4610 - LAB 12 - Blood Pressure

p. 160-167

what does a sphygmomanometer measure

medical instrument used to measure blood pressure

parts of a stethoscope 7
& function of each part
which way should the eartips face

headset

eartip (transmits sound from ear tube into ear canal)

eartube (connects to eartips to direct sound)

tubing (carries sound from chest piece to ears)

stem (connection between tubing/chest piece)

tunable diaphragm (to hear sounds)

chestpiece (placed on body)

eartips face forwards

parts of a sphygmomanometer 9
& functions of each part

cuff = stops circulation in brachial artery when inflated

gauge holder = used to hold manometer gauge

artery position indicator label = shows how to place the cuff

inflation bulb = hand pump to fill cuff with air

air release valve = small valve lets air out of cuff

hose / tube = tube carries air to the cuff

cuff size = shows what arm size fits the cuff

index marking = helps show if cuff fits properly

aneroid manometer gauge = shows blood pressure reading in mmHg

what units are used for measuring blood pressure

mmHg

calculate pulse pressure

PP = systolic pressure — diastolic pressure

calculate mean arterial pressure (MAP)

MAP = diastolic pressure + (pulse pressure/3)

define pulse pressure

numerical difference between systolic (top number) and diastolic (bottom number) BP readings, measured in mmHg

normal range for pulse pressure

40 mmHg

normal range 40-60 mmHg

causes of low / narrow pulse pressure

aortic stenosis (narrowing of aortic valve), congestive heart failure, severe blood loss, and cardiac tamponade (fluid build up around the heart)

causes of high / wide pulse pressure

age-related artery stiffness (Arteriosclerosis), hypertension, aortic valve disease (such as aortic regurgitation), or hyperthyroidism

define mean arterial pressure

average pressure in arteries during one complete cardiac cycle (heartbeat)

normal range mean arterial pressure

70 to 100 mmHg

minimum of above 60 required to provide sufficient oxygen to organs (organ perfusion)

explain clinical significance of mean arterial pressure measurement. use: perfusion pressure, organs, MAP, mmHg, oxygen, ischemic.

ischemic = not enough blood supply

MAP represents the average perfusion pressure driving blood through the systemic circulation during a single cardiac cycle. MAP is a reliable indicator of whether vital organs are receiving enough blood flow. MAP under 60 mmHg indicates poor perfusion leading to ischemia & organ damage.

what event in the cardiac cycle causes S1 sound lub

closing of AV valves (mitral/tricuspid) at the beginning of ventricular contraction (systole)

what event in the cardiac cycle causes S2 sound dub

closing of semilunar valves (aortic/pulmonary) at end of ventricular contraction / start of relaxation (diastole)

define heart murmur

extra / unusual "whooshing" / "swishing" heard between normal heartbeats caused by turbulent or faster-than-normal blood flow through the heart chambers or valves

problems that cause heart murmurs

overall cause: turbulent bloodflow

congenital heart defects like a hole in the heat (septal defect)

infections like endocarditis (infection of heart lining/valves)

Heart Valve Disease like Valve Stenosis (Stiffening) or Valve Regurgitation (Leaking)

auscultation of valves means

using a stethoscope to listen to the specific sounds produced by the heart's valves opening and closing

why does the mitral valve close slightly before the tricuspid valve

the left ventricle begins contracting and building pressure sooner than the right ventricle

what causes the M1 of S1

the closure of the mitral valve at the beginning of ventricular contraction (systole)

what causes the T1 of S1

the closure of the tricuspid valve

what does a split S1 sound like

sounds like a "slurred" or two-component "lub" (lub-lub) instead of a normal single lub

in what positions do you hear split S1 best

lower left sternal border (tricuspid area) heard using diaphragm

does split S1 sound better or worse during inhalation

split S1 becomes more noticeable / better heard during inhalation

why does the aortic valve close slightly before the pulmonary valve

the left ventricle operates under much higher pressure than the right, causing it to finish emptying and relax sooner

what causes the A2 of S2

closure of the aortic valve at the end of ventricular systole

what causes the P2 of S2

the closure of the pulmonary valve at the end of ventricular systole

what does split S2 sound like? what position can you hear it in?

split S2 sounds like the "dub" of "lub-dub" has broken into two distinct, rapid clicks

best heard during inspiration at the left upper sternal border (2nd left intercostal space).

does split s2 sound better or worse during inhalation? what about exhalation? why?

sounds better / easier to hear during inhalation

worse hard to hear during exhalation

easier to hear during inhalation because decrease in intrathoracic pressure increases venous return to the Right side of the heart.

that slows the pulmonary valve closure while accelerating aortic valve closure.

this increased volume makes the pulmonic component occur later and slightly louder making it easier to hear

systole pressure

maximal arterial pressure following ventricular contraction, about 120 mmHg

diastole pressure

minimal arterial pressure following ventricular relaxation, about 80 mmHg

hypertension

elevated systolic or diastolic BP

hypotension

decreased systolic or diastolic BP

heart rate

number of contractions per minute

60 to 100 bpm healthy usually 60 to 80 bpm

S1 is produced by _______ by the closing of the _____ valves

S1 is produced by turbulent flow by closing of the AV valves

S2 is produced by _______ by the closing of the _____ valves

S2 is produced by turbulent flow by closing of the semilunar valves

area of auscultation - aortic valve

right parasternal 2nd intercostal space

area of auscultation - pulmonary valve

left parasternal 2nd intercostal space

area of auscultation - tricuspid valve

left parasternal 5th intercostal space

area of auscultation - mitral valve

5th intercostal space at left midclavicular line