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71 Cards in this Set
- Front
- Back
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arteriole
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PRIMARY REGULATOR OF BLOOD FLOW.
-smallest arteries -branch into capillaries -have rim of smooth muscle bet. inner and outer walls. |
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capillary
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WHERE TRANSFER OF MOLECULES BETWEEN BLOOD AND TISSUE HAPPENS.
- smallest, thin walled vessels. - LARGEST SURFACE AREA between blood and body. |
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BLOOD VESSEL structure and function differences.
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arteriole- controls flow
capillary - exch. materials vein - blood storage, carry to heart venuole - carry CO2 & blood from tissues to venous syst. |
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vein
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thin walled vessels. carry blood back to hear from body. act as reservoirs. hold about 65% of total blood volume. No muscle layer.
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precapillary sphincters
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small rings of muscle - junction of arterioles and capillaries. regulate flow into capillaries. can reduce flow to zero.
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erythrocyte
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RED BLOOD CELL.
produced:red marrow. flat, disc shaped. no nucleus. most abundant element of blood - 45% (this % called hematocrit.) Transport CO2, O2, contain hemoglobin in membrane. |
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leukocyte
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WHITE BLOOD CELLS
defend against disease. formed in marrow. |
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Three general types of leukocytes
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Granulocytes
Lymphocytes Monocytes |
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Three types of granulocytes
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neutrophils
eosinophils basophils |
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what do lymphocytes do?
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immune processes, phagocytosis.
(engulf and kill invaders.) |
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platelet
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THROMBOCYTE
smallest element in blood. 2nd most numerous. shed to cytoplasm by megakaryocytes in marrow. important in CLOTTING.(make platelet PLUGS) |
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red bone marrow
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within spongy bone of long bones
produces erythrocytes (controlled by kidney hormone production - erythropoetin.) |
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hemoglobin
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four sub-unit globin protein molecule. carries oxygen in 4 hemes (iron)
15 grams / 100ml blood (<females.) oxygenated = oxyhemoglobin |
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macrophage
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langerhans cells. destroy foreign particles. engulf. resident in skin, provide protection for body.
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plasma proteins
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ALBUMIN contributes osmotic pressure.
(determines balance between interstitial fluid / plasma volume) carries fatty acids, etc. GLOBULIN - also carrier molecule, but antibody, involved in immune response. |
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erythropoietin
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hormone secreted by kidney - stimulates production of red blood cells by bone marrow.
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phagocyte
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part of immune system, phagocytosis important in killing invaders. these white blood cells engulf and kill bacteria.
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hematocrit
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% of RBC in whole blood.
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Rh factor
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blood antigen-antibody system first isolated in rhesus monkey.
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phagocytosis
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engulfment and destruction of foreign particles by phagocytic cells such as leukocytes.
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inflammation
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increased blood flow to area
accumulation of leukocytes increased capillary permeability chemical cascade: T-cells, histamines. 1. microphages begin phagocytosis 2. neutrophils 3. bone marrow produces more microphages |
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plasma
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carrying medium for blood cells and dissolved solutes, proteins, glucose, hormones, amino acids, Na+, K+, Cl-, HCO3-
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agglutination
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clumping of red blood cells without fibrin strands (i.e. not clotting) caused by antigen response with incorrect blood type mixture
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fibrinogen
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protein in plasma - when contact with enzyme thrombin, fibrin is created from fibrinogen, strands which cause clotting & become entangled with RBC's.
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prothrombin
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protein present in plasma, important in clotting, forms thrombin(enzymes which liberates fibrin from fibrinogen)
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baroreceptors
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pressure-sensitive nerve terminal or region that relays information to CNS
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flow
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ease with which blood is able to pass through the body: amount of pressure divided by amount of resistance. Higher resistance is caused by smaller vessel diameter or by longer vessels. Flow can be increased by greater pressure, but increased resistance can decrease flow.
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cardiac output
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total volume of blood pumped per minute
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resistance
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proportional to length, inversely proportional to diameter, resistance is 1/radius to the power of 4. (This means that small changes in radius lead to large changes in resistance.)
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venous return
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valves in veins
+ ancilliary muscles act as pumps w/valves. |
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systolic pressure
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HIGHEST pressure in aorta
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diastolic pressure
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LOWEST pressure in aorta
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mean arteriole pressure
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(i.e. relationship between cardiac output, peripheral resistance, and blood volume.)
Cardiac output x total peripheral resistance. |
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vasoconstriction
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diameter reduction of veins.
increases: peripheral resistance, therefore pressure. |
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vasodilation
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reduces TPR
increases flow increases volume increases cardiac output |
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reactive hyperemia
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vasodilation response to "oxygen dept" created by pressure. over-reaction of small vessels to compensate for period of oxygen deprivation. (causes redness in skin after pressure relieved.)
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colloid osmotic pressure
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back pressure caused by retention of large ions and proteins in capillaries as too large to filter or diffuse out. causes a force of about 25 mm Hg that pulls water and solutes back into capillary.
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lymphatic system
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takes up excess fluid filtered out of capillaries and brings it back to circulatory system via large lymph vessels which empty into the vena cava near within the thoracic cavity.
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bulk flow
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caused by differences in hydrostatic pressure between a vessel and the interstitial space: filtration movement of plasma, fluids, ions through the vessel membranes into interstitial space down the osmotic pressure gradient. Proteins and large particles moving along in vessels too large to flow out contributes osmotic pressure to vessels further down the capillary, causing other fluids and ions to be drawn back in.
