cardiovascular system Flashcards
what is the sequence of the conduction system
sa node
atrial systole
av node
bundle of his
purkinje fibres
ventricular systole
what is atrial systole
contraction of the right and left atria at the same time, the bp will go up and the blood will be forced out into the ventricles
what is ventricular systole
contraction of the left and right ventricles causing an increase in bp. in left ventricle the aortic valvue will open and oxygenated blood will be ejected
what is cardiac diastole
period of time when the heart relaxes after a contraction in preparation for refilling with circulating blood.
what is ventricular disatole
ventricles relax
what is atrial diastole
atria relax
what happens to the impulse from the SA node
the impulse spreads through the walls of the atria causing them to contract (systole) and force the blood into the ventricles
what happens at the av node
it delays the transmission of the impulse for 0.1s to enable the atria to fully contract
what happens to the impulse after the av node
ventricular systole begins and the impulse is passed down specialised fibres which form the bundle of his
sam aliano always bakes pretty victoria sponges
sa node, atrial systole, av node, bundle of his, purkinje fibres, ventricular systole
path of blood
sup/in vena cava
right atrium
tricuspid valve
right ventricle
pulmonary valve
pulmonary artery
LUNGS
pulmonary vein
left atrium
bicuspid/mitrial valve
left ventricle
aortic valve
aorta
what do valves do
prevent backflow and ensure blood flows in one direction
what are the semilunar valves
aortic and pulmonary
what is the difference between the tri and bicuspid valves
tri has 3 flaps and bi has 2
why is the left side more muscular
because it needs more force to get the blood out of the heart and to the extremities rather than just to the ventricles
what happens at the sa node
cardiac impulse is initiated from this specialised bundle of cells. the impulse travels through atria walls causing both to contract
what does the bundle of his split into
left and right bundle branch
what do the left bundle branch do
carries electrical impulse around left ventricle wall
what does the right bundle branch do
carries the electrical impulse around the right ventricle wall
where is the sa node located
of the right atrial wall (top)
what does sa node mean
sinoatrial node
what does av node mean
atrioventricular node
what is the purpose of the vascular shunt mechanism
to redistribute blood around the body
the distribution of blood to the brain is…..
always the same
The systemic circulation carries blood around…
the body
what are the 3 types of circulation
systemic
pulmonary
coronary
short term effects on the circulation (3 things)
Vasodilation & Vasocontriction
Increase in cardiac output
Increase in carbon dioxide
What hormone causes heart rate to rise when exercising
adrenaline
reasons Venous return increases during exercise?
Skeletal muscle pump
Cardiac output increases
Respiratory pump
During exercise what happens to Blood pressure?
increases
BP increases, therefore flow rate and speed of delivery of O2 and nutrients to muscles increases
During exercise where does Vasoconstriction occur
inactive organs
Peripheral nervous system consists of?
Nerve cells transmitting information to and from CNS
What do Baroreceptors detect
Stretch in arterial wall caused by change in blood pressure
What do Baroreceptors detect
Stretch in arterial wall caused by change in blood pressure
A rise in movement is detected by the proprioceptors, what happens to increase heart rate?
Impulse is sent to the cardiac control centre, impulses sent via the sympathetic nervous system to the SAN
Anticipatory Rise is known as?
The increase in movement prior to exercise stimulating the SAN
The release of adrenaline prior to exercise that stimulates the SAN and increases heart rate
Baroreceptors detect an increase in blood pressure so?
It sends a message to the CCC in medulla to decrease heart rate
