Term
| What are the circulatory systems used by invertebrates? |
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Definition
Gastrovascular - A body wall only two cells thick encloses a central vascular cavity, which serves both in digestion and distribution of substances throughout the body.
Open - Blood is circulatory fluid. Blood vessels distribute blood. Heart is the pump. General body fluid is Hemolymph
Closed - Blood is confined to vessels. Has chambered hearts. Blood vessels differentiate, and there exists circuit organization |
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Term
| How have cardiovascular systems diversified in vertebrates? |
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Definition
Fishes - Two chambered heart and single circuit of blood flow.
Amphibians - Three chambered heart and two circuits of blood flow: pumlocutaneous and systemic. Some mixing of oxygen-rich and oxygen-poor blood occurs in the single ventricle.
Reptiles (except birds) - have three-chambered hearts. However, a septum partially divides the single ventricle, further reducing mixing of oxygen-rich and poor blood.
Mammals and birds - have a four chambered heart that completely segregates oxygen-rich and poor blood. |
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Term
| Where do heart contractions originate? Why is this important during embryogenesis? |
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Definition
| Heart contractions originate at the Sinoatrial Node (aka pacemaker). This is important in embryogenesis because the heart needs to function before innervation. (clarify?) |
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Term
| How does the structure of the arteries, veins and capillaries fit their functions? |
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Definition
Arteries carry blood away from the heart to the organs throughout the body. Within organs, arteries branch into arterioles, small vessels that convey blood to the capillaries
Capillaries are microscopic vessels with very thin, porous walls. Networks are capillary beds. Across the thin walls of capillaries, chemicals are exchanged by diffusion between blood and interstitial fluid around the tissue cells.
Veins return blood to the heart |
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Term
| How does fluid move out of capillaries? How does it move back in to capillaries? |
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Definition
| Fluid moves out of capillaries via blood pressure. Fluid moves into capillaries by osmotic pressure. |
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Term
| What role does the lymphatic system play in circulation? |
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Definition
| part of the immune system, it returns lost fluid from the capillaries to circulation. |
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Term
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Definition
| is a general body fluid, there is no distinction between blood and interstitial fluid. |
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Term
| closed circulatory system |
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Definition
| In this system, blood is confined to vessels and is distinct from the interstitial fluid. |
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Term
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Definition
| In this system there is no distinction between blood and interstitial fluid, general body fluid is hemolymph. |
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Term
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Definition
| Causes heart contractions, sets the rate and timing at which all cardiac muscle cells contract. |
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