3.1.2: Transport in animals Flashcards
1
Q
what needs to be transported around the body?
A
oxygen, nutrients (glucose) and waste products (urea)
2
Q
what does the transport consist of in mammals?
A
blood, heart and blood vessels
3
Q
why do simple organisms, like jellyfish, not need a transport system?
A
they have a large surface area to volume ratio so diffusion is sufficient
4
Q
what factors affect the need for a circulatory system?
A
-size
-level of activity
-surface area to volume ratio
5
Q
why does size affect the need for a circulatory system?
A
Several layers in a cell prevent fast diffusion, this means diffusion is not sufficient for needs due to the increased distance. In lots of organisms hormones/ enzymes are made in one place and needed in another and waste from cells need to travel to excretory organs which is why a cell may need a circulatory system.
6
Q
why does the level of activity affect the need for a circulatory system?
A
-active animals require more oxygen for respiration
-oxygen must be delivered quickly if the organism is metabolically active
7
Q
why does surface area to volume ratio affect the need for a circulatory system?
A
Large multicellular organisms have a smaller surface area: volume ratio so SA is not large enough to absorb/remove substances.
8
Q
do unicellular organisms require transport systems?
A
no
9
Q
why do unicellular organisms not require transport systems?
A
the singe cell can exchange substances with its external environment
10
Q
do multicellular organisms require transport systems?
A
yes
11
Q
why do multicellular organisms require transport systems?
A
cells are a greater distance from their external environments so require transport systems to ensure efficient exchange of substances
12
Q
what is a mass transport system?
A
a system where substances are transported in a mass of fluid
13
Q
what is the transport system of an animal called?
A
a circulatory system
14
Q
what are the two types of circulatory systems?
A
an open circulatory system or a closed circulatory system
15
Q
what are the three components of a circulatory system?
A
-the pump (heart)
-transport medium (blood)
-interconnecting vessels (blood vessels)
16
Q
what are the types of closed circulatory system?
A
-single closed circulatory system
-double closed circulatory system
17
Q
describe a closed circulatory system
A
-blood is confined to vessels
-heart pumps blood into vessels which branch off and infiltrate organs
-chemical exchange between blood and interstitial fluid then interstitial fluid and cells
-widespread among animals
18
Q
describe an open circulatory system
A
-few vessels so organs are bathed directly
-contains haemolymph
-contains haemocoel
-body movements can help circulate haemolymph
-heart extends length of thorax and abdomen
19
Q
what is haemolymph?
A
insect blood/ interstitial fluid
20
Q
what is haemocoel?
A
the insect body cavity
21
Q
where are open circulatory systems found?
A
insects and some molluscs
22
Q
describe haemolymph (insect blood)
A
blood doesn’t carry oxygen or carbon dioxide instead it just transports food and nitrogenous waste and cells for defense against diseases
23
Q
what makes up a double closed circulatory system?
A
two circuits, two pumps (in one organ)
24
Q
what are the two circuits that make up a double closed circulatory system?
A
-pulmonary circuit
-systemic circuit
25
describe the pulmonary circuit
-right side of heart delivers oxygen poor blood to capillaries of gas exchange tissue
-oxygen into blood and carbon dioxide out of blood
-oxygen enriched blood leaves gas exchange tissue and enters left side of the heart
26
describe the systemic circuit
-the left side of the heart delivers oxygen rich blood to capillary beds in organs and tissues
-oxygen, carbon dioxide and nutrients are exchanged
-oxygen poor blood returns to right side of the heart
27
describe a single closed circulatory system
-heart has two chambers: atrium and ventricle
-blood passes through heart once in a complete circuit
-blood passes from atrium to ventricle
-blood then leaves heart and travels through two capillary beds: one where oxygen and carbon dioxide are exchanged and one where substances are exchanged between blood and cells
-blood pressure drops substantially as it travels through capillary bed (blood flow back to the heart is slow)
-as animals muscles relax and contract, pace of circulation increases
28
how can fish be so active with a single circulatory system?
single closed circulatory system normally limits animals to low levels of activity but fish are the exception as they have such an efficient single closed system- they have a counter current gas exchange system (blood can pick up more oxygen)
29
what are the different blood vessels?
