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36 Cards in this Set
- Front
- Back
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What are the components of blood?
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Plasma, Red Blood Cells, platelets, White Blood Cells
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What is plasma?
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Definition: fluid matrix found in blood vessels.
Composed of ions (Na, K, Ca, Mg, HCO3) and nutrients (proteins, sugars, fats, lipoproteins) |
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What is the total blood volume in an adult human?
How much of that volume is plasma? |
Total blood volume of adults is 5 liters. 50 to 60% of that total volume is plasma.
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What is interstitial fluid?
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Fluid from the plasma that has left the blood vessels and surrounds the cells.
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How does fluid move in and out of vessels?
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Through cell junctions.
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What are stem cells?
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Stem cells are constantly dividing undifferentiated cells that can form several different cell types with unique functions.
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Describe Red Blood Cells.
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Also known as erythrocytes.
Biconcave, flexible cells packed with hemoglobin. Each RBC a life span of about 120 days. Anucleated when mature in mammals (except for fish and fowl) |
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Function of RBCs.
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Specialized to transport oxygen (respiratory gases).
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What is erythropoitin?
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Hormone that controls RBC production.
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What is Anemia?
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Condition characterized by a low level of RBCs which yields a low oxygen carrying capacity. Also indicative of a low Iron (Fe) level and tiredness.
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Describe Platelets.
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Cell fragments of a megakaryocyte without cell organelles but packed with enzymes and chemicals.
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Function of Platelets.
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Prevent excess blood loss by sealing leaks in blood vessels and initiating blood clotting.
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Describe blood clotting.
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Platelets initiate clotting. An inactive circulating enzyme (prothrombin) is converted to its active form (thrombin). Thrombin splits molecules of fibrinogen, forming insoluble threads of fibrin. Fibrin threads provide a meshwork that binds platelets, seals the vessel and provides a scaffold for the formation of scar tissue.
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Describe the characteristics of white blood cells.
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AKA leukocytes.
Cells of the immune system (defense, no oxygen exchange) Also found in the lymph as well as the plasma and can be transported in the lymphatic system. |
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What are the two major groups of immune cells?
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1. Polymorhonuclear cells (PMN) have more than one nucleus, react to non-specific antigens, and are responsible for allergic responses.
2. Lymphocytes (B-cells and T-Cells) have antigen specific responses, programmed to destroy a particular antigen. |
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What is an antigen?
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A foreign substance such as bacteria or a virus.
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Order of blood vessels
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Artery>>Arteriole>>Capillary>>Venule>>Veins
Blood leaves the heart in arteries and is distributed throughout the body tissues in arterioles. Arterioles feed capillary beds. Gas exchange occurs in capillaries. Blood leaving the capillaries collects in venules which empty into veins. Veins bring the blood back to the heart. |
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What moves the blood throughout the body?
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Blood is propelled forward by skeletal muscle and the blood coming from behind the capillaries into the venules.
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Define Blood pressure. How is it established? What is normal BP?
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Blood pressure refers to the changing pressure in the arteries as the blood is pushed through. It is established by the contraction of the ventricles.
Normal BP=120/80 mm Hg |
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Define systole and dystole.
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Systole: refers to the pressure generated when the ventricles are contracting.
Dystole: refers to the pressure when the ventricles are relaxing. |
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What is atherosclerosis?
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The collection of cholesterol and fat deposits in the arteries. Can cause high blood pressure because the arteries are resistant (clogged).
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Describe the velocity and pressure of blood flow from the arteries to the capillary beds to the veins.
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Starting at the arteries, the blood has a high velocity and pressure. The velocity and pressure both decrease in the capillary beds because the same blood volume is distributed over a larger surface area. Once is gets to the veins, the velocity increases but the pressure stays low.
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What is the function of arteriole sphincters?
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Arteriole sphincters control the blood flow in and out of capillaries.
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Describe blood pressure throughout the capillaries.
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BP is high at the beginning of the capillary and low at the end of the capillary.
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What creates osmotic pressure in capillaries?
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The build up of solutes, etc, concentrating the blood in capillary beds creates osmotic pressure.
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What causes swelling?
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If the blood pressure is too low, lots of blood collects in the capillary bed and plasma then becomes interstitial fluid which causes swelling.
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function of atrioventricular valves
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Atrioventricular valves between the atria and ventricles prevent backflow into the atria when the ventricles contract.
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What prevents backflow into the ventricles when the ventricles relax?
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The pulmonary valve and aortic valve prevent backflow into the ventricles when the ventricles relax.
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what is artery pulsation
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the surge of blood during systole.
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what is the sinoatrial node
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- the primary pacemaker of the heart
- located at the juncture of the superior vena cava and the right atrium. |
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what part of the nervous system controls heart rate?
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The autonomic nervous system controls heart rate by influencing the pacemaker cells
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What neurotransmitters effect the heart rate?
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- acetylcholine (parasympathetic nerve endings) slows heart rate
- norepinephrine (sympathetic nerve endings) increases the heart rate |
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What fibers are abundant in arteries
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elastin and muscle fibers
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How does each tissue regulate its own blood flow?
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autoregulatory mechanisms
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how does low O2 and high CO2 levels affect the smooth muscle and the blood flow into the capillary beds?
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- smooth muscle relaxes
- blood flow into capillary beds increases |
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How does blood pressure at the beginning of the capillaries affect fluid in the capillary?
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- BP pushes fluid out of the capillary
- ↑concentration of substances in the capillary - ↑osmotic pressure at the end of capillary and draws fluid back in |
