Cardiovascular System - Intro Flashcards
What are the components of the cardiovascular system?
Right heart
Pulmonary Vessels
Left Heart
Elastic Arteries
Muscular Arteries
Arterioles
Capillaries
Venous vessels
Define: Right Heart
volume pump
delivers high volumes of blood at low pressures
supplies blood to lungs
Define: Pulmonary Vessels
Function in blood - gas exchange and serve as volume reservoirs
Define: Left Heart
pressure pump
the energy source for the circulatory system
supplies blood to whole body
Define: Elastic Arteries
(aorta, etc.)
their elastic behavior allows them to serve as a “surge pump”
Energy is stored in the elastic fibers during the contraction phase (systole) and is released during the relaxation phase (diastole)
Define: Muscular Arteries
function as low resistance conduits that rapidly deliver blood to the tissues
Define: Arterioles
Collectively termed “resistance vessels”
serve as variable resistors that regulate the flow of blood into capillary beds
high pressure → low volume
Define: Capillaries
One cell layer separates blood from tissue space
site of nutrient and waste exchange
Define: Venous Vessels
Serve as a volume reservoir
these vessels function in both the storage and mobilization of blood
Low pressure → high volume
What are the two circulations that make up the cardiovascular system?
Pulmonary Circulation
Systemic Circulation
Define: Pulmonary circulation
Blood flow through the lungs
Define: Systemic Circulation
Blood flow through all organs of the body except the lungs
What are the valves of the heart?
Tricuspid - papillary muscles; chordae tendinae
Pulmonic
Mitral - papillary muscles; chordae tendinae
Aortic Valve
What is the valve motion in?
Diastole vs. Systole
What determines Myocardial wall thickness?
Chamber pressures
angle of contractile fiber orientation
Epicardium vs. endocardium
What are the conduction pathways in the heart?
Sinoatrial (SA) node
Atrial Internodal pathways
Atrioventricular (AV) node
Common Bundle of His
Right and Left bundle branches
Purkinje fibers
What makes up the coronary vasculature?
Anatomical distribution
Structure of coronary artery wall
endothelial cell function
How does the Sympathetic Nervous system innervate the heart?
Cardiac sympathetic fibers originate in the intermediolateral cell column of the spinal cord (T1 - T5)
preganglionic fibers can ascend to the stellate, superior, or middle cervical ganglion to synapse or they can synapse at the level of origin in the paravertabral ganglia
postganglionic sympathetic fibers are distributed to the cardiac chambers as an epicardial plexus
What is the distribution/function of postganglionic sympathetic fibers in the heart?
Fibers distributed to the left side primarily affect the fore of contraction of the heart (contractility)
Fibers distributed to the right side affect heart rate (SA node) more than force of contraction
What mediates the effect of sympathetic fibers on the heart?
Beta - adrenergic receptors
How does the Parasympathetic nervous system innervate the heart?
preganglionic fibers are contained in the vagus nerve and synapse with postganglionic fibers within the heart
parasympathetic stimulation reduces force of contraction and heart rate
right vagus primarily innervates the SA node
left vagus primarily innervates the AV node
Where does the right vagus innervate?
SA node
Where does the left vagus innervate?
AV node
The cardiac output of the right heart must ___ the cardiac output of the left heart
EQUAL
What is the cardiovascular circuit?
pumps in series
resistance circuits in parallel
What is the primary site of vascular resistance?
Arterioles
Where is flow velocity most rapid?
at the root of the aorta
Where is the flow velocity slowest?
in the capillaries
What kind of cell lines the cardiovascular system?
endothelial cell
What is the number 1 killer of adults in the USA?
Cardiovascular Disease (CVD)
What heath issues (related to the cardiovascular system) can increase with age?
Prevalence of CVD
Prevalence of HBP
If the left ventricular output is 60ml/beat and the right ventricular output is 0.1% greater, by how much would the pulmonary blood volume increase over 1 hr, if the heart rate is 75 beats/min?
60 X .001 = 0.06 X 75 = 4.5 ml X 60 = 270 ml/hr
Why is it critical for the cardiac output of the left and right ventricles to be equal?
If they don’t pump equal volumes, blood can accumulate in the ventricles and cause pulmonary edema and other issues
Define: Cardiac tamponade
Excess fluid in pericardium that build pressure against the heart
Why does the left atrium have more muscle mass than the right atrium?
So it can generate a higher pressure when it contracts
Define: Diastole
The filling phase
mitral and tricuspid valves are open
pulmonic valve is closed
Define: Systole
The contractile phase
Mitral and Tricuspid Valves closed
Pulmonic vale open
What is the average pressure of the right atrium?
3 mm Hg
What is the average pressure of the right ventricle?
25 mm Hg
What is the average pressure of the left atrium?
8 mmHg
What is the average pressure of the left ventricle?
130 mmHg
What is the average pressure of the pulmonary capillary wedge?
9 mm Hg
What is the pulmonary capillary wedge?
measure of the left atrial pressure
How is the pulmonary capillary wedge measured?
a catheter is inserted through the right atrium through to the pulmonary artery
What does the Endothelium Derived Relaxing Factor (EDRF) do?
Releases nitric oxide and causes blood vessels to relax
Where is total blood volume greatest in the cardiovascular system?
The venous side of the system
How do you calculate cardiac output (CO)?
CO = Heart Rate (HR) X Stroke Volume (SV)
What does the resistance in the arterioles determine?
How much blood flow goes to a part of the body