-arteries
-arterioles
-capillaries
-veins
-venules
30
what are the major components of blood vessels?
-elastic fibres
-smooth muscle
-collagen
31
what are elastic fibres composed of?
elastin
32
where are elastic fibres found in blood vessels?
inner layer of blood vessel
33
what's the function of elastic fibres in blood vessels?
they can stretch and recoil providing vessels with flexibility
34
what's the function of smooth muscle in blood vessels?
contracts and relaxes changing the size of the lumen
35
where is smooth muscle found in blood vessels?
inner layer of blood vessel
36
what is the function of collagen in blood vessels?
provides structural support to maintain the shape and volume of the lumen
37
where is collagen found in the blood vessel?
outer layer of blood vessel
38
what direction do arteries carry blood in?
away from the heart
39
what kind of blood do arteries carry?
mostly oxygenated blood except for the pulmonary artery and umbilical artery in pregnancy
40
what are arteries made of?
elastic fibre, smooth muscle and collagen
41
what are the function of elastic fibres in arteries?
withstand force of blood and recoil between contractions to give a continuous flow of blood
42
what is the function of collagen in arteries?
elastic limit is maintained by collagen
43
what is the lining of the artery called?
tunica intima
44
describe the lining of the artery
it's smooth
45
what do arterioles link?
link arteries to capillaries
46
what are the arterioles made of?
more smooth muscle than elastin
47
what's the function of the arterioles?
they constrict and dilate in processes called vasoconstriction and vasodilation- this controls the volume of blood that enters into capillary beds in individual organs
48
what are capillaries?
microscopic vessels
49
what do capillaries form?
a dense network of bodily tissues
50
where are capillaries found?
between arterioles and venules
51
what are the size of the lumen in capillaries?
narrow lumen
52
what's the function of narrow lumen in capillaries?
only allow one red blood cell through at a time
53
what's the name of the single celled walls that line capillaries?
endothelial walls
54
what's the function of endothelial walls in capillaries?
substances are exchanged through endothelial walls
55
do capillaries have a large surface area?
yes
56
why do capillaries have a large surface area?
for quicker rates of diffusion
57
what do venules link?
link capillaries to veins
58
what are the characteristics of venules?
have very thin walls with just a little smooth muscle
59
what do several venules join to form?
a vein
60
what direction do veins carry blood in?
to the heart
61
what kind of blood do veins transport?
usually deoxygenated blood except pulmonary vein and the umbilical vein during pregnancy
62
what's the blood pressure like in veins?
very low blood pressure
63
what do the walls of veins contain?
lots of collagen and very little elastic fibre
64
what size lumens do veins have?
large lumen
65
what is the name of the lining of the vein?
endothelium
66
why do veins need adaptations?
to transport the low pressure blood against gravity
67
what are the adaptations of veins?
-one way valve which prevents backflow of blood
-large veins are located close to muscles, these muscles help to force blood upwards upon contraction
-the breathing movements of the chest act as a pump which pushes blood towards the chest
68
what are the key external features of the heart?
-cardiac muscle is myogenic
-contains coronary blood vessels
69
what does it mean that the cardiac muscle is myogenic?
contracts without tiring and generates own contraction
70
what do the coronary blood vessels do?
supply heart with nutrients and oxygen
71
where are the coronary blood vessels visible?
on surface of heart
72
how many chambers does the heart have?
4 chambers (2 atria and 2 ventricles)
73
what separates the halves of the heart?
the septum
74
what side of the heart is oxygenated?
left side
75
what side of the heart is deoxygenated?
right side
76
how many valves does the heart contain?
4 valves
77
how do the sides of the heart beat?
both sides beat in unison
78
what is the average heart rate?
60-80bpm
79
describe the features of the left side of the heart
the left heart side has thicker muscle wall as it needs greater force of contraction to created pressure to push blood around the whole body
80
what do the valves do?
