transport Flashcards
2.51 - 2.69
1
Q
2.56B the loss of water vapour from the leaves is called
A
transpiration
2
Q
2.56B examiners definition of transpiration
A
the evaporation of water from the surface of a plant
3
Q
2.57B how does temperature affect the rate of transpiration
A
water will evaporate quickly as the water molecules have more kinetic energy
4
Q
2.57B how does humidity affect the rate of transpiration
A
humid air - water vapour = smaller conc gradient so transpiration slows down
5
Q
2.57B how does wind speed affect the rate of transpiration
A
moving air - water vapour blown away from leaf - speeds up transpiration
6
Q
2.57B transpiration .. as wind speed ..
A
transpiration increases as wind speed increases
7
Q
2.57B transpiration .. as humidity ..
A
transpiration increases as humidity decreases
8
Q
2.57B transpiration .. as temperature ..
A
transpiration increase as temp increases
9
Q
2.57B light intensity does NOT affect
A
evaporation
10
Q
2.57B how does light intensity affect the rate of transpiration
A
in daylight stomata leaves are open to supply CO2 for photosynthesis
allows more water to diffuse out leaves into atmosphere
11
Q
2.58B practical: how to set up a potometer
A
set up underwater
cut the stem
shoot stem in bung
grease joint w jelly (no air entry/water loss)
bung in potometer
tap closed full of water
lift potometer out of water
leave end of capillary tube out of water until air bubble forms & then put in beaker of water
measure rate as distance bubble travelled in 5 mins
12
Q
2.58B practical: a potometer is to measure
A
measure the rate of water uptake from a leafy shoot
13
Q
2.58B practical: we can use potometer to collect readings in normal air or windy conditions by
A
using a hairdryer on cold
14
Q
2.58B practical: we can use potometer to collect readings in temperature
A
increases and decreases
15
Q
2.58B practical: we can use potometer to collect readings in increased humidity by
A
using a clear plastic bag
16
Q
2.58B practical: we can use potometer to collect readings by changing the l & d
A
lightness and darkness
17
Q
2.58B practical: changing the environmental factors stimulates
A
all the different conditions which affect the rate of transpiration
18
Q
2.67 what are the factors that may increase the risk of developing coronary heart disease?
A
- obesity
- high blood pressure
- high cholestrol
- smoking
19
Q
2.67 how can obesity increase risk of developing coronary heart disease?
A
carrying extra weight puts a strain on the heart.
increased weight can lead to type 2 diabetes which further damages the blood vessels.
20
Q
2.67 how can high blood pressure increase risk of developing coronary heart disease?
A
high blood pressure increases the force of the blood against the artery walls and consequently leads to damage of the vessels.
21
Q
2.67 how can high cholestrol increase risk of developing coronary heart disease?
A
high cholestrol speeds up the build up of fatty plaques in the arteries which leads to blockages.
22
Q
2.67 how can smoking increase risk of developing coronary heart disease?
A
chemicals in smoke cause an increase in plaque build up and and increase in blood pressure.
carbon monoxide also reduces the oxygen carrying capacity of the red blood cells.
23
Q
2.68 how many types of blood vessel are there? and name them
A
arteries, veins, capillaries.
each vessel is specifically adapted to carry out its particular function efficiently.
24
Q
2.68 what are the smaller vessels that branch off from the arteries called?
A
arterioles (small arteries)
25
2.68 what are the smaller vessels that branch into veins called ?
venules (small veins)
26
2.68 what are the key features of arteries?
carry blood at high pressure away from the heart
carry oxygenated blood (except pulmonary artery)
have thick muscular walls containing elastic fibres
have a narrow lumen
blood flows through at a fast speed.
27
2.68 how is the structure of an artery adapted to its function?
thick muscular walls containing elastic fibres withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
a narrow lumen also helps to maintain high pressure.
28
2.68 what are the key features of veins?
carry blood at low pressure towards the heart
carry deoxygenated blood (other than the pulmonary vein)
have thin walls
have a large lumen
contain valves
blood flows through a slow speed
29
2.68 how is the structure of a vein adapted to its function?
a large lumen reduces resistance to blood flow under low pressure.
valves prevent the backflow of blood as it is under low pressure
30
2.68 what are the key features of capillaries?
carry blood at low pressure within tissues
carry both oxygenated and deoxygenated blood
have walls that are one cell thick
have 'leaky' walls
speed of blood flow is slow
31
2.68 how is the structure of a capillary adapted to its function?
capillaries have walls that are one cell thick (short diffusion distance) so substances can easily diffuse in and out of them.
