A&P2 Exam 3Lesson 10 ChecklistExplain how blood pressure & resistance impact blood flow.Increase in blood pressure increases blood flowIncrease in resistance decreases blood flowExplain how the mean arterial pressure is calculated.MAP = diastolic pressure + 1/3 pulse pressure*pulse pressure = difference between systolic pressure & diastolic pressureDescribe how blood pressure is maintained by elastic arteries.Arterial walls stretch during systole & rebound during diastole, they kept blood moving during diastoleExplain which vessels provide the most resistance. Arteriole – the vessels with the smallest radius cause the largest resistance, R=1/(r^4)Explain the mechanisms in the venous system that assists the movement of blood back to the heart.Muscular compression – skeletal muscles around veins contract helping push blood towards the heart to overcome gravity (for the lower half of the body), the veins have valves to prevent the blood from moving backwardsRespiratory pump – when you inhale air is pulled into the lungs & pressure in the pleural cavities is reduced,this pulls blood into the inferior vena cava from the lower body, when you exhale internal pressurerises & air is forced out of the lungs which pushes venous blood into the right atriumExplain what happens at the capillaries.Capillaries play a big role in homeostasis – through diffusion, filtration & reabsorption across the wallsDescribe the diffusion routes taken by different molecules at capillaries.Water, ions & small molecules (glucose) – diffuse between adjacent endothelial cells or through fenestrated capillariesSome ions (Na, K, Ca, Cl) – diffuse through channels in plasma membranesLarge, water soluble compounds – pass through fenestrated capillariesLipids & lipid soluble materials (oxygen & carbon dioxide) – diffuse through endothelial plasma membranesPlasma proteins – cross endothelial lining in sinusoidsExplain the difference between filtration & reabsorption at the capillaries.Filtration is driven by hydrostatic pressure, where water & small solutes forced through the capillary wall but largersolutes are left in the bloodstream, movement OUT of the capillaryReabsorption is the result of osmotic pressure, movement of fluid IN the capillary, result of blood proteins thatremain in capillary because they are too large to move across the wallExplain how you can determine if filtration is occurring or reabsorption.Filtration is movement of water OUT of the capillary & happens on the arteriole end, reabsorption is movementof water INTO the capillary & happens towards the venous endDescribe how the net filtration pressure is calculated.NFP = (CHP – IHP) – (BCOP – ICOP)What is the CHP, BCOP, IHP, and ICOP?CHP = capillary hydrostatic pressureBCOP = blood colloid osmotic pressureIHP = interstitial fluid hydrostatic pressureICOP = interstitial fluid colloid osmotic pressureDescribe the factors that can affect tissue perfusion.Cardiac outputPeripheral resistanceBlood pressureWhat are short term? Which are long term?Short term – auto regulation, neural mechanismsLong term – endocrine mechanismsDescribe the various local vasodilators & vasoconstrictors.Vasodilators - act at the tissue level to accelerate blood flow through their tissue of originEx. low pH, nitric oxide, oxygen levels, elevated temperature, chemicals released by inflammationVasoconstrictors – compounds that stimulate precapillary sphincters to constrict, released by damaged tissues& affect a single capillary bedEx. prostaglandins, thromboxanesExplain the function of the baroreceptors.Respond to changes in blood pressureWhere are they located? What are their functions?Carotid sinuses – maintain blood flow to brainAortic sinuses – monitor start of systemic circuitRight atrium – monitors end of systemic circuitDescribe the chemoreceptor reflexes.Respond to changes in chemical composition (I.e. pH, dissolved gases - oxygen and carbon dioxide)Peripheral – in carotid bodies & aortic bodies, monitor bloodCentral – below medulla oblongata, monitor cerebrospinal fluid & control blood flow to the brain & control respiratory functionDescribe the hormones that can affect blood pressure/volume.Antidiuretic hormone (ADH) – elevates blood pressure & reduces water loss at kidneys, increasing blood volumeAngiotensin II – responds to fall in kidney blood pressure, increases thirst, cardiac output & peripheralvasoconstrictionErythropoietin (EPO) – responds to low blood pressure & low oxygen content in blood, stimulates RBC productionExplain how the cardiovascular system responds to exercise.Light exercise – extensive vasodilation occurs increasing circulation, venous return increases with musclecontractions & cardiac output rises (because of venous return & atrial stretching)Heavy exercise – activates sympathetic nervous system, cardiac output is increased to maximum (4x rest level),restricts blood flow to nonessential organs (digestive system), redirects blow flow to skeletal muscles,lungs & heart, blood supply to the brain is unaffectedDescribe how blood flow to the brain & lungs are regulated.Brain – top priority & has high oxygen demand, when peripheral vessels constrict, cerebral vessels dilate whichnormalizes blood flowLungs – regulated by oxygen levels IN the alveoli (high blood vessels dilate, low blood vessels constrict –toshunt blood away from low oxygenated areas of the lungs)Describe the age related changes to the heart & blood vessels.Heart – reduced maximum cardiac output, changes in nodal & conducting cells, reduced elasticity of cardiacskeleton, progressive atherosclerosis, replacement of damaged cardiac muscle cells by scar tissueBlood vessels – arteries become less elastic (pressure change can cause aneurysm), calcium deposits on vessel walls (stroke or infarction could occur), thrombi can form (at atherosclerotic plaques)Lesson 11 ChecklistExplain the function of the immune system.To protect the body against infection and disease (pathogens, toxins, abnormal cells – cancer)Explain the difference between nonspecific and specific defenses.Nonspecific – block/attacks any potential infectious organism, but can’t distinguish 1 attack from anotherSpecific – involves lymphocytes that identify, attack & develop immunity against a specific pathogenDescribe the arrangement of the lymphatic system & its function.Arrangement = Lymph (fluid – similar to plasma)Lymphatic vessels –
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