-prevent backflow of blood
-ensure blood flows in only one direction
81
what are the atrioventricular valves?
the bicuspid and tricuspid valves
82
draw and label a diagram of the heart
*see on paper flashcard*
83
what is the function of the left atrium?
to pump blood into left ventricle
84
what are the top two chambers of the heart called?
atria
85
what are the bottom two chambers of the heart called?
ventricles
86
what type of muscle is the heart made of?
cardiac muscle
87
what is the general name of the valves between the ventricles and the major arteries?
semilunar valves
88
what is the name of the blood vessel that returns deoxygenated blood to the heart?
vena cava
89
what is the name of the blood vessel that returns the deoxygenated blood to the lungs?
pulmonary artery
90
what is the name of the blood vessel that returns oxygenated blood to the heart?
pulmonary veins
91
what is the name of the blood vessel that transports oxygen in the direction of the rest of the body?
aorta
92
what is the name of the atrioventricular valve on the left hand side of the heart?
bicuspid
93
what is the name of the atrioventricular valve on the right hand side of the heart?
tricuspid
94
what is the general name of the valves that separate the top and bottom chambers of the heart?
cuspid valves (atrioventricular valves)
95
what is the name of the network of blood vessels that supply the cardiac muscle with oxygen?
coronary arteries
96
which side of the heart has the thickest muscular wall?
left
97
why does the left side of the heart have a thicker wall than the other side of the heart?
need to have strong contractions to produce enough pressure to pump blood around the body
98
what is the tissue called that separates the left side of the heart from the right side?
the septum
99
name four components of the blood
red blood cell, white blood cell, plasma and platelets
100
what term do we use to describe cardiac muscles, meaning that it contracts without tiring and generates its own contractions?
myogenic
101
define the cardiac cycle
the events of a single heart eat
102
how many stages are there in the cardiac cycle?
three
103
what are the stages of the cardiac cycle?
1. atrial systole
2. ventricular systole
3. diastole
104
define systole
contraction (pumping)
105
define diastole
relaxation (filling)
106
what is the name of the first stage of the cardiac cycle?
atrial systole
107
describe the first stage of the cardiac cycle
1. ventricles relax, atria contract
2. atrial pressure increasing, volume decreasing
3.blood pushed into ventricles
4. slight increase in ventricular pressure and chamber volume as ventricles receive blood
108
what is the name of the second stage of the cardiac cycle?
ventricular systole
109
describe the second stage of the cardiac cycle
1. ventricles contract, atria relax
2. ventricular pressure increases, volume decreases
3. pressure higher in ventricles forces AV valves to shut
4. also forces semi-lunar valves open
5. blood is forced into the arteries
110
what is the name of stage three of the cardiac cycle?
diastole
111
describe stage three of the cardiac cycle
1. ventricles and atria relax
2. high pressure in arteries close semi-lunar valves
3. blood returns to heart, atria begin to fill
4. pressure begins to increase in atria
5. ventricular pressure drops below that of atria forcing AV valves open
112
what can the sound of the heartbeat be heard through?
a stethoscope
113
what is the sound of the heartbeat made by?
blood pressure closing the heart valves
114
what is used to measure the spread of electrical activity in the heart?
electrocardiograms
115
what does Lub mean?
AV valves shut
116
what does Dub mean?
semi-lunar valves shut
117
define cardiac output
the amount of blood the heart pumps through the circulatory system in a minute
118
define stroke volume
the amount of blood pumped by the left ventricle of the heart in one contraction
119
define heart rate
the number of heart beats per unit of time
120
how do you calculate cardiac output?
stroke volume x heart rate
121
when do the atrioventricular valves close?
when the blood can not enter the atria because of the pressure in the ventricles exceeding the pressure in the atria causing the atrioventricular valves to close
122
how long does diastole last?
0.3 seconds
123
how long after the atria contract to the ventricles begin contraction?
0.15 seconds after the atria contract
124
how long does ventricular systole last?
0.4 seconds
125
how long does atrial systole last?
0.15 seconds
126
how long does the whole cardia cycle last?
around 0.7-0.8 seconds
127
are the semi lunar valves closed during ventricular diastole or systole?
diastole
128
what causes the semi lunar valves to close?
ventricles pressure would be below the pressure within the aortic artery
129
what allows blood to pass through the atrioventricular valves?
atria contract at the same time, forcing blood through the atrioventricular valves into the ventricles
130
what prevents the blood from being able to return into the atria from the ventricles?
the atrioventricular valves close
131
what is the size of a red blood cell?
