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80 Cards in this Set
- Front
- Back
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walls of vessels (artery)
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inner → outer
1) Tunica intima -subendthelial layer 2) Tunica media (enclosed elastic fibers) 3) Tunica externa (vasa vasorum) |
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Tunica intima
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-endothelium: simple squamous epithelium
+subendthelial layer (areolar connective tissue- smooth surface for blood flowing) |
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Tunica media
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-smooth muscle cell
+enclosed elastic fiber *contraction (vasodilation & vasoconstriction) |
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Tunica externa
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-areolar connective tissue
-vasa vasorum |
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artery vs vein (artery)
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-thickest: tunica media
-wall: thicker - narrower lumen - more elastic & collagen fibers → keep BP - usually artery remain open (cross- sectional shape) - BP: higher (small 40mm Hg, lager 100mm Hg) |
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artery vs vein (vein)
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-thickest: tunica externa
-wall: thinner -larger lumen -less elastic & collagen fiber -usually collapsed (flatten out) - if not blood in vein -have valves - BP: higher (vena cava 0mm Hg, veins 20mm Hg) |
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Capirally
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- only tunica intima
(endothelium and basement membrane) for gas and nutrients exchange |
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elastic artery
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Lagest (diameters: 2.5- 1 cm)
=conducting artery into muscular artery -larger elastic fibers ( fro streching) 1) tunica intima 2) media 3) externa ex) aorta, pulmonary trunk, brachiocephalic, common carotid, subclavian, common iliac aretery |
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muscular artery
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middle size (diameters: 1 cm- 0.3 cm)
=distributing arteries to regions and organs 1) tunica intima -internal elastic lamina 2)media (thicker some layer or smooth muscle) -external elastic lamina 3)externa ex) most named arteries branch into arterioles |
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arteriole
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smallest (0.3 cm- 10 micrometers)
1) tunica intima 2) media ( 6 layers of smooth muscle) 3) externa *smallest arterioles: think endothelium, enclosed 1 layer of smooth muscle -usually: Vasomotor tone (slightly constricted by vasomotor center in the brain) |
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continuous capillary
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-most common "seal" capillary
-endothelial cells-complete enclose lumen -complete basement membrane -intercellular clefts have tight junctions (diffusion: some WBCs, its contents (except; protein) ex) skin, lungs and central nervous system |
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intercellular cleft
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-the gap between the endothelial cells
-prevent movement of large substances (formed elements, plasma proteins) -allow movement: small substances (glucose, amino acids, and ions) 1) by cellular transport processes (diffusion, pinocytosis) 2) intercellular clefts by diffusion and bulk flow (described slowy) |
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Fenestrated capillariy
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-endothelial cells-complete enclose lumen
-complete basement membrane -some area extremely thin=fenestrations or pores =prevent formed elements, allow small plasma protein -fluid transport (blood- interstitial tissue), absorption -small intestine (absorption of nutrients) -ciliary process (produce aqueous humor) -choroid plexus (produce erebrospinal fluid (CSF) in the brain -most endocrine glands (absorption of H into the blood) -kidneys (filtering blood) -celebrospinal fluid |
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sinusoids
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-discontinuous capillaries
-incomplete lining of the endothelial cell -basement membrane (discontinuous or absent) - allow transport large (formed elements, plasma protein) and plasma -bone marrow (formed elements enter the blood) -liver and spleen (old RBCs are phagocytized by macrophages and taken out of circulation) -some endocrine glands (A pituitary, adrenal & parathyroid) |
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capillary bed
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-10 -1000 capillary (BC not function independently)
- metarteriole (branch of arteriole)-thoroughfare channel ( branch only metarteriole side: true capillaries have precapillary sphincter:smooth muscle ring) -postcapillary venule -encircled by scattered smooth muscle cell -thoroughfare channel (distal parts; NO smooth muscle) |
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precapillary sphincter
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-smooth muscle ring
-controls blood flow into the true capillaries -relax= blood flow into the true capillaries -contraction=blood flow directly from the metarteriole and thoroughfare channel into the post capillary venule -cycles=vasomotion |
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vasomotion
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sphincter's cycle of contracting and relaxing (about 5-10 cycles minutes
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venules
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-smallest vein (8-100 micrometer)
-smallest call postcapillary venules, drain capillaries -Small and medium companion =muscular arteries -largest vein travel though elastic arteries -formed tunica intima and strengthened by elastic and collagen fibers |
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systemic veins as blood reservoris
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=the relatively large amount of blood within veins allow veins to function
-pulmonary circulation (18%) -heart (12%) -systemic circulation (70%) -systemic arteries (10%) -systemic capillaries (5%) ★systemic vein (55%) can hold about 50-80% |
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simple pathway
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one artery (end artery), capillarybed and vein associated with an organ or body region
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end arteries
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arteries that provide only one pathway through which blood can reach an organ (connect with capillaries)
=functional end arteries ( coronary arteries) |
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alternative pathways
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include various type of anastomoses and portal system
-number of arteries, capillarybeds or veins that serve an organ or body region. -designed by anastomosis |
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anastomosis
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joining together of blood vessels (arteries < veins)
2 or more arteries converging to supply (to drain) the same body region -arterial anastomosis: superior & inferior epigastric arteries that serve the abdominal wall) -venous anastomosis: upper limv include the basilic brachial and cephalic veins -ateriovenous anastomosis (transport blood from an artery directly into a vein by passing capillary bed: fingers, toes. palms and ear when becoming hypothermic (cold) |
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arrangement of portal system
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blood flow though 2 capillaries bed, with the 2 capillary beds separated by a portal vein → portal vein delivers blood to another organ first, before the blood is sent back to the heart.