The 'leaky' walls allow blood plasma to leak out and form tissue fluid surrounding cells.
32
2.51 organisms must exchange what substances to function properly
food molecules and waste
33
2.51 the exchange of food molecules and waste in organisms happens via
diffusion, osmosis and active transport across the cell membrane
34
2.51 give an example of a unicellular organism
amoebas
35
2.51 unicellular organisms like amoebas have what
large surface areas relative to their volume
meaning the distance from the surface to the centre is small
36
2.51 unicellular organisms like amoebas do not need
specialised exchange surfaces / transport systems
37
2.51 what are the specialised exchange surfaces / transport systems that unicellular organisms do not need
transport systems such as diffusion, osmosis and active transport through the cell membrane
38
2.51 in an amoeba what does the oxygen do
oxygen diffuses in for respiration
39
2.51 in an amoeba what does the waste products - including CO2
waste products - including CO2 - diffuses out
40
2.51 in an amoeba what does the water do
water moves in / out by osmosis
41
2.51 what do unicellular organisms not require
unicellular organisms such as amoeba do not require transport systems due to their large surface area to volume ratio
42
2.52 an example of a multicellular organism
humans - they are composed of many cells
43
2.52 why are humans multicellular organisms
bodies are composed of many cells
44
2.52 what do multicellular organisms have
they have multiple cell layers
45
2.52 what do the multiple cell layers in organisms mean for the distance
the distance from the surface to the centre too long for diffusion alone
46
2.52 larger multicellular organisms require what
transport systems
47
2.52 why do larger organisms require transport systems
diffusion to all cells would be too slow to meet the organisms needs
48
2.52 in animals what carries essential substances in the blood
circulatory system
49
2.52 what is the transport system in animals
the circulatory system
50
2.52 in plants what transports substances
vascular system
51
2.52 what is the transport system in plants
vascular system
52
2.52 what substances does the vascular system transport in plants
the xylem moves water and minerals from roots to shoots
the phloem distributes sugars and amino acids throughout the plant
53
2.52 what does the xylem do regarding transport systems in multicellular organisms
water and mineral ions from roots to shoots
54
2.52 what does the phloem do regarding transport systems in multicellular organisms
sugars and amino acids from source to sink
55
2.52 what does the circulatory system do regarding transport systems in multicellular organisms
blood carries oxygen, glucose, carbon dioxide, water & waste around the body
56
2.52 what do multicellular systems have
transport systems
57
2.53 what is the role of the phloem
it transports sucrose and amino acids from where they are produced / stored to where they are needed
58
2.53 where are sucrose and amino acids produced
in the leaves while plants photosynthesise so they are transported from the leaves to the other parts of the plant
59
2.53 what is the phloem formed by
it is formed from living cells forming a tube with small holes through which substances can move
60
2.53 & 2.54 what do the xylem and phloem make up
the transport system of vascular plants
61
2.53 & 2.54 what makes up the transport system of vascular plants
the xylem and phloem
62
2.54 what is the role of the xylem
to transport water and mineral ions from the roots to other parts of the plant
63
2.54 what is the xylem formed from
formed from a hollow tube of dead cells reinforced by lignin which provides a route for the column of water to move through the plant by transpiration
64
2.54 what cell content does the xylem have
no cell contents just a continuous column of water
65
2.54 what happens to the original cell wall in the xylem
original cell wall between cells has broken down
66
2.54 what happens to the walls in the xylem
the walls are thickened with lignin
67
2.54 what are the walls thickened with in the xylem
lignin
68
2.54 what does the structure of the xylem allow
it allows it to function as a vessel for the transport of water through the plant
69
2.55B what are root hairs
single-celled extensions of epidermis cells in the root
70
2.55B where do root hairs grow
they grow between soil particles and absorb water and minerals from the soil
71
2.55B how are root hair cells adapted for the efficient uptake of water - by osmosis - ad mineral ions - by active transport
they contain mitochondria which release energy for active transport
root hairs increase the surface are of plant roots increasing the rate at which water and minerals can be taken up
72
2.55B what are root hair cells adapted for
