Animal Transport Flashcards
1
Q
Describe an open circulatory system?
A
Blood is not always held within the blood vessels and can circulate through the body cavity so that cells are immersed directly in the blood.
2
Q
How does an open circulatory system work in insects?
A
In insects it is achieved by a dorsal tube- shaped heart found under the upper surface of the insect. The heart will pump blood towards the head by peristalsis; it re-enters the heart through pores called ostia
3
Q
Describe the open circulatory system of a locus?
A
.Blood bathes in the tissues directly
.Little control over direction of circulation
.No respiratory pigment
.Blood pumped at low pressure in to a fluid filled cavity - the haemocoel
4
Q
How do locus’ get their blood back to their head and heart?
A
Movement of muscles and valves assist
5
Q
Why is an open circulatory system not appropriate for a larger more active animal?
A
Blood will flow at a low pressure through the body cavity and would therefore not be sufficient to supply the demand of the respiring cells in a larger more active animal
6
Q
Describe a closed circulatory system?
A
.The blood is enclosed within the blood vessels
.Tissues are not in direct contact with the blood, a separate fluid called tissue fluid exits in the capillaries and bathes the cells.
.This allows the heart to pump at a higher pressure and therefore the blood can flow more quickly
7
Q
What are the three advantages of a closed circulatory system?
A
- The blood flow can be directed to where it is needed, by vasoconstriction and dilation.
- The blood flow us more rapid and efficient
- More efficient delivery of oxygen and nutrients (glucose) and removal of waste products such as CO2
8
Q
What type of circulatory system do fish have?
A
A single closed system
9
Q
What is a single closed circulatory system?
A
The blood stays in vessels on a single pathway around the body. Blood only passes through the heart once, before returning to gills.
10
Q
What is the route of the blood in a single closed system?
A
Heart
Gills
Body
Heart
11
Q
Why do some mammals require a double circulatory system?
A
.They are endothermic (produce their own body heat)
.They have a high metabolic rate and high energy requirement
. They therefore require a large amount of glucose and oxygen and the removal of waste products such as CO2
12
Q
Describe a double circulatory system?
A
A system consisting of a network of vessel which carry materials round the body in the blood, The heart pumps the blood and it goes twice through the heart.
13
Q
What are the two component to a double circulatory system?
A
The Pulmonary system
The Systemic Circulatory system
14
Q
What are the three advantages to a Double circulatory system?
A
- The heart increases the pressure after it has passed through the lungs, so the blood flows more quickly to the body tissues,
- More efficient delivery of oxygen and nutrients to body tissues.
- The oxygen supply to heart muscles better
15
Q
Between the systemic and pulmonary system, which can carry blood at a higher pressure?
A
The systemic
16
Q
What is the structure of the mammalian heart?
A
.A 4 chambered pump for both pulmonary and systemic circulatory systems.
.A double pump working synchronously keeping oxygenated and deoxygenated blood separated
17
Q
Describe the characteristics of the cardiac muscle?
A
The cardiac muscle is myogenic and therefore beats from within the muscle itself to never gets tired.
18
Q
What is the function on the Vena Cava?
A
Returns blood from all organs except the lungs
19
Q
What is the function on the Right Atrium?
A
receives blood from the body organs and pushes it into the ventricle
20
Q
What is the function on the Avioventricular (tricuspid) valve?
A
Stops blood flowing back into the atrium as the ventricle contracts
21
Q
What is the function on the Right ventricle?
A
Receives blood from the atrium and pushes it into the lungs
22
Q
What is the function on the Pulmonary Artery?
A
Distributes blood to the lungs
23
Q
What is the function on the Aorta?
A
Distributes blood to all organs except the lungs
24
Q
What is the function on the Aortic valve?
A
Stops blood flowing back into the ventricle as the ventricle relaxes
25
What is the function on the left ventricle?
Receives blood from the atrium and pushes it to the body
26
What is the function on the Atrioventricular (bicuspid) valve?
Stops blood flowing back into the atrium as the ventricle contracts
27
What is the function on the left atrium?
Receives blood from the lungs and pushes it into the ventricle
28
What is the function on the Pulmonary Vein?
Returns blood from the lungs
29
What is the first step of the cardiac cycle?
.Atria fill with blood from the Vena Cava and pulmonary vein (all chambers relaxed)
.Pressure in the atria rises
.Blood trickles into ventricles through the open atrioventricular valves (bicuspid and tricuspid valves)
30
What occurs in Atrial Systole?
