Physiology of cardiology - note questions Flashcards
Receptor for Ach
muscarinic cholinergic
Receptor for phenylephrine
alpha adrenergic
Receptor for isoproferenol
beta adrenergic
Receptor for eipnephrine
Beta and alpha
Receptors for norepinephrine
alpha and beta
Effects of Ach
decreased heart rate, conduction and cardiac strenght
dialate arterioles
increase gi motility and relax sphincters
constrict pupil
increase glycogen synthesis
Effects of phenylephrine
Constrict arterioles and veins
inhibit gi motility
constrict spleen
dialate pupil
Effect of isoproterenol
b1 receptors: increase heart rate, conduction and contractility = increase bl. pr. and cardiac output
b2 receptors: dialate arterioles = peripheral resistance and bl. pr. decrease
Effect of norepinephrine
similar to epinephrine, greater effect on bl. pr. and slight increase in heart rate
NB, sudden change in arterial pr. may lead to respiratory inhibition or apnea !
Effect of epinephrine
increase bl. pr., but baroreflex response may decrease the heart rate
systolic, diastolic and mean carotid bl. flow increase
CVP may change with venous constriction or in response to effectivness of heart.
What activates \ blocks muscarinic receptors?
Activates: Ach
Blocks: Atropine
What can Ach cause?
AV block or sinus arrest
Modalities present in vagus nerve?
GVE = parasymph. fibers to stomach, heart and lungs GVA = sensory info from viceral organs, pressure receptors in aortic arch SVA = taste from glottis SVE = motor to muscles of pharynx and larynx
Cutting RIGHT vagal nerve, what happens?
Usually sinus arrest
decrease respiration, heart rate and increase venous pressure
Cutting LEFT vagal nerve, what happens?
Usually AV block
slight bradycardia, increased PR interval
Baroreflexes, where can we find them?
Aortic arch and carotid sinus
What does baroreceptors react to ?
Amount of strech\ pressure
Routes of signal from baroreceptors in carotid sinus and aortic arch
Carotid sinus - carotid sinus nerve - glossopharyngeal nerve - cardiovascular control areas in the medulla
aortic arch - sensory fibers of vagus nerve - medulla
Response of medulla to info from baroreceptors
vagus + symphatetic nerves sends signals to control heart rate + strenght
spinal nerves sends signals to control peripheral vasoconstriction of the arterioles all over body
What drug can we give in an experiment to increase arterial pressure that will give us baroreflex response ?
Phenylephrine
What drug can we use in an experiment to decrease arterial pressure by vasodialation?
nitroglycerin
What happens at inspiration?
Intrapleural pressure becomes negative, which increase compliance of the pulmonary vasculature
increases right atrial filling, increases right heart output
Possitive pressure ventilation, what happens?
alveolar pressure goes positive, decreased transmural pressure, increased blood flow resistance and pulmonary arterial resistance, decreased pulmonary flow and left filling, aortic flow and arterial pressure
Spontaneous respiration, what happens?
Alveolar pressure goes negative, increased transmural pressure of pulmonary blood vessels, decreased pulmonary arterial pressure, increased pulmonary blood flow.
increased left atrial filling pressure, aortic blood flow and arterial blood pressure during inspiration.
What will happen if you add to much of positive pressure ventilation?
The capillaries will collapse !
What artery do you use when you want to put in a catheter to the left heart?
Femoral artery
What vein do you choose if you want to put a chateter to the right heart ?
Jugular vein
How do calculate average of systolic and diastolic pressure ?
systolic + (2x) diastolic / 3
What is atelectasis?
The collapse of parts of the lung when dog is in surgery and positive pressure ventilation is used
What happens during atrial fibrillations?
R-waves are not followed by pressure pulses = pulse deficit
effect : cardiac output continues but is less efficient due to lack of coordination between atrial and ventricular contractions
What happens during ventricular fibrillations?
if ventricular fibrillation occurs with atrial fibrillation = blood pressure = 0
ventricular fibrillation is lethal and atrial = not lethal
cardiac massage can be applied during ventricular fibrillation
requires electric defibrillation to repolarize the entire myocardium and let the sinus node set a new rhythm.
What happens during systole
Contraction of heart
What happens during diastole
Relaxation of the heart
P-wave
atrial depolarization
QRS complex
Ventricular depolarization
T-wave
ventricular repolarization
Heart sounds
S1 and S2
s1= closure of AV valves at beginning of isovolumetric contraction s2= closure of aortic and pulmonary valves at the beginning of isovolumetric relaxation
Mitral insufficiency
Left atrioventricular valve
valve does not close properly
atrial pressure increased + rate of ventricular filling + left atrial filling + diastolic ventricular vol
holosystolic murmur
Mitral stenosis
increased left ventricular pressure
decreased slope of left vetricular volume
prolonged p-wave
continuous diastolic murmur
Aortic insufficiency
increased ventricular pressure, left atrial pressure, ventricular volume
Aortic pressure drops first, then increases during systole.
QRS-complex, R-wave increased
Aortic stenosis
Increased left ventricular pressure, R-wave
Decreased aortic pressure, left ventricular volume
systolic murmur
Combined aortic stenosis and insufficiency
increased left ventricular pressure, left ventricular volume, R-wave
decreased aortic pressure
diastolic + systolic murmur
Patent ductus arteriosus (PDA)
Increased left ventrocular pressure, aortic pressure, left ventricular volume, R-wave
systolic and diastolic murmur
Pulmonic stenosis
increased right arterial pressure, right ventricular pressure, right ventricular volume, R-wave
abnormal heart sounds
Hypertension
Increased pulse pressure, left ventricular pressure during diastole
