circulation Flashcards
explain why bacterium can rely on diffusion for gas exchange but animals need a transport system
bacterium have a larger surface to area volume ratio, meaning that theres a shorter diffusion pathway for gas exchange. animals have a very small surface area to volume ratio, meaning that gases aren’t being exchanged quickly as the diffusion pathway is longer and cells are deprived of oxygen
where are your lungs found
in the chest or thorax
What are your lungs protected by and what are they separted from and by
protected by rib cages, and are separated from the digestive organs by the diaphragm
what is ventilation or breathing
the process of moving air in and out of the lungs
breathing is brought about by the movements of:
diaphragm
intercostal muscle (rib muscle)
describe what happens when you breathe in
intercostal muscles contract, ribcage moves up and out, diaphragm flattens making the volume of the thorax larger. pressure in thorax decreases
describe what happens when you breath out
intercostal muscles relax, ribcage moves down and in, diaphragm relaxes and turns back into a dome shape, volume of thorax decreases, pressure of thorax increases
why doesn’t the glass tube breathing system represent the human breathing system very well
(has balloons as lungs in a glass bell jar etc..)
Balloons don’t show the alveoli and bronchioles
Glass bell jar doesn’t move
features of alveoli which allow large amounts of oxygen to enter the blood
alveoli walls are one cell thick to provide a shorter diffusion pathway
alveoli walls are folded to provide a larger surface area to volume ratio
good blood supply which maintains a steep concentration gradient
breathing allows large amounts of oxygen to enter the blood, explain how breathing does this
breathing allows oxygen into the lungs, this maintains a steep concentration gradient OR keeps oxygen levels high in alveoli
why would a person with emphysema struggle with exercise?
a person with emphysema’s alveolus folds would be reduced, meaning that the surface area to volume ratio is lower and less oxygen is absorbed into the bloodstream for aerobic respitation
what 3 components is the human circulatory system made up of?
the heart - the pump
blood vessels - 3 types, arteries, veins, capillaries
blood - transport medium
humans have a what circulatory system?
double
what does the pulmonary circulation system do?
carries blood from your heart to your lungs and back again. allowing oxygen and carbon dioxide to be exchanged in the air of the lungs
what does the systemic circulation system do
carries blood to respiring cells in all organs from the heart and back
advantage of a double circulatory system
it maintains a high blood pressure, unlike a single circulatory system where blood is pumped once, so the pressure of the blood is not maintained. when the pressure is maintained, oxygenated blood reachers organs much faster, and animals respire at much faste rates as we are more complex
KNOW HOW TO LABEL A HEART
KNOW HOW TO LABEL A HEART
what is the right and left side of the heart separated by?
the septum
what do veins do
bring blood to the heart
what do arteries do
carries blood away from the heart
what does the right side of the heart pump
de-oxygenated blood to the lungs
what does the left side of the heart pump?
oxygenated blood to the organs of the body
how does blood flow through the heart
Deoxygenated blood goes through the vena cava and into the right atrium, then the right ventricle and out through the pulmonary artery to the lungs. the blood becomes oxygenated in the lungs. Blood enters the pulmonary vein, into the left atrium and left ventricle and out the aorta
some people are born with a hole in their septum, why could this be a problem?
it causes oxygenated and deoxygenated blood to mix which means there is a decrease in levels of oxygen in the blood, decreasing the rate of respiration, and less energy is released.
why is the muscle on the left side of the heart thicker
it creates more pressure on the blood, so it can travel to all different parts of the body, meaning that the distance it needs to be carried is much larger. the right side only pumps blood to the lungs, so the distance the blood travels is shorter.
right side is thinner as blood is pumped to the capillaries in the lungs and needs low pressure so they won’t break
which chamber of the heart pumps oxygenated blood to the head and body
left ventricle
which part of the heart recieves deoxygenated blood from the head and body
right atriums
which part of the heart recieves oxygenated blood from the lungs
left atrium
which valve closses when the blood pressure in the aorta is greater than the blood pressure in the left ventricle
semilunar valve
disadvantages of having an artifical pacer
it won’t automatically adjust when doing exercise. Battery will need replacing every year, which will mean that surger with local anesthesia will be involved .
can set off metal detectors at airports
what is unique about the pulmonary artery and the pulmonary vein
arteries usually carry oxygenated blood where as pulmonary artery carries deoxygenated blood from the heart to the lungs.
veins carry mostly deoxygenated blood, whereas the pulmonary vein carries oxygenated blood from the lungs to the heart
structure of an artery
narrow lumen to maintain high blood pressure. elastic fibres in the wall to withstand high blood pressure . thick muscular walls to push blood to the rest of the body
structure of a vein
thinner walls with a wide lumen to carry blood at a low pressure.
valves to prevent backflow
decsribe the differences between a vein and an artery
arteries carry oxygenated blood, where as veins carry de oxygenated blood.
arteries carry blood to the rest of the body, veins carry blood from the heart to the lungs
arteries have a wide lumen and a thick muscular wall to maintain highblood pressure and push blood around the body, where as veins have thinner walls and a wider lumen to carry blood at a low pressure.
