HUMAN ANATOMY – VOLUME 1

c r a n o n), and the other, in the front, is the c o r o n o i d p r o c e s s (procéssus coronoídeus). The latter is shorter than the olecranon and has a radial for articulation with the head of the radius. There is a r a d i a l t u b e r o s - i t y above the coronoid process, which serves for attachment for muscle. The distal part of the radius ends with its h e a d, which continues medially into a s t y l o i d p r o c e s s (procéssus styloídeus). The head has a circular a r t i c u l a r c i r c u m f e r e n c e for articulating with the radius.

Bones of the hand

The hand (mánus) consists of the wrist (carpus), metacarpus and phalanges (Fig. 61).

Fig. 61. Bones of hand. Anterior aspect.

1 — trapezium; 2 — scaphoid; 3 — lunate; 4 — triquetrum; 5 — pisiform; 6 — hamate; 7 — carpal bone; 8 — falanges; 9 — capitate; 10 — trapezoid.

The carpus consists of eight spongy bones arranged in two transverse rows. In the proximal row are the s c a p h o i d, l u n a t e, t r i q u e - t r a l, and p i s i f o r m bones. The distal row includes the trapezium (greater polygonal), t r a p e z o i d (lesser polygonal), c a p i t a t e, and h a m a t e. The name of each bone correlates with the shape of the bone. The bones have articular facets for articulation with neighboring bones.

Carpal bones form a bone arch in this part of the hand, which is convex to the back and concave on the palmar side. Because of this there is a carpal groove on the palmar side of the carpus. This groove is limited by the scaphoid and trapezium from the lateral side, and by the hamate and capitate from the medial side.

Metacarpal bones. The metacarpus (metacarpus) is formed by five short tubular bones. Metacarpals are numerated from I-V starting at the thumb. Each metacarpal bone has a b a s e, a b o d y and a h e a d. The bases are joint with the bones of the second transverse row of the carpus. The semispherical heads of metacarpal bones end with convex articular facets, which articulate with bases of the phalanges.

Phalanges. The shortest and thickest digit is the t h u m b (póllex). Next to it are the f o r e f i n g e r (dígitus sécundus), the m i d d l e f i n g e r (dígitus médius), the r i n g f i n g e r (dígitus annuláris), which is the longest, and the little finger.

Phalanges (phalánges digitórum) are relatively short tubular bones. Each digit, except for the first one has a proximal middle and distal phalanges. The thumb has only proximal and distal phalanges. The proximal phalanges are the longest, while the distal are the shortest. Each phalanx has a b a s e, a b o d y and a h e a d. The end of each distal phalanx is flat and has a tuberosity of the distal phalanx.

Variants and anomalies of the skeleton of the upper extremities

Scapula. The depth of the scapular notch varies and the notch is sometimes turned into a foramen. A cartilage layer may remain between the acromion and the scapular spine throughout the whole life.

Clavicle. The curvatures of the clavicle vary a lot. Sometimes there is no trapezoid line or coneshaped tubercle.

Humerus. There can be an additional process above the medial condyle. It can be long and curved, forming a foramen.

Ulna and radius. The radius may be absent (rare anomaly). The olecranon sometimes does not fuse with the body of the ulna, with a layer of cartilage remaining between them.

Fig. 62. Bones of lower limb. Anterior aspect.

1 — sacrum; 2 — sacroiliac joint; 3 — superior pubic ramus; 4 — symphysial surface of pubic bone; 5 — inferior pubic ramus; 6 — ramus of ischium; 7 — ischial tuber; 8 — body of ischium; 9 — medial epicondyle of femur; 10 — medial epicondyle of tibia; 11 — tuberositas of tibia; 12 — body of tibia; 13 — medial malleolus; 14 — phalanges; 15 — tarsal bones; 16 — metatarsal bones; 17 — lateral malleolus; 18 — fibula; 19 — anterior margin of tibia; 20 — head of fibula; 21 — lateral epicondyle of tibia; 22 — lateral epicondyle of femur; 23 — patella; 24 — femur; 25 — greater trochanter of femur; 26 — neck of femur; 27 — head of femur;

28 — wing of ilium; 29 — iliac crest.

Bones of the hand. There are sometimes additional carpal bones (central bone, etc.) Sometimes there is a development of additional fingers (polydactyly) or fusing of neighboring fingers.

Questions for revision and examination

1.Name the most prominent regions on bones of the upper extremities: processes, crests, tubercles and tuberosities.

2.Name the articular surfaces of bones of the upper extremities and the joints they form.

3.How many bones are there in the hand? Name them.

