Term
| Overall Function of Circulatory System |
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Definition
nutrients & oxygen transport
waste removal
blood is transport medium
blood needs to pass by all cells of body |
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Term
| 3 parts of Circulatory System |
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Definition
Heart
Blood Vessels
Blood |
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Term
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Definition
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Term
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Definition
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Term
| Circulatory System has 2 Separate Loops which are: |
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Definition
Pulmonary: blood moving between HEART & LUNGS
Systemic: blood moving between HEART & BODY |
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Term
| Right side _____ blood from _____ circuit and pumps it to _____ circuit to be oxygenated. |
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Definition
RECIEVES
SYSTEMIC
PULMONARY |
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Term
| Left Side of heart recieves blood from ______ circuit and pump it to _____ circuit so body gets oxygenated blood. |
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Definition
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Term
| Each Side/Half of heart divided into TWO CHAMBERS called... |
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Definition
ATRIUM: upper chamber, receives blood & transfers to
VENTRICLE: lower chamber, pumps blood out of heart |
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Term
| What are blood vessels that RETURN BLOOD TO HEART? |
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Definition
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Term
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Definition
| brings blood from systemic circuit to HEART |
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Term
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Definition
| Bring blood from LUNGS TO HEART |
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Term
| What are blood vessels that carry blood AWAY FROM HEART called? |
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Definition
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Term
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Definition
| carries blood from heart to systemic circuit |
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Term
| Pulmonary Artery does what? |
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Definition
brings blood from heart to lungs
[image] |
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Term
| What amount of blood goes thru the pulmonary circulation? |
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Definition
| ALL blood flows thru lungs |
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Term
| Do both sides pump equal amounts of blood? |
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Definition
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Term
| Pulmonary circulation is ___ pressure ____ resistance. |
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Definition
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Term
| systemic pressure is ___ pressure ____ resistance. |
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Definition
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Term
| what side of the heart has thicker heart muscle? |
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Definition
| the left, because it must pump with more pressure and force to systemic circulation |
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Term
| Does blood flow in more than one direction thru body? |
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Definition
| NO, One-way Valves prevent backflow |
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Term
| Forward pressure causes valves to _____ |
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Definition
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Term
| Backward pressure causes valves to _____ |
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Definition
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Term
| Atrioventricular Valves (AV) valves are located where? |
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Definition
| on each side of heart between atrium & ventricle |
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Term
| Aortic Valve located where? |
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Definition
junction of left ventricle & aorta
[image] |
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Term
| Pulmonary Valve located where? |
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Definition
junction of right ventricle & pulmonary artery
[image]
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Term
| Are there valves between atria and veins? |
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Definition
| No, backflow isnt a problem because atrial pressure not higher than venous pressure & entry sites compressed during atrial contraction |
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Term
| Structure of Cardiac Muscle (Myocardium) |
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Definition
Cardiac Muscle Fibers interlaced & arranged spirally around circumfrence of heart
during ventricular contractions, diameter reduced apex pulled upwards ---> wringing of blood from chambers |
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Term
| What interconnects Cardiac Muscle cells? |
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Definition
1. adjacent cells joined end to end
2. joining points called intercalated discs made up of gap junctions and desmosomes
*no gap junctions between atria & ventricle cells
[image]
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Term
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Definition
hold cells together under mechanical stress
[image]
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Term
| Function of Contractile Cells? |
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Definition
| do mechanical work for pumping (99% myocardial cells) |
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Term
| Function of Autorhythmic Cells? |
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Definition
| Specialized for initiating and conducting action potentials (1% myocardial cells) |
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Term
| AUTORHYTHMIC CELL ACTION POTENTIAL STEPS |
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Definition
1. initial phase of slow depolarization caused by decrease in passive outward leak of K+ by K+ channels closing in membrane and increase of Na+ leaking into cell, drifts toward threshold
2. eventually, a voltage is reached that allows voltage gated Ca+ channels T-type to open, Ca+ enters cell, causing to reach threshold
3. At threshold, voltage gated CA+ L-type channels open, Ca+ RUSHES in, causing rapid depolarization and ACTION POTENTIAL
4. Membrane repolarizes by exit of K+ thru K+ channels |
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Term
| CONTRACTILE CELL ACTION POTENTIALS |
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Definition
When AP reaches a contractile cardiac cell via gap junction Na+ channels open wide & Na+ rushes into the cell = depolarization of membrane
Na+ channels close around 30mv
Depolarization of membrane causes slow Ca+ channels to open, Ca+ moves slowly into cell & K+ channels inactivate
repolarization Ca+ channels close, K+ channels open and K+ moves out of cell |
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Term
| Why is there a long refractory period of cardiac AP & Muscle contraction? |
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Definition
| Prevents cardiac muscle tetanus, tetanus in cardiac muscle would cause death! |
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Term
| What is the pacemaker of the heart? |
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Definition
Sinoatrial Node (SA NODE)
sets AP pace of whole heart, located in right atrial wall near opening of vena cava |
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Term
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Definition
atrioventricular node
helps spread AP to ventricle from rt. atrium |
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Term
| What is the Bundle of His? |
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Definition
tract of specialized cells originates in AV node, travels around tip of ventricles
helps spread AP to rest of ventricles |
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Term
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Definition
small terminal fibers extending from Bundle of His
helps spread AP to rest of ventricles |
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Term
| Spread of Action Potential in Heart |
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Definition
| SA node ---> AV node ----> Bundle of His ---> Purkinje Fibers |
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Term
| Do atria contract simultaneously? |
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Definition
| Yes, interatrial pathway extends from SA node to left atrium, AP moves to l.atrium |
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Term
| Why does Action Potential travel slowly through AV node? |
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Definition
AV nodal delay = 0.1 sec
allows time for complete ventricular filling, enough time for atria to contract and empty contents into ventricles |
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Term
| What does an ECG represent? |
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Definition
change in voltage detected by electrodes that reach body surface, NOT the actual action potential
reads overall spread of electrical activity thru heart, not a single AP
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Term
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Definition
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Term
| What is happening during the P -wave of ECG? |
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Definition
Atrial Depolarization
[image] |
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Term
| What is happening between P - R segment? |
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Definition
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Term
| What is happening during QRS complex? |
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Definition
ventricular depolarization
AND
atrial repolarization (relax)
[image] |
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Term
| what is happening between S - T segment of ECG? |
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Definition
Ventricles are contracting & emptying
[image] |
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Term
| what is happening during T-Wave? |
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Definition
Ventricles are repolarizing
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Term
| What is happening between T -P interval? |
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Definition
| Ventricles relaxing & passively filling |
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