the efficient uptake of water by osmosis & mineral ions by active transport
73
2.55B what does mitochondria do in root hair cells
they release energy for active transport
74
2.55B what do root hairs do in regard to the surface area
they increase the surface area of plant roots, increasing the rate at which water and minerals can be taken up
75
2.55B what do root hair cells take up
mineral ions and water from the soil
76
2.55B which is taken up by active transport with root hair cells
mineral ions from the soil
77
2.55B which is taken up by osmosis with root hair cells
water
78
2.55B root hair cells take up mineral ions from the soil by
active transport
79
2.55B water moves into the root hair cell by
osmosis
80
2.55B the water concentration of the cell cytoplasm is
reduced due to the presence of mineral ions
81
2.55B why is the water concentration of the cell cytoplasm is reduced
due to the presence of mineral ions
82
2.55B what does the structure of a root specifically allow it to do
it allows it to maximise absorption of water by osmosis and mineral ions by active transport
83
2.55B how does water move in the root hair cells
by osmosis into the root hair cells
84
2.55B what does water move through in the root hair cells
the root cortex and into the xylem vessels
85
2.55B when the water gets into the xylem what does it do
it is carried up the leaves where it enters mesophyll cells
86
2.55B what is the pathway for the root of water through the root hair cell
root hair cell -> root cortex cells -> xylem -> leaf mesophyll cells
87
2.59 what does the blood consist of
red blood cells, white blood cells, platelets & plasma
88
2.59 how much of the blood is made up of plasma
over half
89
2.59 statistics - percentage of what is in blood
55% plasma
45% red blood cells
<1% white blood cells & platelets
90
2.59 structure of red blood cells
biconcave discs containing no nucleus to maximise the available capacity to carry the protein haemoglobin
91
2.59 structure of white blood cells
large cells containing a large nucleus - different types have slightly different structures and functions
92
2.59 structure of platelets
fragments of cells
93
2.59 structure of plasma
clear, straw -coloured aqueous solution
94
2.60 what is plasma
a straw-coloured liquid which the other components of blood are suspended with
95
2.60 what does plasma transport
carbon dioxide
digested food and mineral ions
urea
hormones
heat energy
96
2.60 what is plasma important for
the transport of many substances
97
2.60 plasma transports carbon dioxide explain more
carbon dioxide - waste product of respiration dissolved in plasma & transported from respiring cells to the lungs
98
2.60 plasma transports digested food & mineral ions explain more
dissolved particles absorbed from the small intestine and delivered to requiring cells around the body
99
2.60 plasma transports urea explain more
urea is a waste substance dissolved in the plasma and transported to the kidneys
100
2.60 plasma transports hormones explain more
chemical messengers released into the blood from the endocrine organs (glands) and delivered to target tissues/organs of the body
101
2.59 plasma transports heat energy explain more
heat energy (created in respiration) is transferred to cooler parts of the body or to the skin where heat can be lost
102
2.60 plasma transports what substances & explain them
carbon dioxide - the waste product of respiration, dissolved in the plasma and transported from respiring cells to the lungs
digested food and mineral ions - dissolved particles absorbed from the small intestine and delivered to requiring cells around the body
urea - urea is a waste substance dissolved in the plasma and transported to the kidneys
hormones - chemical messengers released into the blood from the endocrine organs (glands) and delivered to target tissues/organs of the body
heat energy - heat energy (created in respiration) is transferred to cooler parts of the body or to the skin where heat can be lost
103
2.61 what are red blood cells
they are specialised cells which carry oxygen to respiring cells
104
2.61 how are red blood cells adapted to carry oxygen to respiring cells
- they are full of haemoglobin
- they have no nucleus which allows more space for haemoglobin to be packed in
- shaped as a biconcave disc which gives them a large surface area to volume ratio to maximise diffusion of oxygen in and out
105
2.62 what are white blood cells a part of
the body's immune system
106
2.62 what are white blood cells
they are specialised cells that defend against pathogenic microorganisms
107
2.62 what are the two main types of white blood cell
phagocytes and lymphocytes
108
2.62 what do phagocytes carry out
phagocytosis by ingesting pathogens
109
2.62 how do phagocytes carry out phagocytosis
by ingesting pathogens
