A review of the literature is devoted to the peculiarities of the lung structure of white rats. Morphological features of rat lungs are an experimental model in the case of the study of the development of left ventricular pulmonary hypertension. Rats have the features of the lungs structure, which differ from the lungs of man. The construction of blood vessels of the rat lungs should be studied in the case of a stressor lung. Peculiarities of innervation of the pulmonary veins of rats in the root of the lung make the left lung of rats an object of study necessary for solving the problems of modern pulmonology, cardiology and morphology. In the anatomical study, the root of the diaphragmatic lobe is located in the caudal sulcus of the left lung. In studying the features of the sintopia and holotopia of the root and gates of the left lung of sexually mature rats, the structural apparatus of the caudal sulcus is discovered, which is located for more than 11-17 mm on the medial surface of the diaphragmatic lobe of the left lung. The structural apparatus consists of the left caudal pulmonary vein, furrows on the surface of the diaphragmatic lobe of the left lung, the adventitial shell of the caudal bronchus, the visceral pleura, the bronchial nerves and blood vessels, the encapsulated receptors. The presence of cardiomyocytes in the intrapulmonary veins in rats confirms the hypothesis of a rhythmic, valve-like action of the transverse striated muscle of the pulmonary venous wall during systole and a possible role in pulmonary circulation. Data obtained through experimental intervention indicate the valve-like effect of the striated muscle of the pulmonary venous wall.