Theme 5. All medical students must know the structure of the human body perfectly well

The Human Body

All medical students must know the structure of the human body perfectly well. Human body is a very complex system consisting of three chief parts: the head, the trunk and the limbs or extremities.

The frame of the body is the skeleton which is composed of more than 200 bones of various sizes and shapes. They give firm but flexible support to soft tissues, muscles and organs.

The skull is composed of 26 cranial and facial bones. The cranial part contains the brain. The facial bones form the face which consists of the forehead, the eyes the nose, the mouth, the cheeks, the ears and the chin. The ear includes 3 main parts: the external, the middle and the internal ear. The mouth has the upper and the lower lips. There are 2 jaws with teeth, the tongue and the palatein the mouth. The head is connected with the trunk by the neck.

The skeleton of the trunk consists of the spinal column (the spine) and the chest (the ribs and the breastbone).The trunk is divided into two cavities. The upper cavity (the chest) contains the heart, the lungs and the gullet (esophagus).The principal organs of the lower (abdominal) cavity are the stomach, the liver, the spleen, the gall-bladder, the kidneys, the bladder and the intestines.

The spine of an adult consists of 32 or 34vertebrae.They are divided into the cervical, thoracic, lumbar, sacral vertebrae and the coccyx.

The chest (thorax) is composed of 12 thoracic vertebrae, the breastbone and 12pairs of ribs.

The upper extremity is connected with the chest by the shoulder and is divided into the upper arm, the forearm and the hand. Each hand has 4 fingers and 1 thumb. The parts of the lower extremity are: the thigh (hip), the leg and the foot.

The bones of the skeleton are connected together by the joints or by the cartilages and ligaments.

The skeleton is covered with more than 400 muscles. Each has an arterial, venous, lymphatic and nervous supply as well as a connective tissue framework.

The skin is the upper layer of the skeleton (body).

There are several main systems of the body: the skeletal, the muscular, the nervous, the digestive, the respiratory, the urinary, the endocrine, the excretory and the reproductive.

The vital activities of the cells, tissues, organs and the whole organism are based on metabolism.

The regulation between various systems of organs can be demonstrated by the coordinated changes in their activities. Intensification of the activity of one organ or system of organs is accompanied by the changes in the other system.

Date: 2015-12-12; view: 674; Нарушение авторских прав