What is the driving force for blood in the circulatory system?
What is the most controlled variable in the circulatory system?
Arterial Blood Pressure
What is the force exerted against wall during contraction?
What is the force exerted against wall during relaxation?
What is the difference between the systolic and diastolic pressure?
- Pulse Pressure
- Normal: 30-40mmHg
What is the determinate of oxygen or tissue perfusion?
Mean Arterial Pressure: Average bp in systemic circulation
How do you determine the mean arterial pressure?
What is the determinate of blood pressure?
Cardiac output x Peripheral Vascular Resistance
What is cardiac output?
HR x SV
What is PVR?
Reflects tone of resistance vessels and the viscosity of blood.
What are the short-term reugulators of blood pressure?
- 1. Neural Mechanisms
- a. Intrinsic - for rapid and short-term reg
- b. Extrinsic - repsonse to pain, cold
- c. Higher neural centers- response due to mood
Mechanisms - Many
**The barorecptro reflex**
Epinephrine and Norepinephrine cause...
- Increase Blood Volume
- Reabsorbs Na and water in kidneys
Vasopressin (ADH) causes...
- reabsorption of Na and water by the kidneys
- (not excreted through urine)
Natriuretic peptides regulate....
- Na excretion
- Diuresis (increased uo)
- Vasodilation (decreased bp)
- and antagonism of the R-A-A system (so it vasodilates & decreases blood volume)
- -fluid and electrolyte balance
- - cardiorenal regulation
What is the long-term regulation of blood pressure and how does it work?
- Renal-Body fluid system (Renin-angiotensin-aldosterone)
- - kidneys response to changes in arterial pressure
- - Increases salt and water excretion
intermittent or sustained elevation of systolic &/OR diastolic BP
How do you determine someone has hypertension?
140/90 on three seperate occasions.
What type of HTN has an unknown cause?
Essential or primary
90% of cases
What type of HTN has a known cause?
What are some risk factors for developing HTN?
- Family Hx
- Gender: men<55, women > 75
- Diet: high-Na, sat fat; Low-K, Ca, Mg
What are the clinical manifestations of HTN?
- Usually asymptomatic.
- High: HR, BP, Bounding pulses
- Abnormal heart sounds
- Retinal changes in eye
What are some complications of HTN?
CAD, HF, angina, MI, CVD, PVD, Renal failure, retinopathy, left ventricular hypertrophy
How do you treat primary HTN?
- Step 1: Implement lifestyle changes (non-pharm)
- Step 2: Start Antihypertensive medications
How do you treat secondary HTN?
Treat the cause
What are compelling indicators of HTN?
- Heart failure
- Post MI
- High CVD risk
- Recurrent stroke prevention
What are some non-pharmacological methods of controlling HTN?
- Diet- restrict Na & fats
- Quit Smoking
- Limit ETOH
- Reduce stress
What is Malignant HTN and what can it lead to?
rapidly progressing diastolic (>140)
can lead to encephalopathy, organ dysfunction.
Considered an EMERGENCY - need IV agents