110
2.62 phagocytes have what type of cell surface
a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
111
2.62 phagocytes have a sensitive cell surface membrane which
can detect chemicals produced by pathogenic cells
112
2.62 when phagocytes encounter the pathogenic cell what do they do
they will engulf it and release digestive enzymes to digest it
113
2.62 what type of response is phagocytosis
a non-specific immune response
114
2.62 process of phagocytosis
bacterial pathogen is engulfed by the phagocyte (phagocytosis)
digestive enzymes are released to destroy the bacteria
115
2.62 what do lymphocytes do
they produce antibodies
116
2.62 what are antibodies
they are proteins with a shape that is specific / complementary to the antigens on the surface of the pathogen
117
2.62 what do lymphocytes provide
a specific immune response
118
2.62 why do lymphocytes provide a specific immune response
as the antibodies produced will only fit one type of antigen on a pathogen
119
2.62 what do lymphocytes do
they produce antibodies that are specific to the antigen on the pathogen
120
2.62 what is the main component of the immune system
white blood cells
121
2.62 what is the role of the immune system
when a pathogen enters the body, the immune system should prevent the infectious organism from reproducing and to destroy it
122
2.62 when does an organism have immunity
when they have sufficient levels of antibodies to protect it from a particular disease
123
2.62 what are the stages of infection
the pathogen enters the blood stream and multiplies
it releases toxins & infects body cells causing symptoms in the patient
phagocytes recognise the invading pathogen and engulf & digest it (non-specific response)
the pathogen encounters a lymphocyte which recognises its antigens
the lymphocyte produces specific antibodies to fight it
the lymphocyte also clones itself to produce lots of lymphocytes - producing the specific antibody required
antibodies destroy pathogens
phagocytes engulf and digest destroyed pathogens
124
2.62 stage 1 of the response to infection
the pathogen enters the blood stream and multiplies
125
2.62 stage 2 of the response to infection
a release of toxins (in the case of bacteria) and infection of body cells causes symptoms in the patient
126
2.62 stage 3 of the response to infection
phagocytes that encounter the pathogen recognise that it is an invading pathogen and engulf and digest (non-specific response)
127
2.62 stage 4 of the response to infection
the pathogen encounters a lymphocyte which recognises its antigens
128
2.62 stage 5 of the response to infection
the lymphocyte starts to produce specific antibodies to combat that particular pathogen
129
2.62 stage 6 of the response to infection
the lymphocyte also clones itself to produce lots of lymphocytes (all producing the specific antibody required)
130
2.62 stage 7 of the response to infection
antibodies destroy pathogens
131
2.62 stage 8 of the response to infection
phagocytes engulf and digest the destroyed pathogens
132
2.62 what is an antigen
is a molecule found on the surface of a cell
133
2.62 what is an antibody
a protein made by lymphocytes that is complementary to an antigen and, when attached, clumps them together and signals the cells they are on for destruction
134
2.63B what are vaccines used for
to induce immunity to infectious diseases
135
2.63B what have vaccines done
they have reduced the cases of certain diseases or even eradicated them
136
2.63B diseases vaccines have eradicated / reduced the case of
smallpox, measles, mumps and tetanus
137
2.63B what does a vaccine contain
harmless versions of a pathogen
138
2.63B what are the different methods scientists use to ensure the vaccines contain harmless pathogens
killing the pathogen
(attenuated vaccine) which means making it unable to grow or divide
using fragments of pathogens rather than whole cells
139
2.63B how may a vaccine be administered
orally, nasally or via an injection
140
2.63B how do vaccines work
when in the bloodstream the antigens in the vaccine trigger an immune response:
lymphocytes recognise the antigens in the bloodstream
the activated lymphocytes produce antibodies specific to the antigen encountered
memory cells are produced from the lymphocytes
memory cells and antibodies subsequently remain circulating in the blood stream
141
2.63B what is the immune response vaccines trigger
lymphocytes recognise the antigens in the bloodstream
the activated lymphocytes produce antibodies specific to the antigen encountered
memory cells are produced from the lymphocytes
memory cells and antibodies subsequently remain circulating in the blood stream
142
2.63B how does long-term immunity work by vaccination
memory cells are produced when reacting & fighting the vaccine, so if the antigen is triggered again the antibodies are produced much faster
