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16 Cards in this Set
- Front
- Back
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What are the Purkinje fibers? What is their function? Where are they?
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-Conductive fibers in ventricular walls
-Action potential moves via gab junctions allowing a more unified and stronger contraction. |
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What is the atrioventricular node? Function?
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AV node- located between atria
-impulse passed from the SA node -slower to contract, creating a delay which allows the atria to finish their contraction and squeeze their contents into the ventricles before the ventricles begin to contract. -Contraction moves to the bundle of His, located between the ventricles connected by Purkinje fibers. |
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When does systole occur?
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When the ventricles contract
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When does diastole occur?
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Contraction of the atria.
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What is the function of the vagus nerve?
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-parasympathetic
-slows heart rate, increases digestive activity |
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What is the function of sinoatrial node?
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SA- specialized cardiac muscle cells located in the right atrium
-Spreads contractions via electrical synapses made from gap junctions -Vagus nerve (parasympathetic) slows the contraction -Causes atria to contract |
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What is the effect of epinephrine on arteries?
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-Causes arteries to narrow, vasoconstrictor
-Larger arteries have less smooth muscle to volume thus epinephrine has less effect on them. -med. arteries have more smooth muscle, thus epinephrine has larger effects |
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How does blood pressure change throughout the body?
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Increases near the heart decreases to its lowest at the capillaries
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What are the 4 methods for materials to cross the capillary walls?
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1.) pinocytosis
2.) diffusion through capillary cell membrane 3.) movement through pores in the cells called fenestrations 4.) movement through the space between the cells |
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What is the continuity equation for blood flow?
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Q=Av
-Velocity is greatest in arteries where cross sectional area is small -Velocity is lowest where cross sectional area is greatest. |
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How is carbon dioxide carried by the blood?
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1.) physical solution
2.) bicarbonate ion 3.) in carb amino compounds (with proteins) |
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What happens to the oxygen dissociation curve when p, (H+) and temp increase?
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The curve is shifted to the right. % saturation decreases.
Hemolgobins affinity for O2 decreases |
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When do problems with Rh factors occur?
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Rh- neg mom
1st birth Rh positive baby -mom has resistance to Rh+ from blood swapping 2nd birth Rh- mom with immune response attacks Rh+ baby |
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What blood type is the universal donor?
What blood type is the universal acceptor? |
Universal donor Type O makes no antigens has all antibodies
Universal acceptor-Type AB makes no antibodies |
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Describe cell mediated immunity?
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T-cells
mature in thymus, never make free antibodies, are tested against self antigens, circulated between blood and lymph, differentiate into helper T-cells, memory T-cells, suppressor T-cells, and killer T-cells Helper and Suppressor-activate B Memory-Similiar to memory B-cells Suppressor- neg feedback of immune system Killer-bind to antigen carrying cell and release perforin which punctures antigen carry cell Do NOT phagocytize cells -Fight cancer and attack transplant tissue |
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Describe humural/B-cell immunity:
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B-lymphocytes-mature in bone marrow and liver. Capable of making single type of antibody.
-Macrophages present antigenic determinants on their surfaces -B lymphocytes assisted by helper T. Differentiates into plasma cells and memory B-cells. Plasma cells begin synthesizing free antibodies *must attach to mast cells) antigen-antibody (marks antigen for phagocytosis)-mast-histamine Memory B-cells- stay in the body to synthesize antibodies later Humural Response- occurs for bacteria, fungi, parasitic protoxoans, viruses, and blood toxins |
