery. Directly under the palmar aponeurosis, in the fiber layer, is the superficial palmar arch, arcus palmaris superficialis. The main part of the palmar arch is often formed due to a. ulnaris, anastomosing with r. palmaris superficialis a. radialis. The ulnar artery appears in the palm after it has passed through the canalis carpi ulnaris. The superficial branch of the radial artery merges with the superficial branch of the ulnar artery distal to the retaining flexor ligament. The palmar arch formed in this case lies with its convex part at the level of the middle third of the III metacarpal bone.

Immediately under the palmar arch are the branches of the median nerve (laterally) and the superficial branch of the ulnar nerve (medially): here, respectively, there are nn arteries. digitales palmares communes, dividing into nn. digitales palmares proprii; they also exit through the commissural openings and go to the fingers. It is generally accepted that the median nerve gives sensory branches I, II, III to the fingers and the radial side of the IV finger, the ulnar nerve - to the V finger and the ulnar side of the IV finger.

However, as shown by the study of differences in the structure of the median and ulnar nerves, only the skin of the thumb is innervated by one median nerve, just as only the skin of the ulnar side of the little finger is innervated by one ulnar nerve. The remaining zones of skin innervation of the fingers should be considered zones of mixed innervation.

The deep branch of the ulnar nerve is predominantly motor. It separates from the common nerve trunk at the base of the hypothenar, and then goes into the depth, between mm. flexor and abductor digiti minimi, together with the deep branch of the ulnar artery involved in the formation of the deep palmar arch.

The deep branch of the ulnar nerve and the median nerve innervate the muscles of the palm as follows. The deep branch of the ulnar nerve innervates the muscles of the eminence of the fifth finger, all the interosseous muscles, the adductor thumb, and the deep head of the flexor pollicis brevis. The median nerve innervates part of the muscles of the eminence of the thumb (abductor brevis, superficial head of the flexor brevis, opposing muscle) and the lumbrical muscles. However, part of the torn muscles has a double innervation.

Immediately upon exiting the carpal tunnel into the middle palmar bed, the median nerve gives a branch to the lateral side to the muscles of the eminence of the thumb. The place where this branch departs from the median nerve is designated in surgery as the "forbidden zone" due to the fact that incisions made within this zone may be accompanied by damage to the motor branch of the median nerve to the muscles of the thumb and dysfunction of the latter. Topographically, the "forbidden zone" roughly corresponds to the proximal half of the thenar region.

Arcus palmaris profundus lies on the interosseous muscles, under the flexor tendons, being separated from the latter by fiber and a plate of deep palmar fascia. In relation to the superficial deep arch lies more proximally. The deep arc is formed mainly by the radial artery, which passes from the rear through the first intermetacarpal space and anastomoses with the deep palmar branch of the ulnar artery. Aa depart from the arc. metacarpeae palmares, which anastomose with the dorsal arteries of the same name and flow into the aa. digitales palmares communes.

Synovial sheaths of the palm. The flexor tendons of the fingers have synovial sheaths. On the I and V fingers, the synovial sheaths of the flexor tendons continue into the palm, and only in rare cases the digital section of these sheaths is separated from the palmar septum. The palmar sections of the vaginas of the I and V fingers are called synovial sacs, or bags. Thus, two bags differ: radial and ulnar. The radial contains one tendon (long flexor of the thumb); the elbow, in addition to the two flexors of the little finger, also contains the proximal part of the tendons of the flexors of the II, III and IV fingers; in total, therefore, there are eight tendons: four tendons of the superficial and four tendons of the deep flexor of the fingers.

In the proximal part of the hand, both bags, radial and ulnar, are located in the carpal tunnel, under the retinaculum flexorum; between them passes the median nerve.

The proximal blind ends of both synovial sacs reach the area of ​​the forearm, located on the square pronator, in the tissue of the Pirogov space; their proximal border is 2 cm superior to the tip of the styloid process of the radius.

Cellular spaces of the palm. Each fascial bed of the palm has its own cellular space: in the thenar muscle bed - the lateral palmar space, in the hypothenar muscle bed - the medial palmar space, in the middle bed - the middle palmar cellular space. Practically the most important are two spaces - lateral and middle.

The lateral cellular space, known in the surgical clinic as the thenar fissure, stretches from the III metacarpal bone to the first interdigital membrane, more precisely to the tendon of the long flexor of the thumb, surrounded by the radial synovial bag. The tenar space is located on the anterior surface of the transverse head of the adductor thumb muscle, lateral to the middle cellular space of the palm, and is separated from the latter by a lateral intermuscular septum. The horizontal part of this partition, as seen in Fig. 84, covers the thenar gap in front.