7.5-8.0 μm
132
what is the size of a white blood cell?
12-20μm
133
what are the adaptations of red blood cells?
-biconcave for larger SA:V ratio
-no nucleus to fit more haemoglobin
-haemoglobin to bind to oxygen
-flexible
134
what are the adaptations of white blood cells?
-multilobed nucleus to engulf pathogens
-contain digestive enzymes
135
what type of cell is a red blood cell?
erythrocyte
136
what type of cell is a white blood cell?
lymphocyte and phagocyte
137
what is the function of a red blood cell?
transport oxygen
138
what is the function of a white blood cell?
to fight off infections
139
what is blood?
blood is one type of fluid found within our bodies
140
what is tissue fluid?
it is the liquid that surrounds the cells, allowing for transport between blood and cells
141
how is tissue fluid formed?
as a result of the interplay of hydrostatic pressure and pressure caused by osmosis
142
what is oncotic pressure?
pressure caused by osmosis
143
what is hydrostatic pressure?
pressure created by the contraction of the left ventricle
144
what is the hydrostatic pressure in the left ventricle?
4.6 KPa
145
what happens to the hydrostatic pressure as it gets further away from the heart?
the hydrostatic pressure decreases to around 2.3KPa
146
why is there a high concentration of solutes in the blood?
due to the bloods composition of plasma proteins such as albumin
147
what is the water potential inside the blood vessels?
it is a low water potential
148
what is the water potential outside the capillaries?
it is a high water potential
149
why is the water potential lower in the blood vessels than outside the capillaries?
there is a high concentration of solutes in the blood, therefore the water potential inside the blood vessels is lower than outside the capillaries
150
what is the direction of the net movement of water always in the body?
the net movement of water is always into the capillary
151
what is the oncotic pressure of water in the blood?
3.3 KPa
152
where is there a high hydrostatic pressure in the blood vessels?
arteriole
153
where is there a low hydrostatic pressure in the blood vessels?
venous
154
why is there a higher water potential outside of the blood vessels compared to inside the blood vessels?
due to the high hydrostatic pressure in the blood vessel liquid is forced out creating a high water potential outside the blood vessel
155
what happens at the arteriole in relation to tissue fluid?
there is a higher hydrostatic pressure than oncotic pressure so tissue fluid is made
156
what happens at the venous in relation to tissue fluid?
there is a higher oncotic pressure than hydrostatic pressure so there is a loss of tissue fluid
157
where does all fluid pass back into?
the capillaries
158
what needs to happen to the excess output of tissue fluid? why?
the excess output needs to be collected to avoid tissue swelling
159
where is the excess of tissue fluid drained to?
this net excess is drained into the vessels of the lymphatic system
160
what is the fluid in the lymphatic system known as?
lymph
161
what does lymph do?
lymph passes through the lymphatic system and drains back into the circulatory system
162
what vein does the lymph drain through into the circulatory system?
subclavian vein
163
what does lymph contain?
lymphocytes
164
what do lymph nodes do?
intercept pathogens and are the place where lymphocytes collect
165
what are lymphocytes?
they are part of the immune system and help to filter out foreign material from the lymph
166
what is odema?
when tissue fluid cannot be drained via lymph vessels
167
draw a diagram to represent the formation of tissue fluid
*see paper flashcard*
168
what is the rhythm of the heart maintained by?
the rhythm of the heart is maintained by a wave of electrical excitation, rather like a nerve impulse
169
what does it mean that the cardiac muscle is myogenic?
its contraction is initiated within the muscle itself, not by impulses from a nerve
170
what are the different nodes and bundles in the heart?
