Phys Lab 5

when you are cold your blood vessles _____

dialate

what is resting heart rate determined by

rate of SA node

effects of innervation by parasympathetic nervous system

What does the SA node want to set the resting heart rate to

100 bpm

What is the true avg resting heart rate due to parasympathetic NS

75 bpm

what is the range of normal values for resting heart rate

60-100 bpm

bradycardia

resting heart rate below 60 bpm

tachycardia

resting heart rate above 100 bpm

what act on the SA node to increase hr / rate of action potentials

sympathetic ns

epiniephrine

what is the formula to estimate HR max

220 - age =

what makes the lub sound

closure of atrioventricular valves

when does LUB sound happen (timepoint)

when ventricular systole begins

what makes the DUB sound

closure of semilunar valves

when does DUB sound happen (timepoint)

ventricular diastole begins

where should you place stethescope to hear the LUB sound

apex of heart

where should you place stethescope to hear DUB sound

second intercostal space

how does inspiration and expiration effect HR

inhale - increases HR

exhale - decreases HR

what is conduction system of the heart made of

non contractile cardiac muscles that spread electrical impulses

what control the contraction of cardiac muscles

conduction system

where is the SA node located

right atrium

what is known as the pacemaker

Sinoatrial node

where is AV (atrioventricular) node located

base of atrium

lable

.

P wave is due to

atrial depolarization

(SA node fires and depol wave spreads through atria)

QRS wave is due to

ventricular depolarization

(depol wave spreads from AV node through the ventricles)

Is atrial repolarization seen on ECG

no, it is hidden by QRS

T wave due to

ventricular repolarization

P-Q interval located where

from start of P to start of Q

what happens during P-Q interval

atria contracts and AP spreading through the AV node

S-T interval located

end of S to start of T wave

what happens during S-T interval

ventricles are depol and contracted, blood ejected from ventricles into arteries

T-P interval

period of time between cardiac cycles when heart at rest (atria and ventricles)

R-R interval located

interval between R waves

what does R-R interval represent

time it takes for one cardiac cycle

what is ECG

graphic record of electrical activity ( all AP generated by nodal and contractile cells)

arrhythmias

irregular rythems caused by abnormal impulse formation or conduction

conduction delays

slower then normal electrical transmission through hearts conduction pathway

what does Bradycardia look like on ECG

longer T-P interval

what does Tachycardia ECG look like

shorter T-P interval

Heart block

atrial impulses fail to conduct through (AV, bundles, Purkinje)

what does heart block look like on ECG

dropped beats, P waves not followed by QRS

Fibrillation

uncoordinated signaling and contraction of atria or ventricles

What does atrial fibrillation look like

multiple irregular waveforms where P value would normally be (no P waves visible)

what does ventricular fibrillation look like

rapid irregular waveforms with no P, QRS, T waves

does atypical pattern always mean unhealthy

not always

R-pulse interval

time it takes from ventricular depolarization to contraction causing pulse pressure

how to calculate HR from ECG

chart speed / QRS distance (mm/beat) = beats per second

60 seconds x beats per second = HR/min

perfusion

the passage of blood to deliver O2 and nutrients

systole

force that blood exerts on arterial walls during contraction

diasole

force that blood exerts on arterial wall during relaxation

blood pressure

force that blood exerts on vessel walls (normally artieries)

systolic pressure

pressure in large arteries at peak ventricular ejection

diastolic pressure

pressure in large arteries during ventricular relaxation

BP is meassured in what?

mm Hg

120/80

what is systolic and diastolic pressure

120 - systolic

80 - diastolic

what is average normal BP

120/80

Hypertension is classified as

> 140/90 with stethoscope

> 135/85 with automatic BP device

what can cause short term hypertension

caffne, nicotine, drugs

chronic hypertension is caused by

aging, lack of exercise, stress

Sphygmomanometer

instruemnt used to obtain BP using auscultatory method.

auscultatory method

listening to sounds of body with stethescope

what arterie is used to meassure BP

bracial artery

what sounds are used to meassure BP with spygmomanometer

sounds of Korotkoff

when is systolic and diastolic pressure meassured with BP cuff

sounds detedcted - systolic

sounds disapear - diastolic

what causes sounds of Korotkoff

turbulent blood flow

pulse pressure

actual working BP (systolic - diastolic = PP)

Mean artieral pressure (MAP) represents

pressure with which blood is being delivered to organs

what is normal MAP

70 - 110 mmHG

what MAP would need medical intervention

under 60 mmHG

what happens if MAP to low

may not reach organ or pass to slowly for adequate delivery

what happens if MAP to high

blood passes through organs to fast for exchange

MAP can be calculated by

PP/3 + Diastolic pressure = MAP

turbulent flow

chaotic / irregular flow

laminar flow

steady flow

what happens to systolic and diatolic pressure during exercise

systolic - increases

diastolic - stable

where is first heart sound heard on ECG

QRS

where is 2nd heart sound heard

T wave