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32 Cards in this Set
- Front
- Back
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Arteries
Veins Capillaries |
Carry blood from the heart
Carry blood towards the heart Carry blood between arteries and veins |
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Open Systems
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Found in molluscs and all arthropods
Circulatory fluid -flows out of open-ended vessels & is sometimes located in open spaces among body. --no distinction b/t blood & interstitial fluid |
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Closed Systems
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found in all other organisms w/ circ. systems
Circulatory fluid-blood, always in vessels or heart circulation of blood in heart, arteries, capillaries, & veins |
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Pulmonary Circuit
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Carries blood between heart and lungs
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Systemic Circuit
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Carries blood between heart and rest of body
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Pulmonary Circuit
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Vena Cava, R atrium, R ventricle, Pulmonary Trunk, L & R Pulmonary valve, L & R lung capillaries, L & R pulmonary valves, left atrium, left ventricle, aorta, rest of the body
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Systemic Circuit part 2
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From aorta to, arteries, arteioles, capillaries, venules, veins, to each vena cava
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Structures of the heart
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Atria- Receives blood
Ventricles- Pump blood out of heart Valves- Prevent backflow |
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Diastole
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Relaxation Phase
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Systole
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Contraction Phase
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Cardiac Cycle
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1) the heart is relaxed. Blood flows into the atria,then the ventricles.
2) The atria contracts. Ventricles completely fill with blood. 3) The ventricles contract. This closes AV valves & opens semilunar valves. Blood leaves ventricles. Blood begins to flow relaxed atria. 4) Ventricles relax, backflow of blood closes semilunar valves. |
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Electrical events in the heart
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All cardiac muscle cells can contract & relax on their own.
Certain cells initiate & distribute electrical signals that coordinate the contraction & relaxation of the cardiac cycle |
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SA Node
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Initiates electrical impulses that set rate of heart impulses then spread through atria.
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AV Node
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Point of contraction between atria and ventricles.
Slows down impulses so atria can empty & ventricles fill up. |
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Specialized muscle fibers
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Distribute impulses throughout ventricles
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Blood Pressure
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High in arteries
Low in veins |
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Artery Structure
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Heart contractions move blood into arteries
Muscular artery walls bulge & recoil to move blood into arterioles & capillaries |
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Capillaries
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-blood moves through b/c of pres. gradient
(hi at arteriole end, low at venule end) -low flow velocity b/c of hi cross- sectional area (facilitates material exchange) |
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Capillaries 2
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- not all capillaries carry blood at all times
(except in heart, brain, liver, & kidneys) --smooth muscle in arteriole walls regulates how much blood gets into capillaries of various body parts -smooth muscle around capillaries (precapillary sphincters) can control how much blood is carried through a set of capillaries -allows blood supply to be diverted to areas that need it most at any given time |
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Capillaries 3
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- MATERIAL EXCHANGE BETWEEN CAPILLARIES & INTERSITIAL FLUID THAT SURROUNDS BODY CELLS
-CO2 & O2 move in & out of capillaries by simple diffusion -proteins (& other large molec.) move by exocytosis/endocytosis -white blood cells, ions, sugars, H2O & other small molec. move b/t spaces around epithelial cells |
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Vein Structure
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-thinner-walled than arteries
(flaccid, less connective tissue & smooth muscle) -Wider Lumen, far from pump, large volume of blood, very low pressure |
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Skeletal Muscle
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-valves allow blood to move in only 1 direction
(for both smooth & skeletal muscle contractions -skeletal muscle contracts squeezes nearby veins |
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Composition of Blood
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-55% Plasma
-Mostly H20 -Functions of Plasma: -transports nutrients (such as glucose), wastes, CO2, ions, & hormones to & from cells -Carries proteins (antibodies) involved in fighting infection & proteins involved in blood clotting --Assists in stabilizing body’s pH, temp., & solute/solvent balance |
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Cellular Elements of Blood
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-RBC, WBC, and platelets
-Formed in bone marrow |
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Red Blood Cells
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Contain hemoglobin
Transport O2 Lose organelles as they mature Live 3-4 months |
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White Blood Cells
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Kills foreign micro-organisms
Many located in interstitual fluid and lymphatic system |
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Platelets
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Thrombocytes
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Lymphatic System
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lymph: interstitial fluid that is collected & transported by lymph vessels
-Fluid leaks out of blood capillary -Fluid enters a lymph vessel |
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Lymphatic System 2
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-returns H2O & other materials that leak out of capillaries (but not used by cells) back to blood
-transports lipids absorbed from small intestine -brings foreign micro-organisms & their toxins to lymph nodes where they can be destroyed |
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Lymphatic System Organs
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-Bone Marrow: site of WBC production
-Thymus: site of WBC maturity & differentiation -Lymph Nodes; small round organs, packed with WBC -Spleen; recycles old RBC, stores blood cells and platelets, fights infection |
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Lymph Transport
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Flap-like openings at ends of lymph capillaries take in interstitial fluid
-Lymph capillaries merge into large lymph vessels. -one-way valves in lymph vessels prevent backflow -lymph vessels move lymph into & out of lymph nodes (which contain WBCs) |
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Lymph Transport 2
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-lymph vessels take
lymph to lymphatic ducts -these drain lymph into subclavian veins of circulatory system |
