Cardiovascluar System Flashcards
Which cardiovascular parameter is describes as the RELATIVE amount of blood pumped out of the left ventricle each heart beat, and the normal value at rest
- ejection fraction
- 55-60% at rest
which blood pressure responses should be expected during exercise?
- SBP increases due to muscular compression of arteries and veins
- DBP increases due to muscular compression of arteries and veins
which steps happen after SA node depolarization but before AV node depolarization?
- RA depolarizes and contracts
- LA depolarizes and contracts
what cardiac events correspond with the feature of the ECG waveform?
P wave- atrial depolarization from SA node
QRS- ventricular depolarization (from AV node) and atrial re-polarization
Twave- ventricular repolarization
How to the intervals change during vigorous exercise
HR- increases dramatically
PR- shortens a little
QRS- shortens
QT- decreases a lot
Which activity condition has the highest HR?
-aerobic exercise –> uses mitochondrial respiration, so there is an oxygen demand. as seen in an increase in breaths per minute to get O2 to the muscle tissues
which activity yields highest SBP and DBP?
Resistance exercise has the highest SBP and DBP. This is due to muscular compression on arteries and viens
which activity condition yields the highest mean arterial pressure?
resistance exercise. MAP is calculated by DPB + (.03 or .05 (SBP-DBP))
so if DPB and SBP are increased the most with resistance exercise, it will be shown in MAP values
which activity yields the highest total peripheral resistance (TPR)
Resistance training- TPR is calculated by MAP/Q.
if MAP is higher in resistance exercise because of higher SBP and DBP, then the TPR will be higher also.
resistance also has a low Q (around 6L/min) compared to aerobic (12L/min)
which activity yield the highest RPP
Aerobic Exercise- HR *SBP
-heart rate is much higher in aerobic. it has more of an impact than the high SBP in resistance training.
which activity hast eh highest SV
aerobic. Q/HR=SV.
increase HR but a much larger cardiac output for aerobic exercise than other types of training/rest.
Which would have the largest minute ventilation? (Ve)
aerobic. taking more breaths to get O2 to tissues
how did f (frequency of breath) and VT (tidal volume) influence the observed changes in Ve
taking more breaths, and increasing the tidal volume with aerobic exercise increase minute ventilation (Ve) the most. an increase was also seen from rest with resistance due to an increase number of breaths per minute, although there wasn’t a big increase in tidal volume
Pulmonary function in lab
partners scores were over by +25%. he is a swimmer…
what might the effect be of a restrictive lung disease such as pulmonary fibrosis on FVC and FEV1.0
- FEV 1.0 would decrease because it would take longer and more effort to expire all the air out.
FVC would decrease
-the ratio FEV1.0/FVC would be normal since both are effected
how might you use testing to screen an athlete for exercise-induced athsma
See if FEV 1.0 is different during exercise because it is harder to expire air
FVC would be the same because the athlete can still breath in the same amount .
-the ratio would decrease because FEV 1.0 is decreased and it is the numerator.
How is heart rate measure on an ECG
R to R (time interval) in ms.
what are the main purposes of the cardio vascular system?
- to deliver O2, nutrients and hormones to the tissue via blood
- removed Co2, waste products and metabolic intermediates from tissues via blood
what is the primary muscle tissue of the heart?
the myocardium
how do myocytes send signals quickly for cardiac contractions
through gap junctions. involuntarily and voluntarily controlled
which part of the heart receives de- oxen gated blood from the right atrium>
right ventricle
what are the two semilunar valves?
- aortic valve (from LV to aorta)
- pulmonic valve (from RV to pulmonary artery to lungs)
where is the SA node located and purposes?
in the RA
“pacemaker” b.c depolarizes at a regular rythem
autonomic nervous system also innervates, and can control HR (EPI and NOREPI)
what do purkinje fibers do?
in the right and left ventricles, stimulate to contract after receiving action potentials and depolarizing
what blood vessels direct blood flow?
ateries and arteriols. away from heart
which blood vessels have one way valves to direct blood return to heart?
veins and venules
What are the smallest vessels that permit gas exchange?
capillaries
Describe the pulmonary circuit
1 deoxygenated blood travels into the right atrium
2. RA depolarizes and contracts. when the pressure is around 10 mmHg during contraction –> tricuspid opens and flow to RV
3/6. RV depolarizes and contracts. when Part = 15-25 closes tricuspid and opens pulmonary valve –> blood to pulmonary artery to lungs
4. O2 blood comes back to LA
5/2. LA depolarizes and contracts when Part is around 10 the mitral valve opens and flow to LV
6/3. LV depolarizes and contracts pressure to 15-25. mitral closes –> opens aortic –>
7. to systemic ciruclation
what establishes HR?
