Hypertension Flashcards
Review of the Circulatory System
- Right side of the heart pumps deoxygenated blood to the lungs to pick up oxygen and the oxygenated blood is returned to the left side of the heart where it is pumped away from the heart all the way through arteries, arterioles, and capillary bed
- In the capillary bed there’s gas exchange
- Once gases have been exchanged, there’s a return flow to the heart through the capillary bed, the venules, and veins
- Largest veins are superior and inferior vena cavas
- Largest artery is the aorta
?
Is the force of blood pushing against the artery walls as it flows through them (arterial pressure [AP])
Blood pressure
- High pressure over time may cause inflammation, fatty accumulation, & atherosclerosis
AP = CO x PVR
AP = Arterial Pressure
CO = Cardiac Output
PVR = Peripheral Vascular Resistance
CO = Heart Rate (HR) x Stroke Volume (SV)
?
Is the volume of blood expelled from the ventricles w/each beat (SV) multiplied by bpm (HR)
CO
?
Is the resistance to the flow of blood determined by the tone of the vascular musculature, the diameter of blood vessels; whether they are dilated or constricted will effect BP
PVR
An increase in CO or PVR will increase BP
CO = ? x ?
Heart rate, contractility
Blood volume
Venous blood return to heart
PVR
> Arterial constriction
HR x Stroke Volume
Mean arterial pressure (MAP)
MAP = DP + 1/3 (SP - DP)
- A minimum MAP of ___ mmHg is required to perfuse vital organs
60
Autoregulation of BP - Compensatory mechanisms to maintain homeostasis
- Sympathetic baroreceptors
- Regulation of fluid volume
- Renin-Angiotensin System, aldosterone
- Vascular autoregulation
- ?
Are pressure-sensitive nerve endings located in the aorta, left ventricle, and carotid sinus
Slow HR and dilate vessels when BP elevated; increase HR and constrict blood vessels when BP is low
Baroreceptors
__ receptors in blood vessels cause vasoconstriction - increases PR
Alpha
__ receptors in heart stimulate increase in HR - increase in CO
Beta
Beta
Respond to ___ (increase HR and decrease bronchospasm) and beta blockers (decrease HR)
> Increases rate and force of heart
> Relaxation of bronchial muscles
epinephrine
Alpha
Responds to ___
Causes increased PVR, dilation of pupils, contraction of pilomotor muscles (goose bumps)
norepinephrine
- Regulation of Fluid Volume
Excess sodium or water increases CO & BP
Kidneys will diurese the extra volume and sodium
If BP dropping, kidneys will reabsorb sodium and water to increase BP
- Renin-Angiotensin System
A) Decreased blood volume - the body senses a decreased BP