Circulatory System S1M3

  1. Veins and arteries (excluding capillaries and venules) are made up of what primary components
    • Endothelial Cells
    • Elastic Fibers
    • Smooth muscle
    • Collagen fibers
  2. What are the three layers of most blood vessels
    • Tunica intima
    • Tunica media
    • Tunica adventitia
  3. Capillaries only contain what layer
    Tunica intima of endothelial cells lying on a basal lamina
  4. What is the tunica intima made up of
    Single layer of epithelial cells (aligned parallel), loose connective tissue, and a few scattered smooth muscle cells
  5. What does the tunica media consist of
    • Losts of smooth muscle cells
    • Elastic fibers, Coll. III, and proteoglycans between the smooth muscle cells
  6. What is the tunica adventitia composed of
    Mainly fibroblasts, type I Coll., and longitudinally oriented elastic fibers
  7. The tunica adventitia becomes continuous with what
    With the connective tissue elements surrounding the blood vessel
  8. What do large vessels have in them that other vessels lack
    The tunica advantitia and outer part of the tunica media has vessels called the vaso vasorum that supply blood to the walls
  9. What are the three types of arteries and how do they differ
    • Elastic Arteries (Biggest, closest to the heart)
    • Muscular Arteries (2nd biggest)
    • Arterioles (Smallest arteries)
  10. What are the alternate names for the three types of arteries
    • Elastic (Conducting)
    • Muscular (Distributing)
    • Arterioles (Includes metarterioles)
  11. What is it called when the elastic arteries contract for continual blood flow while the heart is resting
    Windkessel effect
  12. What properties make the elastic arteries recoil
    The tunica media is formed by layer of smooth muscle with elastic lamins in between them
  13. In an elastic artery, what makes the collagen and elastin
    Smooth muscle cells, fibroblasts are only in the tunica adventitia
  14. Smooth muscle in both elastic and muscular arteries in the tunica media are connected how
    Gap junctions
  15. Elastic arteries have holes in the elastic lamellae allowing what
    Nutrients and oxygen to diffuse through, as well as allow smooth muscle cells to contact each other across layers
  16. Smooth muscle cells in the elastic vessels have the ability to proliferate and repair intima in response to what
    Growth factors secreted by the endothelial cells
  17. In elastic vessels, what is the thicker layer
    Tunica media is thicker then the tunica adventitia because of the large amount of elastic laminas
  18. In large muscular arteries what separates the tunica media from the tunica adventitia
    External elastic lamina or membrane
  19. How is the internal elastic lamina different, and in what vessels is it found
    It is only in the arteries (mainly muscular), and it separates the tunica media from the tunica intima. It is made up of elastin
  20. Internal elastic lamina is well developed in what vessels
    In the muscular arteries
  21. What is a good way to determine if it is a muscular artery from a histological view
    There is one definative row of internal elastic lamina in muscular vessels, Elastic vessels have many rows of it
  22. Most vessels arising from the aorta are what kind of vessels
    Muscular (distributing) arteries
  23. If a vessel has a large tunica media with a lot of smooth muscle cells, and a small tunica intima, what is it
    Muscular artery
  24. What is the tunica adventitia of the muscular vessels made up of
    • Fibroblasts
    • Elastic fibers
    • Collagen fibers
    • Ground substance
    • Blood vessels
    • Nerves
  25. What is found in the layers of arterioles
    • In very small arterioles there is no external or internal elastic lamina
    • The media is composed of 1-2 layers of smooth muscle
    • The advantitia is very thin
  26. What are the layers found in metarterioles
    They are surrounded by a discontinuous layer of smooth muscle, no external or internal elastic lamina
  27. What is the difference between the capillaries and a metarteriole
    Metarterioles have discontinuous smooth muscle, capillaries have none
  28. What is the important function of the arterioles and how do they achieve it
    They regulate blood pressure by constriction or relaxing the smooth muscle cells tightly arranged around them
  29. Veins have a much smaller what then arteries
    Tunica media, but a large lumen
  30. Veins are able to help move blood due to what
    Valves, Smooth muscle in the tunica adventitia
  31. Valves in a vein are part of what layer, reinforced by what
    Tunica intima, reinforced by collagen and elastic fibers
  32. What causes varicose veins
    This is when the valves in the veins don't close properly
  33. Where does the gas exchange happen
  34. How is blood flow regulated from reaching the capillaries
    By the smooth muscle cells and sphincters on the arterioles and metarterioles
  35. Nitric oxide and norepinephrine have what effects on the capillaries
    • NO dilates
    • Norepinephrine Constricts
  36. When the precapillaries sphincters are closed where does the blood flow
    Through the thoroughfare channel bypassing the true capillaries
  37. How do the capillaries assist in the release of heat from the body
    The metarteriole sphincters open letting the blood pass to the capillaries putting them susceptible to the periphery the body
  38. Capillaries are all made of
    Single layer of Endothelium attached to a basal lamina
  39. What are the three different types of capillaries
    • Continuous (No gaps)
    • Fenestrated (Small gaps)
    • Discontinuos/Sinosoidal (large gaps)
    • All but discontinuous are on a continuous basal lamina.