SA node. but SNS and PNS can have an effect
SNS- up regulates by norepi and eli
PNS- down regulates
what happens to heart rate during exercise?
aerobic- up to 200-220 BPM due to increased blood flow and a need for O2 to tissues
resistance is only slightly elevated because it relies on anaerobic respiration
what is stroke volume?
the ABSOLUTE amount of blood pumped out of the left ventricle each heart beat
what influences stroke volume?
total blood volume and venous return
SV= End diastolic volume(all the way filled) - End systolic volume (how much is left after squeezed)
how is ejection fraction different than stroke volume
EF is the relative amount of blood pumped out of the left ventricle every heart beat, while SV is the absolute amount
how does stroke volume change with exercise?
aerobic- increases to get more blood pumping through heart
resistance-doesnt change
how does EF change during exercise?
it is based on SV, so
aerobic- increases ( up to 70-75% pumped out)
resistance won’t change
rest (55-60%) is pumped out every beat
what determines ejection fraction %
EF= (SV/EDV) * 100%
what is defined as the Rate of blood flow through the heart per minute that determines blood pressure?
Cardiac output (Q) Q=HR*SV
how does cardiac output change during exercise?
resting- 5 L/min
aerobic- 20-25L/min (more relying on mitochondrial, more O2 needed, more circulation)
exercise- slightly elevated
How does systolic blood pressure (contraction) change during exercise?
rest 115-120 mm HG (increased pressure on arterial walls)
aerobic- up to 200 mmHG, when SV increases then EF increases
resistance- up to 300, muscular contraction put pressure on veins and arteries (shrinking the space with a set amount of “stuff” in it
how is diastolic blood pressure (relaxation)
rest- 75-80 mmHg- not pumping so pressure falls
aerobic- to changed or slight decrease. nothin is going into vessels so nothing should change
resitance>250. pressure on walls
Why does MAP have two different equations?
because there is a different systolic and diastolic response to different types of exercise. resistance effects muscles and pressure
Explain TPR
it is opposition to normal blood flow. it is MAP/Q
- increasing TPR is harder to push blood out
- decrease- easy to push blood out because less resitance/opposition
how does TPR change during exercise?
resting 18-19mmhg
aerobic- decreases. due to a larger Q value and normal MAP
resistance- huge increase from rest b/c of HUGE increase in MAP from rest due to HUGE increase in SBP and DBP (during CONTRACTIONS)
what value indicates O2 requirement of the Heart?
Rate Pressure Produce
RPP= HR * SBP
how does it change with exercise
resting- 7200,-12,000
aerobic- increase (increase HR & SBP)
resistance- increases during contraction b/c of big increase in SBP
How does the autonomic nervous system govern heart circulation by releasing NOrepinephrine
norepi comes from the SNS which up-regulates cardiac fxn by B1 receptors (increase force and rate of contraction).
activates alpha 1 receptors that causes vaso-veno-constriction by constricting smooth muscle in arteries and veins and closes vessels down to increase BP and speed up blood flow (not to muscle)
how is heart circulation governed by parasympathetic nervous system?
actylcholine down regulates SNS activity by decreasing cardiac function with M2 heart receptors
B2 arterial receptors tell smooth muscle to relax by faso/venodialation, decreasing BP and slowing blood flow
what feedback do barorecptors and chemoreceptors have on the heart function?
they work in the shymapthetic and parasympathetic system in the aortic arch and corotid artery
they are feedback loops that try to get to homeostasis by increasing or decreasing blood pressure
which autonomic system dominates during exercise?
SNS
what are 4 factors that regulate cardiovascular regulation?
- Autonomic nervous system
- Heart
- systemic circulation
- others (muscle pump, respiratory pump, exercise pressor reflex)
how does the heart regulate cardiovascular regulation?
the heart regulates that magnitude(how fast) of blood flow through body by:
- preload
- afterload
- contractility
what happens if you increase pre load?
increase SV and decrease BP to keep same Cardiac Output
how can body position influence cardiovascular regulation?
- increases ability to return blood back to the heart
- recumbant bike. enhances venous return
what is afterload
the pressure the heart must over come to get blood into systemic circulation
what influences aferload
decree of vasoncstriction and vessel health
how does ACH effect contractility of heart
if too much ACH - decrease function of norepinephrine- increases contraction and function
what influences contractility?
intracellular calcium, preload and ANS
how does systemic circulation regulate cardiavascular?
-distrubution of blood flow by:
neural mechanisms
metabolic conditions
what neural mechanisms up regulate in systemic circulation
central command center
baroreceptors- monitor blood pressure
which metabolic conditions influence systemic circulation?
EDRFs - enotherlial-derived relaxing factors
increased H+, co2 lactate, adenosine promote increased blood flow and local vasodilatation
how does the muscle pump influence blood flow
it helps push blood up and through one way valves
how does the respiratory pump influence blood flow
expanding the thoracic cavity increases volume and decreases pressure which facilitates venous return to heart
what is the exercise pressor reflex?
response to muscle contraction that increases SNS to ensure adequate blood delivery to muscles
-it increase BP, HR, CO, and vasoconstriction
reflex activated–> brain –> SNS increase –> spike in BP, HR.. –> eventually goes down to match exercise intenisty
why is it important for sns to predominate during activity?
?
how does sns innervation work in concert with EDRFs to direct blood flow where its needed?
SNS causes vaso=veno constriction but EDRFs override SNS at local level to vasocodialate at places where we need blood flow
how would exercise effect preload on the heart?
exercise increases HR- increase SV increase preload
how much the heart adapt in response to chronic exercise?
?
how do different forms of exercise influence muscle pump, reap, and exercise pressor reflex?
?body position –> better venous return
contracting muscles can push blood up through valves & stimulates reflex