=an artery, capillary bed, portal vein, capillary bed, and a vein ex) hypothalamus hypophyseal portal system |
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capillary exchange
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blood vessels- interstitial fluid- tissue cell
higher concentration →lower concentration 1) diffusion (intercellular cleft or epithelial cell) 2) fenestration in fenestrated capillaries or gaps in sinusoid -vesicular transport |
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vesicular transport
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when endothelial cells use pinocytosis to fuse fluid- filled vesicles with the plasma membrane and transport their contents either from the blood to the interstitial fluid or from the interstitial fluid into the blood.
ex solute) cerain hormones (insulin), fatty acid, |
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bulk flow
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the movement of large amounts of fluids and their dissolved substances in one direction down a pressure gradient
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filtration
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process that occurs on the arterial end of a capillary
the movement of fluid by bulk flow out of the blood though the opening in the capillaries (ex) intercellular cleft, fenestrations (arterial end : HP> osmotic pressure) |
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reabsorption
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movement of fluid by bulk flow back into the blood
(venous end: osmotic pressure > HP) |
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Hydrostatic pressure (HP)
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OUT > INTO
physical force exerted by fluid on a structure 1) blood hydrostatic pressure (HPb) 2) interstitial fluid hydrostatic pressure (HPif) |
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blood hydrostatic pressure (HPb)
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★pressure→filtration from capillary (OUT from capitally)
force exerted per unit area by the blood as it presses against the vessels wall |
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interstitial fluid hydrostatic pressure (HPif)
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★pressure→filtration from capillary (INTO the capitally)
the force of the interstitial fluid on the external surface of the blood vessel -in tissue pressure: close to zero |
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osmotic pressure
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OUT < INTO
force regulation filtration and reabsorption ="pull" of water into an area by ososis due to the higher concentration of solute |
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colloid osmotic pressure (COP)
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=clinical:oncotic (onkosis=swelling) pressure
the pull of water back into a tissue by the tissue's concentration of protein (colloid) 1) blood colloid osmotic pressure( COPb) 2) interstitial fluid colloid osmotic pressure (COPif) |
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blood colloid osmotic pressure( COPb)
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★pressure→Reabsorption from capillary (OUT of the capitally)
force that draws fluid back into the blood due to the proteins in blood (ex) albumin. ←→ hydrostatic pressure |
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interstitial fluid colloid osmotic pressure (COPif)
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low pressure, BC few proteins are present in the interstitial fluid
range (0-5 mmHg) |
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Net filtration pressure (NFP)
bluk flow at capirallies |
Direction determent (NEP +=out: -=IN)
Net HP (HPb - HPif) - Net COP (COPb- COPif) = NEP [arterial end] (35 mmHg-0)-(26-5)=14 mmHg =Out from capillaries [venous end] (16-0)-(26-5)=-5 = INTO capillaries (5 mmHG) |
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starling's law
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hydrostatic and osmotic force work against one another to drive the filtration and reabsorption of materials across a capillary membrane
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NEP arteial end vs venous end
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filtration (arterial end): 85% (fluid in interstitial fluid) reabsorption (veous end)
lest 15% →picked up by lymphatic system |
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local blood flow
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the blood delivered locally to the capillaries of a specific tissue (ml/ minute)
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perfusion
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amount blood entering capillaries
