When deoxygenated blood returns from circulation, it passes through the heart chambers and valves in what order?
RA > mitral valve > RV > pulmonary valve > LA > tricuspid valve > LV > aortic valve
RA > tricuspid valve > RV > pulmonary valve > LA > mitral valve > LV > aortic valve
LA > mitral valve > LV > pulmonary valve > RA > tricuspid valve > RV > aortic valve
LA > pulmonary valve > LV > tricuspid valve > RA > aortic valve > RV > mitral valve
What artery directly provides the blood supply to the heart?
subclavian artery
coronary arteries
interlobular artery
pulmonary artery
What is the correct order of an vein's structure, starting from the layer closest to the lumen?
endothelium > internal elastic lamina > tunica media > tunica adventitia
epithelium > tunica muscularis > serosa > vaso vasorum > tunica media
endothelium > tunica adventitia > internal elastic lamina . tunica media
epithelium > tunica adventitia > serosa > tunica media > external elastic lamina
What provides proteins to nourish a capillary's endothelium?
pericytes
endothelial cell
internal elastic lamina
basal lamina
Sympathetic vasoconstrictor fibers are located in which arterial layer?
tunica media
tunica adventitia
tunica intima
What are known as capacitance vessels?
veins
arterioles
capillaries
large arteries
Which part of the capillary has the lowest filtration rate?
venous end
the filtration rate is the same throughout the capillary
arterial end
What is considered the pacemaker of the heart?
sinoatrial node
atrioventricular node
purkinje system
aortic valve
What is the correct order of conduction of the cardiac system?
SA node > atria > AV node > purkinje system > ventricular muscle
SA node > purkinje system > AV node > ventricular muscle > atria
AV node > atria > SA node > purkinje system > ventricular muscle
AV node > purkinje system > SA node > ventricular muscle > atria
What causes the "funny" current?
calcium using leaky channels to enter the cell
opening of potassium channels
sodium using leaky channels to enter the cell
opening of calcium channels
Once threshold is hit during a pacemaker action potential, which ion channels open?
calcium
potassium
sodium
both potassium and sodium
What is the electrochemical link that allows cardiac muscle to act as a functional syncytium?
gap junctions
desmosomes
high mitochondrial density
sarcomere
"Fast" type action potentials occur in which cardiac region?
pacemaker
ventricles
Which cardiac tissue has a shorter action potential duration?
ventricular tissue
AV valves are open during which stage(s) of the cardiac cycle?
ventricular diastole only
ventricular diastole and atrial systole
ventricular systole only
ventricular systole and atrial systole
What valves are open during the isovolumetric phase of the cardiac cycle?
both AV and semilunar valves
AV valves only
no valves are open
semilunar valves only
Overall, diastole makes up approximately what fraction of the cardiac cycle?
2/3
1/2
1/4
1/3
Aortic pressure is highest during
atrial systole
ventricular systole
isovolumetric phases
ventricular diastole
The dicrotic notch is caused by
the closure of the aortic valve
the closure of the pulmonary valve
the bulging of the AV valves
the closure of the AV valves
"Lub dub" is often used to describe the heart sounds of the cardiac cycle. What causes the "dub?"
closure of the AV valves
closure of the semilunar valves
the rapid movement of blood in the ventricles
opening of the AV valves
The QRS complex of an electrocardiogram refers to
atrial depolarisation
ventricular depolarisation
ventricular repolarisation
AV conduction time
Using an ECG, what defines a first degree AV block?
prolonged PR intervals
more P waves than QRS complexes
P waves and QRS complexes are complete dissociated
What would cause a decrease in heart rate?
increasing vagal tone
increasing sympathetic tone
decreasing vagal tone
An abnormally low heart rate is known as
bradycardia
tachycardia
normocardia
arrhythmia
What could cause a lowered ventricular ejection fraction?
increased stroke volume
decreased stroke volume
decreased end diastolic volume
Which would increase cardiac output?
beta-adrenoceptor agonist
muscarinic agonist
increased afterload
decreased preload
Preload is synonymous with
venous pressure
arterial pressure
peripheral resistance
arterial volume
The energy of contraction of a cardiac muscle fiber is proportional to the initial fiber length at rest. This is known as
bohr's law
starling's law
wolff's law
poiseuille's law
Which of the following is a short-term regulator of blood pressure?
baroreceptor regulation
renin-angiotensin-aldosterone system
natriuretic peptides
vasopressin
What type of myocytes directly respond to both sympathetic and parasympathetic stimulation?
atrial myocytes
ventricular myocytes
both atrial and ventricular myocytes
What type of innervation would result in decreased inotropy?
parasympathetic innervation
sympathetic innervation
Baroreceptors are located in which layer of the arterial wall?
endothelium
Baroreceptors are located in the
aortic arch
carotid sinus
aortic arch and carotid sinus
How would a decrease in blood pressure affect baroreceptor firing?
baroreceptor firing would rapidly increase during the change in pressure but eventually stabilize at a slightly faster firing rate
there would be a brief halt in firing during the change in blood pressure with a lowered rate of firing after the change
baroreceptor firing would be unaffected
baroreceptor firing would rapidly increase during the change but eventually stabilize at a lowered firing rate
Changes in blood pressure are sensed by which part of the brain?
medulla oblongata
pons
cerebral cortex
hypothalamus
What would activate the renin-angiontensin-aldosterone system (RAAS)?
increased blood pressure
increased parasympathetic innervation
increased sympathetic innervation
decreased NaCl load
What regulates vasopressin release?
baroreceptors
atrial receptors
ventricular receptors
both baroreceptors and atrial receptors
What is NOT caused by natriuretic peptide release?
glomerular arteriole dilation
lowered TPR
inhibition of RAAS
increased blood volume
'Internal transfusion' occurs during
hypertension
hypovolaemia
hypervolaemia
Which type of thrombosis has a large platelet component?
arterial thrombosis
venous thrombosis
all types of thromboses
What would inhibit platelet adhesion?
increased release of serotonin
increased thromboxane synthesis
increase in platelet cGMP
decrease in platelet cAMP
What is the enzymatic process in platelet adhesion involving the conversion of proenzymes to active enzymes?
coagulation cascade
haemostasis
contact activation
fibrinolysis
Which of the following is an endogenous anticoagulant?
thromboxane
ATIII
serotonin
ADP
Which of the following would inhibit coagulation?
increasing vitamin K synthesis
blocking ATIII synthesis
use of a calcium chelator
lowering platelet cAMP
Which drug acts independently of ATIII?
hirudin
heparin
LMW heparin
Which parasite can cause pulmonary thromboembolism in dogs?
Toxocara
Dirofilaria
Leishmania
Filaroides
Which lead is most commonly displayed on an ECG?
Lead I
Lead II
Lead III
Lead IV
Which pulse site is more sensitive to lowered blood pressure?
peripheral
central
there is no difference
While monitoring anesthesia for a patient during an orthopaedic procedure, you noticed the O2 saturation is at 99% while EtCO2 is 80 mmHg as well. Is the patient well ventilated? Which value would determine this?
No because of the high EtCO2
No because of the high O2
Yes because of the high O2
Yes because of the high EtCO2