143
2.63B future infection from the same pathogen to someone who was vaccinated means
the response will be much faster and much larger compared to the initial response
144
2.63B why is an individual said to be immune after vaccinated
due to the rapid nature of the response, the pathogen is unable to cause disease
145
2.64B what are platelets
they are fragments of cells
146
2.64B what are platelets involved in
they are involved in blood clotting and forming scabs
147
2.64B what happens after the skin is broken involving platelets
platelets arrive to stop the bleeding
148
2.64B what is the series of reactions that occur within the blood plasma after the skin is broken
platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
this forms an insoluble mesh across the wound
red blood cells become trapped, forming a clot
the clot eventually dries and develops into a scab
149
2.64B stage 1 of the series of reactions after the skin has been cut
platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin
150
2.64B stage 2 of the series of reactions after the skin has been cut
there is an insoluble mesh formed across the wound
151
2.64B stage 3 of the series of reactions after the skin has been cut
red blood cells become trapped, forming a clot
152
2.64B stage 4 of the series of reactions after the skin has been cut
the clot eventually dries and develops into a scab
153
2.64B how does the reactions that occur after a cut help the individual
it helps to prevent excessive blood loss and protect the wound from bacteria entering until new skin has formed
154
2.65 what is the heart organ in terms of pumps
a double pump
155
2.65 what is pumped into the left side of the heart from the lungs
oxygenated blood
156
2.65 where does oxygenated blood from the lungs enter the heart
on the left side
157
2.65 what is done with the oxygenated blood from the lungs when it is pumped into the left side of the heart
it is pumped to the rest of the body
- the systemic circuit -
158
2.65 which ventricle is thicker & why
the left has a thicker muscle wall as it has to pump blood at high pressure around the entire body
159
2.65 which ventricle pumps blood around the whoe body
the left ventricle
therefore it has a thicker muscle wall
160
2.65 where does deoxygenated blood from the body enter the heart
on the right side
161
2.65 what is pumped into the right side of the heart from the body
deoxygenated blood
162
2.65 what is done with the deoxygenated blood from the body when it is pumped into the right side of the heart
it is pumped to the lungs
- the pulmonary circuit -
163
2.65 which side of the heart uses the pulmonary circuit
the right side with deoxygenated blood
164
2.65 which side of the heart uses the systemic circuit
the left side with the oxygenated blood
165
2.65 what pressure is the right ventricle pumping blood at
a lower pressure to the lungs
166
2.65 what separates the two sides of the heart
the septum - muscle wall
167
2.65 what does the septum - muscle wall - do in the heart
it separates the two sides of the heart
168
2.65 where is blood pumped in veins
towards the heart
169
2.65 where is blood pumped in arteries
away from the heart
170
2.65 where is blood pumped towards the heart
in the veins
170
2.65 what do the coronary arteries do
they supply the cardiac muscle tissue of the heart with oxygenated blood
170
2.65 where is blood pumped away from the heart
in the arteries
171
2.65 as the heart is a muscle what constant supply does it need
it needs a constant supply of oxygen (and glucose) for aerobic respiration to release energy to allow continued muscle contraction
172
2.65 what do valves do
they prevent blood flowing backwards
173
2.65 what prevents blood flowing backwards
valves
174
2.65 why does the heart need a constant supply of oxygen (and glucose) for aerobic respiration to release energy to allow continued muscle contraction
because it is a muscle
175
2.65 describe the flow of oxygenated blood in the heart
on the left side
in through the pulmonary vein
into the left atrium
through the bicuspid valve
into the left ventricle
through the semi-lunar valves
out of the aorta
176
2.65 describe the flow of deoxygenated blood in the heart
on the right side
in through the vena cava
into the right atrium
through the tricuspid valve
into the right ventricle
through the semi-lunar valves
out of the pulmonary artery
177
2.65 how to remember veins go into the heart
veIN into the heart
178
2.65 how to remember arteries go away from the heart
Arteries are Away from the heart
179
2.65 what is the pathway of blood through the heart BOTH DEOXYGENATED & OXYGENATED
DEOXYGENATED blood coming from the body flows through the vena cava and into the right atrium
