Circulatory System Flashcards
what does the circulatory system do?
transportation, homeostasis, protection
what does the circulatory system transport?
nutrients (O2, ions), waste, hormones
what does the circulatory system maintain homeostasis for?
maintains body temp, and fluid/ solute levels in cell
why is it important for cell to maintain homeostasis of body temp?
for enzymes to work optimally
how does the circulatory system provide protection?
immune system defends against foreign materials
what are the 3 main parts of the circulatory system?
the heart, blood vessels, blood tissue
what is the heart (formal definition)?
muscular organ, which pumps blood through blood vessels of the circulatory system
what are the blood vessels (formal definition)?
channels or conduits through which blood is distributed to body tissues
what is blood classified as?
a tissue
what is blood (formal definition)?
body fluid that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells
how big is the heart?
about the size of the fist
where is the heart located?
between the lungs and thoracic cavity. middle
what is the heart protected by?
sternum in the middle of the rib cage
what is the sternum?
hard bone that helps protect the heart
what side of the heart is bigger? what does that mean?
the left side of the heart is bigger than the right. this makes the left side louder and easier to hear.
what is the heart surrounded by?
pericardium
what is the pericardium?
a fluid like membrane that allows there to be no friction or damage when the heart is beating
what is the average heart beat rate?
70 beats/ min
when does heart rate increase?
faster when stressed or during exercise
what does the heart consist of?
two parallel pumps that contract at the same time
what are the two pump separated by?
the septum
what do the muscle contracts mirror?
muscle contractions on right side mirror the muscle contractions on the left side
what does the pump on the right side recieve? where does it send it?
deoxygenated blood from the body systems. it pumps it to the lungs.
what circulation are vessels that carry blood to and from the lungs a part of?
pulmonary system
what does the pump on the left side recieve? where does it send it?
oxygenated blood from lungs and pumps it to the cells of the body.
what circulation are vessels that carry blood to and from the body cells?
systemic circulatory system
how many chambers does the heart have?
four chambers
what are the two thin walled chambers called?
atria - atrium (singular)
what are the two thick walled chambers called?
ventricles
what do the atria act as?
holding chambers for blood that enters from either the systemic or pulmonary circuit
what are arteries?
vessel carrying blood away from heart (usually oxygenated)
what are veins?
vessel carrying blood to heart (usually deoxygenated)
what are exceptions to oxygenated / deoxygenated, arteries/ veins
pulmonary vein and artery
what is the superior vena cava?
a type of vein that carries deoxygenated blood from the head to the right atrium
what is the inferior vena cava?
a type of vein that carries deoxygenated blood from tissues of the body to the right atrium
what are the pulmonary veins?
the type of vein that carry oxygenated blood from the lungs into the left atrium
what are pulmonary arteries?
the type of artery that carries deoxygenated blood from the heart to the lung. once it’s in the lungs, blood gets O2 by diffusion, and returns to the left side.
what is the aorta?
the largest artery. it carries oxygen-rich blood away from heart to body tissues. this branches off into all other major arteries
what are the coronary arteries?
arteries that branch of the aorta. they supply the heart muscle with blood.
why does the heart muscle need blood?
because it needs ATP.
how many ways does blood move? what makes this possible?
one way because of valves.
what is prolapse of blood?
blood going backwards
what prevents prolapse?
the atrioventricular valve.
what does the atrioventricular valves separate?
the atrium from the ventricle on either side of the heart
how many flaps of tissue does the right AV valve have?
3 - called tricuspid
how many flaps of tissue does the left AV valve have?
2 - bicuspid
what are the valves supported by?
chordae tendineae
what are the semilunar valves?
valves found where the blood vessels attach to the heart. it helps prevent blood from the blood vessels prolapsing into the ventricles again
what is the sound the heart makes?
lubb dubb
what makes the heart sound?
by the closing of the heart valves
what is systole?
contraction
what is diastole?
relaxation
when does the lub sound happen?
when the AV valve closes
when does the dub sound happen?
when the semilunar valve closes
explain the cardiac cycle.
- heart muscle is completely relaxed to get blood into atria.
- when the atria fills up, it contracts, forcing blood into the ventricle
- ventricle contracts, forcing blood up artery
do the atria and ventricle contract at the same time?
no
where does the cardiac muscle appear?
only in heart
what does the cardiac muscle display?
a branching pattern. it appears striated when viewed under a microscope.
does cardiac muscle need external nerve stimulation?
no it can contract on its own
what is the cardiac muscle called?
myogenic muscle
what is the heart tempo set by?
a bundle of specialized nerves and muscles located where the vena cava enter the right atrium
what is the pacemaker?
the sinoatrial node
explain the node system.
the sinoatrial node initiates each cardiac cycle. a group of cells sends out a stimulus to generate an electrical signal. the electrical impulse travels down right and left atria. the atrioventricular node picks up the impulse from the SA node, and relays it on the AV bundle (bundle of his). the impulse travels down the septum and spreads over the ventricle, causing it to contract upwards.
how can contractions be made faster or slower?
the brain can adjust it
what happens if the pacemaker malfunctions?
doctors can monitor and implant a pacemaker to ensure it beats regularly.
what is an electrocardiograph?
ECGS monitor electrical activity of the heart. waves are produced as specific events of the cardiac cycle occur. it helps to diagnose heart problems.
explain the PQRST wave.
p - atrium contracting
qrs - ventricle contracting (biggest wave)
t - recovered ventricle
what factors can change the pace of a heart? explain.
activity level - CO2 level (not O2 level)
stress - sympathetic (fight/flight muscles)
excitement
what part of your brain sends messages to SA node?
the medulla