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67 Cards in this Set
- Front
- Back
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3 layers of arteries and veins
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tunica intima w internal elastic membrane
tunica media middle layer with external elastic membrane tunica externa |
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3 layers of veins and arteries the difference and distinctions
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the arteries have internal and external elastic membranes, the arteries have a rippled tunica intima
The veins have a thinner tunica media and they have elastic fibers and smooth muscle cells in the tunica externa. |
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Vasoconstriction and vaso dilation
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two processes that occur in the arteries; the former is a constriction the latter a relaxation.
they both affect the afterload of the heart, peripheral bp, and capillary blood flow |
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several elastic arteries
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the pulmonary branches, common carotid, subclavian, common iliac
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Muscular arteries
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med sized, most vessels of the arterial system are muscular: thick tunica media
External carotid, brachial arteries of the arms, the mesenteric arteries of the abdomen, the femoral arteries of the thighs. |
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Resistance vessels and resistance
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Arterioles are called resistance vessels, resistance is the force apposing the blood flow
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Anuerism
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Bulge or weakening of an artery wall
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Arteriosclerosis
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Hardening of the arteries;
2 types Focal calcification atherosclerosis |
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Focal calcification
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deposition of calcium salts degeneration of smooth muscles. can be from aging atherosclerosis or diabetes mellitus
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Atherosclerosis
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fatty degeneration, formation of lipid deposits that harden
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Continuous capillaries vs Fenestrated capillaries
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1 has endothelium that is a complete lining ( one cell after the other) found in all tissues except epithelia and cartilage
2. has windows, or pores for rapid exchange. found in the choroid plexus of the brain, and some endocrine organs (hypothalamus, pituitary, pineal and thyroid. and intestines and kidneys |
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Sinosoids
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similar to fenestrated capillaries, but gaps btw endothelial cells, thinner or no basal lamina; permit large exchange of fluid found liver bone marrow spleen and many endocrine organs.
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Capillary bed aka
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capillary plexus or network of capillaries.
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Arterial anastomosis
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joining of bvs, when collaterals fuse and give rise to arterioles prior to a cap bed.
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Ateriovenous anastomoses
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bypass cap beds to the venous circulation. regulated by sympathetic innervation, and medulla oblongata
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VEGF
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Vacular endothelial growth factor responsible for angiogenesis, occurs embryologically, or in response to hypoxia.
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Vasomotion
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Blood flow through capillary beds, with contracting and relaxation of smooth muscles: controlled by conc of chemicals and such.
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SIZEs:
Venules Med- veins capillary arterioles muscular arteries elastic arteries |
1 20 um
2. 2-9 mm 3. 8um 4. 30um 5. .5mm-4.0mm 6. 2.5 cm (1inch) |
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venoconstriction
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reduces the venous sytem blood vol, and increases arterial system and capillaries.
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Venous reserve
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about 20% of total bv, blood from veins in liver skin and lungs that can be shifted to general circulation
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BP @
Avg systemic arterial @ cap network at right atrium of the venous side |
1. 100 mm HG
2. 35mm HG to 18 mm HG 3. fabout 18mm HG close to zero. |
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MAP
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mean arterial bp = diastolic pressure + 1/3 pulse pressure
pulse is the difference btw the systolic and diastolic pressures. |
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What does elastic rebound do?
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vent contract pushing and stretching the artery walls, then during diastole some blood flows back to the lt. vent supplying the coronary arteries and closing the valves, but most goes towards the capillaries.
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List the 7 blood vessels from Highest to lowest BP
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Aorta /Elastic arteries
Muscular arteries Arterioles Capillaries Venules Veins Venae Cavae |
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Which bv cover the largest area?
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Capillaries
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Calculate the MAP of a person' who is 120/80
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80+40/3 = 93ish
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Why is venous return so important? What happens with impaired Respiratory Pump and muscular compression?
