Department of Physiology, Faculty of Medicine, Masaryk University, Brno1
Cardiovascular system I
Organization of cardiovascular system. Blood. Arteries and veins. Microcirculation. Cardiac electrophysiology and ECG.
Compendium of Physiology – autumn 2020
Tibor Stračina
Compendium of Physiology2
Organization of CVS
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-17/figure-17-3
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-20/figure-20-1
Blood
Compendium of Physiology3
̶ Blood plasma
̶ Water
̶ Ions
̶ Proteins
̶ Urea, glucose, etc.
̶ Erythrocytes
̶ Leukocytes
̶ Platelets
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-18/figure-18-1
Compendium of Physiology
Red blood cells. Haemolysis
̶ Erythropoiesis
̶ Life span
̶ Degradation
̶ Function
̶ Transport (O2, CO2)
̶ Buffer (hemoglobin)
Haemolysis
̶ Physical
̶ Mechanical
̶ Osmotic
̶ Thermic
̶ Chemical
̶ Biological
̶ Immune responce
4
Compendium of Physiology5
Blood groups. AB0 system
̶ Surface antigents on the RBCs
̶ AB0 system
̶ The highest imunoactivity
̶ 2 surface antigens (A, B), co-dominance
̶ 4 blood groups: A, B, AB, 0
̶ Antibodies constantly produced
̶ Other systems: Rh, MNS, P, Kell, Lewis, Duffy, Diego
5
Compendium of Physiology6
AB0 system – slide method
6
Serum (antibodies)
Anti-A
Anti-B
Anti-A + Anti-B
Blood group
Legend:
Negative reaction
Positive reaction
0 AB B A
Compendium of Physiology7
Rh system and other systems
̶ Rh system
̶ Antigen D
̶ Anti-D antibodies
̶ Rh incompatibility (Rh- mother vs. Rh+ fetus)
7
Compendium of Physiology8
Arteries: blood pressure, R, blood flow
̶ Systemic arteries – high-pressure system
̶ Elastic arteries (low resistance, high compliance)
̶ Resistance arteries (high and regulable resistance)
̶ Pulmonary arteries – low-pressure system
Compendium of Physiology9
Veins: blood pressure, R, blood flow.
Venous return. Venostasis.
̶ High capacity - volume reserve
̶ Low pressure gradient
̶ Mechanisms of venous return
̶ Muscle pump
̶ Valves
̶ Blood flow (pressure) through capillaries – vis a tergo = force from behind
̶ Suction force of ventricular systole – vis a fronte = force from the front
̶ Suction force of inspiration
Compendium of Physiology10
Microcirculation
̶ Net filtration pressure
(Starling forces)
̶ Hydrostatic (blood) pressure in capillary
̶ Hydrostatic pressure in interstitium
̶ Osmotic pressure in capillary
̶ Osmotic pressure in interstitium
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-20/figure-20-9
Compendium of Physiology11
Heart. Cardiac muscle as an excitable tissue
̶ Excitability
̶ Task: Draw AP of working ventricular cardiomyocyte.
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-1
Compendium of Physiology12
Action potential: Ventricular muscle cells
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-2
Compendium of Physiology13
Cardiac automaticity. Condactive system
̶ Pacemaker aktivity
̶ SA node >> AV node >> Purkinje fibres
̶ Condactive system
̶ Fast conduction
̶ Delay (AV-His)
https://studentconsult.inkling.com/read/boron-medical-physiology-3e/chapter-21/figure-21-2
Compendium of Physiology14
Electric vector of the heart. ECG
̶ Potential differences
̶ Summary of all partial vectors
̶ Changes in time
Author: MN; https://is.muni.cz/auth/el/med/jaro2020/aVLFY0422p/um/ECG-2020-GM.pdf
Compendium of Physiology15
ECG electrodes. ECG leads
̶ ECG electrode
̶ ECG lead – connection of two active exploring electrodes (bipolar
lead) or one exploring electrode and one reference
electrode/clamp (unipolar lead)
Compendium of Physiology16
Standard 12-lead ECG
̶ 3x bipolar limb leads
̶ I, II, III
̶ 3x unipolar augmented limb leads
̶ aVR, aVL, aVF
̶ 6x unipolar chest leads
̶ V1, V2, V3, V4, V5, V6
R L
F
aVR
aVF
aVL
IIIII
I
V
V1
V6
Einthoven
triangle –
frontal plane
horizontal
plane
Compendium of Physiology17
Standard 12-lead ECG record
Patient‘s name; date and
time of measurement
Time and voltage scale
Bipolar limb leads (I, II, III)
Unipolar augmented limb
leads (aVR, aVL, aVF)
Lead II in long time scale
Values from automatic
analysis (TF – heart rate)
Unipolar chest leads
(V1 – V6)
Calibration mark
Compendium of Physiology18
Normal ECG curve - nomenclature
̶ Changes of voltage (mV) in time
Pwave
PQsegment
QRScomplex
STsegment
Twave
PQinterval
QTinterval
RRinterval
The level of the isoline
A negative
deflection
A positive
deflection
Compendium of Physiology19
ECG evaluation – basic algorithm
1. Heart rhythm (regular/irregular; sinus/junctional/ventricular/other)
2. Heart rate (a value in bpm)
3. The duration of the P wave, the PQ interval, the QRS complex, and the QT
interval (in ms)
4. Position of ST segment (in isoline/elevated/depressed)
5. Transitional zone (position; lead V1 – V6)
6. Electric axis of the heart (position in degrees)
Compendium of Physiology20