Cardiovascular Health Flashcards
The pulmonary system is a ____________ pressure system and the systemic system is a __________ pressure system.
low ; high
Damage to the endothelial cells such as plaque buildup ….what will happen to the blood pressure?
It will increase the blood pressure because there is more resistance
What prevents vasoconstriction ?
Calcium channel blockers
Blood pressure =
cardiac output x systemic vascular resistance
cardiac output =
heart rate x stroke volume
heart rate is the
frequency with which blood is ejected from the heart
Stroke volume consists of
preload and afterload
What is preload?
The volume of blood at the end of diastole
What is afterload?
(Resistance) The amount of pressure the heart must develop during the period of isovolumetric contract to overcome the pressure in the aorta and pulmonary artery
What happens to the blood pressure if you decrease preload?
If you decrease preload, you are decreasing afterload, thereby decreasing blood pressure
Mechanisms of BP regulation
autonomic nervous system
- short term regulation
RAAS (Renin-angiotensin-aldosterone system)
- longer term regulation
Kidneys - control blood volume as well as the RAAS
- a long term mechanism of blood pressure control
If baroceptors are not responsive what is a potential complication ?
orthostatic hypertension
What is hemodynamics ?
The dynamics of blood flow
Factors governing the function of the Cardiovascular system
Volume
Pressure
Resistance
Flow
What are factors that determine resistance to blood flow ?
Blood viscosity, vessel radius and whether the vessels are aligned with each other in a series or parallel
How do arteries help control blood flow ?
They have a middle layer of smooth muscle that is connected to alpha receptors of the Sympathetic nervous system to regulate diameter. The diameter of the arteries can alter blood pressure
What organs require a large, continuous flow of blood?
The brain, the heart, the liver and the kidneys
The skin and skeletal muscle require varying flows dependent on exertion and needs
What vessels are very significant in determining systemic vascular resistance ?
Arterioles - they are the major resistance vessels for the circulatory system
Are veins a low pressure system or higher pressure ?
They are a very low pressure system -
Pressure in venules is ~10mm Hg and in the vena cava ~0 mmHg
How many cells thick are capillaries ?
A single endothelial cell
Calcium channel blockers within the smooth muscle of vessels prevent ______________
vasoconstriction
Tissue _____________ to a given organ is regulated on minute-to-minute basis in relation to ______________________.
blood flow; Tissue needs
Neural mechanisms regulate _____________ and ______________________ (BP) to support local mechanisms
Cardiac output; systemic vascular resistance
What are the role of factors in blood flow ?
Factors are released from an organ or the endothelium that acts on the smooth muscle to produce a vasoconstriction or vasodilation
Vasodilating substances
Nitric Oxide
Vasoconstricting Substances
Angiotensin II, Prostaglandins, Endothelins
An increase in preload increase _______________
Cardiac Output
Afterload
the resistance the left ventricle must overcome to circulate blood
It is increased in hypertension and vasoconstriction
Increased afterload =
increased cardiac workload
What are the primary actions of the angiotensin II polypeptide?
It stimulates vasoconstriction
and the release of aldosterone, both actions which raise the blood pressure
What does renin do ?
What causes the release of renin ?
Renin converts angiotensinogen into angiotensin 1.
Renin is released from the juxtaglomerular cells of the kidney in response to decline in blood pressure, blood volume, plasma sodium content or reduced renal perfusion pressure.
Factors that lower blood pressure turn the RAAS ____________ . Factors that lower blood pressure turn the RAAS ___________.
on; off
RAAS is a major factor in maintaining _______________ blood pressure in the presence of hemorrhage, dehydration or sodium depletion.
Blood pressure - True
Hypertensive urgency occurs when
systolic pressure is greater than 180 mm Hg and/or diastolic pressure is greater than 120 mmHg
Hypertensive emergency occurs when
systolic pressure is greater than 180 mm Hg with target organ damage and/or diastolic pressure is greater than 120 mm Hg with target organ damage
Modifiable risk factors for hypertension
stress, smoking, heavy alcohol consumption, diabetes, inactivity, unhealthy dietary habits, obesity, high sodium intake, low potassium, increased cholesterol levels.
Lifestyle modifications to combat hypertension
DASH diet, reduce sodium intake, consistent physical activity, reduce and keep a healthy weight, moderation of alcohol consumption