mg/minute cardiovascular system is charged |
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amount of blood delivers to a specific organ or tissue is dependent upon several factors
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1) the degree of vasocularization of the tissue
2) local regulatory factors (alter blood flow) 3) total blood flow |
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1) the degree of vasocularization of the tissue
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1) extent of blood vessels distribution within tissue
2)active metabolic organs =highly vasoculated (ex)brain, skeletal muscle, heart, liver -limited:tendons and ligaments 3) amount of vasoculation may change over time through the process of angiogenesis 4) regression or return to previous state ex) ↓physical exercise, losing weight =↑physical exercise |
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angiogenesis
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-formation of new blood vessels in tissues that require them
-for provide adequate perfusion though long term anatomic change (weeks to months) ex: skeletal muscle: aerobic training adipose tissue:gain weight coronary vessels: occlusion to provide alternative |
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2) local regulatory factors (alter blood flow)
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-changing metabolic activity of tissue, response to damage or body's defense systems
- vasoactive chemicals are controled by autoregulation (↑vasodilation =vasodilators & ↑vasoconstriction=vasoconstrictors) |
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2) [1]autoregulation
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the process by which a tissue itself regulates or controls its local blood flow in response to its changing metabolic needs
LOCAL BASODILATION (stimulation: disrupted) ↑metabolic activity=↓blood perfusion=↓ O2 & nutrients level =↑CO2, lactic acid, H+,K+ levels -reactive hyperemia occur (restored) ↑ blood flow to affected tissue |
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reactive hyperemia
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(restored) ↑ blood flow to affected tissue
ex) when entering a warm home from cold outside, our cheek is turned red. |
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2) [2] inflammation
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damage tissue release vasoactive chemicals (leukocyte & platelets) as body defense
ex) histamin & bradykinin →direct stimulation or vessels release Nitric oxide → vasodilation |
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Local substances & Hormones (vasodilators)
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-↓ O2, nutrients
-↑ CO2, H+,K+, lactic acid levels -Histamine, Bradykinin, Nitric oxide [hormones] -Atrial naturiuretic peptide (ANP) form heart -Epinephrine (bound beta-adrenergic receptors within coronary and skeletal muscle blood vessels) |
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Local substances & Hormones (vasoconstrictors)
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-↑ O2, nutrients
-↓ CO2, H+,K+, lactic acid levels -Endothelins, Prostaglandins, Tromboxanes [hormones] Angiotensin II, Aldosterone, ADH, norepinephrine( bound to alpha adrenergic receptors of most blood vessels) |
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3) total blood flow
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amount of blood transported throughout the entire vasculature in a given period of time (l/min)
-Total blood flow= Cardiac output (CO -↑ by exercise, ↑CO -depends or cardiovascular system (heart, vessels & blood) |
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3) [1]Blood pressure
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force per unit area that blood exerts against the inside wall of a vessel
ALL BP = highest aorta, lowest vena cava |
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3) [2]blood pressure gradient
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change in blood pressure from one end of a blood vessel to its other end.
it is in the vasoculature |
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systolic pressure & diastolic pressure
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normal average 120/ 80 mmHG
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pulse pressure
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pressure on arteries- heart: relax→contracting
120 -80 =40 mmHG (pulse pressure) masure: ekasticity and recoil of arteries -temporary change= ↑CO = exercise -permanent changes =unhealthy arteries |
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Mean arterial pressure (MAP)
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the average (or mean) measure of the blood pressure forces on the arteries.
