Physiology Of Circulatory System - Physical Examination, Blood Pressure Analysis, ECG - PP ----DONE Flashcards
Ausculation position for tricuspid valve
Left 4 ICS PSL
Ausculation position for pulmonary valve
Left 2 ICS PSL
Ausculation position for mitral valve
Left 5 ICS MCL
When does the first heart sound, “lub”, occure?
When atrioventricular valves close
When does the first heart sound, “dup”, occure?
When semilunar valves close.
When will the Korotkoff sounds be heard?
Korotkoff sound will be heard until cuff pressure equals diastolic pressure, causing the sound to dissapear.
When will the blood flow during a measurment of bloodpressure?
A blood pressure cuff is initiated above systolic pressure, occluding the artery. As cuff pressure is lowered, the blood will flow only when systolic pressure is above blood pressure, producing the sounds of Korotkoff.
Where can baroreceptors be found?
- carotid sinus
- aortic arch
What are baroreceptors?
Mechanoreseptors sensitive to the streching of the vessl wall in which they are located, high pressure receptors.
What reduces the activity of the baroreceptors?
The factors leading to the reconstruction of the arteries and reducing its compliance (untreated hypertention, aging) are reducing the activity of baroreceptors.
Ausculation position for aortic valve
Right 2 ICS PSL
Baroreceptor reflex:
⇧BP⇛ ⇧ baroreceptor activation ⇛ ⇧ firing rate in afferent fibers of nerve IX (carotid artery baroreceptor) and X (aortic baroreceptor) ⇛ increased activity of nerve X ⇛ inhibited sympathetic activity ⇛ domination of parasympathetic ANS ⇛ ⇩ BP ⇩ HR
What leads to the cracles during physical examination?
- Pulmonary congestion leads to a poor O2 exchange in lungs»_space;> Hypoxia
- In physical examination - cracles
- There is water in the air sacs (alveoli)
Respiratory sinus rhythm irregularity
- Inspiration ⇛ parasympathetic nerve inhibition (vagus - X) ⇛ ↑ sinus rhythm.
- Expiration ⇛ stimulation of vagus nerve ⇛ ⇛ ↓sinus rhythm.
What creates a diploe?
Partially depolarized myocardium creates a diploe.
When are diploes present? And when are they not formed?
- Diploes are present only when myocardium is in the process of of depolarization or repolarization.
- They are not formed when the entire myocardium is depolarized or repolarized.
ECG
Presents electrical activity and conduction in the atria and ventricles.
What causes the P wave?
P wave is caused by depolarization of the atria.
PR interwal:
PR interwal (from beginning of P wave to the start of QRS complex) – time when potential is traveling from SA node to the end of Purkinje system
PR segment:
PR segment (from the end of P wave to the beggining of the QRS)– time when atrial muscle is totally depolarised, and the wave of depolarization moves through the AV node, the AV bundle, the bundle branches, and the Purkinje system
QRS:
- QRS complex is a potential caused by depolarization of the ventricles (≤ 110 ms).
- After QRS complex entire ventricular mass is depolarized
ST segment:
ST segment – ventricles are totally depolarised, corresponds to the plateu
T wave:
T wave is a time of ventricular repolarization, repolarization of atria occurs during QRS so we don’t see it in ECG
QT interval
- QT interval – time between initiation of QRS and the end of T wave.
- It corresponds to the entire action potential.
- It is inversely proportonal to the HR.
What happens with the QT if the ventricular repolarization is delayed?
If ventricular repolarization is delayed -QT is prolonged - delayed repolarization is associated with the genesis of ventricular arrhythmias
What is associated with the genesis of ventricular arrhythmias?
If ventricular repolarization is delayed -QT is prolonged - delayed repolarization is associated with the genesis of ventricular arrhythmias
TP segment:
TP segment – isoelectric line (ventricular diastole)
P wave:
Atrial excitation (from SA node – spreads over the atria) – P wave
Q wave:
Depolarization of the septum (from left side to the right side of septum) - Q wave
R wave:
Depolarization of free wall ventricular muscle from subendocardium to the subepicardium (because LV mass is much greater than RV - dipole is on the left side) – upward defelction of R wave
R wave and S wave:
Last portions of LV (basal portions) are depolarised – downward deflection of a R wave and S wave
Phase 2 when the ST segment appears:
When ventricular muscle becomes totally depolarised tracing returns to a baseline and ST segment apears – phase 2
read the rest, starting from page 23 on the PP
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