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Biology Paper 1 (1-4) > Mass Transport In Animals > Flashcards

Mass Transport In Animals Flashcards

1
Q

Draw and label the order of the blood vessels starting from the heart

A
  • heart
  • arteries
  • arterioles
  • capillaries
  • venules
  • veins
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2
Q

In which direction do arteries carry blood?

A
  • away from the heart
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3
Q

Does the arteries carry oxygenated or deoxygenated blood?

A
  • oxygenated
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4
Q

In which direction do veins carry blood?

A
  • return blood to the heart
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5
Q

Do the veins carry oxygenated or deoxygenated blood?

A
  • deoxygenated
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6
Q

Draw and label a capillary bed

A
  • venous end of capillary bed (vein)
  • venule
  • capillaries
  • arteriole
  • arterial end of capillary bed (artery)
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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
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8
Q

What is the endothelium?

A
  • single layer of cells, very smooth
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9
Q

What does the tunica media of an artery contain?

A
  • elastic fibres
  • collagen fibres
  • smooth muscle
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10
Q

What does the tunica externa of an artery contain?

A
  • collagen fibres
  • some elastic fibres
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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
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12
Q

Draw and label the structure of an arteriole

A
  • tunica externa
  • tunica media
  • tunica intima
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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
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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
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15
Q

Draw and label the structure of a capillary

A
  • pores/fenestrations
  • basement membrane
  • wall made of endothelium
  • lumen
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16
Q

What is a basement membrane?

A
  • delicate membrane of protein fibres
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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
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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
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19
Q

Draw and label the structure of a venule

A
  • tunica externa
  • tunica media
  • tunica intima
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20
Q

What are venules?

A
  • the smallest veins that drain blood from capillaries, channeling it into larger veins
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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
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22
Q

Draw and label the structure of a vein

A
  • tunica externa
  • tunica media
  • endothelium
  • relatively large lumen
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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
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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
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25
Q

Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (arterioles)

A
  • 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
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26
Q

Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (capillaries)

A
  • 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
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27
Q

Describe and explain the pressure changes in the heart and blood vessels during circulation of the blood (veins)

A
  • 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
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28
Q

Explain how hydrostatic pressure changes in different blood vessels

A
  • 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
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29
Q

What are the adaptations of an arteriole?

A
  • 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
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30
Q

What is the blood pressure of arteries?

A
  • high
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31
Q

What is the blood pressure of veins?

A
  • low
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32
Q

What is the blood pressure of capillaries?

A
  • low
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33
Q

What is the speed of blood flow for arteries?

A
  • rapid
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34
Q

What is the speed of blood flow for veins?

A
  • slow (can be increased by massaging)
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35
Q

What is the speed of blood flow for capillaries?

A
  • slow (for gaseous exchange)
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36
Q

What is the cross sectional area for arteries? I

A
  • low
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37
Q

What is the cross sectional area for veins?

A
  • low
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38
Q

What is the cross sectional area for capillaries?

A
  • large (reduces blood flow)
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39
Q

Do arteries contain valves?

A
  • no (only in heart)
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40
Q

Do veins contain valves?

A
  • yes (pocket valves)
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41
Q

Do capillaries contain valves?

A
  • no
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42
Q

Compare arteries to vein

A
  • 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
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43
Q

Compare the capillaries to the blood vessels

A
  • 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
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44
Q

Compare the arterioles to arteries

A
  • 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
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45
Q

Define the double circulatory system

A
  • blood flows twice through the heart for each circulation of the body
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46
Q

What are the advantages of the double circulatory system?

A
  • 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
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47
Q

What does pulmonary circulation do?

A
  • carries blood to the lungs and picks up oxygen
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48
Q

What does systemic circulation do?

A
  • carries oxygen and nutrients to the rest of the body
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49
Q

Define closed circulatory system

A
  • have the blood closed at all times within vessels of different size and wall thickness
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50
Q

Which organisms have a double circulatory system?

A
  • mammals
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51
Q

Which organisms have a closed circulatory system?

A
  • vertebrates and earthworms
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52
Q

Why is the right ventricle thinner?

A
  • Only has to pump blood back to the heart
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53
Q

Why is the left ventricle thicker?

A
  • has to pump blood all around the body
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54
Q

Draw the general pattern of blood circulation in a mammal

A
  • 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
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55
Q

Which of the blood vessels entering and leaving the heart contain oxygenated blood, and which contain deoxygenated blood?

A
  • Oxygenated = aorta and pulmonary vein,
  • deoxygenated = vena cava and pulmonary artery
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56
Q

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.

A
  • 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.
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57
Q

What do the coronary arteries provide the cardiac muscle with?

A
  • blood and therefore oxygen and glucose
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58
Q

What do the coronary arteries branch off?

A
  • aorta
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59
Q

What are the steps of the cardiac cycle?

A
  • atrial systole (contraction)
  • ventricular systole (contraction)
  • diastole (relax)
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60
Q

Describe atrial systole

A
  • 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
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61
Q

Describe ventricular systole

A
  • 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
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62
Q

Describe diastole

A
  • 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)
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63
Q

Why do the AV valves close?

A
  • greater pressure in ventricle than in atrium
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64
Q

Why do AV valves open?

A
  • greater pressure in atrium than in ventricle
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65
Q

Why do semilunar valves open?

A
  • greater pressure of ventricle than aorta
66
Q

Why do semilunar valves close?

A
  • greater pressure in aorta than ventricle
67
Q

Why has ventricular pressure increased in the graph?

A
  • greater pressure as blood is being pumped around whole body
68
Q

Why is atrial systole on graph small?

A
  • less pressure as blood doesn’t travel as far
69
Q

Give two safety precautions when dissection a heart

A
  • cut away from self
  • use sharp scalpel
70
Q

Describe the control of the heartbeat

A
  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
Q

Myogenic definition

A
  • can contract and relax without nervous or hormonal stimulation
72
Q

What are the two properties of cardiac muscle?

A
  1. Myogenic
  2. Never fatigues as long as it has a supply of oxygen
73
Q

What is a risk of coronary arteries becoming blocked?

A
  • cardiac muscle won’t receive oxygen and will not be able to respire and cells will die
  • results in myocardial infarction
74
Q

What are the features of the atria?

A
  • 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
Q

What are the features of the ventricles?

A
  • 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
Q

Describe the structure of the right ventricle

A
  • 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
Q

Describe the structure of the left ventricle

A
  • 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
Q

Role of vena cava

A
  • carries deoxygenated blood from body to right atrium
79
Q

Role of pulmonary vein

A
  • carries oxygenated blood from the lungs to the left atrium
80
Q

Role of pulmonary artery

A
  • carries deoxygenated blood from right ventricle to lungs to become oxygenated
81
Q

Role of aorta

A
  • carries oxygenated blood from left ventricle to rest of body
82
Q

Where are semi lunar valves found?

A
  • aorta and pulmonary artery
83
Q

Where are atrioventricular valves found?

A
  • between atria and ventricles
84
Q

Which side of the heart is bicuspid/mitral valves found?

85
Q

Which side of the heart are the tricuspid valves found?

A
  • right side
86
Q

Explain how valves work

A
  • open when pressure is higher behind valves
  • close when pressure is higher in front of the valves
87
Q

What is the role of the septum?

A
  • separates the deoxygenated and oxygenated blood
88
Q

Why is the septum important/why is it important to separate oxygenated and deoxygenated blood?

A
  • maintains high concentration of oxygen in oxygenated blood to maintain concentration gradient to enable diffusion at respiring cells
89
Q

How to calculate cardiac output?

A
  • = heart rate x stroke volume
90
Q

What is the stroke volume measured in?

91
Q

What is heart rate measured in?

A
  • beats of heart per min
92
Q

What happens to the left ventricle when the left atrium is in systole?

A
  • left ventricle is in diastole
93
Q

What happens to left ventricle when left atrium is in diastole?

A
  • left ventricle is in systole
94
Q

What happens after both left atrium and ventricle have went through diastole and systole?

95
Q

What happens to the volume of atria in atrial systole?

96
Q

What happens to the pressure in atria in atrial systole?

97
Q

What happens to the volume of ventricles in atrial systole?

98
Q

What happens to the pressure in ventricles in atrial systole?

99
Q

What happens to the volume of atria in ventricular systole?

100
Q

What happens to the pressure of atria in ventricular systole?

101
Q

What happens to the volume of ventricles in ventricular systole?

102
Q

What happens to the pressure in ventricles in ventricular systole?

103
Q

What happens to the volume of atria in diastole?

104
Q

What happens to the pressure in atria in diastole?

105
Q

What happens to the volume of ventricles in diastole?

A
  • slow increase
106
Q

What happens to the pressure in ventricles in diastole?

A
  • slow increase
107
Q

Why does the blood flow through the lungs at a lower pressure?

A
  • prevent damage to capillaries in alveoli and reduces speed at which blood flows enabling more time for gas exchange
108
Q

Why is the oxygenated blood from lungs through the heart pumped out at a higher pressure to the rest of the body?

A
  • important to ensure the blood reaches all the respiring cells in the body
109
Q

What is haemoglobin?

A
  • groups of proteins found in different organisms and is a quaternary structure
110
Q

What is the role of haemoglobin and red blood cells?

A
  • transport of oxygen
111
Q

What is another type of haemoglobin?

112
Q

In which organisms is myoglobin found?

A
  • muscle tissue in vertebrates
113
Q

Define affinity of haemoglobin for oxygen

A
  • the ability of haemoglobin to attract or bind oxygen
114
Q

Define saturation of haemoglobin with oxygen

A
  • when haemoglobin is holding the maximum amount of oxygen it can bind
115
Q

Define loading/association of haemoglobin

A
  • the binding of oxygen to haemoglobin
116
Q

Define unloading/dissociation of haemoglobin

A
  • when oxygen detaches, or unbinds from haemoglobin
117
Q

Describe the oxyhaemoglobin dissociation curve

A
  • 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
Q

Advantage of low partial pressures, lower affinity for oxygen

A
  • haemoglobin unloads at a site where oxygen is needed
119
Q

Advantage of high partial pressure, higher affinity for oxygen

A
  • loading lots of oxygen to unload at areas where respiration occurs
120
Q

What is cooperative binding due to?

A
  • haemoglobin changing shape when the first oxygen binds
  • this makes it easier for further oxygens to bind
121
Q

Describe the Bohr effect

A
  • when a high concentration of carbon dioxide causes the oxyhaemoglobin curve to shift to the right
122
Q

Why does the affinity for oxygen decrease when there is a high concentration of carbon dioxide?

A
  • acidic carbon dioxide, due to increase in hydrogen ions, changes shape of haemoglobin slightly
  • hydrogen ions bind with oxyhaemoglobin and dissociates oxygen
123
Q

Describe the graph in relation to the partial pressure of oxygen and saturation of oxygen

A
  • 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
Q

Describe fetal haemoglobin

A
  • has higher affinity for oxygen at the same partial pressure of oxygen
125
Q

Advantage of fetal haemoglobin having higher affinity for oxygen

A
  • 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
Q

Describe llama haemoglobin

A
  • 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
Q

Advantage of llama haemoglobin

A
  • 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
Q

Describe dove haemoglobin

A
  • curve shifted to right
  • dove haemoglobin has decreased affinity for oxygen
  • unloads oxygen at the same partial pressure
129
Q

Advantage of dove haemoglobin

A
  • 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
Q

Describe earthworm haemoglobin

A
  • shifted to left
  • higher affinity for oxygen as they live underground where there is a lower partial pressure of oxygen
131
Q

Advantage of earthworm haemoglobin

A
  • 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
Q

Explain why the combination of haemoglobin with oxygen must be reversible

A
  • to allow oxygen to dissociate from haemoglobin and diffuse to cells where it is required for aerobic respiration
133
Q

Where in the body would oxygen combine with haemoglobin to form oxyhemoglobin?

134
Q

Where in the body would oxyhemoglobin dissociate to release oxygen?

A
  • tissues and muscles (eg. Liver)
135
Q

Is the concentration of oxygen high or low in lungs?

136
Q

Is concentration of oxygen high or low in muscles?

137
Q

Is concentration of carbon dioxide high or low in lungs?

138
Q

Is concentration of carbon dioxide high or low in the muscle?

139
Q

Is temperature high or low in the lungs?

140
Q

Is temperature high or low in the muscle?

141
Q

What should high oxygen, low carbon dioxide and low temperature do?

142
Q

What should low oxygen, high carbon dioxide and high temperature do?

A
  • dissociate
143
Q

Why does oxygen dissociate from haemoglobin at a slower rate than higher carbon dioxide concentration?

A
  • less oxygen needed for aerobic respiration
144
Q

Why does oxygen dissociate from haemoglobin of higher concentration of carbon dioxide at an increased rate?

A
  • oxygen needed in tissues for aerobic respiration through diffusion
145
Q

Describe what occurs when there is a lower partial pressure of carbon dioxide

A
  • haemoglobin has a lower affinity for oxygen, dissociates
146
Q

Describe what occurs when there is a higher partial pressure of carbon dioxide

A
  • haemoglobin has a higher affinity for oxygen, associates
147
Q

Describe lugworm haemoglobin

A
  • shifts left
  • higher affinity for oxygen
148
Q

Advantage of lugworm haemoglobin

A
  • 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
Q

Describe the formation of tissue fluid

A
  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
Q

Draw and label the net inflow and outflow of tissue fluid

A
  • 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
Q

Draw and label the net inflow and outflow of tissue fluid

A
  • 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
Q

What happens to the remaining 10% of tissue fluid not returned to capillary?

A
  • returned to blood by the lymphatic system and is called lymph
153
Q

Why is there a higher hydrostatic pressure at the arteriole end?

A
  • closer to the heart
154
Q

How to calculate pulmonary ventilation

A
  • tidal volume x ventilation rate
155
Q

What is tidal volume measured in?

156
Q

What is ventilation rate measured in?

157
Q

What is pulmonary ventilation measured in?

A
  • dm^3min^-1
158
Q

Why would bronchitis or asthma cause a decrease in gas exchange

A
  • 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
Q

Why may emphysema decrease gas exchange?

A
  • 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
Q

Why may pulmonary fibrosis cause a decrease in gas exchange?

A
  • breakdown of alveoli walls and thicker walls
  • decreases surface area for diffusion and thicker walls means less expansion of the alveoli
161
Q

Evaluation question against (smoking deaths)

A
  • 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
Q

Evaluation question for (smoking deaths)

A
  • positive correlation between … and …

Biology Paper 1 (1-4) (28 decks)

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