The medial cellular space, otherwise the hypothenar fissure, is located within the medial fascial bed. This gap is tightly delimited from the middle cellular space.

The middle palmar cellular space is limited laterally by intermuscular septa, in front by the palmar aponeurosis, and behind by the deep palmar (interosseous) fascia. This space consists of two slits: superficial and deep. The superficial (subaponeurotic) gap is located between the palmar aponeurosis and the tendons of the flexors of the fingers, the deep (subtendonous) gap is between the tendons and the deep palmar fascia. In the subaponeurotic fissure are the superficial palmar arterial arch and branches of the median and ulnar nerves. Along the course of the vessels and nerves, the fiber of this gap communicates through the commissural openings with the subcutaneous tissue in the region of the heads of the metacarpal bones. The dry tissue gap of the palm leads distally to the back surface of the III, IV and V fingers through the channels of the worm-like muscles: this is how in practical surgery connective tissue gaps are noted, in which the worm-shaped muscles pass, surrounded by fiber. Through these channels, pus from the middle cellular space of the palm can reach the back surface of the fingers. The tendinous fissure of the palm can communicate through the carpal tunnel with the deep cellular space of Pirogov on the forearm.

REAR OF THE BRUSH (DORSUM MANUS)

In the superficial layers are the saphenous veins and nerves. Numerous veins (in particular w. metacarpeae dorsales) serve as sources of v. cephalica (on the radial side) and v. basilica (on the ulnar side) and form rete venosum dorsale manus.

The nerves of the rear of the hand are g. superficialis n. Radialis and n. dorsalis manus n. ulnaris. From both branches of the radial and ulnar nerves, exchanging connecting fibers, 10 sensory dorsal digital nerves arise, and usually five of them belong to the radial nerve, five to the ulnar (each nerve supplies 2 "/ 2 fingers). However, due to the presence of connections between both nerves on the back of the hand, as well as on the palm, there are zones of mixed skin innervation related to the II, III and IV fingers; the skin of the back surface of these fingers can be innervated by the branches of both the radial and ulnar nerves.

Under the retinaculum extensorum, thanks to the partitions extending deep from the ligament, 6 canals are formed, in which the extensor tendons surrounded by synovial sheaths pass.

The first channel (counting from the outside inwards) passes the tendons of the long abductor muscle and the short extensor of the thumb, the second - the tendons of the short and long radial extensor of the hand, the third - the tendon of the long extensor of the thumb; the fourth is the tendons of the common extensor of the fingers and the extensor of the index finger; in the fourth canal, along with the tendons of the common extensor of the fingers, the dorsal interosseous nerve of the forearm passes, located deeper than these tendons; the fifth channel contains the extensor tendon of the thumb, the sixth - the tendon of the ulnar extensor of the hand.

Throughout the rest of the metacarpal region of the rear of the hand, the extensor tendons pass under the dorsal aponeurosis. Deeper than them lie the dorsal interosseous muscles.

The radial artery, passing to the back of the hand through the "anatomical snuffbox", gives off to Mr. carpeus dorsalis, which goes towards the ulna and is part of the dorsal network of the wrist, and itself goes under the tendon m. extensor pollicis longus in the first interosseous space.

External landmarks of the palmar surface of the fingers. On the skin of the palmar surface of the fingers, metacarpophalangeal and interphalangeal folds are clearly visible. They are located below the corresponding joints.

projections. The articular gap of the metacarpophalangeal joints corresponds to a line located 8-10 mm below the heads of the metacarpal bones. The projection of the gaps of the interphalangeal joints is determined in the position of full flexion of the fingers 2-3 mm below the bulges of the heads of the phalanges.

Layers of the palmar surface of the fingers

Skin of the palmar surface of the finger in dense, inactive.

Subcutaneous tissue of the palmar surface of the fingers cellular due to the many connective tissue partitions extending from the skin in depth. On the terminal (nail) phalanges, these septa connect the skin and bone (periosteum), on the rest, the skin and fibrous sheaths of the tendons of the flexor muscles. In this regard, with panaritiums (purulent inflammation of one or another layer of the finger), the purulent process spreads from the surface to the depth. On the nail phalanx, this can lead to the rapid emergence of bone panaritium (Fig. 3.46).

In the subcutaneous tissue of the palmar surface of the fingers along the lateral surfaces of the fingers, just below the middle, there are neurovascular bundles, consisting of the palmar own digital vessels and nerves. The skin of 1, II, III and the radial side of the IV finger is innervated by nerves extending from the median nerve. The ulnar side of the IV and both sides of the V fingers are innervated by the branches of the ulnar nerve.

