Term
| What is Blood flow through vessels dependent on? |
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Definition
| Pressure Gradient within the vessel and Resistance to blood flow. |
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Term
| Need (higher or lower) pressure at one end of the vessel which results from--. What maintains blood flow? |
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Definition
| Higher pressure results from heart contraction which forces blood into arteries. There must be a pressure gradient throughout the circulatory system. |
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Term
| What is resistnace to blood flow within the vessel caused by? What does more resistance mean? |
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Definition
| Caused by friction between blood and vessel wall. More resistance=harder for blood to flow through vessel. |
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Term
| Factors affecting resistance to flow. Which factors don't change. |
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Definition
| diameter of vessel, length of vessel, viscosity of fluid. Lenght and viscosity don't change. |
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Term
| What is blood viscosity dependent on? |
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Definition
| Amount of RBCs and proteins. |
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Term
| What is blood flow a balance between? |
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Definition
| pressure gradient (favors flow) and resistance (slows flow) |
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Term
| Where does most blood flow resistance occur in? |
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Definition
| Arterioles (resistance vessels) |
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Term
| How can resistance in arterioles be regulated by? |
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Definition
| Increasing or decreasing the diameter. |
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Term
| What type of muscle is in Arterioles walls? This causes what? |
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Definition
| Smooth muscle. Contraction causes shrinking diameter, and relaxation causes larger diameter |
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Term
| In arterioles smooth muscle cells are arranged in what way? |
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Definition
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Term
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Definition
| decreasing diameter= increased resistance |
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Term
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Definition
| increasing diameter- decreased resistance |
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Term
| Total Peripheral Resistance (TPR) |
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Definition
| sum of all resitance of all blood vessels within the systemic circuit |
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Term
| In a network of vessels, blood resistance depends on |
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Definition
| the resistance of all vessels. |
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Term
| What controls arterioles diameter and thus TPR |
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Definition
| Neural control, Sympathetic and Hormones |
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Term
| Sympathetic control of arteriolar diameter means, muscles have-- receptors, Norephinephrine causes --, and it (increases or decreases?) TPR? |
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Definition
| Adrenergic receptors, vasoconstriction, increases TPR |
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Term
| Which Hormones control of arteriolar diameter. What do these hormones cause? How fast does it change TPR? |
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Definition
| Epinephrine. Vasopressin (ADH). Angiotensin 2. All cause vasoconstriction and increase TPR. Long term changes |
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Term
| Epinephrine is released from --, binds to --, causes--, which causes TPR to --? |
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Definition
| Adrenal Medulla, alpha adrenergic receptors, vasoconstriction, Increases |
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Term
| Vasopressin (ADH) is secreated by--, causes -- water reabsorption by kidneys, which means--, Binds to --, causing-- |
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Definition
| Posterior pituitary, increases water reabsorption, minimizes loss of water, binds to arterioles smooth muscle cells, causing a contraction which causes Vasoconstriction, increasing TPR and has long term control of TPR |
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Term
| Angiotensin 2 is synthesized from precursor -- synthesized in --. |
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Definition
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Term
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Definition
| Pressure in the aorta and large arteries |
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Term
| Arterial Blood Pressure varies with- |
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Definition
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Term
| Arterial Blood Pressure, systolic- |
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Definition
| maximum pressure. due to ejection of blood into aorta |
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Term
| Arterial Blood Pressure, diastolic |
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Definition
| minimun pressure, not zero bc of elastic recoil. |
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Term
Mean Arterial Pressure=
Regulated by- |
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Definition
Average blood pressure in arteries over time.
Cardiovascular center in brainstem |
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Term
| Controld of Mean Arterial Pressure depends on- |
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Definition
| Cardiac Output and Total Peripheral resistance (TPR) |
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Term
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Definition
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Term
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Definition
| hypertenstion, stress on heart and vessels |
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Term
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Definition
| hypotenstion, inadequate blood flow to tissue |
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Term
| Parasympathetic Control of MAP- |
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Definition
decreases HR
decrease in Cardiac output, which decreases MAP. |
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Term
| Sympathetic control of MAP |
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Definition
| Increases, heart rate, stroke volume, TPR (vasoconstriction) which all increase MAP |
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Term
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Definition
| control of map- negative feedback loop to maintain blood pressure at normal level |
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Term
| components of baroreceptor reflex |
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Definition
detectors-baroreceptors= strecth in the walls of large arteries to monitor BP.
Integration center- cardio control in brainstem,
efferents- autonomic nervous syster
effectos- heart and arterioles |
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Term
| Where are baroreceptors located? |
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Definition
| carotoid sinus and aortic arch |
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Term
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Definition
| increases sympathetic input to heart and arterioles. |
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Term
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Definition
| increase parasympathetic input |
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Term
| Barorecptor reflex quickly to--, not to--. Long term regulation occurs throug- |
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Definition
| compensate for cahnges in BP. Not correcting problem. Long term reg. comes thru renal regulation of blood volume |
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Term
| Histamine released in allergic rxns causes: |
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Definition
| bodywise vasodilation, decreases TRP and MAP, bloodflow to organs= organ failure. |
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