Chapter 19: Blood Vessels

  1. Blood Vessels
    • Delivery system of dynamic structures that begins and ends at heart
    • Vessels vary in length, diameter, wall thickness, tissue makeup
  2. Arteries
    • Carry blood away from heart
    • Oxygenated except for pulmonary circulation and umbilical vessels of fetus
    • Large thick walled vessels
    • Aorta and its major branches
    • Act as pressure reservoirs - expand and recoil as blood ejected from heart
    • Deliver blood to body organs
    • Pressure in the arteries is greater than any other veins - will spurt blood when they are cut
  3. Arterioles
    • Smallest arteries
    • Lead to capillary beds
    • Control flow into capillary beds via vasodilation and vasoconstriction
  4. Venous System: Venules
    • Formed when capillary beds unite
    • Very porous
    • Allow flids and WBCs into tissues
  5. Veins
    • Carry blood toward heart
    • Formed when venules converge
    • Have thinner walls compared with corresponding arteries
    • Blood pressure lower than in arteries - when cut, blood oozes instead of spurting
    • Adaptations ensure return of blood to heart despite low pressure
  6. Venous Valves
    • Prevent backflow of blood
    • Most abundant in veins of limbs
  7. Capillaries
    • Microscopic blood vessels
    • Diameter allows only single RBC to pass at a time
    • In all tissue (except cartilage, epithelia, cornea and lens of eye)
    • Provide direct access to almost every cell
    • Functions - exchange of gases, nutrients, wastes, hormones, etc., between blood and interstitial fluid
  8. Circulation Assessment
    Clinicians assess the efficiency of circulation by measuring pulse and blood pressure
  9. Pulse
    alternating expansion and recoil of arteries during each cardiac cycle
  10. Systolic Blood Pressure
    Pressure exerted on the blood by vessels walls during ventricular contraction
  11. Diastolic Blood Pressure
    Arterial blood pressure due to ventricular relaxation
  12. Hypertension
    • Elevated blood pressure
    • Can lead to heart failure, vascular disease, renal failure or stroke
    • Contributing factors: heredity, diet, obesity, age, stress, smoking
  13. Hypotension
    • Low blood pressure
    • Usually not problematic
Card Set
Chapter 19: Blood Vessels
Blood Vessels