BC diastolic pressure is longer than systolic pressure. MAP= diastolic pressure + 1/3 pulse pressure provides a numerical value for how well body tissues and organs are perfused average:70-100 mmHg ↑ cause edema "cerebral edema" |
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capillary blood pressure
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systolic and diastolic BP disappear = pulse disappear
too high =damage the fragile vessels arterial end of capillary = about 40 mmHg venous end of capillary 20 mm hg |
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Venous blood pressure
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venous return (movement going back from capillary to herat)
no pressure 20 mmHg - 0mm Hg (inferior vena cava) -need skeletal muscle pump & respiratory pump |
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3) [3]skeletal muscle pump
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within limbs
skeletal muscle contract = veins squeezed to help propel the blood toward the heart =valve prevent back flow ↑= walking ↓=↑ risk of veinthrombosis |
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3) [3]respiratory pump
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movement within thoracic cavity,
breathing rate↑ =blood going back heart↑ -diaphragm contract (inspiration) =↑ intraabdominal pressure, ↓ intrathoracic pressure =↑ blood flow into thoracic veins -diaphragm relax (expiration) = ↓ intraabdominal pressure, ↑ intrathoracic pressure =↑ blood flow into heart and abdominal veins |
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Blood pressure gradient
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↓↑Blood pressure gradient= ↓↑total blood flow
↓↑ Blood pressure gradient = ↓↑ CO |
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3) [4] resistance
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peripheral resistance -the resistance of blood in the blood vessels ( as opposed to the resistance of blood in the heart
1) blood viscosity 2)blood vessels length 3) size of lumen of blood vessels |
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3) [4] resistance
-blood viscosity |
RBCs, platelets, formed elements, proteins
aminic (↓erythrocytes) = lower viscosity =low resistance dehydrated= higher viscosity =higher resistance |
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3) [4] resistance
-vessel length |
↑ length =↑ resistance
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3) [4] resistance
-vessel lumen radius |
laminar flow =difference flow rate within a blood vessel
↑ diameter =↑ center ↑ ,↓ near edges =↑ blood flow 1mm →2mm =16 times greater |
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vasodilation and vasoconstriction are controled by control
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ANS
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BP
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cardiac output, resistance and blood volume
-maintain homeostasis and occur through short term mechanism of the nervous system or both |
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short term regulation of BP
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autonomic reflexes involving nuclei within the medulla oblongata
(rise from sitting position to standing position by altering CO, resistance, or both) |
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Cardiovascular center
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-cardiac center and vasomotor center (nuclei within the medulla oblongata)
-cardiac center regulates heart activity (=CO) -vasomotor center controls the degree of vasoconstriction (=resistance) |
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cardiac center
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2 regulatory nuclei
-cardioacceleratory center (sympathetic - SA node- myocardium)→↑HR, CO and force of constraction -cardioinhibitory center (parasympathetic -SA node and AVnode→↓HR,slow the conduction of eletrical signals though the heart's conduction system, ↓CO |
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Vasomotor center
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sympathetic extended (Vasomotor center-blood vessels)
-response, depends on type of receptors associated with smooth muscle within the wall of blood vessels Receptors: 1) alpha receptors (vasoconstriction) 2) beta receptors (epinephrine=vasodilation) -skeletal muscle, coronary vessels |
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activation of the vasomotor center and increased nerve signal along sympathetic pathways cause the flowing :
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1) increased peripheral resistance (alpha > Beta)
=↑ BP 2)larger circulation blood volume=↑ BP 3)redistricution of blood flow (more blood flow towards skeletal muscle and heart and less blood to other organs=organs need tissue O2 =↑ BP [↓ sympathetic stimulation from vasomotor center- blood vessels] =↓ peripheral resistance, blood shifts to venous reservoirs and blood flow distribution returns toward its previous level |
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baroreceptors
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specialized sensory nerve ending that respond to the stretch in blood vessels wall
-for cardiovascular system(aortic arch baroreceptors and carotid sinuses -basoreceptors transmit nerve signal to cardiovascular center -firing rate change when the stretch in the blood vessel wall change |
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aortic arch baroreceptors
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located in the tunica externa of the aortic arch.
they transmit nerve signals back to the cardiovascular center through the vagus nerve( CN X) -regulate systemic blood pressure |
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carotid sinuses
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-located in the tunica externa of each internal carotid artery
-they transmit nerve signals back to the cardiovascular center through the vagus nerve( CN IX) -monitor BP change in the heard and neck (protect brain) -more sensitive |
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baroreceptor reflex
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baroreceptors are activated in response to changes in stretch to initiate autonomic reflexes that help regulate blood pressure
-initiated by ↑↓ blood pressure |
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although more important in regulation respiration are
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regulating blood pressure
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chemoreceptor reflexes
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chemoreceptors are stimulated by ↑CO2, ↓pH, O2→vasomotor center→(sympathetic)→B vessels=↑ resistance, shift B from venous reservoirs to ↑ venous return→↑BP, B flow, O2
1)artic bodies 2)carotid body (external carotid artery →cardiovascular center (artic: via the vagus nerve, carotid: along glosspharyngeal nerve) |
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Higher brain center
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BP
-↑body temp- hypothalamus ↑CO= ↑resistance = ↑ BP -epinephrine, norepinephrine, angicotensin II, ADCH, Aldsterone, atrial natriuretic peptide =resistance BV |
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limbic system alter BP in response to
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emotions or emotional memories
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