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lymph
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clear fluid within the vessels of the lymph system, gathered as excess from tissue, being delivered back to the blood system.
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edema
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localized swelling caused as a chemical response to damage. Histamines and phagocytes as well as other chemical responders (chemotaxis) cause the response.
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cardiovascular control centre
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located in the brainstem, within the central nervous system, the portion of the brain that controls the heart activity.
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hypertension
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high blood pressure
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hypotension
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low blood pressure
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capillary bed structure that make it ideal for material exchange, versus arteriolar structure?
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one single flattened layer - HUGE surface area, thin walled, pores between cells allow passage of water and molecules. No smooth muscle. Versus arterioles? muscle - regulates blood flow - can't easily transfer materials through muscle.
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peripheral resistance and blood flow changes in exercising versus stationery?
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exercising = increased capillaries open because more blood needed, more muscle units recruited for work. more capillaries open = decreased peripheral resistance.
increased exercise increases heart rate, increases blood flow. |
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negative feedback system controlling erythropoiesis?
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red blood cell count down
kidney secretes erythropoeitin red marrow production of RBC's up red cell count up sensed by kidney kidney inhibits secretion of erythropoeitin, marrow inhibits RBC production. |
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hemoglobin - purpose
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-transports oxygen within body
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hemoglobin structure
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- 4 part structure, four proteins (globins), each interlaced with an iron molecule (heme)
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hemoglobin - produced where
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red marrow of long bones - integral part of structure of red blood cells.
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hemoglobin does what and is then called what?
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- hemes form easily reversible bond with oxygen when passing through lungs
- oxyhemoglobin when oxygenated. |
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hemoglobin - normal concentration in blood?
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15g/100ml blood
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hemoglobin - reduced in body called what?
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anaemia. reduced oxygen carrying capacity.
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Patient with type A blood be given type B?
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No. A contains A antigens, B antibodies. would reject B blood, causing agglutination.
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effect of gravity on blood pressure system? If adult with normal pressure stands up suddenly?
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would be less. blood pooled in upper body would immediatly go to lower body. = less venous return to heart, slower heart rate and lower blood pressure for a few moments. (Heart can't pump blood it doesn't have.)
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Baroreceptor reflex negative feedback system
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-pressure drop in blood
-baroreceptors (in carotid sinus and aortic arch) sense drop - baroreceptors signal CV centre - brainstem - CV centre excites sympathetic NS, inhibits parasympathetic - heart rate increases (norepinephrine) - heart stroke volume increases - vasocostriction (arteries and veins) -blood pressure rides -baroreceptors sense rise, send signal to CNS that pressure again normal. |
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strenuous exercise - mean arterial pressure decrease, or increase?
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decrease. more muscle capillaries open during exercise, total resistance down, pressure down.
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why does standing for several hours cause fainting?
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homeostatic response to correct problem.
standing causes increased hydrostatic pressure in venous system over time. veins distend, hold more blood (venous pooling) increase in capillary filtration occurs as semi-stagnant blood increases capillary hydrostatic pressure + depleted blood volume. blood pressure falls. When low enough, fainting results. falling down recirculates blood and lymph, solving problem. |
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cardiovascular responses to severe bleeding
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decrease in blood volume (bleeding) = decrease in venous return = decreased cardiac output = decreased blood pressure = decreased capillary pressure = absorption of more interstitial fluid = STIMULATES BARORECEPTORS, so stimulates CNS, CV centre= increased TPR,heart rate, venous constriction, increased blood volume, increased cardiac output, therefore increase in blood pressure. (keeps patient conscious.)
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clot formation
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1. plug - platelets adhere to exposed subendothelium, make a physical barrier plug.
2. clotting factors act in sequence to form clot, requiring calcium at each stage, and vitamin K required to initiate clotting process - clot factors always present in blood. PROTHROMBIN-->LIBERATES THROMBIN-->LIBERATES FIBRIN FROM FIBRINOGEN (produced by liver)--> FIBRIN forms clot, tangles with RBCs. |
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antigen
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complex protein molecules on surface of blood - stimulates immune system production of specific antibodies.
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antibody
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immunoglobulin protein - produces immune response to foreign molecules
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anti-clotting mechanisms in blood?
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antithrombin III and heparin (endothelial cell surface protein.) Both inhibit thrombin, inhibiting clot formation.
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cardiovascular pathology:alcohol
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vasodilation, heat loss, arrhythmias, hypertension, cerebrovascular accidents (clots) + stroke.
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cardiovascular pathology - smoking
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increased damage to blood vessels
clots in arteries arrhythmia reduced oxygen carrying capacity (not to mention pulmonary pathologies...) |
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hemophilia
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hereditary
x linked deficiency of clotting factors requires blood replacements |
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A type blood antigens, antibodies?
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A antigen
B antibody |
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B type blood antigens, antibodies?
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B antigen
A antibody |
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AB type blood antigens, antibodies?
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AB antigen
no antibodies |
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O type blood antigens, antibodies?
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no antigens
AB antibodies |
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why venous return significantly lower in bed-ridden versus exercising person?
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Muscles within the body, in addition to providing heat, movement, and restricting movement (posture), also work to aid in actively pumping the venous return of the blood to the heart. bedridden is not actively aiding the blood to flow back to the heart, but is instead relying on the passive force of the arterial blood flow to push the venous blood through the system of one-way valves back to the heart.
VENOUS RETURN DIRECTLY RELATED TO CARDIAC OUTPUT (MEAN BLOOD PRESSURE OVER TOTAL PERIPHERAL RESISTANCE.) |
