Mass Transport In Animals Flashcards
(162 cards)
1
Q
Draw and label the order of the blood vessels starting from the heart
A
- heart
- arteries
- arterioles
- capillaries
- venules
- veins
2
Q
In which direction do arteries carry blood?
A
- away from the heart
3
Q
Does the arteries carry oxygenated or deoxygenated blood?
A
- oxygenated
4
Q
In which direction do veins carry blood?
A
- return blood to the heart
5
Q
Do the veins carry oxygenated or deoxygenated blood?
A
- deoxygenated
6
Q
Draw and label a capillary bed
A
- venous end of capillary bed (vein)
- venule
- capillaries
- arteriole
- arterial end of capillary bed (artery)
7
Q
Draw and label the structure of an artery
A
- tunica externa
- tunica media
- tunica intima (endothelium and elastic layer under)
- relatively narrow lumen
8
Q
What is the endothelium?
A
- single layer of cells, very smooth
9
Q
What does the tunica media of an artery contain?
A
- elastic fibres
- collagen fibres
- smooth muscle
10
Q
What does the tunica externa of an artery contain?
A
- collagen fibres
- some elastic fibres
11
Q
What are the adaptations of the artery?
A
- muscular wall layer is thick to stretch and elastic recoil as the heart beats, which helps maintain blood pressure
- elastic layer is relatively thick
- inner endothelium is folded allowing artery to stretch, helps maintain blood pressure
- no valves (except in arteries leaving heart) as blood is under high pressure so not needed
12
Q
Draw and label the structure of an arteriole
A
- tunica externa
- tunica media
- tunica intima
13
Q
What are the features of arterioles?
A
- Less than 0.1mm in diameter (average = 30μm);
- Tunica media is restricted to one or two smooth muscle cell layers in thickness;
- Control blood flow into capillaries
14
Q
What is the role of the arteriole?
A
- Muscle in ARTERIOLES control diameter using smooth muscles in the tunica media to alter blood flow.
- This causes vasoconstriction when smooth muscle contracts and vasodilation when smooth muscle relaxes
15
Q
Draw and label the structure of a capillary
A
- pores/fenestrations
- basement membrane
- wall made of endothelium
- lumen
16
Q
What is a basement membrane?
A
- delicate membrane of protein fibres
17
Q
What are the adaptations of capillaries?
A
- endothelium which is one cell thick for a shorter diffusion pathway
- there are many capillaries and are highly branched to increase surface area for gaseous exchange
- narrow lumen which is the size of a red blood cell for a short diffusion pathway
18
Q
What are the adaptations of leaky capillaries?
A
- Pores/ Fenestrations: Allows easy transfer of substances dissolved in plasma to the surrounding cells.
- Plasma proteins and blood cells do not pass through
19
Q
Draw and label the structure of a venule
A
- tunica externa
- tunica media
- tunica intima
20
Q
What are venules?
A
- the smallest veins that drain blood from capillaries, channeling it into larger veins
21
Q
What are the features of a venule?
A
- do not have pocket valves to prevent backflow
- wider lumen than capillaries which send blood into them
- send blood to veins
- muscle and elastic layer relatively thin
22
Q
Draw and label the structure of a vein
A
- tunica externa
- tunica media
- endothelium
- relatively large lumen
23
Q
What are the adaptations of veins?
A
- wider lumen than arteries
- muscle and elastic layer relatively thin so blood travels at lower pressure and do not need stretch and recoil as much
- contain valves at intervals throughout to stop back flow
24
Q
Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (arteries)
A
- Pulsatile (due to pumping of heart and elastic recoil of arteries);
- declining slightly, reducing amplitude as distance from heart increases
25
Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (arterioles)
- Friction of arterioles vessel wall causes progressive pressure drop
- Arterioles have large total surface area and relatively narrow bore causing substantial reduction from aortic pressure
- Their pressure depends on whether they are dilated or contracted
26
Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (capillaries)
- even greater resistance in the capillaries with large cross sectional area
- velocity of blood flow is directly related to the pressure
- In the capillary beds the pressure drops further due to leakage from capillaries into tissues
27
Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (veins)
- Return flow to the heart is non-rhythmic and the pressure in the veins is low but can be increased by the massaging effect of muscles
28
Explain how hydrostatic pressure changes in different blood vessels
- higher hydrostatic pressure in the arteries
- the more further away arterioles are from the heart, the more the pressure drops
- in capillaries, blood pressure drops due to leakage of water from plasma from capillaries to surrounding tissues in form of tissue fluid and large cross sectional area so reduces blood flow
- lower hydrostatic pressure in the veins
29
What are the adaptations of an arteriole?
- form a network throughout the body to allow the blood to be directed to different areas of the demand of the body
- muscles present within arterioles to contract to restrict blood flow and relax to allow full blood flow to different areas of the body
30
What is the blood pressure of arteries?
- high
31
What is the blood pressure of veins?
- low
32
What is the blood pressure of capillaries?
- low
33
What is the speed of blood flow for arteries?
- rapid
34
What is the speed of blood flow for veins?
- slow (can be increased by massaging)
35
What is the speed of blood flow for capillaries?
- slow (for gaseous exchange)
36
What is the cross sectional area for arteries? I
- low
37
What is the cross sectional area for veins?
- low
38
What is the cross sectional area for capillaries?
- large (reduces blood flow)
39
Do arteries contain valves?
- no (only in heart)
40
Do veins contain valves?
- yes (pocket valves)
41
Do capillaries contain valves?
- no
42
Compare arteries to vein
- veins have thinner muscle layer so cannot control blood flow whereas arteries have thicker muscle layer than veins so that constriction and dilation can occur to control volume of blood
- elastic layer of veins are thinner as pressure is lower whereas arteries have a thicker elastic layer to help maintain blood pressure so the walls can stretch and recoil in response to heart beat
- veins have thin wall thickness as pressure is lower so lower risk of bursting, allows vessels to be easily flattened which helps flow of blood to the heart whereas arteries have thicker wall to help prevent vessels bursting due to high pressure
43
Compare the capillaries to the blood vessels
- do not contain muscle layer and elastic layer unlike arteries and veins
- once cell thick consisting of only a lining layer to provide short diffusion distance for exchanging materials between blood and cells
44
Compare the arterioles to arteries
- muscle layer is thicker than in arteries to help restrict blood flow into capillaries
- elastic layer is thinner than in arteries as pressure is lower
- wall thickness is thinner than in arteries as pressure is slightly lower
45
Define the double circulatory system
- blood flows twice through the heart for each circulation of the body
46
What are the advantages of the double circulatory system?
- Blood pressure increases, therefore rate of blood flow to the tissues is great
- Delivery of oxygen to the cells is quicker, this is important in mammals as they have a high metabolism
47
What does pulmonary circulation do?
- carries blood to the lungs and picks up oxygen
48
What does systemic circulation do?
- carries oxygen and nutrients to the rest of the body
49
Define closed circulatory system
- have the blood closed at all times within vessels of different size and wall thickness
50
Which organisms have a double circulatory system?
- mammals
51
Which organisms have a closed circulatory system?
- vertebrates and earthworms
52
Why is the right ventricle thinner?
- Only has to pump blood back to the heart
53
Why is the left ventricle thicker?
- has to pump blood all around the body
54
Draw the general pattern of blood circulation in a mammal
- blood from lungs is transported through pulmonary vein into left atrium
- from left ventricle blood is taken from aorta to kidney by renal artery and to the right atrium through the vena cava by renal vein
- from left ventricle blood is taken from aorta to the lower body and to the right atrium through vena cava
- blood from right ventricle is taken to the lungs through pulmonary artery
55
Which of the blood vessels entering and leaving the heart contain oxygenated blood, and which contain deoxygenated blood?
- Oxygenated = aorta and pulmonary vein,
- deoxygenated = vena cava and pulmonary artery
56
Starting from the left side of the heart, describe the exact journey of blood as it goes round the body. Make sure you mention which veins or arteries the blood is going through, whether the blood passes through any valves, and explain if the blood is oxygenated or deoxygenated.
- Aorta, oxygenated blood leaves the left ventricle to rest of body,
- gaseous exchange of CO2 at cells (short diffusion pathway).
- Deoxygenated blood returned to right atrium via Vena cava.
- Deoxygenated blood leave right ventricle via pulmonary artery where travels to lungs.
- Gaseous exchange at alveoli in the lungs.
- Oxygenated blood returns to left atrium via pulmonary vein.
- Oxygenated blood once again leaves left ventricle via aorta.
57
What do the coronary arteries provide the cardiac muscle with?
- blood and therefore oxygen and glucose
58
What do the coronary arteries branch off?
- aorta
59
What are the steps of the cardiac cycle?
- atrial systole (contraction)
- ventricular systole (contraction)
- diastole (relax)
60
Describe atrial systole
- atrium contracts, ventricles relax
- blood flows from vena cava and pulmonary vein to the right and left atrium and right and left ventricles
- tricuspid and bicuspid valves open and semilunar valves close due to greater pressure in atria than ventricles
61
Describe ventricular systole
- ventricles contract, atria relax
- blood flows from right and left atrium through bicuspid and tricuspid valves, through semilunar valves through the aorta and pulmonary artery
- semilunar valves open and tricuspid and bicuspid valves close as pressure in ventricles greater than pressure in arteries
62
Describe diastole
- ventricles and atria relax
- blood flows from vena cava and pulmonary vein to the right and left atrium to the right and left ventricles
- tricuspid and bicuspid valves open and semilunar valves close as pressure in atria is greater than in ventricles (blood fills atria due to greater pressure in pulmonary veins and artery)
63
Why do the AV valves close?
- greater pressure in ventricle than in atrium
64
Why do AV valves open?
- greater pressure in atrium than in ventricle
65
Why do semilunar valves open?
- greater pressure of ventricle than aorta
66
Why do semilunar valves close?
- greater pressure in aorta than ventricle
67
Why has ventricular pressure increased in the graph?
- greater pressure as blood is being pumped around whole body
68
Why is atrial systole on graph small?
- less pressure as blood doesn’t travel as far
69
Give two safety precautions when dissection a heart
- cut away from self
- use sharp scalpel
70
Describe the control of the heartbeat
1. Sinoatrial node in right atrium sends out electrical impulse to the atrioventricular node in the atrial walls causing right and left atrium to contract
2. To prevent ventricles contracting at the same time as atrium, there is a band of non conducting collagen tissue. This stops the waves of electrical activity from being passed directly from the right atrium to the ventricles
3. Atrioventricular node passes the waves of electrical impulse to the bundle of his in the septum of the heart
4. There is slight delay before the atrioventricular node reacts to ensure the atria have emptied before ventricles contract
5. The bundle of his conduct the waves of electrical impulse between the ventricles to the bottom (apex) of the heart
6. The Purkynje tissues carry the waves of electrical, activity into the muscular walls of the right and left ventricles causing contraction
71
Myogenic definition
- can contract and relax without nervous or hormonal stimulation
72
What are the two properties of cardiac muscle?
1. Myogenic
2. Never fatigues as long as it has a supply of oxygen
73
What is a risk of coronary arteries becoming blocked?
- cardiac muscle won’t receive oxygen and will not be able to respire and cells will die
- results in myocardial infarction
74
What are the features of the atria?
- thinner muscular walls
- don’t need to contract as hard as not pumping blood far (only to ventricles)
- elastic walls to stretch when blood enters
75
What are the features of the ventricles?
- thicker muscular walls to enable bigger contraction
- creates a higher blood pressure to enable blood to flow longer distances (lungs and rest of body)
76
Describe the structure of the right ventricle
- pumps blood to lungs and needs to be lower pressure to prevent damage to capillaries in lungs so blood flows slowly to allow time for gas exchange
- so thinner, muscular wall in comparison to left ventricle
77
Describe the structure of the left ventricle
- pumps blood to body at higher pressure to ensure blood reaches all cells in body
- so thicker, muscular wall in comparison to right ventricle to enable larger contractions of the muscle to create higher pressure
78
Role of vena cava
- carries deoxygenated blood from body to right atrium
79
Role of pulmonary vein
- carries oxygenated blood from the lungs to the left atrium
80
Role of pulmonary artery
- carries deoxygenated blood from right ventricle to lungs to become oxygenated
81
Role of aorta
- carries oxygenated blood from left ventricle to rest of body
82
Where are semi lunar valves found?
- aorta and pulmonary artery
83
Where are atrioventricular valves found?
- between atria and ventricles
84
Which side of the heart is bicuspid/mitral valves found?
- left side
85
Which side of the heart are the tricuspid valves found?
- right side
86
Explain how valves work
- open when pressure is higher behind valves
- close when pressure is higher in front of the valves
87
What is the role of the septum?
- separates the deoxygenated and oxygenated blood
88
Why is the septum important/why is it important to separate oxygenated and deoxygenated blood?
- maintains high concentration of oxygen in oxygenated blood to maintain concentration gradient to enable diffusion at respiring cells
89
How to calculate cardiac output?
- = heart rate x stroke volume
90
What is the stroke volume measured in?
- dm^3
91
What is heart rate measured in?
- beats of heart per min
92
What happens to the left ventricle when the left atrium is in systole?
- left ventricle is in diastole
93
What happens to left ventricle when left atrium is in diastole?
- left ventricle is in systole
94
What happens after both left atrium and ventricle have went through diastole and systole?
- diastole
95
What happens to the volume of atria in atrial systole?
- decreases
96
What happens to the pressure in atria in atrial systole?
- increases
97
What happens to the volume of ventricles in atrial systole?
- increases
98
What happens to the pressure in ventricles in atrial systole?
- decrease
99
What happens to the volume of atria in ventricular systole?
- no change
100
What happens to the pressure of atria in ventricular systole?
- no change
101
What happens to the volume of ventricles in ventricular systole?
- decreases
102
What happens to the pressure in ventricles in ventricular systole?
- increases
103
What happens to the volume of atria in diastole?
- increases
104
What happens to the pressure in atria in diastole?
- increases
105
What happens to the volume of ventricles in diastole?
- slow increase
106
What happens to the pressure in ventricles in diastole?
- slow increase
107
Why does the blood flow through the lungs at a lower pressure?
- prevent damage to capillaries in alveoli and reduces speed at which blood flows enabling more time for gas exchange
108
Why is the oxygenated blood from lungs through the heart pumped out at a higher pressure to the rest of the body?
- important to ensure the blood reaches all the respiring cells in the body
109
What is haemoglobin?
- groups of proteins found in different organisms and is a quaternary structure
110
What is the role of haemoglobin and red blood cells?
- transport of oxygen
111
What is another type of haemoglobin?
- myoglobin
112
In which organisms is myoglobin found?
- muscle tissue in vertebrates
113
Define affinity of haemoglobin for oxygen
- the ability of haemoglobin to attract or bind oxygen
114
Define saturation of haemoglobin with oxygen
- when haemoglobin is holding the maximum amount of oxygen it can bind
115
Define loading/association of haemoglobin
- the binding of oxygen to haemoglobin
116
Define unloading/dissociation of haemoglobin
- when oxygen detaches, or unbinds from haemoglobin
117
Describe the oxyhaemoglobin dissociation curve
- oxygen is loaded/associates in regions with a high partial pressure of oxygen (alveoli) and is unloaded/dissociated in regions of low partial pressure of oxygen (respiring tissues)
118
Advantage of low partial pressures, lower affinity for oxygen
- haemoglobin unloads at a site where oxygen is needed
119
Advantage of high partial pressure, higher affinity for oxygen
- loading lots of oxygen to unload at areas where respiration occurs
120
What is cooperative binding due to?
- haemoglobin changing shape when the first oxygen binds
- this makes it easier for further oxygens to bind
121
Describe the Bohr effect
- when a high concentration of carbon dioxide causes the oxyhaemoglobin curve to shift to the right
122
Why does the affinity for oxygen decrease when there is a high concentration of carbon dioxide?
- acidic carbon dioxide, due to increase in hydrogen ions, changes shape of haemoglobin slightly
- hydrogen ions bind with oxyhaemoglobin and dissociates oxygen
123
Describe the graph in relation to the partial pressure of oxygen and saturation of oxygen
- pH 7.6 - low partial pressure of carbon dioxide in alveoli, curve shifts left as affinity is increased and uploads more oxygen
- pH 7.2 - high partial pressure of carbon dioxide at respiring tissues, curve shifts right as affinity is decreased and unloads more oxygen
124
Describe fetal haemoglobin
- has higher affinity for oxygen at the same partial pressure of oxygen
125
Advantage of fetal haemoglobin having higher affinity for oxygen
- foetus cannot inhale and exhale as its only source of oxygen is from its mothers haemoglobin in the blood supply through the placenta
- foetal haemoglobin must have a higher affinity for oxygen in order for it to be able to associate to oxygen from the adult’s haemoglobin
126
Describe llama haemoglobin
- llama haemoglobin is shifted to the left
- llama haemoglobin has a higher affinity for oxygen than human haemoglobin at same partial pressure of oxygen
127
Advantage of llama haemoglobin
- allows llama to associate/load oxygen due to higher affinity for oxygen even when there is a lower partial pressure of oxygen as they live in high altitudes
128
Describe dove haemoglobin
- curve shifted to right
- dove haemoglobin has decreased affinity for oxygen
- unloads oxygen at the same partial pressure
129
Advantage of dove haemoglobin
- they have faster metabolism so needs more oxygen for respiration to provide energy for contracting muscles
- so require oxygen to dissociate and have a lower affinity
130
Describe earthworm haemoglobin
- shifted to left
- higher affinity for oxygen as they live underground where there is a lower partial pressure of oxygen
131
Advantage of earthworm haemoglobin
- higher affinity to oxygen means oxygen can be associated/loaded even in areas with low partial pressure of oxygen such as underground where they live
132
Explain why the combination of haemoglobin with oxygen must be reversible
- to allow oxygen to dissociate from haemoglobin and diffuse to cells where it is required for aerobic respiration
133
Where in the body would oxygen combine with haemoglobin to form oxyhemoglobin?
- alveoli
134
Where in the body would oxyhemoglobin dissociate to release oxygen?
- tissues and muscles (eg. Liver)
135
Is the concentration of oxygen high or low in lungs?
- high
136
Is concentration of oxygen high or low in muscles?
- low
137
Is concentration of carbon dioxide high or low in lungs?
- low
138
Is concentration of carbon dioxide high or low in the muscle?
- high
139
Is temperature high or low in the lungs?
- low
140
Is temperature high or low in the muscle?
- high
141
What should high oxygen, low carbon dioxide and low temperature do?
- associate
142
What should low oxygen, high carbon dioxide and high temperature do?
- dissociate
143
Why does oxygen dissociate from haemoglobin at a slower rate than higher carbon dioxide concentration?
- less oxygen needed for aerobic respiration
144
Why does oxygen dissociate from haemoglobin of higher concentration of carbon dioxide at an increased rate?
- oxygen needed in tissues for aerobic respiration through diffusion
145
Describe what occurs when there is a lower partial pressure of carbon dioxide
- haemoglobin has a lower affinity for oxygen, dissociates
146
Describe what occurs when there is a higher partial pressure of carbon dioxide
- haemoglobin has a higher affinity for oxygen, associates
147
Describe lugworm haemoglobin
- shifts left
- higher affinity for oxygen
148
Advantage of lugworm haemoglobin
- higher affinity for oxygen so allows oxygen to associate to haemoglobin even when there is a low partial pressure of oxygen such as in its burrow where it pumps seawater
149
Describe the formation of tissue fluid
1. Higher hydrostatic pressure at the arteriole end of the capillary bed
2. And lower osmotic pressure
3. Greater hydrostatic pressure forces water, molecules and ions out through gaps of endothelium of capillary
4. Large plasma proteins remain in the blood and thus water potential in the blood decrease
5. Water returns to the capillary by osmosis due to water potential gradient, higher water potential in tissue fluid than blood plasma
6. Net outflow out of water at arterial end of capillary and net inflow in at venous end of capillary
150
Draw and label the net inflow and outflow of tissue fluid
- arteriole end, net outflow of hydrostatic pressure greater than osmotic pressure which is flowing in
- venule end, net inflow of osmotic pressure greater than outflow of hydrostatic pressure
- direction of blood flow from arteriole end to venule end
151
Draw and label the net inflow and outflow of tissue fluid
- arteriole end, net outflow of hydrostatic pressure greater than osmotic pressure which is flowing in
- venule end, net inflow of osmotic pressure greater than outflow of hydrostatic pressure
152
What happens to the remaining 10% of tissue fluid not returned to capillary?
- returned to blood by the lymphatic system and is called lymph
153
Why is there a higher hydrostatic pressure at the arteriole end?
- closer to the heart
154
How to calculate pulmonary ventilation
- tidal volume x ventilation rate
155
What is tidal volume measured in?
- dm^3
156
What is ventilation rate measured in?
- min^-1
157
What is pulmonary ventilation measured in?
- dm^3min^-1
158
Why would bronchitis or asthma cause a decrease in gas exchange
- narrowing of lumen due to inflammation
- less air entering alveoli and exiting
- so won’t have as large a concentration gradient and won’t be receiving enough oxygen delivered to the alveoli for gas exchange
159
Why may emphysema decrease gas exchange?
- alveoli walls start to breakdown so end up with far fewer alveoli air sacs and much larger sacs
- decreases surface area for gas exchange so not enough oxygen diffuses into the lungs and not enough carbon dioxide diffusing out
160
Why may pulmonary fibrosis cause a decrease in gas exchange?
- breakdown of alveoli walls and thicker walls
- decreases surface area for diffusion and thicker walls means less expansion of the alveoli
161
Evaluation question against (smoking deaths)
- correlation does not prove causation could be due to another factor such as genetics, pollution
- data overlaps
- there is no correlation coefficient statistic to know if correlation is significant (if no t test)
162
Evaluation question for (smoking deaths)
- positive correlation between … and …