  40. What is important about pericytes and where are they found
    They contain actin, myosin, and tropomyosin, and can therefore contract. They are found on some capillaries and post capillary venules
  41. Pericytes are surrounded by what
    A basal lamina that is continuous with the basal lamina of the endothelial cells
  42. Continuous capillaries are found in what tissues
    • Muscle
    • Connective
    • Exocrine glands
    • Nervous tissue
  43. How does the transportation of molecules happen in continuous capillaries
    They contain numerous pinocytotic vesicles with the ability to transfer large macromolecules in both directions
  44. Capillaries are endothelial cells but differ from many others with the lower amount of what
    Zonula occludens, allowing diapedesis
  45. What organs contain fenestrated capillaries
    • Kidneys
    • Intestine
    • Endocrine Glands
  46. The pores in the fenestrated capillaries are bridged by what
    An ultrathin diaphragm (thinner then the plasma membrane)
  47. Renal glomerulus fenestrated capillaries lack what
  48. Sinusoidal/Discontinuous capillaries are found in what organs
    • Liver
    • Bone marrow
    • Spleen
    • (Where large cells have to pass)
  49. What is the primary difference between fenestrated and discontinuous capillaries
    Discontinuous don't have diaphragms, endothelial cells are more separated, they conform to the shape of the structure to which they are located and holes are large enough for whole cells to pass through
  50. What vesicles can capillaries use to transport large substances across the membrane
  51. What is the size of a large pore in a capillary
    50-70nm found in fenestrae and transport vesicles
  52. What is the size of a small pore in capillaries
  53. Calveolae transportation has names for the sides of the lumen, what are they
    • Adluminal - side facing the lumen
    • Abluminal - side facing away from the lumen
  54. What are the different ways that a capillary can transport material
    • Diffusion (lipid soluble substances)
    • Leaky tight junctions (water soluble substances)
    • Movement through fenestrations (water soluble substances)
    • Vesicles (large subtances)
  55. How do the capillaries in the BBB limit transportation
    • Very extensive tight junctions
    • Very few pinocytic vesicles
  56. What is the role of astrocytes in the BBB
    They wrap around the endothelial cells and secrete factors that induce capillary cells to produce tight junctions
  57. What is an ateriovenous anastomosis
    • Direct communication between arterioles and venules (no capillaries)
    • Found in penis and clitoris
  58. What is a arterial portal system and where can it be found
    • Arteriole to capillary to arteriole
    • In the kidneys
  59. What is a venous portal system and where can it be found
    Venule to capillary to venule, found in the liver
  60. What are the different layer of the heart
    • Endocardium
    • Myocardium
    • Epicardium
  61. What makes up the endocardium
    • Simple squamous epithelium
    • Fibroelastic connective tissue
    • Subendothelial layer (Dense connective tissue)
  62. What is found in the subendothelial layer of the heart
    Dense connective tissue with blood vessels, nerves, and perkinje fibers
  63. What is the thickest layer of the heart an what does it contain
    The myocardium (center layer) contains cardiac muscles arranged in complex spirals around the chambers
  64. What does the epicardium contain
    The coronary heart vessels, nerves, ganglia, and fat
  65. Arteriosclerosis
    A chronic disease characterized by the thickening and hardening of the arterial walls (hardening of the arteries)
  66. Atherosclerosis
    A form of Arteriosclerosis with deposits of fatty substances, and fibrosis of the inner layer of the arteries (Intima layer)
  67. Artheroma
    Lipid deposits in the intima of arteries
  68. What are the steps to atherosclerosis formation
    • Monocytes migrate to damaged site
    • Monocytes become macrophages taking up excess LDL forming foam cells
    • Smooth muscles cells respond to the release of GF's secreted by the foam cells surrounding them
    • Smooth cells form fibrous tissue forming a muscle cap
  69. Where does the fibrous cap form in artherosclerosis
    Under the endothelial cells
  70. HDL is good because it has what effect
    It romoves LDL's from the blood stream
  71. What differentiates into foam cells
    Smooth muscle cells and macrophages
  72. In what ways does smoking lead to atherosclerosis
    • Production of carbon monoxide
    • Nicotine is a potent vasoconstrictor
    • Smoking promotes oxidation of LDL
Card Set
Circulatory System S1M3
Micro Anatomy