biology test - Circulatory System Flashcards
what is closed circulation
it’s when blood is transported from the heart through blood vessels around the body, to the lungs etc… and it eventually makes it back to heart and restarts the cycle
what is a single circulatory system?
when blood flows in one circuit around the body
what kind of organism would have a single circulatory system?
fish, because they are less active and so only need a single one
what is a double circulatory system?
the blood flows in two circuits around the body:
heart to lungs and heart to rest of the body
what kind of organism would have a double circulatory system?
a mammal, e.g. a person, since the blood is at two different pressures - low pressure from heart to lungs and high pressure from heart to rest of body
we label the heart normally - true or false
false, we label it backwards e.g. what we perceive to be the left side we would label the right side
which side of the heart has oxygenated blood and how would we label this?
the left side however we would label it as the right side as we see it
why is the left ventricle bigger than the right ventricle?
Because it’s handling the blood that’s going to the rest of the body, meaning it’s at a higher pressure so needs thick walls to be able to handle the higher pressure
what do we call the valves between the atria and ventricles?
atrioventricular valves
what are valves anchored by?
tendonous chords
what are the valves that when closed block blood from leaving the ventricles called?
semi lunar valves
what blood vessel goes into the left atrium
pulmonary vein
what blood vessel goes out of the right ventricle
pulmonary artery
what blood vessel goes out of the left ventricle
aorta
what blood vessel goes into the right atrium
vena cava
why are ventricle walls thicker than atria walls?
Because the blood has got to travel a further distance, and with a slightly higher pressure (especially in the left ventricle) as the blood needs to travel through the ventricles, through the semi lunar valves and out to the lungs or the rest of the body
where does the vena cava bring blood from
the body
where does the pulmonary artery bring blood to
the lungs
where does the aorta bring blood to
the body
where does the pulmonary vein bring blood from
the lungs
what is the septum
a wall of muscle which separates the ventricles and two sides of the heart from one another
characteristics of arteries
has :
small lumen, no valves, very thick walls (which aren’t permeable)
also:
carries blood from the heart
blood is under a very high pressure and has a pulse
carries oxygenated blood(apart from pulmonary artery)
characteristics of veins
has:
thinner walls - not permeable, large lumen, valves
also:
blood flows under low pressure, carries blood to heart, carry deoxygenated blood (apart from the pulmonary vein)
characteristics of capillaries
has :
one cell thick walls - very permeable, no valves, high C02 concentration
also:
gas exchange occurs, blood slowly loses oxygen, carries blood from arteries to veins, blood flows under low pressure, but can transport both oxygenated and deoxygenated blood
what happens after blood has entered the atria and the atria contract
because of the atria contracting the pressure of the blood is raised and so therefore the atrio ventricular valves are forced open
what do the ventricles do once full of blood
they contract and close the atrioventricular valves, which stop backflow of blood into the atria
as the ventricles continue to contract what happens to the pressure of the blood
it increases and because of that forces open the semi lunar valves
what happens when the semi lunar valves open
blood is ejected into two arteries - the pulmonary artery going to the lungs and the aorta going to the rest of the body
what happens as the ventricles empty
because of higher pressure in the pulmonary artery and aorta, the semi lunar valves are forced to close
what happens once all the blood has emptied from the ventricles, all the valves are closed and the arteries have started to transport the blood?
the cycle begins again
three comparisons of designs of arteries and veins
an artery has thick muscular walls, while a vein has relatively thin walls. an artery has a small lumen, whereas a vein has a large lumen. arteries transport blood at a very high pressure ( it has a pulse), whereas veins transport blood at a lower pressure.
what four things make up blood:
white blood cells, red blood cells, platelets and plasma
design of red blood cells:
no nucleus, biconcave shaped, similar diameter as the capillaries
why are red blood cells a similar diameter to that of capillaries:
it slows the red blood cells down, creating more time for diffusion : gas exchange
what do red blood cells carry
haemoglobin
what is haemoglobin called when it is bonded to oxygen
oxyhaemoglobin
what is haemoglobin
a chemical pigment, that carries oxygen - in the red blood cells - to the body
where is haemoglobin most likely to be found
in the blood vessels (capillaries) in the lungs
what key nutrient is needed to make haemoglobin in the body
iron
what is anaemia
deficiency to iron, don’t have enough iron in the body
why is anaemia a problem?