-sino atrial node (SAN)
-atrioventricular node (AVN)
-bundle of His
171
what does the sino-atrial node do?
it is the natural pacemaker, this node initiates the atria to contract, therefore initiating the heartbeat
172
what does the atrioventricular node do?
this node delays the impulse and sends the wave of excitation down the bundle of His
173
what is the bundle of His?
it is a bundle of conducting tissue made of purkyne fibres which penetrate through the septum between the ventricles
174
draw a diagram to represent the co-ordination of the heart beat
*see on paper flashcard*
175
describe the process of the co-ordination of the heart beat
1. SAN initiates a wave of excitation- this is why it's called the natural pacemaker
2. as the wave of excitation passes through the tissue of the atria it contracts the muscle (downwards)
3. wave of excitation cannot pass through the non conducting tissue between the atria and ventricles
4.the wave of excitation arrives at the AVN, the AVN delays the release of the wave of excitation as a threshold must be reached
5. the AVN releases the wave of excitation down the bundle of His starting contraction from the bottom of the heart
6. the ventricles then contract from the bottom up
176
what are electrocardiograms?
they measure the electrical differences in skin as a result of the electrical activity of the beat
177
what does a normal electrocardiogram look like?
*see paper flashcard*
178
*look at diagram on paper flashcard*
what does the P wave show?
electrical activity of atrial systole
179
*look at diagram on paper flashcard*
what does the QRS wave show?
electrical activity of ventricular systole
180
*look at diagram on paper flashcard*
what does the T wave show?
ventricular diastole
181
what is the bpm for a normal electrocardiogram?
60-80bpm
182
how can you calculate bpm from an ECG?
60 seconds / time for one heartbeat
183
what are the names of the irregular electrocardiograms?
-bradycardia ECG
-tachycardia ECG
-ectopic ECG
184
what is the bpm for a bradycardia electrocardiogram?
<60bpm
185
what is the bpm for a tachycardia electrocardiogram?
>100bpm
186
what is an ectopic ECG?
extra beat out of rhythm
187
what does a bradycardia ECG look like?
*see paper flashcard*
188
what does a tachycardia ECG look like?
*see paper flashcard*
189
what does a ectopic ECG look like?
*see paper flashcard*
190
what does a fibrillation ECG look like?
*see paper flashcard*
191
what is arrythmia?
when there is not a regular rhythm in the heart
192
what are the types of arrythmia?
atrial or ventricular
193
what is fibrillation?
when the heartbeat is not coordinated- it 'flutters' or beats irregularly
194
what happens if it is ventricular arrythmia?
blood is not being pushed around the body, leading to a lose of consciousness the death
195
what causes the flow of blood?
heart and muscle contractions
196
what cells are present in the blood?
erythrocytes (RBCs), platelets and leucocytes (WBCs)
197
what proteins are present in the blood?
hormones and plasma proteins
198
what fats are present in the blood?
some lipoproteins
199
how much glucose is in the blood?
80-120mg per 100cm³
200
what has more amino acids: blood, tissue fluid or lymph fluid?
blood
201
what has more oxygen: blood, tissue fluid or lymph fluid?
blood
202
what has more carbon dioxide: blood, tissue fluid or lymph fluid?
tissue fluid and lymph fluid
203
where is tissue fluid found?
surrounds tissues
204
what is the direction of flow of tissue fluid?
there is no flow
205
what cells are found in tissue fluid?
usually phagocytes
206
what proteins are found in tissue fluid?
some hormones and cell secreted proteins
207
what fats are found in tissue fluid?
none
208
where is lymph fluid found?
lymph vessels
209
what is the direction of flow of lymph fluid?
tissues to blood
210
what is the cause of flow of lymph fluid?
tissue fluid pressure and one way valves
211
what cells are found in lymph fluid?
lymphocytes
212
what is happening at the P wave on an electrocardiogram?
wave of excitation sweeping over atrial walls
213
what is happening at the QRS wave on an electrocardiogram?
wave of excitation in the ventricle walls
214
what is happening at the T wave on an electrocardiogram?
recovery of ventricle walls
215
where are red blood cells formed?
in bone marrow
216
how long do red blood cells live for?
around 120 days
217
what is the structure of haemoglobin?
-a globular conjugated protein
-conjugated= bound to inorganic group
-4 subunits (2 alpha, 2 beta)
218
how many hameoglobins are there per red blood cell?
around 300 million
219
how many haem groups does each subunit contain in haemoglobin?
