Term
Why do complex organisms require a cardiovascular system? |
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Definition
They cannot rely on simple diffusion alone to provide the cells with enough nutrition |
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Term
What are the three functions of the CVS? |
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Definition
Homeostasis, Flow of blood and the transport of hormones |
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Term
What are the two circulatory systems? |
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Definition
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Term
What is the sytemic system responsible for? |
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Definition
Pumping blood round the body |
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Term
WHat is the pulmonary system responsible for? |
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Definition
Pumping blood to and from the lungs |
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Term
Which system pumps blood at a high pressure? |
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Definition
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Term
Which system pumps blood at a low pressure? |
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Definition
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Term
What are the four blood vessels fo the CVS? |
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Definition
Arteries, Arterioles, Capillaries and Veins |
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Term
Which blood vessel has a high pressure? |
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Definition
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Term
Which blood vessel has the highest resistance? |
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Definition
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Term
Which blood vessel has the lowest pressure? |
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Definition
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Term
Which blood vessel has the thinest diffusion distance? |
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Definition
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Term
How is flow through a system generated? |
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Definition
From a high pressure to a low pressure |
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Term
What creates blood pressure? |
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Definition
The pumping mechanism of the heart |
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Term
In which blood vessel is the greatest fall in pressure? |
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Definition
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Term
Why does there need to be a sudden drop in blood pressure? |
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Definition
So that the capillaries do not burst under a high blood pressure |
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Term
What is systolic blood pressure? |
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Definition
The maximum blood pressure of the system at that time |
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Term
What is diastolic blood pressure? |
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Definition
The minimum blood pressure of the system at that time |
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Term
What is the pressure gradient equation? |
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Definition
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Term
In the pressure gradient equation what does PD stand for? |
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Definition
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Term
In the pressure gradient equation what does P1 stand for? |
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Definition
Pressure at the artey end |
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Term
In the pressure gradient equation what does P2 stand for? |
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Definition
Pressure at the venous end |
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Term
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Definition
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Term
In Darcy's Law what does Q stand for? |
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Definition
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Term
In Darcy's Law what does P stand for? |
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Definition
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Term
In Darcy's Law what does R stand for? |
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Definition
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Term
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Definition
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Term
In Poiseuilles Law what does Q stand for? |
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Definition
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Term
In Poiseuilles Law what does DP stand for? |
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Definition
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Term
In Poiseuilles Law what does r stand for? |
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Definition
Radius of the blood vessel |
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Term
In Poiseuilles Law what does L stand for? |
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Definition
Length of the blood vessel |
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Term
In Poiseuilles Law what does n (eta) stand for? |
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Definition
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Term
What and why is the most important factor in Poiseuilles Law? |
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Definition
Radius because it changes the most and is affected by the power of four |
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Term
What is the blood velocity equation? |
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Definition
V = Flow/ Cross Sectional Area |
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Term
In which blood vessel is velocity at its lowest? |
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Definition
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Term
In which blood vessel is cross sectional area at its highest? |
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Definition
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Term
Which side of the heart is recieving from pulmonary and delivering to systemic? |
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Definition
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Term
Which side of the heart is recieving from systemic and delivering to pulmonary? |
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Definition
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Term
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Definition
The volume of blood pumped by one ventricle |
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Term
What is the average stroke volume? |
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Definition
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Term
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Definition
The total volume of blood pumped out by the heart in one minute |
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Term
How do you work out cardiac output? |
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Definition
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Term
What does CO mean in the cardaic output equation? |
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Definition
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Term
What does HR mean in the cardaic output equation? |
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Definition
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Term
What does SV mean in the cardaic output equation? |
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Definition
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Term
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Definition
The amount of blood returning to the heart in one minute |
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Term
Under steady condition Venous return equals what? |
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Definition
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Term
What are the two types of valves? |
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Definition
Semi-lunar and atrioventricular |
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Term
What produces the sounds of the heart? |
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Definition
The closing of the valves |
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Term
What causes the first sound produced by the heart? |
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Definition
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Term
What causes the second sound produced by the heart? |
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Definition
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Term
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Definition
Causes it's own contractions due to pacemakers independant of the brain |
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Term
What are the two types of mycoytes? |
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Definition
Conductive and Contractive |
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Term
Outline the electronic mechanism of a heart contraction? |
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Definition
1. SAN send a wave of excitation across the atria causing them to contract 2. SAN impulse reaches AVN which causes another wave of excitation to travel down the bundle of HIS to the purkinje branches and finally up the purkinje fibres of the ventricle walls causing them to contract 3. There is a phase of no electronic activity where the heart refils |
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Term
How does the SAN impulse not spread to the ventricles? |
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Definition
There is a band of unconductive tissue that seperates the atriums from the ventricles |
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Term
Outline the action potential mechanism of a pacemaker signal? |
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Definition
1. -60mV Na+ voltage gated ion channels open 2. -40mV Ca2+ voltage gated ion channels open 3. 18mV Na+ and Ca2+ voltage gated ion channels shut and K+ voltage gated ion channels open 4. -60mV K+ voltage gated ion channels close |
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Term
Which is the fastest pacemaker? |
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Definition
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Term
How does the SAN control the pace of the AVN? |
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Definition
How fast and frequent the signal is sent by the SAN directly effects how fast and frequent the signal of the AVN is sent |
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Term
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Definition
The decrease in Ca2+ ions after the plateu of the action potential that causes the voltage to drop due to the Ca2+ ion acting as a releaser of Ca2+ from the sarcoplasmic reticulum |
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Term
How does a cardiac contraction differ from a skeletal contraction? |
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Definition
No refractory period in cardiac and no tetany |
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Term
What is an electrocardiogram? |
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Definition
A machine that measures the electrical activity of the pacemakers in the heart |
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Term
What does the P wave show? |
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Definition
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Term
What does teh QRS complex show? |
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Definition
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Term
What does the T wave show? |
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Definition
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Term
WHy is atrial repolarisation not shown on an ECG? |
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Definition
It is masked by the intensity of the QRS complex |
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Term
Outline the mechanism of the cardiac cycle? |
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Definition
1. Ventricles fill 2. Atrial contraction 3. Ventrcile contraction 4. Ventricle ejection 5. Ventricle relaxation |
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Term
What is a phonocardiogram? |
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Definition
A machine that records the pressure in the different chambers of the heart |
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Term
What is considered normal blood pressure? |
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Definition
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