BONES OF THE LOWER

EXTREMITIES

Whereas bones and joints of the upper extremities are well-suited for handling different objects /instruments of labor/, lower extremities have other functions.

The lower extremities perform functions of support and movement of the body in space. Conforming to these functions, they contain larger

and more massive bones compared to the upper limbs. Joints of the lower extremities are also larger, while their mobility is less.

Skeleton of the lower extremities consists of the pelvic girdle and bones of the free lower extremities (Fig. 62).

The pelvic girdle (cíngulum mémbri inferióris) is formed by paired hipbones, which are joint with each other in the front and are attached to the sacrum in the back. The skeleton of the free part of the upper extremities (skeleton membri inferioris liberi) has three parts. The proximal part is the femur, the middle is formed by the tibia and fibula, and the distal part consists of bones of the foot. The skeleton of the foot is formed by the tarsal and metatarsal bones and phalanges. In the region of the knee joint lies the largest sesamoid bone — the patella.

Bones of the pelvic girdle

The hipbone (os cóxae) is formed as a single bone by fusion of three individual bones: the ilium, pubis and ischium (at the age of 12–14). The bodies of these three bones together form a cotyloid cavity (acetábulum), which is an articular fossa for the head of the femur. On the periphery of

broad upper portion, which forms the a l a o f t h e i l i u m. On the top of the iliac wing is a broad i l i a c c r e s t. On the top the iliac crest has three uneven lines, which are the o u t e r l i p, the i n n e r l i p, and the i n t e r - m e d i a t e z o n e between them. These lines serve for attachment of abdominal muscles. In the front and back the iliac crest ends with bony

the ileac crest ends with the posterior superior iliac spine, below which is the p o s t e r i o r i n f e r i o r i l i a c s p i n e. On the dorsolateral surface of the iliac wing there are three uneven lines. These are the a n t e r i o r, p o s t e r i o r and i n f e r i o r g l u t e a l l i n e s, which are attachment sites for the gluteal muscles and their fasciae.

On the concave surface of the wing of the ilium there is a slight recess called the i l i a c f o s s a. At the bottom the iliac fossa is limited by an arched line. At the back this line extends to the a u r i c u l a r s u r f a c e, and in the front it continues into the i l i o p u b i c e m i n e n c e. Above the auricular surface is the i l i a c t u b e r o s i t y, which serves for attachment of ligaments.

The p u b i c b o n e (ó s p ú b i s) has a b o d y (a thickened portion) and two rami. The pubic bone body forms the anterior portion of the acetabulum. The s u p e r i o r r a m u s of the pubis extends forward from the

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body. In the region of the body the bone makes a sharp turn and continues into the i n f e r i o r r a m u s of the pubis. On the superior ramus there is a p u b i c t u b e r c l e. Below the tubercle is a flat s y m p h y s i a l s u r - f a c e, which serves for joining the pubic bone with its pair.

The b o d y of the i s c h i a l b o n e (ó s í s c h i i) forms the inferior portion of the acetabulum. The r a m u s of the ischium extends downwards from the body, forming a thickening called the i s c h i a l t u b e r - o s i t y. The i s c h i a l s p i n e, located on the body of the ischium, separates the g r e a t e r and l e s s e r s c i a t i c n o t c h e s. The ramus of the ischium is fused with the inferior ramus of the pubis, limiting the o b t u - r a t o r f o r a m e n (forámen obturátum). On the superior anterior border of this foramen is the o b t u r a t o r g r o o v e.

Skeleton of the free lower extremity

The femur (fémur) is a typical long tubular bone with an elongated body and two thickened ends. Its proximal end is rounded and forms the h e a d o f t h e f e m u r (c á p u t f é m o r i s) for the joint with the hipbone. Below the head is the n e c k o f t h e f e m u r. At the boundary between the neck and the body there are two prominences — the greater and lesser trochanters.

The g r e a t e r t r o c h a n t e r (t r o c h á n t e r m á j o r) is located at the top on the lateral side. The l e s s e r t r o c h a n t e r (t r o c h á n t e r m í n o r) is situated medially and to the back. The two trochanters are

(c ó r p u s f é m o r i s) has an almost cylindrical s h a p e. On its posterior surface there is a linea aspera, which diverges at the top and bottom, forming m e d i a l and l a t e r a l l i p s. At the top the medial labium passes into the p e c t i n e a l l i n e, and the lateral labium ends as the g l u t e a l t u - b e r o s i t y, which serves for attachment of the gluteus maximus muscle.

Fig. 63. Pelvic bone, right.

