CARDIO-Pump Flashcards
How many pumps are occuring at same time in the heart?
2 pump system: separate. 2 chamber/pump. Simultaneous contract. Electrically _Separated inf and sup by cardiac skeleton
What are difference btwn cardiac and msk cells?
Cardiac- fibers interwoven/interdigitated-cell-cell, gap junctions, striated. One nuclei. 25-40% mitochondria. 1 T tubule MSK- linear, parallel, fibers contract differently for strength, striated, Nerve fiber to stimulate. Multinucelus. 2% mitochondria. Two T-tubules
What is function of gap junctions?
Located btwn intercalated discs. Important during AP. Sharing cytoplasm and electrolytes with neighbor cell.
PUMPS contract as a single unit in order to contract the same time to reduce Fib, by what mech?
- intercaled discs 2. gap junctions, 3. fibers interwoven 4. Heart separated connective tissue skeleton to keep electricy separate
What is path of ejection in heart?
IVC/SVC_RA_RV_pulmo trunk_pulmo vein_LA_LV_aorta_body
What is difference btwn pacemaker cell threshold and cardiac cells?
- Pacemaker is -45-55, 2. Cardic/contraction MSK cell -85-95mV, 3. conduction is +90-100. Resting 85-90 is high magnitude AP**
What is time during action potential where cell cannot be stimulate again?
Refractory period- cell reset electroyltes
what channel affects the plateau phase?
slow Ca channel
What is way to excitation of a muscle/action potential on the muscle cell membrane to actual contraction of the muscle
Excitation contraction coupling
Which contribute to mucsle contaction?
- T tubule- external to fiber/cell, holds Ca. 2. Ca starts sliding filiament 3. Sacoplasmic reticulum internal w/ cell. Ca pumps removal in sacroplasm
What information does the Wigger provide?
- Electical 2. volume 3. EKG 4. Sounds 4. Ion channel phases 5. chambers
What does length of cardiac cycle correlate to in time?
.08s correlate with 70-72bpm
Diastole at 60%- time to fill, reset for metabolic demand. MAP-93-110, related to diastole. Systole 40%.
What defines the cardiac cycle
1.Beg-to-beg 2. AP by SA node 3. Delay in AV node 4. Excitation and relaxation both chambers.
*what causes the valve to open or close?
Always blood FLOW. NEVER MSK. PRESSURE changes open valve
What is happening in phase 7 resting?
Diastole. Finishing cardiac cycle, get ready for beg. 1. Heart sounds quiet, 2. no electrical activity. NO Pwave or QRS 3. Vol. Ventricles slowly filling 4. Pressure- Atria and Ventricle low pressure 5. Blood is filling into Atrium via pulmonary veins
What is occuring in Phase 1?
Atrial contraction. Many waves 1. Pressure- atria pressure builds. 2. ECG- P wave atrial contration 3. Volume- atria inc. LV rapid rise in volume
Why is there rapid rise in LV during atria contraction?
Atrium doesnt fill ventricle completely put tops it off. Means volume still remains in LV after contracion.
What occurs at end of Phase 1, and beg of 2.
- Aortic pressure drops, LV pressure rises, LA drops a little 2. Vol stays the same 3. Tricuspid and Mitral valve closing
What occurs at phase 2?
- Sounds-S1 (M+T closes) 2. ECG-QRS starts 3. Vol LVEDV stays same ISOVOLUMIC contraction 4. Pressure LV INCs, Aortic presure DEC
What occurs during Phase 3?
- Sounds none 2. ECG-QRS starts 3. Vol LVEDV drops 4. Pressure LV INCs, Aortic presure INC, C-wave rise in LA
What is occcuring in C-wave and why?
Atria rise in LA pressure. Valve balloons. D/t LV contracts trying to push thru great vessel and atrium.
What occurs in Phase 4?
- Sounds quiet 2. ECG-Twave LV repolarizatoin 3. Vol LVEDV drops 4. Pressure: LV and Aortic peak, LA slow rise, holding tight d/t ballon AV valves
What occurs at phase 5?
Isovolumic relaxation. 1. Sounds semilunar (aortic, PT) close 2. ECG quiet 3 Vol. plateau/same, lowest peak 4. Pressure Aortic/PT low, LV/RV drops sig, V-WAVE LA/RA rise/plateu back flow after AV close.
What occurs during Phase 6?
- Sounds quiet 2. ECG quiet 3. Vol LVESV after contraction 4. Pressure: LV/LA drops, Aortic slow drop
Where is passive filling of ventricles occuring?
Phase 1, Phase 6-7.
What is occuring in isovolumetric contraction during phase 2?
Volume is staying the same as LV pressure RISES. Highest LV vol. NO filling, MT closed.AP closed QRS occurs. Aortic press low
What is occuring in isovolumetric relaxation during phase 5?
Volume is staying the same as LV pressure DROPS. Lowest LV vol. NO filling, AP close. No electrical activity. Aortic higher pressure
Why is LV pressure rising during isovolmeric conractions?
