the cardiac cycle and circulation Flashcards
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The heart: Explain the ablood pathway within the heart + General structures
Superrior vena cava and the inferior vena cava (Bringing deoxygenated blood into the body) –> Right atrium –> Tricuspid valve (AV valve) –> Right ventricle –> Semilunar valve –> Pulmonary arteries (Left pulmonary artery and a right pulmonary artery) –> Lungs (Picks up oxygen, gets rid of co2) –> Pulmonary veins –> Left atrium (Oxygenated blood) –> Bicuspid valve –> Left ventricle –> semilunar valve –> aorta —> Arteries
Septum: wall of muscles that seperate left side and rightside
–> Papillary muscles (WIthin the ventricles)
–> Chordae tendineae attached to papillary muscles and the AV valves
What is the heart? What is it’s general structure>
A musclular organ at the center of the circulatory system, located in the middle of the chest (Slightly left)
2 sides (the 2 parallel pumps) of the heart are separated by a wall of muscle (septum)
Each side has an atrium and a ventricle
Heart is surrounded by pericardium:
2 layered fluid filled membrane*
surrounds the heart & prevents friction between the heart and other tissues/organs (SImilar to a pleural cavity)
What is a atrium/atria?
Located?
Thickness?
Function?
Type of blood?
Both a left and right atrium –>
located @ the upper chambers of the heart
receive blood from veins (Specifically the vena cava [the largest veins] or the pulmonary veins)
–> Known as the reciving chambers.
-> Right = vena cava = deoxygenated blood
-> Left = Pulmonary veins = oxygenated blood
Surrounded by thinner walls/muscles
–> Does not need to pump blood far (only to ventricles)
What is a ventricles/ventricle?
Located?
Thickness?
Function?
Type of blood?
lower chambers of the heart (Left ventricle and right venticle)
–> receives blood from the atria/atrium.
–> Surrounded by thicker muscular walls
(Pumps blood to father locations, circulatig to both the pulmonary circuit and system circuit) (Both the body [left] and the the lungs [right])
–> Responsible for pumping blood out of the heart
—> Right ventricle = oxygen poor
—> Left ventricle = oxygen rich
How does the heart survive on its own?
Heart = muscuclar organ, therefore needs oxygen and nutrients
Blood vessels that circulate blood to and from the muscles of the heart (Cornary blood vessels) (Providing oxygen, nutrients, and removing waste products)
Coronary arteries: branch from the aorta (Suppliex oxygen rich blood to the heart)
Coronary veins: collecting deoxygenated blood from the heart and draining it into the right atrium
–> The largest coronary vein is the coronary sinus.
The circulation of all the system, in relation to which system, type of blood, and what is structures are involve
–> Mentioning contraction and relaxation
@ the ending of the systemic circuit, the superior and inferior vena cava bring back deoxygenatted oxygen
–> Right atrium (Holds deoxygenated blood)
—> Contracts (Going through the trricuspid valve)
–> Deoxyganted blood enter the right ventricle
–> Contracts (Going through the pulmonary valve)
–>Dexoygenated blood goes to the lungs
@ the lungs, oxygen diffuses into the blood as the blood passes through the capillairies network, oxygen and co2 diffuses through the concentration gradient (Gas exchange
–> Oxygenated blood enters back to the hear through the pulmonary veins
–> Oxygenated blood enters the left atrium
(End of the pulmonary system, start of the systemic system)
–> Heart contracts and blood goes through the bicuspid valve
–> Oxygenated blood enters left ventricles
–> Contracts (Blood flows through the aoratic valve)
–> oxygenated blood flows through the aorta
In the body:
Aorta –> Arteries – arterioles –> Capilliaries (Where body cells receive oxygen due to diffusion and concentration gradient)
–> Venules (BLOOD STARTS TO GO BACK TO THE HEART AND BLOOD IS DEOXYGENATED) –> Veins –> Vena cava
Cycle beings again
What are valves?
Structure in the heart and veins, that prevent backflow and only allow the flow of blood to move in one direction
WHat are the two sets of valves in the heart and where are they located?
2 sets of valves:
Semilunar (SL) valves:
between the ventricles and their arteries
Atrioventricular (AV) valves:
between the atria and ventricles
AV Valves: General function?
–> Structure?
Prevent back flow into the atrium, because when ventricle contracts, the ventricle pressure increases (therefore the valve closed).
But the ventricle pressure is so high, that this vavle is supported by chordae tendineae
attached to muscles in the inside of the ventricles (papillary muscles)
prevent valve from opening into atria
Semilunar valves —> FUnction?
–> Prevent backflow into the ventricles, when the ventricles relace, the pressure in the ventricles drop which closes the valve
–> Have no support
The cardiac cycle? 2 terms and what is happening?
The contractions and relaxations of the heart muscles during a complete heartbeat
Diastole:
period of relaxation
heart fills with blood (atria/ventricles fill)
Systole:
period of contraction
blood pushed out of the heart (ventricles empty)
How do vavlves work with the cardiac cycle?
–> Valves open and close because of the pressure difference.
-> Pressure is higher upstream (Where the blood comes from) than valves open
–> Pressure is higher down stream (WHere blood is flowing to), valves close (preventing blood flow)
During diastole which valve is open and Why?
–> AV Valves are open, because blood is filling the heard, therefore the atria’s pressure is higher then the ventricles .
Fill atria with blood = av vales open = fills relaxed ventricles = when atria contracts that means ventricles are full = leading the the ventricles to contract, which signal systole.
During systole what is happening which valve is open?
Semilunar valves are open
ventricles are contracting = high pressure in the ventricles = valves are open and blood flows to arteries, as there is less and less blood in the ventricles, the ventricles begin to relax
More volun in the ventricles = decrease pressure in the ventricles, which restarts the cycle.
What are heart sounds, what are you hearing and when does it occur?
heart sounds (lubb-dubb) are caused by the closing of heart valves
lubb: when the AV valves close (ventricles contract)
dubb: when the SL valves close (ventricles relax)
