Anatomy Test Wed.

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Anatomy Test Wed.
2013-04-09 09:35:58

Show Answers:

  1. function of blood vessels
    take blood to the tissues and back
  2. arteries
    • leave the heart and become smaller and smaller, carry blood away, high pressure
    • thick walled, smaller
  3. arterioles
    lead to capillary beds
  4. capillaries
    embedded in tissues and empty into venules
  5. venules
    carry deoxygenated blood to veins
  6. veins
    • return deoxygenated blood to the heart
    • large thin walled with valves
    • veins (vena cava) large blood vessels
    • -carries blood from tissues to the heart
    • -blood is not under great pressure
    • -blood travels uphill (legs and arms)
  7. lumen
    central cavity
  8. 3 layers of lumen
    • (tunics)
    • tunic intima, tunic media, tunic externa
  9. tunic intima
    • thin endothelium
    • lines the lumen
    • -in contact with blood
    • squamous epithelial cells
    • decreases friction for blood flow
  10. tunic media
    • smooth muscle and elastic tissue (fibers)
    • controlled by symphathetic nervous system
    • constrict (vasoconstriction) makes lumen smaller
    • dilate (vasodilation) makes lumen larger
  11. tunic externa
    • mostly fibrous connective tissue
    • protect and support vessel
  12. walls of arteries are...
    very thick
  13. tunica media is heavier because ___ to heart, and must expand when blood is forced __
    closer; out
  14. walls of arteries have ____ blood pressure
  15. lumens of veins are larger
    • further from heart
    • lower blood pressure
    • must get blood back to heart against gravity
    • contain valves to prevent backflow
  16. movement of blood through vessels
    • arterial blood is pumped by the heart
    • veins also use the milking action of skeletal muscles to help move blood
    • respiratory pump occurs when we inhale, pressure lowers and veins near heart expand and fill
  17. varicose veins
    • blood pools in the feet andĀ legs
    • poor return from pressure on veins
    • veins become twisted and dialated
    • extreme case can lead to thrombophlebitis (clot in a vessel with poor circulation) and can cause a pulmonary embolism and death
  18. capillaries
    • microscopic blood vessels (walls=1 cell thick)
    • red blood cells move through single file
    • thin capillary walls allow nutrients and gases to diffuse easily between blood cells and surrounding tissues
  19. capillaries form interweaving networks called _______; which have _______
    capillary beds; microcirculation
  20. capillary beds consist of 2 types of vessels
    • vascular shunt- directly connects an arteriole to a venule
    • true capillaries- exchange vessels, branch off shunt
  21. pre-capillary sphincter
    regulates flow of blood into the capillaries
  22. direct diffusion
    lipid soluble molecules (respiratory gases)
  23. endocytosis or exocytosis
    lipid insoluble molecules (nutrients, wastes)
  24. intercellular clefts
    • capillary gaps
    • plasma membrane not joined by tight junctions
  25. fenestrations of some capillaries
    • small solutes and fluids
    • fenestrations=pores
  26. systolic pressure
    • ventricle systole
    • heart contracts
  27. diastolic pressure
    • ventricle diastole
    • heart relaxes, between contractions
  28. tools used to measure blood pressure
    • sphygmomanometer
    • stethoscope
  29. blood pressure is measured at:
    brachial artery in arm (near heart)
  30. normal blood pressure
    • 140-100 mm Hg
    • 80-70 mm Hg
  31. hypotension
    • low systolic (below 110 mm Hg)
    • often associated with illness
  32. hypertension
    • high systolic (above 140 mm Hg)
    • can be dangerous if chronic
    • very few symptoms, silent killer
    • consequences: heart failure, vascular disease (poor circulation), renal failure, stroke
  33. cardiac output
    • amount of blood pumped by each side of the heart in one minute
    • CO=(heart rate x stroke volume)
  34. stroke volume
    volume of blood pumped by each ventricle in one contraction
  35. in one minute ____ of blood are pumped by the heart
    5250 cc (1 cc=1 ml)
  36. on average, ___ of blood is pumped through the heart every minute
  37. about ____ quarts of blood a day
  38. Starling's law of the heart
    the more the cardiac muscle is stretched, the stronger the contraction
  39. heart adjusts its pumping rate to ____
    the rate of blood return
  40. what's the most common way to change cardio output
    changing heart rate
  41. noise heard when taking blood pressure caused by:
    vibrations in the walls of the blood vessel
  42. 5 sounds of Korotkoff:
    • 1. snapping sound heard at the systolic pressure
    • 2. "murmurs" between the systolic and diastolic pressures
    • 3 and 4. "thumping" and "muting"
    • 5. "silence" as cuff pressure drops
  43. causes of increased heart rate or Tachycardia
    • heart rate over 100 beats per minute
    • sympathetic nervous system (controls internal organs, nerves in vert. column, fight or flight)
    • -crisis (physical or emotional stress); low blood pressure
    • hormones
    • -epinephrine, mimics sympathetic nerves; thyroxine, secreted by thyroid to increase metabolism
    • exercise
    • electrolyte (blood chemical) imbalance
    • decreased blood volume
  44. Arterial BP=
    CO x PR
  45. CO
    • cardio output
    • amount of blood pumped out of left ventricle per minute
  46. PR
    • peripheral resistance
    • amount of friction in the blood vessels
    • increase in blood viscosity (thickness) increases PR
  47. neural factors on blood pressure
    • autonomic nervous system adjustments in the sympathetic division
    • causes vasoconstriction (narrowing of blood vessels) which will increase BP
    • increased heart rate=increased CO=increased BP
    • decreased HR=decreased CO=decreased BP
    • vessel diameter goes up (vasodilate)=decreased BP
    • vessel diameter goes down (vasoconstriction)=increased BP
  48. effects of kidneys
    • increased BP=increase in urine leaving body
    • fluid in urine comes from water in bloodstream so decreased blood volume and decrease in BP
    • kidneys retain water to increase BP
  49. effect of temperature
    • heat has a vasodilation effect= decrease BP
    • cold has a vasoconstricting effect= increase BP
  50. effect of chemicals
    • epinephrine= increased HR and increased BP
    • nicotine= increased BP (vasoconstriction)
    • alcohol and histamine= decreased BP (vasodilation)
  51. effect of hormones
    • some will increase BP
    • -adrenaline
    • -antidiuretic (vasopressin), increased water retention
    • -anglotension (released by kidney)
  52. pulse
    • pulse- pressure wave of blood
    • normal pulse= 75 beats/min
    • monitored at "pressure points" where pulse if easily palpated
    • common pulse taking artery is the radial artery