the atrium contracts and the blood is forced through the tricuspid valve into the right ventricle
the ventricle contracts and the blood is pushed through the semilunar valve into the pulmonary artery
the blood travels to the lungs and moves through the capillaries past the alveoli where gas exchange takes place
low pressure blood flow on this side of the heart prevents damage to the capillaries in the lungs
OXYGENATED blood returns via the pulmonary vein to the left atrium
the atrium contracts and forces the blood through the bicuspid valve into the left ventricle
the ventricle contracts and the blood is forced through the semilunar valve and out through the aorta
thicker muscle walls of the left ventricle produce a high enough pressure for the blood to travel around the whole body
180
2.65 what is the pathway of blood through the heart - just DEOXYGENATED
DEOXYGENATED blood coming from the body flows through the vena cava and into the right atrium
the atrium contracts and the blood is forced through the tricuspid valve into the right ventricle
the ventricle contracts and the blood is pushed through the semilunar valve into the pulmonary artery
the blood travels to the lungs and moves through the capillaries past the alveoli where gas exchange takes place
low pressure blood flow on this side of the heart prevents damage to the capillaries in the lungs
181
2.65 what is the pathway of blood through the heart - just OXYGENATED
OXYGENATED blood returns via the pulmonary vein to the left atrium
the atrium contracts and forces the blood through the bicuspid valve into the left ventricle
the ventricle contracts and the blood is forced through the semilunar valve and out through the aorta
thicker muscle walls of the left ventricle produce a high enough pressure for the blood to travel around the whole body
182
2.66 how is the heart rate measured
by counting the number of times the heart beats in a minute - bpm
183
2.66 the natural resting heart rate is controlled by what
a group of cells located in the right atrium called the pacemaker
184
2.66 what is the role of the pacemaker
to coordinate the contraction of the heart muscle & regulate the heart rate
185
2.66 how does the pacemaker function
pacemaker cells send out electrical impulses which initiate a contraction in the cardiac muscle
186
2.66 why does the heart pumps blood to respiring cells
to supply oxygen and glucose and remove respiratory waste
187
2.66 during exercise what do muscle cells do
they respire faster to increase energy supply
188
2.66 when is respiration aerobic & anaerobic
aerobic during moderate exercise and anaerobic during intense exercise
189
2.66 what types of respiration occur during moderate & intense exercise
aerobic during moderate exercise and anaerobic during intense exercise
190
2.66 why do muscles respire faster during exercise
to increase energy supply
191
2.66 what do muscles do during exercise
they respire faster
192
2.66 how do muscle cells increase the energy supply during exercise
they respire faster
193
2.66 what does increased respiration raise the need for
oxygen, glucose and waste removal
194
2.66 how does the nervous system respond to an increased respiration rate
increasing heart rate to deliver oxygen and glucose more frequently
& increasing the volume of blood pumped to supply larger amounts of oxygen and glucose
195
2.66 what happens to the heart rate at the end of exercise
it main remain high as oxygen is required in the muscles to break down the lactic acid from anaerobic respiration
196
2.66 why does heart rate remain high after exercise
it main remain high as oxygen is required in the muscles to break down the lactic acid from anaerobic respiration
197
2.66 production of the hormone adrenaline also does what
it also increases heart rate as part of a 'fight or flight' response
198
2.66 as part of the fight or flight response what hormone is released
adrenaline
199
2.66 what hormone increases the heart rate
adrenaline
200
2.67 what are the coronary arteries
the blood vessels which supply cardiac muscle with oxygen glucose
201
2.67 what happens in coronary heart disease
layers of fatty material (plaque) build up inside the coronary arteries
202
2.66 what are the fatty deposits in coronary heart disease made from
the fatty deposits are mainly formed from cholesterol
203
2.66 where are the two main sources of cholesterol in the body
dietary cholesterol - from animal products eaten
cholesterol synthesised by the liver
204
2.66 what happens to the artery wall when plaque builds up
it becomes less elastic
205
2.66 what is plaque made from
cholesterol and white blood cells
206
2.66 what happens to the coronary artery when plaque builds up
coronary artery narrows restricting blood flow
207
2.66 what can lead to coronary heart disease
a diet too high in saturated fat and cholesterol
