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421 Exam 1
Flashcards
Question | Answer |
---|---|
respiratory quotient indicates? | at rest or steady state exercise this indicates what youre burning |
what is homeostasis? | maintenance of the internal environment (melie) of the body |
Dynamic Consistency is what? | Maintenance of a certain range of biological control systems |
What are the key components of the biological control system dynamics? | receptors, integration center, effectors |
What are receptors? | capable of detecting a change in a variable (temp, chem, or physcial variable) and sends a message to the integration center |
What is the integration center? | IS the processing center (control box) assesses the degree of change of a variable and sends out the appropriate message to the effectors |
What are effectors? | Effectors: corrects the disturbance/deviation; allows maintenatnce of homeostatic environment |
Different parts of the aorta Arch? | L SubClav (nurishes shoulder and arm) L Common Carotid --> feeds brain on Right side: brachial sephalic --> R Subclav (right side) and R Common Carotid (which goes to external branch) and R internal carotid |
Blood Pressure is an example of whattype of feed back loop? | Negative feedback |
Blood pressure? | Force of blood against the walls of the arteries; it equals Q(cardiac output: bpm X blood/beat) X TPR |
Baroreceptors? | senses rise in blood pressure when walls stretch and responds with a negative feedback cycle to bring BP down |
Steps of baroreceptor action? | See notes for right answer |
Cardio Acceleratory center | increase in heart rate (positive chronotropic = increase in HR) |
cardio inhibitory cente | decrease in HR (negative chronotropic) |
positive inotropic? | increase force of contraction (cardio accel) |
Negative inotropic | force of contraction is lesser (cardio inhibitory) |
Lateral Pressor | resposnible for increasing vasocontrision |
Medial depressor | kepes vessels open |
Older people, or people who have a long period of high blood pressure run into what kind of problem? | thick dense wall (older, athroclerotic) wont detect as much. |
Peripheral resistance | arteries/arterioles are resistance vessels; greater amount of smoothe muscle (allows to constrict/contract) |
3 layers of vasculator | tunica intima = inner tunica media = middle layer, smooth tunica adventisia = outer layer, preserves integrity of vessels (collagen, and elastin tissue) |
What are capasitance vessels | veins and venulees. Inverse relationship with venous return |
What does lowered blood pressure and inhibiting medial depressors do? | the capsitance will increase and veouns return is lower |
Synchope/Fainting? Is it a Negative feedback? | barorceptors unloading; medulla senses lowering BP and cardioaccel is stimulated; medial depressor is inhibted and capistance goes down and venous return goes up=more blood to brain. Yes, Neg. feedback |
the cario aceleratory stimualtes is stimualted to prevent you from fainting. is this positive or negative inotpropic response? | Positive ionotrpic response: increase SV, HR, and CO goes up. TPF goes up as well. (if you are about to faint)= stable environment |
WHen youre exercising : increasing CO2, lactic acid combines with bicarbonate and forms carbonic acid and dissociates into ? | CO2 and H2O, and youre blowing it off |
what is hypercapnea? | when youre exercising this means a lot of CO2 is being produced. |
What happens with you accumulate CO2? | you are stimulating the carotid body and the arortic body (bifercatin of carotid body) = chemorecotive nerves (sensitive to Co2), if youre exercisng , hypercapnea - meaning a lot of CO2 is being produced. |
Excess CO2 is picked up by? | the carotid body and aortic body picks what up, and the nerves (aortic depressor and arorta nerves) go up to the medulla center which has a respiratory center. sends message to phrenic nerve and actiated the diaphragm |
Equation of Tidal Volume | depth of each breath = L/min |
Minute ventillation equation | tidal volume (l/min) X breathing frequency |
When brain accumulates CO2, what happens? | H+ ions dont cross blood brain barrier. they are turned into H2O and CO2 increases breathing rate and tidla volume because they can then cross |
Why do swimmers hyperventillate? | they are lowering their CO2 in blood, and arent perfusing blood to aorta, and losing stimulus to breathe, and can stay under water, O2 in brain is lowered along with low CO2 in brain everything metabolically goes down, and you dont breathe or dont move. |
If running in Miami in August at noon, and sweat drips off, are we cooling off? Is this positive or negative feedback? | if sweat drips off skin we arent cooling off = just losing water = increases core temp = Positive feedback |
How do we get blood to cool off? | Increase sweat rate = Cutaneous vasodilation = dialtion of skin's blood vessels The blood is coming to skin and passing under the skin which (blood hotter than skin), the blood cools = convection (force moving underneath a cooler substance) |
Is positive feedback stable or unstable? | Unstable |
What is systolic | Force of blood during Contraction phase |
Diastolic | Force of blood during Relaxation phase |
Pulse Pressure | The difference between systolic and diastolic pressure. Used as an indicator of CV risk. |
If pulse pressure is too wide, what is most likely happening? | if pressure is too high the ventrcile has to generate a force strong enough to open aortic valve to shoot thru the rest of the body; Isolated systolic pressure. Heart has to work extra hard over time the person undergoes cardiac failure |
If pulse pressure is too high, DBP is high but difference is low, what is most likely happening? | Congested heart failure; or not enough time to fil wich leads to eschemia. cant fill coronary arteris with blood. |
