Cheatography
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Bio class unit 8 circulatory system
This is a draft cheat sheet. It is a work in progress and is not finished yet.
circulatory system
Brings materials directly to/from cells brings nutrients, Oxygen to cells, removes CO2/wastes from cells, delivers hormones to cells |
Open vs Closed
Open System- A circulatory system in which fluid is pumped through open-ended vessels and bathes the tissues and organs directly. In an animal with an open circulatory system, blood and interstitial fluid are the same. |
Closed System- A circulatory system in which blood is confined to vessels and is kept separate from the interstitial fluid |
Single vs Double
Single circulation- A circulatory system with a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart |
Double circulation- A circulatory system with separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit; ensures vigorous blood flow to all organs. |
A double circulation is more efficient than a single circulation because there are two pumps, one from each side of the heart as the blood goes through the circut. Because there is an additional pump, the blood gets around faster. |
Pulmonary/Systemic Circut
Pulmonary Circut- The branch of the circulatory system that supplies the lungs. |
-> right atrium -> tricuspid valve-> right ventricle -> pulmonary valve -> pulmonary arteries -> lung capillaries -> pulmonary veins -> left atrium -> |
Systemic Circut- The branch of the circulatory system that supplies oxygen-rich blood to, and carries oxygen-poor blood away from, organs and tissues in the body. |
-> left atrium -> mitral valve -> left ventricle -> aortic valve -> aorta -> arteries -> arterioles -> body capillaries -> venules ->veins -> superior/inferior vena cava -> right atrium -> |
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Parts of the heart
Atrium (left/right) - collects blood returning to heart; pumps to ventricles. Thin-walled |
Ventricle (left/right) - pumps blood out of heart. Thick-walled, muscular |
Arteries – carry blood AWAY from heart Arteries – Thick-walled, muscular - Blood under high pressure - Largest artery: aorta |
Arterioles- between artery and capillary bed |
Precapillary sphincters - open/close to increase/decrease blood flow to capillary beds in particular regions |
Capillaries- allow for exchange of materials – microscopic vessels with thin, porous walls - Net diffusion of substances: capillaries → interstitial fluid |
Veins – carry blood BACK TO heart - Less muscle: lower pressure - Skeletal muscle assists blood flow - Contain valves - 2 major veins returning to right atrium: superior and inferior vena cava |
Venules – connect capillary bed and veins |
Valves
Valves prevent the backward flow of blood |
Atrioventricular (AV) valves - |
Between atrium and ventricle | tricuspid valve: right | mitral valve: left |
Semilunar valves - |
Between ventricles and vessels | pulmonary: to pulmonary arteries (from R) | aortic: to aorta (from L) |
2 phases
Systole |
Diastole |
heart contracting |
heart resting |
Systolic pressure – pressure on artery walls when ventricles contract |
Diastolic pressure – pressure on artery walls when heart relaxed |
AV valves:open |
semilunar valves:open |
semilunar valves:closed |
AV valves:closed |
Heart murmur - a defect in one or more heart valves that permits a backflow of blood and reduces the cardiac output (volume pumped/minute) |
Blood pressure = systolic pressure/diastolic pressure |
Hypertension – a serious cardiovascular problem in which blood pressure is persistent at or above 140 systolic and/or 90 diastolic |
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Regulation of Heartbeat
Pacemaker (sinoatrial or SA node) |
Atrioventricular or AV node |
cells that set rate of heart contraction – self-starting |
spread electrical impulse to ventricles |
In right atrium | Electrical impulse to atria |
Between atria | Electrical impulse to ventricles |
Electrocardiogram (EKG) – detects electrical currents; graphed against time |
Automated External Defibrillator (AED) - Shocks the heart and resets SA node |
Pacemaker - Small battery-powered device that helps the heart beat in a regular rhythm |
Chart
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Capillaries |
Arteries |
Veins |
Carry blood from: |
Arteries |
Heart |
Capillaries |
Carry blood to: |
Veins |
Capillaries |
Heart |
Thickness |
Thin |
Thick |
In-between |
Valves? |
No |
No |
Yes |
Cellular Elements of Blood:
Red Blood Cells - Transport O2, some CO2 using hemoglobin |
White Blood Cells - Defense and immunity; fights infections |
Platelets - A pinched-off cytoplasmic fragment of a bone marrow cell. Platelets circulate in the blood and are important in blood clotting. |
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