people have less iron, so can’t make as much haemoglobin therefore less oxygen in the lungs
what are good dietary sources for anaemia
red meat, spinach and lentils
what colour are red blood cells without oxyhaemoglobin ( still with haemoglobin tho)
dark red
what colour are red blood cells with oxyhaemoglobin
bright red
how is oxyhaemoglobin formed
haemoglobin ( red chemical pigment) binds with oxygen
once oxygen has bonded to haemoglobin in the red blood cells where do the red blood cells go
they are carried by the blood to the organs
what happens once the red blood cells reach the organs
haemoglobin releases oxygen (oxygen disassociates) and the oxygen diffuses into the cells
what happens once oxygen has diffused into the cells in the organs:
blood carries the now dark red red blood cells to the lungs to pick up oxygen and begin the cycle again
what is plasma
the fluid of the blood
what is plasma made of
mostly water and also contains other useful and waste substances dissolved in it
what waste substances are dissolved in the plasma
C02, urea and lactic acid
what useful substances are dissolved in the plasma
digested food e.g. glucose and amino acids
what is glucose used for in the body
respiration (mitochondria)
what are amino acids used for in the body
protein synthesis (ribosomes)
white blood cells characteristics:
have a large nucleus, can change their shape
what do white blood cells do
fight infection
what are the two types of white blood cells
lymphocytes and phagocytes
what do lymphocytes do:
produce antibodies/antitoxins to fight infection
what do phagocytes do:
they’re attracted to bacteria, since bacteria create chemicals called toxins, phagocytes then surround the bacteria and engulf it this is called phagocytosis
what is an antitoxin:
chemical/s used to destroy the poisons produced by bacteria.
what are platelets
small fragments of cells involved in blood clotting
what is the role of platelets:
to help protect the wound when you’re cut and stop the bleeding (with clotting)
what is blood clotting
a series of enzyme - controlled reactions resulting in the change of fibrinogen to fibrin, which then forms a network of fibres to trap the red blood cells and forming a clot
what is fibrinogen
a soluble blood protein
what does a blood clot turn into after hardening
a scab
what is fibrin
an insoluble blood protein!!
what 3 things float in plasma
red blood cells, white blood cells and platelets( small fragments)
what’s a pacemaker
a group of cells located in the right atrium which sends electrical impulses to the heart telling it to contract (beat)
what problems arise if someone’s pacemaker stops working/ malfunctions
there may not be any electrical impulses sent to their heart, therefore the heart doesn’t contract and isn’t beating so the person will probably die
what’s an artificial pacemaker
same as a pacemaker but located just under collarbone and artificial, is the size of a (small) matchbox
extra facts about an artificial pacemaker
stores info about heart rate etc…, is implanted by keyhole surgery - so on local anaesthetic, can either make heart contract/ constantly or just turn on when the natural rhythm goes wrong/ awry
advantages of artificial pacemaker
heart is now contracting/beating as normal, heart rate is controlled, can go home soon after procedure, can start exercise/ normal routine quite soon after surgery, pretty minor surgery
disadvantages of an artificial pacemaker
magnets interfere with the tech, have to keep quite far away from them e.g. devices, induction hobs and escalators, can’t do much - especially drive - for 6 weeks, have to get better insurance/ tell company about the artificial pacemaker, have to carry ID everywhere
what’s a hole in the heart and why is it a problem
between the right and left ventricles, a hole in the septum, so the ventricles are not separated properly - blood can easily flow between
why is a ‘hole in the heart’ a problem?
oxygenated and deoxygenated blood mixes - oxygenated - is a waste of oxygen as it goes to lungs so waste of oxygen and transportation of blood, deoxygenated - blood goes to the body, less oxygen/02 for aerobic respiration!!