1 haem group (Fe)
220
how many oxygen does each haem group bine to?
each haem group binds to one oxygen
221
when oxygen binds to haemoglobin what does it become?
oxyhaemoglobin
222
what is it called when oxygen binds to haemoglobin?
loading
223
what is oxygen affinity?
a measure of how easily the haem group can bind to oxygen
224
what does haemoglobin demonstrate when binding to oxygen?
positive cooperativity
225
what is positive cooperativity?
as oxygen binds to haemoglobin, it causes a shape change to close chains which makes binding more oxygen easier (increases hameoglobins affinity for oxygen)
226
what is the equation to demonstrate the formation of oxyhaemoglonin?
Hb + 4O2 ⇌ Hb(O2)4
227
what does the ability of haemoglobin to load with oxygen depend on?
it depends on the partial pressure of oxygen
228
what is total pressure?
all gases exert a pressure- the total pressure is the pressure of all gases in an area
229
what is the partial pressure?
the force exerted by the oxygen molecules in the air
230
what is partial pressure proportional to?
the concentration of that gas
231
what is oxygen tension?
partial pressure of oxygen in the plasma
232
draw the oxygen dissociation curve
*see paper flashcard*
233
describe what is happening on the oxygen dissociation curve
1. at the start it is difficult to load oxygen at low partial pressure, but it allows for rapid unloading of oxygen to occur
2. after the first successful collision of oxygen and Haem group, the shape of the neighbouring polypeptide chains changes increasing the haemoglobins affintity leading to rapid loading, this is called positive cooperativity
3. at the end due to the partial pressure of oxygen there are frequent collisions between the oxygen and the haemoglobin. If the oxygen collides with a non saturated haem group loading will occur
234
how do haemoglobin and carbon dioxide interact?
haemoglobin helps transport carbon dioxide and buffers the blood
235
what are the three main pathways that haemoglobin transport carbon dioxide?
1. only about 5% of carbon dioxide is transported in blood plasma
2.10%-20% forms carbaminohaemoglobin inside the red blood cell
3. 85% goes directly into the red blood cell and undergoes a series of reactions
236
what is the reaction that occurs between carbon dioxide and water?
*see paper flashcard*
237
what does the transformation of carbon dioxide to carbonic acid do?
maintains the concentration gradient for carbon dioxide into the red blood cell
238
what happens to the carbonic acid that is formed when carbon dioxide and water react?
-it dissociates into hydrogen carbonate ions (HCO3-) and hydrogen ions (H+)
239
what forms when the hydrogen ions (formed from the dissociation of carbonic acid) combines with haemoglobin?
haemoglobonic acid
240
what does the process of hydrogen ions and haemoglobin combining do?
this process causes haemoglobin to release oxygen to cells, haemoglobin acts as a buffer, preventing hydrogen ions altering cells pH
241
when hydrogen carbonate ions diffuse out into blood plasma what is this called?
the chloride shift
242
what happens to the chloride ions in the plasma after the chloride shift?
from the plasma chloride ions diffuse back into the red blood cell to maintain the charge of the cell
243
what is the oxygen dissociation curve?
graph showing relationship between O2 and Hb at different partial pressures of O2
244
what is affinity?
the degree to which a substance combines with another
245
what is bohr shift?
the decrease in the affinity of haemoglobin for oxygen in the presence of carbon dioxide
246
what direction does the oxygen dissociation curve move in bohr shift?
to the right
247
what would the dissociation curve look like during bohr shift?
*see paper flashcard*
248
how does bohr shift work?
1. more H+ ions are released from the dissociation of carbonic acid
2. H+ ions compete with O2 for Hb
3. H+ displaces O2 causing O2 to be released to the tissue
249
what direction does the oxygen dissociation curve shift in when it involves fetal haemoglobin?
to the left
250
what is fetal haemoglobin?
it is haemoglobin that has a higher affinity for oxygen than adult haemoglobin
251
how does fetal heamoglobin work?
-oxygenated blood from the placenta runs close to deoxygenated blood from the fetus
-fetal haemoglobin combines more readily with oxygen, so it is then able to remove oxygen straight from the placenta
252
why once the baby is born is fetal haemoglobin replaced with adult haemoglobin?
otherwise the haemoglobin holds on to the oxygen and does not release it to respiring tissue
253
what would the dissociation curve look like when it involves fetal haemoglobin?
*see paper flashcard*
