Lab 5: Intro to Cardio Vasc Phys Flashcards
What causes the heart sounds
lubdub
-turbulent backwash of blood in heart chambers and large arteires which follow the closure of the heart valves
LUB: closure of atrioventricular (AV) valves at the beginning of ventricular systole
-when ventricles contract, backflow against valves cause them to close and bulge backwards towards atria, and elastic ventricles cause blood to backsurge to ventricles, which make the noise
DUB:
closure of semilunar values (aortic vakve on left, pulmonary on right) after ventricular systole
-again, backsurging blood revertebrate against walls and make vibrations in the pulmonary artery and aorta
Where to place stethescope to hear heart sounds LUB
5th left intercostal space on left margin of sternum (tricuspid area)_
Where is your radial pulse? Where is your carotid pulse
on wrist, on neck
When is carotid pulse heard, when is radial pulse
Carotid: heard after the first heart sound, because this carotid artery is closer to heart so there is minimal delay
Radial: felt slightly after the carotid becaiuse this has an additional distanc eit must trvel from aorta to arm
where to hear heart sound DUB
2nd left or right intercostal space
Blood presure determination
using ausculatory method
-use sphygmomanometer to hear the appearance and disapearence of Korotokoff sounds from the brachial artery
what is the firstkorotokoff sound:
-blood rushing back thru constricted artery with each systole (contraction) of the heart
What is systolic pressure:
pressure of the cuff when thefirst korotokoff sound is heard
when is second korotokoff sond heard:
-when there isa disapearance of the rushing because it reaches equilibrium withdiastolic pressure and blood flow normalnow
What is dyostolic pressure
-pressure of cuff when sound disapeears (2nd korotokoff sound)
what does the sphygmomanometer constist of
compression bag surrounded by cuff (toapply pressure to arm)
inflating bukb for creating pressure
manometer to measure pressure
a valve which can be used to delflate pressure in controlled manner
Ausculatory method steps
- Subject sits and cuff applied just (2-3cm) above elbow, arrow on cuff(or rubber tube) should be over brachial artery
2.Place sthesthecope over aretey on part just under elbow
- Pump cuff to 140 mmHg rapidly, then release at 2-3mmHg per heartbeat until a sound is heard, SYSTOLIC PRESURE
4.
Systolic pressure:
DIasoltic pressure represents:
represents work done by left ventricle to overcome resistance of entire circ system
represents the condition of the arteryies bc theis is min pressure they are sbjecteive to
what is high blood pressure
160/95 mm of Hg, more thant 3 times. aday its higher than this
Pulse pressure meaning and calculation
difference in systolic and diastolic pressure
=Sys-dia
Cardiac output and eqn
the measure of how well the heart is delivering blood to circ system
what causes it to be reduced:
-diseases like hypertension, cardiomyopathy, heart faikeure
what causes it to be increase:]
-diseases like infection and sepsis
EQN
cardiac output (Liters of blood ejected from left ventricle in a min)= (heart rate)(stroke volume)
Q=HRxSV
-increases due to increase in heart rate (60-180)
SV
Stroke volume
EDV-ESV
(end di volume -end sys)
usually 70-120ml (1.7 factor)
OR calculated by
SV=101-(0.50xsyspressure)-(1.09xDiaP)-(.61xAge)
What is cardiac output regulated by
1)O2 demand
-as rate of metabolsim increases, demand for o2 increases and cardiac output increases
2)Change in Circ System(dia of vessels)
-vasoconstrictors/vasodialators
-ie if vasoconstrict are present in systm, diameter of vessels decreaess so increased resistance in vessels and system so decreased cardiac output
-changes mediated thru symp and parasymp nervous system
3)Breathing
-affects intrathoraic pressure
-during inhalation this intrathoraic pressure decreases, allowing ventricles of heart to fill more during diastole (so INCREASES CARDIAC OUTPUT)
change in cardiac output in response to breathing is known as
stroke volume variation
Medical tools to determine cardiac output
MRI, Doppler Ultrasound, Impedance Cardiigraphy, thermodilution techniques
Since it is hard to measure BP with sthestcope and pressure cuff, what do we use to assist students
pulse transducer, records appearance and disappearance of pulsatic blood flow (indicate when systolic and dia pressures are)
Equip
Same
+PPG-320 Pulse Transducer
+BP-220 Non-invasive blood pressure transducer
Stethescope
BP-220 and PPG320 set up and Software Setup
PPG- PT port on ixta roam
BP: need additional tube to connect,and connect thru A2 port
Start Software:
same
1)Human Circulation File and click Cardiac Output
how to calibrate BP-220
1) if signal of pulse channel upside down, click down arrow next to channel title
