BLOOD PRESSURE

• Vital Signs - measurements of arterial pulse, blood pressure, respiratory rate, and body temperature
• Arterial pulse - alternate expansion and recoil of a blood vessel wall that occurs as the heart beats; averages 70 to 76 bpm in a healthy person
• Blood pressure - pressure the blood exerts against the inner walls of the blood vessels and causes blood to continue to flow
• Blood pressure gradient:

  • Pressure decreases in blood vessels as distance from the heart increases
  • Pressure is high in the arteries, lower in the capillaries, and lowest in the veins
• 2 types of arterial blood pressures that are measured:

  • Systolic - pressure in the arteries when ventricles contract
  • Diastolic - pressure when ventricles relax

  Expressed as systolic over diastolic in mm Hg; ex. 120/80 mm Hg
• Auscultatory method - an indirect method of measuring systemic arterial blood pressure, most often in the brachial artery
• Normal blood pressure range:

  • Systolic pressure - 110 to 140 mm Hg
  • Diastolic pressure - 70 to 80 mm Hg
• Hypotension - low blood pressure, systolic pressure below 100 mm Hg
• Hypertension - high blood pressure, 140/90 mm Hg
• Various routes during capillary exchange of gases and nutrients:

  • Direct diffusion through membranes
  • Diffusion through intercellular clefts
  • Diffusion through pores
  • Transport via vesicles
• Fluid movements at capillary beds:

  • Blood pressure - forces fluid and solutes out of capillaries
  • Osmotic pressure - draws fluid into capillaries
• • Blood pressure is higher than osmotic pressure at the arterial end of the capillary bed
  • Blood pressure is lower than osmotic pressure at the venous end of the capillary bed