Intercostal arteries: there are 12 pairs of posterior and anterior arteries, 11 intercostal pairs, and 1 subcostal pair. Anterior intercostal arteries.
Pairs 1–6 are derived from the internal thoracic arteries.
Pairs 7–9 are derived from the musculophrenic arteries.
Posterior intercostal arteries: the first two pairs arise from the superior intercostal artery, a branch of the costo—cervical trunk of the subcla vian artery.
Nine pairs of intercostal and one pair of subcostal arter ies arise from the thoracic aorta.
Intercostal veins: Anterior branches of the intercostal veins drain to the internal thoracic and musculophrenic veins.
Posterior branches drain to the azygos system of veins.
Lymphatic drainage of intercostal spaces: anterior drainage is to the internal thoracic (parasternal) nodes.
Posterior drainage is to the paraaortic nodes of the po—ste rior mediastinum.
New words
thoracic – грудной
wall – стенка
clavicle – ключица
xiphisternal – грудинный
groove – углубление
intercostal – межреберный
subcostal – подкостный
transversus – поперечный
musculophrenic – мышечный грудобрюшной
paraaortic – парааортальный
mediastinum – средостение
18. Blood. Formed elements of the blood. Erythrocytes and platelets
Blood is considered a modified type of connective tissue. Mesodermal is composed of cells and cell frag ments (erythrocytes, leukocytes, platelets), fibrous proteins (fi—brinogen), and an extracellular fluid and proteins (plasma). It also contains cellular elements of the immune system as well as humoral factors.
The formed elements of the blood include erythrocytes, leukocytes, and platelets.
Erythrocytes, or red blood cells, are important in trans porting oxygen from the lungs to tissues and in returning carbon dioxide to the lungs. Oxygen and carbon dioxide carried in the RBC combine with hemoglobin to form ox—yhemoglobin and carbaminohemoglobin, respectively.
Mature erythrocytes are denucleated, biconcave disks with a diameter of 7–8 mm. The biconcave shape results in a 20–30 % increase in sur face area compared to a sphere.
Erythrocytes have a very large surface area: volume ratio that allows for efficient gas transfer. Erythrocyte membranes are remarkably pliable, enabling the cells to squeeze through the narrowest capillaries. In sickle cell anemia, this plasticity is lost, and the subsequent clogging of capillaries leads to sickle crisis. The normal concentration of erythrocytes in blood is 3,5–5,5 million/mm >3 in women and 4,3–5,9 million/mm >3 in men. The packed volume of blood cells per total volume of known as the he—matocrit. Normal hematocrit values are 46 % for women and 41–53 % for men.