Veins have valves to prevent backflow, arteries don’t
structure of capillaries
walls are one cell thick to provide a shorter diffusion pathway
wide lumen
what is blood
a group of tissue consisting of a watery plasma, in which red blood cells, white blood cells and platelets are suspended
what does plasma carry around the body
nutrients, urea, carbon dioxide, glucose, amino acids, lactic acid, vitamins, hormones, mineral ions
structure of a red blood cell
- bioconcave shape to provide a larger surface area for oxygen to be absorbed
-flexible which allows them to fit through narrow blood vessles
-no nucleus, so there’s more room for oxygen to bind with haemoglobin
-contains haemoglobin which binds to oxygen to create oxyhaemoglobin
what are white blood cells and what do they do
they are large cells, which have a nucleus. they protectr the body from invasion of pathogens like bacteria and viruses.
in what three ways do white blood cells protect body against pathogens
phagocytosis, antibody production, antitoxin formation
what are platelets
small fragements of large cells made in the bone marrow. they don’t jave a nucleus. they form scabs at the site of cuts
how do platelets form scabs
when a wound is formed, platelets release chemicals which causes fibrinogen (a soluble protein) to turn into fibirn which is insoluble. the fibrin forms across a network trapping red blood cells, causing a clot to form. the clot prevents the further loss of blood and any pathogens from entering the body
what is coronary heart disease
if a person has developed plaques in their coronary arteries. -> fatty substances including cholesterol
what does a build up of fatty deposit do to the artery
decreases lumen size, causing blood to flow less
why could a blockage in a coronary artery cause cells in the heart to die
The blockage could rupture causing the blood to clot, so less blood is delivered to the heart and cells aren’t recieving as much oxygen for respiration.
risk factors of CHD
-not doing enough exercise
-obesity
-smoking
-type 2 diabetes
-high lipid and cholesterol diet
treament of CHD
statins and surgery
what are statins
slows development of cholesterol, reducing the build up of cholesterol in arteries
disadvantages of taking statins
need to take them daily: you might forgot to take them
stopping medication can cause cholesterol levels to rise again within a few weeks
how does surgery help treat CHD
a stent (a small mesh tube) reduces the chance of artery becoming narrow or blocked by supporting its walls. once installed, a balloon is inflated to open up the stent then removed. allows blood to flow through artery
disadvantages of a heart bypass
complex and expensive procedure
replacing affected coronary with sections of veins from other parts of body
explain why a person with a leaking AV valve has difficulty exercising
causes backflow of blood of the ventricles into the atria. meaning there is a reduced flow of oxygenated blood around the body. therefore rate of respiration decreases and less energy is released for muscle contraction, causing the person to be tired quickly.
what is stemosis
occurs when the flaps of a valve thickens, stiffens are fuse together, preventing the valve from fully opening. so not enough blood flows through the valve
biological valves
valves from human or other animals. last around 12-15 years
mechanical valves
made of metals such as titanium or synthetic materials. increased risk of blood clotting so person must take blood thinning pills. lasts for a long time
evaluate use of mechanical valve replacement
-mechanical valces last longer than a biological valve, meaning it won’t be replaced as often, meaning you’d need surgery less often
-biological valves don’t require patient to take anticlotting tablets, lower risk of excessive bleeding
-chance of rejection with biological valves, so patient has to take immunosuppressents, making them prone to infection
whats an artificial heart
device that is used occasionally to temporarily replace the heart. people use it to wait until a suitable transplant is available or allows a diseased heart to rest while it is recovering.
risk associated with heart transplants
human body could reject the heart
risk of infection
explain how circulatory system is adapted to:
-supply O2 to tissues
-remove waste products from tissues
- double circulatory system which increases blood pressure and flow to tissues
-heart pumps blood to lungs via pulmonary artery so oxygen can diffuse in from air in alveoli and CO2 can diffuse out
-blood returns to heart via pulmonary vein where muscles pump blood to rest of body via aorta
-veins have valves which prevent backflow
-waste products removed like CO2 diffuse from cells into blood plasma
explain the effect of a partily blocked artery on the body
there is reduced blood flow to the heart muscle, so less oxygen is delivered to the heart, so heart respires aerobically less and anaerobically more. this means less energy is released and causes a build up in lactic acid, muscles become fatigued and tired and person gets tired and breathless.
