Skeleton of Man

 

 

In Fig. 12. The sternum (front view):

 

1 - jugular notch;

2 - clavicular notch;

3 - Handle the sternum;

4 - cutting edge;

5 - the body of the sternum;

6 - xiphoid process

 

In Fig. 13. The edges (top view)

 

A - I rib; B - II edge:

1 - tubercle of rib;

2 - a corner edge;

3 - neck edge;

4 - head of rib;

5 - the body of an edge

Edge (Fig. 13) is a long flat spongy bone forms, curving in two planes. In addition to the actual bone, each edge also has a cartilaginous portion. The bone part, in turn, consists of three clearly distinct sections: the body of an edge (Fig. 13), head of the edge (Fig. 13) with the articular surface on it, and dividing their neck ribs (Fig. 13).

The body edges produce external and internal surfaces and top and bottom edges (except I, which distinguish the upper and lower surfaces and inner and outer edges). In place of the transition of cervical ribs in the body is rib hump (Fig. 13). At I-X rib tubercle of the body is bent to form a corner edge (Fig. 13), and the tubercle of rib has a joint surface, whereby the rib articulates with the transverse processes corresponding thoracic vertebra.

The body of an edge, represented by spongy bone, has a different length: from I to the ribs VII (rarely VIII) body length gradually increases, with the following edges of the body consecutively shortened. Along the lower edge of its inner surface of the body has a longitudinal groove edges of the edge, and in this groove are the intercostal nerves and blood vessels. The front end of the rib as I have on their upper surface of the scalene tubercle, which passes in front of the subclavian vein groove, and behind it - groove for the subclavian artery.

6 Skeleton of upper limb

The bones of the upper extremity of the upper limb girdle represented (scapula and clavicle bone) and the skeleton of the free part of the upper limb (shoulder, elbow, radiation, metatarsal, metatarsals and phalanges).

 

In Fig. 14. The skeleton of the upper limb (front view):

1 - the collarbone;

2 - Shoulder;

3 - the humerus;

4 - radius;

5 - the ulna;

6 - the bones of the wrist;

7 - metacarpal bone;

8 - phalanges

7 Skeleton of lower limb

In the skeleton of the lower extremity are isolated lower extremity (hip bones) and the free portion of the lower limb (paired femur, patella, tibia bones - tibia and fibula - the bones of the foot).

Pair pelvic bone (Fig. 15), forming a belt of the lower extremity, in turn, consists of a fused pubic, iliac and ischial bones. Together with the sacrum and the coccyx bone, they form the basis of the pelvis. To adolescence (14-17 years) make up the pelvic bone, pubic, iliac, and ischial bones are individually connected to each other by cartilage.

 

In Fig. 15. Pelvic bones and the skeleton of the free part of the lower extremity:

 

1 - the sacrum;

2 - pelvic bone;

3 - Tibia;

4 - patella;

5 - fibula;

6 - the tibia;

7 - foot bones

 

8 The skeleton of the head

The skeleton of the head, that is, the skull (Fig. 16), consists of cerebral and facial skull.

 

 

 

   

 

In Fig. 16. Skull

A - front view, B - lateral view:

1 - parietal bone;

2 - the frontal bone;

3 - sphenoid bone;

4 - temporal bone;

5 - lacrimal bone;

6 - nasal bone;

7 - zygomatic bone;

8 - the upper jaw;

9 - the lower jaw;

10 - the occipital bone

Cerebral skull is ovoid in shape and is formed by the occipital, frontal, sphenoid, ethmoid, and a couple pair of temporal parietal bones. The facial skull is formed by six paired bones (upper jaw, lower turbinate, lacrimal, nasal, zygomatic, and palatine bones) and three unpaired (lower jaw, hyoid bone, the opener) and represents the initial division of digestive and respiratory apparatus. The bones of the two skulls joined together by sutures, and virtually immobile. The lower jaw connects to the skull joint, therefore the most mobile, the need for its participation in the act of chewing.

Cranial cavity is a continuation of the spinal canal, it contains the brain. The upper section of the cranial, formed by the parietal bones and scales of the frontal, occipital and temporal bones, called the vault or roof of the skull. The bones of the cranial vault flat, their outer surface is smooth and flat, and the interior is smooth, but uneven, since it marked the furrows of the arteries, veins and the adjacent convolutions of the brain. Blood vessels are located in the spongy material - diploic, located between the outer and inner plates of compact substance. The inner plate is not as strong as the external, it is much more delicate and fragile. Lower part of the cranial, formed by the frontal, occipital, sphenoid and temporal bones, called the base of the skull.

9 The structural features of the newborn skull

The aspect ratio of the newborn with parts of the skull length and weight of his body other than an adult. The skull of the child is much greater, and the skull bones are separated. The spaces between the bones are filled with layers of connective tissue or cartilage neokostenevshego. Cranial size substantially predominates over the facial. If the ratio of adult facial skull to the brain is approximately 1: 2, then the newborn is a ratio of 1: 8.

The main feature is the presence of neonatal cranial fontanelles. Springs - is neokostenevshie membranous areas of the skull, which are located in areas of future joint formation.

In the early stages of fetal development the roof of the skull is membranous formation, which covers the brain. At the 2-3rd month, bypassing the stage of cartilage, bone shaped nucleus, which subsequently merged with each other and form a bony plate, that is the basis of skeletal bones of the skull roof. By the time of birth between the formed parts are preserved bones of narrow lanes and wider spaces - fontanelles. It is through these sections of the membranous skull that can sink down and stuck out, there is a significant shift of the skull bones themselves, allowing the passage of the fetal head through the narrow places of the birth canal.

The front, or large fontanelle (Fig. 17) has a diamond shape and is located at the junction of the frontal and parietal bones. He is completely ossified by age 2. The rear, or small, fontanelle (Fig. 17) is located between the occipital and parietal bones. He has ossified into 2-3rd month after birth. Sphenoid fontanelle (Fig. 17) pair, located in the anterior lateral surface of the skull between the frontal, parietal, sphenoid and temporal bones. It ossifies almost immediately after birth. Mastoid fontanelle (Fig. 17) pair, located posterior to the wedge, at the junction of the occipital, parietal and temporal bones. Ossifies at the same time with the wedge.

   

 

In Fig. 17. Skull of a newborn

 

A - lateral view, B - view from above:

1 - a large fontanelle;

2 - Small fontanel;

3 - sphenoid fontanelle;

4 - mastoid fontanelle