Text B

The human body is obviously separate (разделять, делить) into the head, the trunk and the limbs. In the head, the brain-case or skull is distinguishable (различимый) from the face. The trunk includes the chest or thorax (грудная клетка), and the abdomen (брюшная полость, живот). Of the limbs there are two pairs – the upper, or arms, and the lower, or legs; and the legs and arms again are separable (отделять, разделять) into several parts – the thigh (бедро), the leg ( and the toes (пальцы ног) in the lower limb and the upper arm (плечо, плечевая кость), the forearm (предплечье), the wrist (запястье) and the fingers in the upper limb.

The whole body is bilaterally symmetrical. There are special bones in the trunk which are bound (связаны) together by a very strong and tough substance (вещество) into a long column, which lies nearer the dorsal that ventral part of the body. The bones are called the vertebrae (позвонки). They separate a long narrow (узкий) canal (канал), the spinal canal (спинной канал), which lies (лежит) upon the dorsal side.

The spinal canal contains (содержит) a long white cord – the spinal cord (спинной мозг) – which is an important part of the nervous system. The diaphragm (диафрагма) divides (отделять) the ventral (вентральный) chamber (отдел, камера) into two cavities (полости): the thorax and abdomen. The alimentary canal (пищеварительный канал) transverses (пересекает) these cavities from one end to the others and pierces (проходит сквозь) the diaphragm. In the abdomen there are also two kidneys (почки), which lie against each side of the vertebral column, the ureters (мочеточники), the bladder(мочевой пузырь), the liver (печень), the pancreas (поджелудочная железа) and the spleen (селезёнка). The thorax encloses (заключать) the heart and two lungs. The latter lies one on each side of the heart.

The dorsal (дорсальный) chamber, or cavity of the skull, opens into the spinal canal. It contains the brain, which is continuous with the spinal cord. The brain and the spinal cord together constitute (образуют) the cerebrospinal system (спинно-мозговая система). The ventral chamber or cavity of the face encloses mouth and pharynx (глотка), into which the upper end of the alimentary canal (gullet or oesophagus (пищевод)) opens.