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You can faint if you don't have venous return, as the there is less blood in the heart and thus your HR inc, yet no filling time so you get no oxygen to your cells.
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3 important processes of capillaries
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Diffusions filtration and reabsorption
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Diffusion has 5 different routes for substances to cross the cap, walls what are they?
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1 water ions and such can enter and leave via pores of fenerstrated capillaries or btw adjacent endothelial cells
2 Na+ K+ ect. pass through cahnnels 3. Lg water soluble need fenestrated capillaries 4. Lipids can just go right through 5. Plasma proteins can only cross at sinusoids, such as liver. |
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Filtration
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Removal of solutes as a soln flows across a porous membrane:
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Driving force for filtration
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hydrostatic pressure
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Reapsorbion, why does it occur?
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Osmosis, water follows solutes:
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Filtration vs Reabsoption in capillaries
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At the filtration side Cap P > than Blood colloid osmotic pressure causing blood to flow out (and solutes)
At the Reabsorption (venule side) Cap Pressure is < than Blood colloid osmotic pressure causing Water and solutes to come back in (not all some goes to lymph) |
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What factors contribute to total peripheral resistance?
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Turbulence big areas, (Atria ventricles aorta)
Friction longer and smaller more friction Viscousity, thicker slower |
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Tissue perfusion
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blood flow through tissues.
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3 factors that effect tissue perfusion
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CO
peripheral resistance BP |
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3 important factors that help maintain homeostasis of BP and BV
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Autoregulation
and if that fails: Endocrine (suprarenals via jxa and hormones such as Angiotensin I, AngT II,) Neural mechanisms, such as heart innervation via symp. and para symp. and peripheral vasoconstriction and vasodialation via the cardiovascular centers in the medulla oblongatta |
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Autoregulation uses local vasodilators that dilate the precapillary sphincters, what are a few factors?
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Dec tissue O2 lvl or inc Co2 lvl
Lactic acid in tissues NO from endothelial Inc [K+] or [H+] Inflammation chem Histamine and NO Inc Temp |
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Neural mechanisms use the CV centers what are two parts of the cv center?
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Cardioacceleratory center: sympathetic inc C/O
cardioinhibitory center: parasympathetic slows C/O |
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The Neural Mechanism uses the Vasomotor centers what are two groups of neurons and their function?
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1 a very large group for widespread vasoconstriction, it ups BP
2. smaller group responsible for vasodilation of areterioles in skeletal muscles and brain dec bp |
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The vasomotor center also effects the sympathetic motor neruons via two ways:
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1 control of vasoconstriction: adrenergic (adrenaline)
2. Control of vasodilation: cholinergic (Ach) which controls NO |
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How do Cardiovascular centers detect BP ph and [] changes in blood?
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They monitor Arterial Blood via chemo and baro receptors.
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Where are baroreceptors located
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1. Sinuses: Carotid sinuses & aortic sinus
2. Right atrium 3. Aorta |
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Where are chemoreceptors located
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Carotid bodies in the neck and aortic bodies near the arch
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If BP falls:
What detects this? What does the Vaso motor do? What does the cardiocenter do? |
-The Baroreceptors detect this via being inhibited
-The vasomotor center is stimulated to cause vasoconstriction -The Cardioinhibitory is inhibited -The cardioacceleratory is stimulated causing C/O to inc All of this elevates BP and is neg. feedback |
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BP rises too high! What detects this?
What happens? |
-BP too high baroreceptors become stimulated and inhibits both vasomotor and cardioacceleratory center
- the cardioinhibitory is stimulated causing dec in C/O -With the vasomotor center inhibited vasodilation occurs (as it is normally chronically stimulated) All of this raises BP back to normal levels which is regulated via neg. feedback |
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Girl is locked in the trunk, she is suffocating what does the body do in response to hypoxia?!
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Dec in pH and O2 lvls inc in CO2 causes chemo receptors to become stimulated.
