Ch 11 vesselsPhysiology of

circulation

Ch 11 vesselsPhysiology of

circulation

PPT 2

PULSEPULSE

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

Blood PressureBlood 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

Measured in mm of Hg

Instruments: Sphygmomanometer & Stethoscope

Blood pressureBlood pressureKorotkov’s soundsKorotkov’s sounds -1st sound during ventricular systole, pause during ventricular diastole; use these to determine pressures

Average bp= 110-120 / 70-80

Ventricular SystoleVentricular Diastole

FACTORS AFFECTING BP

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

OTHER FACTORS AFFECTING BP

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

FACTORS AFFECTING BP

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

FACTORS AFFECTING BP

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

Homeostatic Imbalances

Homeostatic Imbalances

Spider veins

Small and superficial

Homeostatic Imbalances

Homeostatic Imbalances

Varicose veins

Enlarged veins

Homeostatic Imbalances

Homeostatic Imbalances

atherosclerosis

Narrowing by plaque & constriction of BV

Homeostatic Imbalances

Homeostatic Imbalances

hypertension

High blood pressure 140/100 or higher

Homeostatic Imbalances

Homeostatic Imbalances

AneurysmEnlargement of artery walls; ruptured artery

Homeostatic Imbalances

Homeostatic Imbalances

Stroke/CVA

Lack of blood to brain

Practical applications

Practical applications

Coronary bypass surgery- treatment, but not cure for atherosclerosis or coronary artery disease

Practical applications

Practical applications

Angioplasty including balloon catheterization

stents