Layers of the palmar surface of the fingers

Bone fibrous canals of the fingers

Next volar surface of the fingers layer on the main (proximal) and middle phalanges of the fingers are to osteofibrous canals, which are formed by the phalanges of the fingers and tendon bundles: annular at the level of the diaphysis of the phalanges and cruciform in the region of the interphalangeal joints. In the areas of the annular ligaments, the fibrous canals are narrowed, and in the area of ​​the cruciate - expanded. Between the ligaments and the bone, only the synovial sheath is located, through which the tendon shines through. The most proximal annular ligament is at the level of the metacarpophalangeal articulation.

At the level of the head of the main phalanx superficial flexor tendon diverges into two legs, attached to the lateral surfaces of the middle phalanx, and passes into this splitting the tendon of the deep flexor, which is attached to the base of the terminal (distal) phalanx.

Synovial tendon sheaths II, III and IV fingers isolated.

synovial sheath consists of a parietal sheet adjacent to the inner surface of the fibrous sheath, and an internal one covering the tendon itself (Fig. 3.47). At the point of transition of one sheet to another, a tendon mesentery, mesotendineum, is formed. In its thickness are located the vessels and nerves running from the periosteum of the phalanx to the tendon. In the area of ​​interphalangeal joints, it is absent. Damage to the mesentery, including during surgery, can lead to necrosis of the corresponding part of the tendon.

Video lesson of topographic anatomy of the phalanx of the finger

Characterization of brush layers

The skin of the fingers of the palmar surface has a number of practically important structural features. First of all, it should be noted the significant development of all layers of the skin and, first of all, the stratum corneum, the epithelial cells of which are arranged in several dozen rows, in particular on the nail phalanx, more than 100 rows (usually there are four of these rows on the skin of other areas). Significant development of the malpighian and papillary layers of the skin of the palmar surface of the fingers plays an important role in the regeneration of the stratum corneum, which died due to injury or as a result of the inflammatory process.

The skin of the palmar surface of the fingers contains a very large number of sweat glands, and a large number of tactile bodies (Meisser bodies) and nerve endings, providing high sensitivity and a specific sense of touch. She does not have hair and sebaceous glands, which excludes the possibility of the formation of a boil.

The subcutaneous tissue of the palmar surface contains an abundant amount of adipose tissue and has the character of spherical accumulations, separated by strong fibrous bridges. The latter are located mostly vertically, and not parallel to the surface of the skin, as usual, and go in the region of the nail phalanges from the papillary layer of the skin to the periosteum, and in the region of the middle and main phalanges, to the fibrous sheaths of the flexor tendons.

On the back of the fingers, the skin is thinner than on the palmar; the subcutaneous fat layer is poorly developed. The skin of the dorsal surface of the main, and often the middle phalanx, is covered with hair.

The skin and subcutaneous tissue of the fingers have an abundant network of lymphatic capillaries, especially on the palmar surface. Small vessels arising from this network, merging on the lateral surfaces of the fingers, form 1-2 efferent trunks. The latter in the region of the interdigital folds pass to the back of the hand. And on the palmar surface of the hand, small lymphatic vessels also pass in large numbers to the back of the hand, in particular in the region of the interdigital folds.

Lymph flowing from the integument of the fingers reaches the regional nodes located in the axillary region. However, the lymphatic vessels of the integument of the V and partly of the IV fingers flow into the ulnar nodes.

The superficial veins of the fingers are much better expressed on the back surface.

The digital arteries pass in the subcutaneous tissue and lie on the lateral surfaces, with the palmar arteries being larger and located closer to the palmar surface: the less developed dorsal arteries run along the lateral surface closer to the rear. The dorsal arteries do not reach the terminal phalanges, while the palmar arteries form an arc on the terminal phalanges, from which small branches arise, distributed in the form of a network in the pulp of the finger.

The digital arteries are not accompanied by veins; the same veins that collect blood from the tissues of the palmar surface of the fingers pass to the rear.

The nerve supply of the fingers is carried out by branches: on the palmar surface - the median and ulnar nerves, on the back - the radial and ulnar. Thus, two nerves pass on the lateral surface of each finger, of which one lies closer to the palmar surface, the other to the back. The dorsal nerves reach the middle phalanges, the palmar nerves supply the skin to both the palmar and dorsal surfaces of the terminal phalanges.

The palmar fascia of the fingers, attached along the edges of the palmar surface of the phalanges, and the periosteum of the latter form dense fibrous canals on the fingers for the flexor tendons, lined from the inside with a parietal sheet of the synovial sheath. The connective tissue bundles that form these fibrous canals are unevenly distributed and in places have the character of ligaments (annular, cruciform) that hold the tendons in place when the fingers are bent. Particularly important for the function of the fingers are the annular ligaments located at the level of the interphalangeal joints, which should be spared during operations on the fingers.