2)if pulse signal noisy, hold the pulse transudcer to ur finger tighter
3) record data for10 seconds of the cuff just on table
Unit conversion
1) move cursor to left of screen and another to the right
2)click v2-v1 on right side of BP channel, click SET OFFSET
3) Set mean value to 0, click “apply calculated offset for this block to all blocks” and “apply units to next recorded nlock”
General procedure:
1)Place on cuff and pulse transucer
2)click record
3)inflate cuff until pulse wavers and disapeeras
4) onceit disappears, released cuff presure at rate of -10mmHg / second
5) release until gauge reads 20mmHg
6)record additional 30 seconds after
7)stop
How to get Systolic pressure, diastolic and heart rate from the data
Sys: place cursor on the first pulse that reappears after pulse gone
(will be value1)
Diastolic: place cursor on the first largest pulse after systolic
(will be value 2 on table)
Heartrate: place a cursor just after the dia and a cursor 10 seconds later
-value will be the mean (average heart rate after BP determine)
FInd stroke volume using eqn and find cardiac output (ml/min) = Stroke Volume (ml/beat)xHeartRate (beats/min)
what will we test all these things for
sitting
reclinging
standing
sitting after exercise
sitteing after 30 s exercise
“” 60 sec
“ 90 sec “
120 sec
How does sys and dia p compare for sitting recling and standing
Sitting
sys: may slight decrease or stable cuz not much graviy to work against
dia: stabl
Reclinging:
sys: again decrease or stable cuz no gravity really to work against
doa; stable
Standing
sys: , initial drop when first stand sinve gravity, slightly increased compared to the other two cuz have to work against gravity to maintain it
dia: might increase to maintain flow
higher resistance in entrire circ system so keft ventricle has to work more
How does heartrate compare
similar to pressures.
lowest at reclining
highest at standing bc need to make sure blood going to brain so need to pump against gravity
Diving reflex is what
-air breathing animals developed ways for them to survive while submerged under water
do this by…
-using stored o2, decreasing o2 consumption and using anerobic metabolism (and aquatic res if possible)
What is selectice peripheral vasoconstriction
prioritizes where oxygen is delivered (going to highest priorities… brain, heart and adrenal glands)
-other organs use local stores or anaerobic metanolis
-since vasoconstrict increases BP, BP is maintained by reduction in its cardiac output (by decreasing heart rate)
Submersion hypothermia
-drowning in cold water
-young skinny ppeople survived while being drowned for 1 hour because it cooled the core of the individual
usualy only can do diving reflex for 2-3 mins
-dr martin niemeroff (did stuff with cold water drowing kids)
Diving reflex setup
same everything, no BP220 cuff tho
open human heart, Diving Reflex
how to data analysis for this
have max min mean, so just put cursors around data and do it , should be in function table already
also sometimes heart rate at certain points like apnea (stop breathing)
What are we doing for Diving reflex
1) Resting Heart Rate
2)Heart rate and apnea (holding breath for as long as possible, apnea means when u stop brething)
how do subjects max and min heartvrates while resting compare to heart rates while holding breath
initislly increase then decrese lower due to diving reflec
so max and min will be better in holdign breath (better as in lower for min and higet for max)
what temps water
25, 15, 5
what happens when face submerged in water
decreases heart rate
may have a initial quick increase due to the shock (symp systemn will increase it) but this is brief and the decreased heartrate is wayyyyyy more prominnent
what causes the cahnge in heartrate
initial :symp system having fight for lgiht resone
diving reflex is the main cause fo the lowered heart rate, conserving 02, preserving it
how does mammlian dibing reflex help a person wjo falls into cold wter
prioritizes the important organsn called selective peripheral vasoconstriction
hyperemia def
increased amt of blood frow to organ
valves help overcome pressure of gravity how
by divingbblood in viens in these lower limbs into many segments
Repiratory pump and skeletal muscle pump
-resp: squeezes and releases presure to hep force blood toward the heart during inhalation
skeletal: properls blood forward from limbs to truunk
Active hyperemia (arterial) vs passive (venous) vs reactive
-when there is an unusual demand such as increased waste products, increased blood flow in that area occurs
-when venous drainage of an area is distrupted so blood accumulates ratherthan drains
reactive:
apply ice pack to constrict then dialaite when removed allowing more