208
2.66 what does a buildup of plaque in the coronary arteries do
it narrows the lumen
209
2.66 what happens if coronary artery becomes partially or completely blocked by these fatty deposits
the flow of blood through the arteries is reduced, resulting in a lack of oxygen for the heart muscle
210
2.66 what does partial blockage do to the coronary arteries
it creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
211
2.66 what does complete blockage do to the coronary arteries
means cells in that area of the heart will not be able to respire aerobically, leading to a heart attack
212
2.66 what is the effect of a narrowed lumen in a coronary artery
reduced blood flow to the heart
213
2.66 what does carrying extra weight mean for CHD
carrying extra weight puts a strain on the heart
increased weight can lead to type 2 diabetes which further damages your blood vessels
214
2.66 what does a high blood pressure mean for CHD
this increases the force of the blood against the artery walls and consequently leads to damage of the vessels
215
2.66 what does high cholesterol mean for CHD
speeds up the build up of fatty plaques in the arteries leading to blockages
216
2.66 what does smoking mean for CHD
chemicals in smoke cause an increase in plaque build up and an increase in blood pressure
carbon monoxide also reduces the oxygen carrying capacity of the red blood cells
217
2.68 what are the three main types of blood vessel
arteries, veins or capillaries
218
2.68 what are the smaller vessels that branch of arteries
arterioles (smaller arteries)
219
2.68 what are arterioles
smaller arteries that branch off arteries
220
2.68 what are the smaller vessels that branch of veins
venules (smaller veins)
221
2.68 what are venules
smaller veins that branch off veins
222
2.68 what do each blood vessel do
they have a particular function and are specifically adapted to carry out that function efficiently
223
2.68 what are the key features of arteries?
carry blood at high pressure away from the heart
carry oxygenated blood (except pulmonary artery)
have thick muscular walls containing elastic fibres
have a narrow lumen
blood flows through at a fast speed.
224
2.68 how is the structure of an artery adapted to its function?
thick muscular walls containing elastic fibres withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
a narrow lumen also helps to maintain high pressure
225
2.68 what are the key features of veins?
carry blood at low pressure towards the heart
carry deoxygenated blood (other than the pulmonary vein)
have thin walls, have a large lumen, contain valves
blood flows through a slow speed
226
2.68 how is the structure of a vein adapted to its function?
a large lumen reduces resistance to blood flow under low pressure.
valves prevent the backflow of blood as it is under low pressure
227
2.68 what are the key features of capillaries?
carry blood at low pressure within tissues
carry both oxygenated and deoxygenated blood
have walls that are one cell thick
have 'leaky' walls
speed of blood flow is slow
228
2.68 how is the structure of a capillary adapted to its function?
capillaries have walls that are one cell thick (short diffusion distance) so substances can easily diffuse in and out of them
the 'leaky' walls allow blood plasma to leak out and form tissue fluid surrounding cells
229
2.68 capillaries are the site of what
capillaries within body tissues where exchange of substances take place
230
2.68 why are arterial walls thicker than vein walls
to withstand higher blood pressure
231
2.69 the circulatory system consists of what
a closed network of blood vessels connected to the heart
232
2.69 where oxygenated blood carried
oxygenated blood is carried away from the heart and towards organs in arteries
233
2.69 the steps in network
oxygenated blood is carried away from the heart and towards organs in arteries
these narrow to arterioles and then capillaries as they pass through the organ
in the organs, respiring cells use up the oxygen from the blood
the capillaries widen to venules and finally veins as they move away from the organs
veins carry deoxygenated blood back towards the heart
234
2.69 a different network of lymphatic vessels collect what
all the excess tissue fluid that leaks out of the capillaries and delivers it back to the circulatory system
235
2.68 which network collects all the excess tissue fluid that leaks out of the capillaries and delivers it back to the circulatory system
lymphatic vessels
236
2.69 what moves towards the heart
vena cava & pulmonary vein
237
2.69 what moves away the heart
aorta & pulmonary artery
238
2.69 what moves towards the lung
pulmonary artery
239
2.69 what moves away the lung
pulmonary vein
240
2.69 what moves towards the kidney
renal artery
241
2.69 what moves away the kidney
renal vein