Mean arterial Pressure | (systolic-diastolic)/3 + 80 |
What is the problem with hypertensives in terms of their systolic blood pressure? What about Diastolic? | They start too high and the levels can get dangerously high as well. will never go down, goes up a little bit more than the normaltensives. start higher and go up more in terms of diastolic blood pressure. |
If blood pressure increases during exercise, where are the baroreceptors? Are they overridden? | barorecptors are active during exercise, and help support arteriole pressure during exercise; Located on located in in the carotid Sinus AND Aortic Depressor Nerve |
Are Local mechanireceprs, nerves goes to cardiov center and says we need more HR, BP, and motor units. Can they be overrode? | During moderate exercise what can be ovverode by local factors -- muscle splidnles increase sympth NS . Barorectors operating to constrcit inactive tissues |
How do Barorcetpros operate during intensive exercise? | These stay connected to peripheral resistance but we have an increase in chemoreceptors during what type of exercise? |
What happens if during intensive exercise If there is an accumulation of CO2, Lactic Acid, K+ if there is a mismatch and there is an accumulation the nerves commuicate to brain that CO2 is accumulating. And thses are pressure rainng responses? | they increase vasoconstriction, they get a lot of vasocon. to the inactive tissues even more. And the active tissues are overrode by the local vasodil. factors. |
How do barorectprs sense the chemorecptors operating in active tissue (when there is an accumulation of waste products) and causes brain to increase flow | Carotid Sinus, aortic pressure nerve senses more vasoc. to inactive tissues, and say they need more vasod. to active tissues. brain opens up the vasculature to working tissues, and orking with local vasod. you get further vasod. to working tissues, |
What happened if you fainted? | lost blood from heart, cp receptors unloaded; catecholamines were elevated; contracted empty blood, cp recptors touched. Baroreceptors: say they need an increase in peripheral resistance. and argue w/ cardio pulm. this is an unstable autonomic condition |
What happens with loss of blood volume? | Not as much blood coming into the heart. and there are a lot of catecholamines during contraction. Pre-disposer of fainting. |
What happens with decrease in SV? | Decrease in filling pressure leads to a decrease in venous return which is a pre-disposer of fainting |
What happens with increase pooling in legs | congenital absence of valves in veins; blood seeps trhough and not enough goes to heart. blood exapns in vericose veins in lower vasculature and heart isnt getting enough blood and lost of elasticity as we get older=no sense for barorecptors |
What happens with dysfunctional afferent nerves? | the nerve of herring that goes o cardiov wont get the message to the medulla |
What happens when there is an inability of end organs to respond? | Effects ability to regulate blood pressure |
What do beta blockers do? | they dont allow the end organs to respond to the integration center because they wont allo wthe HR to go up |
What happens if you are in bedrest or are an astronaut? | Loss in blood volume and less ability to respond to changes in blood pressure; changes in blood volume and zero gravity affects barroreceptors to make the people faint more readily |
What happens if highly trained athletes have vasovagal syncope? | More vulnerable to problems with blood pressure especially aerobic athletes because they have an increase in plasma and blood volume; carotid sinus becomes desensitized; vagal dominance (vagus nerve has neg chronotropic effect b/c its part of PSNS=dec. HR |
Is inotropic force of contraction positive or negative? | Positive because of the high amount of catecholamnes |
When you stop exercising what happens ? | Cap. vessels inc. and blood sits in veins and heart contracts the vessels are empty and almost touch which activates of stretching which tells brain pressure is too high, then you faint |
Why is there an increased risk of syncope with long term exercise? | increase in catecholamines, sns is turned off and Hr is decreasing if you stop the muscle pump keeps going and the cp receptors can touch. Inc heat load =vasod; blood is viscos |
What are the three layers of the vessels? | Tunica Intima; endotheliia tissue, and tunica media |
What are the components of stress relaxation after exercising; assuming blood is viscous | incr blood flow in endothelium secrets EDRF, NO releases from arginine, and NO diffuese into Tunica media (smoothe muscle). TM increases Cyclic GMP (vasod.)and opens smoothe muscle of vessels to decr. BP |
WHere would you be more prone to vaso synchope, ...after a long run in heat or basktball drill? | aerobic exercise in heat is more at risk for what? becuase you have the heat lode, stress relation, increase in NO , and more vasodiliation (outside exercising in the heat for a long period of time) |
happens when you have a heart attack, and youfeel the squeezing in chest? | Nitroglycerin is put under the tongue and has NO, the nitoglycerin opens vessels in heart and release pain and constriction in heart; more specific for coronary vessels so you dont have the anginal pain |
What is vaso vagal synchope ? | when everything drains to the legs and you cant get enough blood to heart or brain and you just faint with inability to get HR up, and usually ha[ppens after exercise |
What is atropene? | PSNS blocker is given ; blocks PSNS and vagal inttervation; it makes the RHR go up. |
Why does peripheral resistance go up? | Becuase of the increase in catecholamines |