A — external surface: 1 — ilium; 2 — outer lip; 3 — intermediate zone; 4 — inner lip; 5 — anterior gluteal line; 6 — superior anterior iliac spine; 7 — inferior gluteal line; 8 — inferior anterior iliac spine; 9 — lunate surface; 10 — obturator crest; 11 — obturator groove; 12 — inferior pubic ramus; 13 — acetabular notch; 14 — obturator foramen; 15 — ramus of ischium; 16 — body of ischium; 17 — ischial tuberosity; 18 — lesser sciatic notch; 19 — ishium; 20 — ischial spine; 21 — greater sciatic notch; 22 — posterior inferior iliac spine; 23 — posterior

superior iliac spine.

B — internal surface: 1 — iliac crest; 2 — iliac fossa; 3 — terminal line; 4 — iliac tuberosity; 5 — auricular surface; 6 — greater sciatic notch; 7 — ischial spine; 8 — lesser sciatic notch; 9 — body of ischium; 10 — ramus of ischium; 11 — inferior ramus of pubic bone; 12 — obturator foramen; 13 — symphysial surface; 14 — superior pubic ramus; 15 — pubic tubercle; 16 — pubic crest; 17 — iliopubic eminence; 18 — inferior anterior iliac spine; 19 — superior

anterior iliac spine.

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At the bottom the two diverging labia limit the p o p l i t e a l s u r f a c e. The distal end of the femur is thickened and forms t h e m e d i a l and l a t e r a l c o n d y l e s (c ó n d y l u s m e d i á l i s e t c ó n d y l u s l a t e - r á l is). The medial condyle is larger than the lateral. Between the condyles in the back there is a deep i n t e r c o n d y l a r f o s s a, and in the front is a slightly concave patellar surface. At the top and to the side the medial condyle continues into the m e d i a l e p i c o n d y l e. Above the lateral condyle is a smaller l a t e r a l e p i c o n d y l e.

The patella (patélla) is the largest sesamoid bone. It has a b a s e at the top and a narrowed a p e x at the bottom. The posterior a r t i c u l a r s u r f a c e of the patella faces the patellar surface of the femur. The anterior surface of the patella is easily palpated through the skin.

Bones of the leg

Bones of the leg include the tibia, or shinbone, located medially, and the fibula, located laterally. Between these bones is the i n t e r o s s e a l s p a c e o f t h e l e g (spátium interósseum crúris). These are both long tubular bones. Each has a diaphysis and two epiphyses.

The tibia (tíbia) is the larger bone of the leg. Its proximal end has two thickenings on which are the m e d i a l and l a t e r a l c o n d y l e s. The upper portions of both condyles form the s u p e r i o r a r t i c u l a r s u r f a c e for the joint with the femur. Between the two condyles, on the surface of the articular surface, there is i n t e r c o n d y l a r e m i n e n c e. This eminence has medial and lateral i n t e r c o n d y l a r t u b e r c l e s, to which the cruciform ligaments of the knee joint are attached. To the lateral and below the laterral condyle is the f i b u l a r a r t i c u l a r f a c e t.

surface there is an oblique s o l e a l l i n e of the soleus muscle. The body of the bone also has three borders. The a n t e r i o r b o r d e r is the most acute and can be easily palpated through the skin. In its upper portion it is thickened and forms the t i b i a l t u b e r o s i t y, which is an attachment site for the tendon of the quadriceps of the femur. The i n t e r o s s e o u s b o r d e r of the tibia is on its lateral side, and confines the interosseous space of the leg. The m e d i a l b o r d e r of the bone is rounded.

On the thickened distal epiphysis of the tibia, on the lateral side, there is a f i b u l a r n o t c h. A flattened process called the m e d i a l m a l l e o - l u s (malleólus mediális) extends medially at the bottom of the tibia. On the lateral side of the malleolus is an a r t i c u l a r s u r f a c e, situated at an angle to the i n f e r i o r a r t i c u l a r s u r f a c e of the tibia.

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The fibula (fíbula) has almost the same length as the tibia, but is significantly thinner. The proximal end of the fibula forms its h e a d. On the medial side of the head there is an a r t i c u l a r f a c e t for articulation with the tibia. Beneath the head the bone narrows, passing into its neck and then its b o d y. The medial, or i n t e r o s s e o u s, b o r d e r of the fibula confines from this side the interosseous space of the crus. The distal end of the fibula is thickened and forms the l a t e r a l m a l l e o l u s (malleólus laterális), on the inner surface of which is an articular surface.

Bones of the foot

The foot (pes) is divided into the tarsus, metatarsus and the phalanges. The tarsal bones include seven spongy bones. These are the t a l u s and c a l c a n e u s, located in the proximal row, and bones of the distal row: the n a v i c u l a r, c u b o i d a l and m e d i a l, i n t e r m e d i a t e and

l a t e r a l c u n e i f o r m b o n e s (Fig. 64).

