1. Ch 11 vessels Physiology of circulation
PPT 2

2. PULSE
Alternate expansion/recoiling of a superficial arterial wall in response to ventricular systole
Measured in artery (carotid, radial, or brachial arteries)
Average resting pulse usually around 75 b/min

3. Blood Pressure
Force of blood against blood vessel wall due to ventricular systole, corresponds with cardiac cycle
Measured in artery with highest pressure (that is accessible) - brachial artery
Systolic pressure- maximum pressure during ventricular systole, 1st sound
Diastolic pressure- lowest pressure during ventricular diastole, pause

4. Measured in mm of Hg
Instruments: Sphygmomanometer & Stethoscope

5. Blood pressure
Korotkov’s sounds -1st sound during ventricular systole, pause during ventricular diastole; use these to determine pressures
Average bp= / 70-80
Ventricular Diastole
Ventricular Systole

6. FACTORS AFFECTING BP
1.peripheral resistance of blood (friction in BV) atherosclerosis
2.viscosity of blood
3.blood volume (due to water in blood and salt in body)
4.ANS(autonomic nervous system)- by vasoconstriction
Sympathetic division increases bp
Parasympathetic division decreases bp

7. OTHER FACTORS AFFECTING BP
Cardiac output
Age
Weight
Exercise
Body position
Emotional state
Time of day- alters bp, but depends on specifics
Exs. Older, out-of-shape, or stressed people have higher bp

8. FACTORS AFFECTING BP Kidneys: alter blood volume
Aldosterone: increases water content of blood, Increases Blood Volume
Renin: enzyme affects vasoconstriction
(both increase bp)
Diet: salt, cholesterol, & saturated fat increase bp

9. FACTORS AFFECTING BP
Temp.- cold increases vasoconstriction, increases bp
Chemicals(stimulant drugs) - nicotine, adrenalin, epinephrine cause vasoconstriction which increase bp
Chemicals (depressants) - alcohol, and histamine cause vasodilation which decrease bp

10. Homeostatic Imbalances
Spider veins
Small and superficial

11. Homeostatic Imbalances
Varicose veins
Enlarged veins

12. Homeostatic Imbalances
atherosclerosis
Narrowing by plaque & constriction of BV

13. Homeostatic Imbalances
hypertension
High blood pressure 140/100 or higher

14. Homeostatic Imbalances
Aneurysm
Enlargement of artery walls; ruptured artery

15. Homeostatic Imbalances
Stroke/CVA
Lack of blood to brain

16. Practical applications
Coronary bypass surgery- treatment, but not cure for atherosclerosis or coronary artery disease

17. Practical applications
Angioplasty including balloon catheterization
stents