The flexor tendons are found in the fibrous canals. Each tendon of the superficial flexor of the fingers splits into two legs, which are attached to the body of the middle phalanx. The tendon of the deep flexor passes into the hole between the legs of the superficial and is attached to the base of the terminal phalanx.

The synovial membranes that form the tendon sheath consist of two sheets - parietal and visceral, covering the tendon around the entire circumference, with the exception of a small area where it penetrates to the tendon of fiber with vessels. The latter are enclosed between the sheets of the synovial membrane, which forms a kind of mesentery of the tendon (mesotenon) at the site of the transition of the parietal sheet into the visceral sheet. These mesentery are located on the deep surface of the tendon facing the bone. On the fingers of the hand there are significant areas of the tendon, where the mesotenson is almost absent; its remaining parts are narrow and have the appearance of shackles.

The synovial sheaths of all fingers end distally at the bases of the nail phalanges. Proximally, the tendon sheaths of the II, III and IV fingers begin at the level of the heads of the metacarpal bones; here, at the site of the transition of the parietal sheet of the synovial membrane to the visceral one, a blind sac is formed. The tendon sheaths of the I and V fingers pass to the palm, where, expanding, they form synovial sacs.

The extensor tendons of the fingers on the rear of the phalanges pass into tendon extensions (dorsal aponeurosis of the fingers), which is divided into three legs: the middle leg is attached to the base of the middle phalanx, and the lateral ones to the base of the terminal phalanx.

The musculature of the hand is a complex complex of about 33 muscles. Most of them are located in the forearm and are connected by tendons to the phalanges of the fingers through several joints. Two groups of muscles form two elevations on the palmar surface of the hand: thenar (thenar) - the elevation of the thumb and hypothenar (hypotenar) - the elevation of the little finger. On the hand, the muscles are located only on the palmar side. Here they form three groups: middle (in the middle section of the palmar surface), a group of muscles of the thumb and a group of muscles of the thumb. A large number of short muscles on the hand is due to the fine differentiation of finger movements.

The middle group of muscles of the hand consists of worm-like muscles that start from the tendons of the deep flexor of the fingers and are attached to the base of the proximal phalanges of the second to fifth fingers; palmar and dorsal interosseous muscles, which are located in the interosseous spaces between the metacarpal bones and are attached to the base of the proximal phalanges of the second to fifth fingers. The function of the muscles of the middle group is that they are involved in the flexion of the proximal phalanges of these fingers. In addition, the palmar interosseous muscles bring the fingers of the hand to the middle finger, and the dorsal interosseous muscles spread them apart.

A group of muscles of the thumb forms the so-called elevation of the thumb on the hand. They start on the nearby bones of the wrist and metacarpus. Among them, there are: a short muscle that removes the thumb, which is attached to its proximal phalanx; a short flexor of the thumb, attached to the external sesamoid bone, located at the base of the proximal phalanx of the thumb; muscle that opposes the thumb, going to the first metacarpal bone; and the adductor thumb muscle, which inserts on the internal sesamoid bone located at the base of the proximal phalanx of the thumb. The function of these muscles is indicated in the name of each muscle.

The group of muscles of the small finger forms an elevation on the inside of the palm. This group includes: a short palmar muscle; muscle that removes the little finger; the short flexor of the little finger and the muscle that opposes the little finger. They originate from nearby carpal bones and insert at the base of the proximal phalanx of the fifth toe and fifth metacarpal. Their function is determined by the name of the muscles themselves.

wrist bones arranged in two rows. The first, proximal, row (counting from the radial edge) is made up of the scaphoid, lunate, trihedral and pisiform bones, the second, distal, row is the large and small polygonal, capitate and hamate bones. Both rows of carpal bones articulate with each other, as well as with adjacent bones, forming the radiocarpal, intercarpal, and carpometacarpal joints, which, together with the distal radioulnar and intercarpal joints, function as a single carpal joint. It allows movements such as palmar flexion up to 90°, dorsiflexion up to 70°, radial abduction up to 30°, and ulnar abduction up to 40°.

The metacarpus (metacarpus) consists of 5 tubular bones that form metacarpophalangeal joints with the main phalanges of the fingers. These joints have a spherical shape, provide flexion, extension, abduction and adduction of the fingers.

The bone basis of the fingers is made up of three phalanges: the main, middle and nail (except for 1 finger, where there is no middle phalanx). Between them there are block-like interphalangeal joints, in which phalangeal flexion is possible (with an amplitude of about 90 °). There are distal and proximal interphalangeal joints of the II-V fingers.