The talus (talus). This bone has a h e a d, extending to the front, a b o d y and a neck. On the top of the body is the t r o c h l e a o f t a l u s, the s u p e r i o r f a c e t of which articulates with the inferior articular surface of the tibia. At the sides of the trochlea are the m e d i a l and l a t e r a l m a l l e o l a r f a c e t s, which articulate with homonymous malleoli of the tibia and fibula. Beneath the lateral malleolar surface is the l a t e r a l p r o - c e s s of the talus. On the inferior side of the talus are the a n t e r i o r, middle and p o s t e r i o r c a l c a n e a l a r t i c u l a r f a c e t s. Between

Fig. 64. Bones of foot. Superior aspect.

1 — calcaneus; 2 — trochlea of talus; 3 — talus; 4 — navicular; 5 — middle cuneiform; 6 — intermediate cuneiform; 7 — I metatarsal bone; 8 — proximal phalanx; 9 — distal phalanx; 10 — middle phalanx; 11 — tuberositas V metatarsal bone; 12 — cuboid; 13 — lateral cuneiform; 14 — tuber of calcaneus.

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the middle and the posterior surfaces there is a deep groove of the talus (c u l c u s t a l i).

The calcaneus (calcáneus), the largest bone of the tarsus, is located under the talus. In the back the body of the calcaneus ends with a pronounced c a l c a n e a l tiberósity. The superior surface has an anterior and m i d d l e t a l a r a r t i c u l a r s u r f a c e s for the talus, between which is a c a l c a n e a l s u l c u s. On the back of the body is the p o s t e r i o r a r - t i c u l a r t a l a r s u r f a c e for the talus. On the superior anterior border of the bone there is a thick short process called the s u s t e n t a c u l u m t a l i of calcaneus. On the lateral surface there is a longitudinal g r o o v e f o r t h e t e n d o n o f t h e f i b u l a r i s l o n g u s. On the front of the head of the calcaneus there is a cuboid articular surface.

The navicular bone (os naviculáre) is flattened and lies between the talus and the cuneiform bones.

The cuneiform bones (ossa cuneiformia). The medial, intermediate and lateral cuneiform bones are located in front of the navicular bone. They are situated in the medial portion of the tarsus.

The cuboid bone (os cuboídeum) lies in front of the calcaneus. It is situated in the lateral portion of the tarsus.

Metatarsal bones (óssa metatársi). The skeleton of the metatarsus is formed by five short tubular bones. These bones are numerated I–V starting at the big toe. Each metatarsal bone has a base, a body and a head. The bases of metatarsal bones are connected with bones of the tarsus. The heads of these bones have a semispherical shape with convex articular surfaces for joints with bases of the phalanges.

Phalanges of the foot (óssa digitórum pédis) are significantly shorter and thicker then the fingers of the hands. All toes, except for the first one, consist of three p h a l a n g e s: a p r o x i m a l, a m i d d l e and d i s t a l. The big toe (hallux) has only proximal and distal phalanges. Phalanges are short tubular bones, each one composed of a base, a body and a head.

Variants and anomalies of the skeleton of lower extremities

The hipbone. Sometimes the iliac bone can be very elongated. The thickness of the iliac crest and the length of the ischial spine may significantly vary.

The femur. Often the gluteal tuberosities have the appearance of a process (a third trochanter).

Bones of the leg. The shape of the tibiae may be flattened. Sometimes the malleoli are underdeveloped.

Bones of the foot. Sometimes there are additional tarsal bones. Additional digits can develop on the foot as well as on the hand. Neighboring toes may fuse together.

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Questions for revision and examination

1.Name the prominences (tuberosities, processes, lines) found on the hipbone, femur tibia and fibula, which serve as sites of beginning and attachment of muscles.

2.Name the articular surfaces of bones of the lower extremity. What joint does each surface participate in?

3.How many bones compose the skeleton of the foot. Name these bones.

4.On the surfaces of which bones are there grooves created by adjoining tendons? What are these grooves called?

JOINTS

Joints are part of the support and locomotion apparatus. They retain bones close to each other and provide their mobility during various movements.

CLASSIFICATION OF JOINTS

All joints are subdivided into three large groups: continuous articulations, symphyses and discontinuous (synovial) joints.

Continuous articulations can be formed by different kinds of connective tissue (Fig. 65).

Fig. 65. Synostosis and semi-joint.

A — syndesmosis: 1 — interosseus membrane of forearm; B — synchondrosis: 2 — intervertebral disk; C — symphysis (secondary cartilaginous joint): 3 — pubic symphisis.

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