LV is fight against aterial pressure from aorta
When will blood be ejected?
when the pressure within the ventricle is greater than the pressure in the aorta because it’s a Delta P that causes the valve to open
When is ejection happening?
Phase 3-4. LV and Aortic pressue match. LV volume lowest, bc blood is leaving
Does LV reach 0 pressure?
Almost, during phase 5 isovolmeric relaxion, pressure rises slightly as blood fills
How is ejectin fractin determine off Wiggers?
- LVEDV 120mL-60 LVESV= 60ml. 60/120= 50% EF, 55-60% is Normal EF
What is function of valves?
maintains one-way flow of blood not to allow backflow where you have turbulent flow where blood can clot
What connects to chordae tendinae that come off vavles?
Papillary muscles -nipple like
What stimulates the chordae and papillay tissues?
electrical signal travels through the Purkinje fibers and into the wall of that ventricle. 1. Ventrical contracts cause them to PULL DOWN to CLOSE vavles
What is main function of chordae and papillary structures?
Prevent collapse during ventricle contratcion to prevent back flow to MT/AV vavles. Thus blood flows path of least resistace, thus flows to semilunar valves
Which valves are more prone to damage
Semilunar valve Aortic/Pulmonic by arteries. MC calcificatin, fibrotic_pressure_stenosis
Are LV and aortic pressures equal during cardiac cycle?
LV slightly higher during ejection. Aortic blunted b/c complance of tissue expansion. Pressure never as higher as expect w/ blood leaving
Does aortic pressure ever reach zero?
NO, d/t blood flow stoping if it did. Thus death. Aortic balloons out, and compresses on volume to leave vessel. Even when LV drops, Aortic still high to maintain BF. Expands and Contracts constantly
What does the incisura/notch indicate on Wiggers?
Semilunar valve closed. phase 5. LV starts to drop. Aortic pressure drops,then compresses slight to inc in pressure. Blood flow backward, valves close, turbulent blood flow in aorta creates pressure notch
which form of cardiac work is overcoming the pressure in the arterial system, moving low pressure veins to high pressure aa?
External work
which form of cardiac work is accelerating blood through pulmonar and aortic valve?
Kinetic energy
Does blood flow spill fast or slow into the atriu from the viens?
Slow d/t low press of veins
What does heart do to compensate for low pressure of blood input?
Works hard by takin heavy vicsous fluid, try to accelerate to body w/ enough pressure to drive cardiac return via kinetic energy
Stroke work output =
output/beat, cardiac contractions
Minute outpiut
Cardiac output= stroke vol x HR
What is important about ventricular pumping w/ vol. and pressure?
Systolic pressure rises sig dt sacromeres filed w/ volume, which will inc systolic pressure as it contracts. IF DBP over 150 LV pressure rises fast.
What are four phases of ventricle pump?
- Passive filling 2. Isvoll contraction-same vol 3. Ejection 4. Isovol relaxation
What occurs durinng LV Phase 1 passive filling?
Mitral valve open_LV @ 50ml LVESV_DBP 2-3mm_LV vol INC 120ml_LVEDV_DBP 5-7. Blood vol up but pressure not changing
What occurs during LV Phase 2 Isovolumetric contraction?
Mitral valve closes_LV @120ml LVEDV not changing all vavles colsed_LV presure ~80m matches aortic pressure
What occurs during LV Phase 3 ejection?
Aortic valve opens_LV SBP rises_LV volume DEC, flow out
What occurs durinng LV Phase 4 isovolumetric?
Aortic valve closes_LV DBP drops_LV volume same as 50ml_DBP arteral 2-3mmHg
Describe the starting pressure of valves the is called the end diastolic pressure?
Preload- pressure as begin to contract
Describe the pressure in oppostion to ejection?
Afterload- aorta against venticule contract
What energy source does the heart ues?
Fatty acids, O2, lactate, glucose. INC mitochondria, thus made to resist fatigue
Frank starling intrinsic mech for pumps states flow into heart is determined by venous return. how does RA and LV affect Cardiac ouput?
RA- inc vol will stretch the walls_INC HR. LV- will stretch w/ in strong conctractino_INC stroke vol. Venus retun increases cardiac output
What system affects the pump extinsically?
ANS- PNS, SNS
Why does SV go down overtime with inc. HR?
Cardiac output will go up, but will not have time fill due to reduced diastole. SV will go down. RAAS activated. Cycle. INC HR not good overtime…INC HR via SNS, or INC VOL via RAAS not good
What does excess K do to the heart?
EFFLUX-Makes flaccid, repolarize, prevents beating again from lock membrane potential_ blood continue to flow_flaccid heart dialates_ Peak t-wave. LOW K spastic Peak T-waves
What does excess CA do to the heart?
INFLUX- spastic contraction, can’t relax. LOW CA_flaccid
A vavle that doesn’t close and regurgtates backwards is?
Incompetent or Regurgitant- blood back to atrium_volume overload_atriu will pump excess vol back into ventricle_MAY lead to remaining vol.
Narrow, scarred, calcified heart means?
Stenotic_pressure overload_ventricles have to build enough pressure to overcome narrow valve_damage