cardiovascular system Flashcards
what is the cardiovascular system made up of
heart, blood vessels, blood
why is the heart called a double circulatory system
there are two different circulations and the heart acts a a link between the two, one side pumps deoxygenated blood back to the heart from the body and the other side pumps oxygenated blood around the body
explain how the pulmonary circulatory system works
the heart pump blood to the lungs, where it picks up oxygen to become oxygenated, in the lungs carbon dioxide is also diffused out of blood,
blood then returns to the heart using veins
explain how the systematic circulatory system works
heart pumps blood so that it flows into arteries and reaching capillaries in the body, here the oxygen in the blood diffuses out and carbon dioxide is produced.
deoxygenated blood is then transported back to the heart using blood vessels and veins
which side of the heart deals with oxygenated blood?
the left side, left ventricle pumping blood all around the body
which side of the heart deals with deoxygenated blood
the right side
what do arteries do
supply oxygenated blood to the heart muscles so it can contract.
what are the names of the two arteries that are at the top of the atriums
the aorta and the pulmonary artery,
they carry blood away from the the bottom chambers, the ventricles .
what are the names of the two major veins, what do they do
the vena cava and the pulmonary vein
they carry blood into the heart and into the top chambers, the atriums
describe the pathway of blood around the circulatory system
in the lungs oxygen is picked up by the lungs, this then travels from the lungs, entering the left atrium via the pulmonary vein.
deoxygenated blood travels from the body and enters the right atrium via the vena cava to get more oxygen through the lungs. this process repeats itself
what happens when the atriums contract
blood is forced into the ventricles which is below them, the blood goes through the atrioventricular valves ( AV valves)
how do these valves prevent blood from flowing the wrong way
they are attached to the walls of the heart by tendinous cords, they prevent them from turning inside out
what happens when the left ventricle contracts
blood leaves the heart, going into the body through arteries, oxygenated blood gets pumped out of the body by the left ventricle , by the aorta and supplying blood to all parts of the body.
what happens when the right ventricle contracts
deoxygenated blood is pumped through the ventricle into the lungs to be reoxygenated, via the pulmonary artery
what are the valves that are at the base of the aorta and pulmonary artery
they are the semi lunar valves, they prevent blood from going back into the ventricles when the heart relaxes
what is the septum and where do you find it
the septum is a wall of muscle in the middle of the heart that separates the ventricles from each other , ensuring oxygenated blood and deoxygenated blood do not mix
explain the cardiac cycles 5 steps
- the atria both fill up with blood, this is called ATRIAL SYSTOLE.
-the atria contract and force AV valves to open, blood flows into the ventricles and they fill up, VENTRICULAR DIASTOLE - the av valves close when pressure in ventricles rises, to prevent backflow.
- ventricle walls contract and increase the pressure in the ventricles, forces semi lunar valves to open so blood flows into both arteries on each side of the heart .
- the semi lunar valves then close up, after this there is a short delay before VENTRICULAR SYSTOLE, this is where the ventricles contract at the same time.
- there is then another short pause where all chambers relax and fill again, this is called DIASTOLE
what is the sino- atrial node (SAN)
a node that generates electrical activity in the heart to initiate beats, also known as a pace maker. it causes both atria to contract
what is plasma
liquid part of blood, contains proteins,amino acids, glucose
describe red blood cells
their role is to transport oxygen throughout the body, they have a biconcave shape to them which allows them to hold more oxygen and they also have no nucleus, haemoglobin allows them to hold more oxygen too
what do platelets do
they promote blood clotting
why does the right side of the heart not need thicker muscle walls
because there is not high blood pressure as the blood is not oxygenated, if there was high blood pressure this would cause damage to the aveoli in the lungs
describe the features of arteries
they have a thin lumen to increase blood pressure
they have thick muscle walls so that they can take the pressure of the blood
elastic tissue so they can withstand high pressure
smooth endothelium to reduce friction
pulse, no valves
describe arterioles features
they are smaller vessels that come after the arteroes that help with sending blood to other parts of the body, they dialate to increase blood flow, as the lumen largens
they have thinner elastic as the pressure lowers
describe the features of veins
they carry blood back to the heart
they have a very large lumen and they also have valves inside of them to prevent the backflow of blood,
this outer layer with low amount of muscle as it is not needed because there is not high blood pressure.
no pulse
describe the features of capillaries
they are important in the exchange of gases and nutrients inside of the body, they have a very thin layer 1 cell thick which allows for a short diffusion distance - this increases the speed of diffusion/ rate
narrow lumen which reduces flow rate so there is more time for diffusion
pores in the wall
partially permeable membrane so things can come in and out e.g white blood cells can come out
what does the renal artery do
carries large amounts of blood to the kidneys
what does the renal vein do
carries deoxygenated blood from the kidneys to the aorta so it can be oxygenated again
what are baroreceptors
they an detect changes in blood pressure, the are found in the aorta, they help the heart to know that it should reduce heart rate when blood pressure is high and increase it when blood pressure is low
what are changes to the cardiac output regulated by
what does this lead to
the autonomic nervous system,the ANS sends signals from the brain to release more NORADRENALINE to stimulate the SAN
this leads to an increase of the frequency of signals being sent by the SAN/ pacemaker so the heart beats more quickly. and increase the force of contractions.
give an example where cardiac output would been to be changed
during exercise when the heart needs to beat faster
what do chemoreceptors do
they detect changes in PH eg when blood carbon dioxide levels rise, blood ph falls and this is detected by chemoreceptors.
what is the normal blood pressure range for a healthy person
120/80mmHg
what does the first number in a blood pressure reading mean
the pressure of the artery when ventricle contract, this is called the systolic pressure. the highest number will always be first in a blood pressure reading. 10 is a healthy range for this
what does the second number mean in a blood pressure reading
the pressure in the artery when the heart relaxes, diastolic pressure, 80 i a healthy range for this
how do the kidneys play a role in blood pressure
they control water volume in the body, if an increased volume of water is lot from the body, by urine then blood pressure is decreased, if more water is conserved then blood pressure increases
what is tissue fluid
the fluid found in spaces around cells, comes from substances that leak out of capillaries
what does it help with
substance exchange between cells and it helps with bringing oxygen and nutrients to cells
