(fibres or membranes) (4) blood vessels supply only its outer portion, the inner portion is
supplied by diffusion
19. The arteries are classified into the following types:
(1) muscular (2) muscular-elastic (3) elastic (4) without muscles
20. The following statements regarding the muscular-elastic arteries are true:
(1) are branches of elastic arteries (2) blood pressure is higher in these arteries than in
aorta (3) their tunica media contains approximately an equal amount of smooth muscle
cells and elastic elements (4) blood vessels supply three layers of their wall
21. The following statements regarding the muscular arteries are true:
(1) blood pressure is the highest in these arteries (2) they are small-calibre arteries (3)
they lack the internal and external elastic membranes (4) smooth muscle cells are
predominant in their tunica media
22. In embryogenesis the blood vessels are derived from:
(1) endoderm (2) ectoderm (3) mesoderm (4) mesenchyme
23. The capillaries are divided into the following types:
(1) continuous (2) fenestrated (3) discontinuous (4) mixed
24. The following statements regarding the fenestrated type capillaries are true:
(1) are characterized by fenestrations (2) their fenestrations provide channels in the
capillary wall (3) have pinocytotic vesicles (4) typically found in muscles
25. The following statements regarding the discontinuous type capillaries are true:
(1) typically found in the liver, spleen, and bone marrow (2) are characterized by multiple
pores in endothelial cells and between them (3) are characterized by the absence of the
basal lamina under pores (4) pericytes may be found in their wall
26. The veins are classified into the following types:
(1) elastic (2) muscular (3) muscular-elastic (4) muscle-free or fibre type
27. The muscular veins are subdivided into the following groups:
(1) with a small muscle content (2) with a moderate muscle content (3) with a large muscle
content (4) muscular-elastic
28. The following statements regarding the fibre type veins are true:
(1) they usually convey blood towards gravity (2) their wall consists of the tunica intima
and the tunica adventitia (3) their wall is devoid of the tunica media (4) they contain
muscles in the tunica adventitia
29. The smooth muscle cells are located in the veins with a large muscle content:
(1) circularly in the tunica media (2) longitudinally in the tunica intima (separate cells) (3)
longitudinally in the tunica adventitia (bundles of cells) (4) longitudinally in the tunica media
30. The heart embryonic origins are as follows:
(1) endoderm (2) mesoderm (3) ectoderm (4) mesenchyme
31. The following statements regarding the arteriovenous anastomoses are true:
(1) may be simple and complex (2) convey blood to venules bypassing the capillary bed
(3) regulate organ blood filling (4) serve in termoregulation at body surface
32. The following statements regarding the Purkinje fibres are true:
(1) contain few myofibrils (2) are rich in glycogen (3) are glycolytic (anaerobic) cells (4)
transmit excitation to typical cardiac muscle cells
12. HEMOPOIESIS. CENTRAL ORGANS OF HEMOPOIESIS
Directions
: each of the following statements contains five suggested completions. Choose
the one that is best in each case.
1. The first phase of hemopoiesis in fetal life occurs in:
