adaptations for transport in animals Flashcards
(240 cards)
1
Q
how does blood travel in a closed circulation system
A
blood travels through blood vessels with the stimulus being generated by a muscular pump or heart
2
Q
what organisms have closed circulation
A
earthworms, fish and mammals
3
Q
what does the blood do in an open circulatory system
A
the blood bathes all the cells and organs of the body
4
Q
what is the blood in a open circulatory system called
A
haemolymph
5
Q
where is haemolymph
A
its in the body cavity or haemocoel
6
Q
open circulation is a feature of all what
A
all arthropods
7
Q
in open circulation what isn’t there
A
there isnt any red blood cells to transport oxygen
8
Q
how is oxygen delivered in open circulation and by what
A
oxygen is delivered directly to the tissue by the trachea
9
Q
what do many animals with an open circulation have
A
a heart
10
Q
what does the heart do in a open circulation system
A
the heart pumps the haemolymph from 1 area of the heamocoel to another the blood returns to the heart without the aid of blood vessels
11
Q
what can closed circulations do when delivering blood
A
it can deliver blood quickly to tissues under pressure
12
Q
what do red blood cells contain and what does this do within the circulatory system
A
red blood cells contain haemoglobin which transports oxygen within the circulatory system
13
Q
what has the rapidity of transport enabled the evolution of
A
larger size in animals
14
Q
what is single circulation
A
when blood passes through the heart once in each circulation
15
Q
what have an single circulation
A
fish
16
Q
what 2 chambers does the heart have
A
the atrium and the ventricle
17
Q
what does the atrium do in a single circulatory system
A
it receive deoxygenated blood from the veins of the body
18
Q
what does the ventricle do in a single circulatory system
A
pumps blood to the gill capillaries via different arteries
19
Q
what does the blood gain and then where does it flow in a single circulatory system
A
blood gains oxygen and flows through different arteries to the organs
20
Q
what does fish’s blood contain and what does it have
A
it contains haemoglobin which has a high affinity for oxygen
21
Q
where does blood get transported from and to in fish
A
from the gills to the tissues
22
Q
what does lower pressure in the circuit in a single circulatory system result in
A
slower circulation
23
Q
what is the disadvantage of single circulation
A
the blood loses pressure around the circuit which result in a slower circulation
24
Q
what are the 2 features of fish circulation
A
closed and single
25
who have double circulatory systems
humans and other mammals
26
what happens in a double circulatory system
blood passes through the heart twice in 1 circulation of the system
27
where does the right side of the heart pump blood to
the lungs
28
what is blood pumped to the lungs for
gas exchange
29
what is pulmonary circulation
its the right side of the heart pumping blood to the lungs for gas exchange
30
what happens of the left side of the heart
its the side which blood returns to and is pumped out of the tissue
31
what side does the blood return to the heart and gets pumped out to the tissues from
the left Side
32
what is systemic circulation
when the blood returns to the heart and gets pumped out to the tissues from the left side
33
what is the advantage of a double circulation system
the blood is repressurized when it leaves the gas exchange surface giving it a faster and more efficient circulation to the tissues
34
what gives a double circulatory system a faster and more efficient circulation to tissues
it being repressureized when it leave the gas exchange surface
35
in a double circulatory system when is the blood repressureized
when it leaves the as exchange surface
36
where does systemic circulation take blood to and from
the gas exchange system
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where does systemic circulation take blood to and from and what type of blood
systemic circulation takes oxygenated blood to the body tissue and deoxygenated blood back to the heart
38
where does pulmonary circulation take blood to and from and what type of blood
pulmonary circulation takes deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart
39
whats and advantage of double circulation
that blood travels faster under higher pressure
40
what circulation returns blood to the heart
pulmonary circulation
41
what do arteries do
they take blood away from the heart
42
what do veins do
they take blood into the heart
43
blood moves to the heart from
artery to arteriole to capillary to venule to vein then back to heart
44
what are capillaries the site of
gas exchange and tissue fluid formation
45
wear are arteries, arterioles, venules and veins
organs of the circulatory system consisting of different tissues
46
what are the organs of the circulatory system consisting of different tissues
arteries, arterioles, venules and veins
47
what is the outermost layer of an artery
the tunica externa
48
what does the tunica externa consist of
collagen rich connective tissue
49
what does the tunica externa resist
it resists the stretching of the blood vessel due to the hydrostatic pressure of the blood
50
what causes the blood vessel to stretch
the hydrostatic pressure of the blood
51
what is the middle layer of a blood vessel
the tunica media
52
what does the tunica media contain
elastic fibres and muscle tissue
53
what do the elastic fibres in the tunica media allow the blood vessel to do
the blood vessel to expand to accommodate the blood flow
54
why does the blood vessel need to expand
to accommodate the blood flow
55
what is the inner most layer of a blood vessel
a single layer of endothelial cells
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what does the single layer of endothelial cells in the inner most layer of a blood vessel provide
a smooth surface with little friction and resistance to blood flow
57
what is the endothelium in the innermost layer of a blood vessel surrounded by
the tunic intima
58
what does the heart generate
pressure
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what adaptation do arteries have
arteries are adapted to carry blood at high pressure
60
why do arteries have the adaptation of carrying blood at a high pressure
as the heart is a pump that generates pressure
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what do artery's have
a thick tunica externa
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what does the thick tunica externa contain
collagen fibres
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what do the collagen fibres in the thick tunica externia resist
overstreching under pressure
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why is the layer of muscle and elastic tissue thick in a artery
to provide elastic recoil
65
what does elastic recoil due to the layer of muscle and elastic tissue in an artery aid
it aids propulsion of blood and maintains blood pressure
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what does propulsion mean
the force that allows the movement of blood
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what is the lumen of arteries
relatively small
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what is the lumen of arteries relatively small
to maintain the pressure of blood
69
compare arterioles and arteries
they are similar but arteries have more muscle
70
why do arteries have more muscle that arterioles
as they constrict and dilate to control the flow of blood to the capillaries
71
why do arteries constrict and dilate
to control the flow of blood to the capillaries
72
name 3 features of arteries
thick tunica media, small lumen and thick tunica externa
73
what do capillaries consist of
a single layer of endothelial cells
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what are capillaries
they are a tissue rather than a organ
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what are capillaries the site of
gas exchange
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what does the single layer of flattened cells in capillaries give it
a short diffusion path
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what are capillary beds
they are extensive and have a massive surface area for diffusion
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why do capillary beds have a massive surface area
for diffusion
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what happens to the pressure when blood passes through capillaries
the pressure is lowered
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why is the pressure lowered as blood passes through capillaries
as the capillary bed has a much greater criss sectional area than the arteriole feeding into it
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what does capillaries being narrow allow them to have a greater resistance to and what does blood do
so the resistance to blood flow is greater and blood flows slow
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why is capillaries being narrow good for gas exchange
as being narrow means blood flows slower and thus gives more time for diffusion
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what do blood cells have to do to fit through a capillary
they have to bend and squeeze through
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what are capillaries compared to red blood cells
they have a slightly smaller diameter than red blood cells
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what do capillaries do to the pressure of blood
they reduce the pressure of blood
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what do capillaries drain into
small veins called venules
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what do many venules join
larger veins
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what do veins have
a large lumen
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what does a veins having a large lumen provide
it provides little resistance to the blood which is flowing through at low pressure
90
what is the tunica media and externa in veins compared to arteries
they are far thinner than in arteries
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why is the tunica media and externa far thinner in veins
as he blood is under much lower pressure and less resistance to pressure is needed
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how is blood kept flowing up to the heart from the lower body
by skeletal muscles squeezing on the veins pushing th blood forward
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how is back flow of blood prevented
by valves at intervals along the veins
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what is pressure in the circulatory system generated by
contractions of the ventricles in the heart
95
where is the highest pressure in the heart
in the main arteries leaving the heart
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why does blood entering the main artery on the left side so the aorta has the highest pressure
as the eft ventricle muscle is thicker and generated the most pressure
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what happens to the blood vessel web kid enters the aorta
the vessel expands until it reaches a maximum and recoils pushing the blood forwards
98
what happens where arteries pass close under the skin
it expands and recoils
99
what is the expansion and recoil where arteries pass close under the skin felt as
a pulse
100
what is the flow in the aorta, arteries and arterioles described as
pulsatile
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what happens to the pressure when the ventricle contract and relax
the pressure goes up when ventricles contract and drop when the ventricles relax
102
where does pressure drop from
the aorta to the arteries to the arterioles
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why does the pressure drop from the aorta to the arteries to the arterioles
as the total cross sectional area of smaller vessels is larger than that of large vessels
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what do narrower vessels have
more resistance to the flow of blood
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why does blood lose pressure rapidly in capillaries
as capillaries are small and numerous and very narrow
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what does capillaries being small, numerous and very narrow mean for pressure
that blood loses pressure rapidly
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without elastic fibres in the walls of capillaries what there be
no pulsatile flow
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what happens to flow is it isn't pulsatile as the capillary doesn't have elastic fibres in the walls
the flow become laminar
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where does blood drain into
the venules, veins and the vena cava
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what happens to the pressure as the vessel gets wider when blood drains into it
the pressure drops further
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why is the pressure much lower in pulmonary circulation
as the right ventricle has a much thinner muscle than the left
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what does the heat is a double pump mean
its divided into 2 by an internal septum making the left and right side separate
113
how do the 2 sides contract
the 2 sides contract simultaneously
114
where does the right side pump blood to
the lungs
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where does the left side pump blood to
the body
116
what are the top 2 chambers of the heart called
the atria which are small
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what is the bulk of the heart
the ventricles
118
what does blue represent
deoxygenated blood
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what does red represent
oxygenated blood
120
why does the pulmonary artery branch
to take blood to the right and left lungs
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what do the superior and inferior vena cava do
return blood to the heart from the head and body
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what does the pulmonary veins do
they return blood form the lungs
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what does the coronary artery do
it supply the heart muscle with oxygen and glucose
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what separates the right and left side of the heart
the septum
125
what are the walls of each chamber made of
cardiac muscle
126
what is cardiac muscle
a specialised skeletal muscle that is resistant to tiring
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where is the atria
at the top of the heart
128
where are they ventricles
at the bottom of the heart
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wear are between the ventricle and atria and why
valves to prevent back flow
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what are the valves between the ventricle and atria called
atrioventricular valves
131
what is the right atrioventricular valve called
the tricuspsid valve
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what is the left atrioventricular valve called
the bicuspid valve
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where does blood enter the heart from and where does it go to
blood enters the heart from the vena cava and pulmonary veins into the atria and then its pushed through to the ventricles as the atria contracts
134
what happens to the atria when the ventricles contract
the atria releases
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when the ventricles contract where is blood pushed out through
the aorta and the pulmonary arteries and the top of the heart
136
when the ventricles contract what happens to the atrioventricular valves and why
they are forced shut to prevent back flow ti the atria and the heart strings which prevent the valves from turning inside out
137
what are at the base if the 2 arteries
semilunar valves
138
what valve is at the base of the aorta
the aortic valve
139
what valve is at the base if the pulmonary artery
the pulmonary valve
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what happens to the semi lunar valves when the ventricles relax and why
the semi lunar valves fill with blood and close preventing back flow form the arteries to the ventricles
141
where does blood always flow from and to
blood always flows from the veins to the atrium to the ventricle to the artery
142
why does blood flow from the atria to the ventricles and then to the arteries
due to pressure generated by the heart muscles
143
what is the movement of pressure
from high to low pressure
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what happens to pressure and where when blood enters and artery
as blood enters and artery the pressure increases in th vessel
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what is back flow to the ventricles prevented by
the closure of the semi lunar valves
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what is blood flow described as starting with
the atria contracting
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what is the atria contracting called
atrial systole
148
what happens when the atria contracts
the pressure in the atria us gusher than that in the ventricles and blood is pushed through the open atrioventricular valves into the ventricles
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where is the blood pushed through during atrial systole
blood is pushed through the open atrioventricular valves into the ventricles
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what happens to the ventricles when blood is pushed into the ventricles from atrial systole
the ventricles are in diastole - relaxed
151
when the ventricles are full where do they contract from
they contract from the apex upwards
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what happens when the ventricles contract from the apex upwards
the pressure in the ventricles increase rapidly and excess that if the atria using the atrioventricular valves shut
153
what happens to the pressure once the artriventricukar valves shut and what does this cause
the pressure is raised above that of the arteries and the semi lunar valves are forced open
154
what happens once. the semi lunar valves are forced open
blood is pushed up and into arteries
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what happens to the pressure once the ventricles relax
the pressure falls below that in the arteries. the semi lunar valves fill with blood and close which prevents blood flowing backwards into ventricles
156
what happens to the pressure in the ventricles once the semil lunar valves have filled with blood
the pressure un the ventricles continues to drop until its below that of the atria and blood flows form the veins through the atria and ventricles start to fit so the heart is in diastole
157
what makes the sub dub heart sound
the valves closing
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what is the heart described as
myogenic
159
what does myogenic mean
that the heart is stimulated to beat from within ins muscle wall
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what happens if the heart is isolated form its nerve supply
it will continue to beat but at a irregular rhythm
161
what is heart rate regulated by
nerve impulses from the medulla oblongata in the brain
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what sends out a wave of excitation across the muscle of the atria
a group of cells in the right atrium called the Sinoatrial node (SAN)
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what does the group of cells in the right atria called the SAN do
send out a wave of excitation across the muscle of the atria
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how does the muscle respond to the wave of excitation for the SAN
the muscle responds by contracting - atrial systole
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what is the wave of excitation a wave of
depolarisation of muscle cells
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what happens when the cells depolarise
they contract
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what happens when cells repolarise
they relax
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what is the wave of excitation prevented from passing to the ventricles by
fibrous tissue between the atria and ventricles
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where does the wave of excitation pass to and where is located
it passes to the atrioventricular node (AVN) which is located in the septum at the atrioventricular junction
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what does the AVN do
it delays the wave of excitation allowing he atria to complete contraction and the ventricles to fill, ensuring the the ventricles contract after the atria
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where does the AVN pass the wave of excitation to
the bundle of his in the septum
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where is the wave of excitation pass through from the bundle of his
to the apex of the heart
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why is the wave of excitation being passed to the apex important
as the ventricles will contract from the apex upwards so that blood will be pushed up to the arteries
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from the bundle of his where is the wave of excitation pass through
the purkinjie fibres in the muscle of the ventricles
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what is an ECG
its a graphical trace produced form electrodes placed around the chest that detect electrical changes in the heart during the cardiac cycle
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what does the P wave on an ECG represent
the wave of depolirasation of the atrial walls from the SAN that causes atrial systole
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what does the QRS complex on an ECG represent
the depolarisation of the ventricular walls causing ventricular systole
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what does the T wave on an ECG represent
the repolarisation of the ventricular walls during ventricular diastole
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what does the shape of a red blood cell provide
a large surface are to maximised diffusion of oxygen into the cells
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what does the disc shape of a red blood cell minimise
the diffusion pathway for oxygen
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what does the thinner central section of a red blood cell allow
it allows the red blood cell the flexibility to squeeze through capillaries
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what do red blood cells not have
a nucleus or organelles
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why don't red blood cells have a nucleus or organelles
as it gives it more space to maximise the number of haemoglobin molecules
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what does a lack of mitochondria in a red blood cell mean
that oxygen isn't used up in aerobic respiration while the oxygen is transported
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what protein structure is haemoglobin
quaternary structure
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what does haemoglobin consist of
4 polypeptide chains 2 alpha chains and 2 beta chains
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what group does haemoglobin contain
a prosthetic group obtaining iron ion
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how many oxygen molecules can each haemoglobin molecule carry
4 oxygen molecules so 8 atoms of oxygen
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what is haemoglobin called when its attached to oxygen
oxyhemoglobin
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when blood enters the ling capillaries from the pulmonary arteries what odes it have
it has low oxygen and high carbon dioxide
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what is loading or association
when oxygen diffuses into the red blood cells and binds to the haemoglobin inside
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where does the blood which has bonded to haemoglobin inside return to and what via and what is it them pumped to
the blood returns to the heart via the pulmonary veins and is them pumped into the systemic circulation
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when does no gas exchange happen until loading
no gas exchange happens until the blood reaches the capillaries of the body tissues
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what happens to the red blood cells that have bonded to haemoglobin at the body tissues
at the body tissues the haemoglobin unloads oxygen to be used in respiration
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what is the unloading of oxygen from haemoglobin called
dissociation
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what is the amount of loading or unloading dependant on
the partial pressure of oxygen surrounding the capillaries
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why do the capillaries in the lungs load oxygen
as in the lungs the capillaries are in close contact with air high in oxygen in the alveoli and therefore load oxygen
198
what will a tissue have if iy ha a high rate of aerobic respiration and what will this cause
if a tissue has a high rate or aerobic respiration it will have a low partial pressure pd oxygen and haemoglobin will unload more oxygen that it exiled to a tissue with a lower rate of respiration
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what can the relation ship between partiall pressure of oxygen and unloading and loading be represented graphically as
as an oxygen dissociation curve
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what does an oxygen dissociation curve show
the relationship between the oxygen partial pressure and how much oxygen is carried by haemoglobin
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what dies the flat part of the oxygen dissociation curve mean
full saturation of haemoglobin even if air pressure drops a small amount
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what do organisms that are adapted to live in low oxygen environments have
haemoglobin that fully saturates at lower partial pressure of oxygen
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why do organisms that are adapted to live in a low oxygen environment have haemoglobin that fully saturates at lower partial pressure of oxygen
as their haemoglobin has a higher affinity for oxygen than adult human haemoglobin
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what is the oxygen dissociation curve of an organism that is adapted to live in low oxygen environments
to the left of the standard oxygen dissociation curve
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what does the oxygen dissociation curve being to the left mean
that their haemoglobin is fully saturated at lower partial pressure of oxygen
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how does a foetus gain its oxygen
from its mothers blood across the placenta
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what does foetal haemoglobin have compared to adult haemoglobin
foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin
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why does foetal haemoglobin have a higher affinity for oxygen than adult haemoglobin
so it can absorb oxygen from the mother blood at all partial pressure of oxygen
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what is the dissociation curve for foetal haemoglobin
to the left of the adult curve
210
what is a disadvantage of the curves to the left
oxyhemoglobin doesn't dissociate as easily
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what is myoglobin
a respiratory pigment found in muscle cells
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what can myoglobin bind to
only 1 molecule of oxygen
213
what does myoglobin load at
a much lower partial pressure of oxygen
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what does myoglobin act as
as an oxygen store
215
when does myoglobin release oxygen
only at very low partial pressure when muscles are repairing quickly
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what is the main advantage of having haemoglobin with the curve to the left for a llama
that haemoglobin is fully saturated at lower ppo2
217
wen is carbon dioxide produced
in cells during respiration
218
where does carbon dioxide diffuse into
the red blood cells
219
where does carbon dioxide dissolve in a what is produced
it dissolves in water and forms carbonic acid
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what is the reaction of carbon dioxide into carbonic acid catalysed by
the enzyme carbonic anhydrase
221
what does carbonic acid dissociate into
protons and hydrogen carbonate atoms
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where do the hydrogen carbonate ions diffuse into
the plasma
223
what is carbon dioxide carried in the plasma as
hydrogen carbonate
224
why doe chloride ions diffuse into red blood cells
to maintain electrochemical neutrality in the cells
225
why is the exchange of hydrogen carbonate ions and chloride ions one to one
the exchange is one to one as one hydrogen carbonate ion diffuses out of the cell and one chloride ion diffuses into the red blood cell
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what is it called when one hydrogen carbonate diffuses out of the cell and one chloride ion diffuses into the cel
the chloride shift
227
what does the chloride shift do
balances the charge in the plasma and the red blood cells
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what do the protons bind to and what does this do
protons bind to haemoglobin displacing oxygen from the oxyheamoglobin
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what happens to the oxygen when protons bind to haemoglobin and displace oxygen form oxyhemoglobin
the oxygen diffuses into the cells
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what does some carbon dioxide diffuse into and then attach to and what does this form
some carbon dioxide diffuses from red blood cells and attaches to haemoglobin forming carbamnohaemoglobin
231
what is produced when respiration rates are high
more carbon dioxide is produced by cells
232
what respiration rates are high what diffuses into the rbc
more carbon dioxide diffuses into the rbc
233
what happens when more carbon dioxide dissolves in the rbc
more carbonic acid is formed
234
what happens when there is more carbonic acid formed
the more carbonic acid formed the more dissociation there is
235
what does more dissociation cause
more H+ ions are released causing more oxyhemoglobin to dissociate
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what happens when more oxyhemoglobin is dissociated
more oxygen is released into the cells as the oxyhemoglobin dissociates at higher ppO2 than usual
237
what happens to the oxygen dissociation curve when more oxygen is released into the cells as the oxyhemoglobin dissociates at higher ppO2 than usual
the oxygen dissociation curve is shifted to the right
238
what causes the shift further to the right
the higher the carbon dioxide produced
239
what gets released more the further the curve is shifted and why
the further the curve is shifted the more oxygen is released to be used in aerobic respiration
240