**Same as BP falling in barro receptors** -Cardioinhibitory is inhibited -Cardioacceleratory is stimulated causing heart's C/O to inc -Vasomotor center is stimulated causing vasoconstriction -Chemoreceptors ALSO stimluat respiratory centers and Lungs Inc breatheing. All of this helps inc pH O2 lvl dec CO2 levels in the blood; regulated via neg feed back. |
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Difference btw Vasodilators and local vasodilators?
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local at tissues, vasodilators is anything that dilates bvs
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Endocrine response is long term and there are 4 ways which help regulate homeostasis what are they?
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ADH
Angiotensin II Erythropoeitin Natriuretic peptides |
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ADH w respect to BP/BV dec
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Adh released via NeuroHypophysis: Inc water retention and thirst, and peripheral vasoconstriction.
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Angiotensin II does what when BP falls?
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Justaglomerular cells in the kidney make and secrete renin when BP falls (they have receptors too)
-Renin activates Ace (angiotensinogen enzyme) -Ace Converts Angiotensin I that is circulating in blood to Angiotensin II which inc BP and BV |
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4 ways Angiotensin II Inc bp?
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Stimultes aldosterone Na+ absorption at kidneys and kick K+ casuing water retention
secretes ADH stimulates thirst stimulates c/o & vasoconstriction of arterioloes inc bp *this effect is 4-8x greatter than NorEpi |
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Erythropoeitin
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EPO released from kidneys when no oxygen:
causes more mature rbc's which inc oxygen carrying capacity. |
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Atrial natriuretic peptide
brain natriuretic peptide ANP BNP 4 things they do? |
They are released by the heart:
kicks Na+ at kidneys Increased urination reduces thirst Block adh aldosterione epi NEpi Peripheral Vasodilation All of this causes mass reduced BP and BV causes homeostasis to return -Regulated via neg. Feedback -Inverse to EPO ATII and ADH |
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How does applying slight pressure to the common caratid artery affect heart rate?
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It dec
By inc BP by dec the diameter then... Cardio inhibitory center will slow the heart down |
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What effect would the vasoconstriction of the renal artery have on bp and bv?
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If that were to happen, the BP that reaches the kidneys, specifically the Juxtaglomerular cells will be ...
well nothing happens..they react to vasodilation, and lowered BP... |
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What does hemmorhaging cause?
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it causes bp and bv to dec, as it is bleeding...
When BP and BV dec Angiotensin EPO ADH and such all work to get it back up as well as E/NEpi, and the sympathetics, |
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CVA
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cerebrovascular accident
stroke: the person can die... blood flow to the brain is impaired. |
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Coronary spasms
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When blood flow to the coronary circulation is impaired: angina, and can cause a myocardial infarction
-if left untreated can cause heart failure |
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Pulmonary Edema
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if bp in pulmonary capillaries rises above 25 mm HG then fluid will enter the alveoli
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What are 3 things that aging does in the blood?
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dec hematocrit
constriction/block peripheral veins via thrombus pooling of blood in viens of the legs bc valves don't work properly |
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Age does to the heart?
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reduces the max c/o
changes in the activities of nodal and conducting cells reduces the elasticity of the fibrous skeleton pregressive atherosclerosis restricts coronary circulation replacement of dmg;d cardiac muscle cells by scar tissue |
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age does to blood vessels?
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weakens walls can form an aneurysm
deposits of calcium salts on weakened walls inc risk of stroke or myocardial infarction the formation of a thrombus at atherosclerotic plaques |
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What happens during exercise:
blood flow |
dec from non-essential organs to skeletal muscles C/O inc
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Athletes vs non athletes
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lower resting HR larger stroke volumes and cardiac reserves and non athletes
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Special circulations
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Blood brain barrier
Coronary circulation Alveolar capillaries in the lungs (different pressure) |
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Why not take anti-allergy and drugs that lower BP?
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Bc antiallergy will act negatively inatropic decreasing heart rate, that and combination of low BP can be fatal.
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