When the walls of the atria contracts. The volume of the atria decreases and the pressure increases, blood enters the ventricles down a pressure gradient.
31
What occurs after Atrial Systole?
Atria empties as the rest of the blood is forced into the ventricles, through the Atrioventricular valves.
32
What occurs when the ventricles are full of blood?
.After a short delay to allow full contraction of the atria, the walls of the ventricles contract (ventricular systole). Atria relax.
.The walls of the ventricles contract from the bottom up, reducing the volume and increasing the pressure in the ventricles
33
What occurs to the atrioventricular valves after ventricular contraction?
They close to prevent backflow of blood
34
What causes the semi lunar valve to open?
The pressure in the ventricles is greater than the pressure in the aorta and pulmonary artery. This pushes open the semilunar valves (pulmonary and aortic valves) in the arteries.
35
What is the last step in the cardiac cycle?
.Blood is forced out of the heart into the aorta and pulmonary arteries
.Ventricles relax, pressure falls
.Semilunar valves shut
36
When do the Atrioventricular valves open?
The AV valves are open when the pressure above the valves is greater than below it.
.The atrioventricular valves opens when the pressure in the atrium is greater than the ventricle
37
When does the Semilunar valve open?
Semilunar opens when the pressure in the ventricle is greater than the artery
38
Why do the valves in the heart close?
To prevent backflow
39
What causes the lub-dub sound in the heart?
This occurs due to the closing of the atrioventricular valve followed by the closing of the semilunar valve
40
What is the pressure in the atria like? Why?
The atria have a thin muscle wall which exerts a small pressure to push blood into the ventricles
41
What is the pressure in the Right Ventricle like? Why?
The right ventricle has higher pressure than the atria, as it has to push blood to the lungs therefore the m muscle wall is thicker than the atria.
42
What is the pressure in the Left Ventricle like? Why?
The left ventricle has the highest pressure as it has to pump blood through the aorta to the rest of the body. This means that the muscle wall is up to 3 times thicker than the right ventricle.
43
Define Myogenic?
Muscle contractions initiated within the muscle itself
44
What is the Sino Atrial Node (SAN)? Where is it located?
.The heart's internal pacemaker
| .Located on the top right atrium
45
What is the function of the Sinoatrial node (SAN)?
It initiates the wave of excitation (electrical stimulation)
46
What is atrial systole and what causes it?
Atrial systole is when the walls of the atria contract simultaneously, this is caused by the wave of excitation.
47
What is the layer of non-conductive tissue called? What is its function?
The atrioventricular septum which prevents the wave spreading to the ventricles.
48
What happens to the wave of excitation after passing the atrioventricular septum?
The wave of excitation reaches the AVN (Atrioventricular node) and is delayed to allow the atria to complete contraction before ventricular systole.
49
After a brief pause at the Atrioventricular node what happens to the wave of excitation?
The wave of excitation then travels down highly conductive tissues in the septum called the bundle of His. As it reaches the apex it passes along the branching Purkinje Fibres up the walls of the ventricles, causing them to simultaneously contract from the bottom upwards: ventricular systole.
50
What is diastole?
When all the chambers of the heart simultaneously relax, the last stage of the cardiac cycle.
51
How can the electrical signal that passes through the heart be monitored?
Using an ECG (Electrocardiogram), this involves using detective electrodes on the skin.
52
What are the three layers to a blood vessel?
Tunica Externa
Tunica Media
Tunica Intima/ Interna
Lumen
53
What are the main features of the tunica externa?
.Made of collagen
| .Strong fibrous protein which helps vessels withstand high pressure
54
What are the main features of the tunica media?
.Smooth muscle which can contract and constrict the vessel
| .Elastic tissue which allows stretch and recoil of the vessel - this layer helps sustain blood pressure
55
What are the main features of the tunica intima/ interna?
.Single layer of endothelial cells
| .Smooth and flat for reduced friction of the flowing blood
56
What is the lumen?
The cavity through which the blood flows
57
What is an artery and what is its function?
A blood vessel that takes high pressure blood away from the heart to other regions of the body
58
What is a vein and what is its function?
A blood vessel that returns low pressure blood to the heart from the lungs and the body
59
What is a capillary and what is its function?
A blood vessel that connects small arteries (arterioles) with small veins (venules) and allows exchange of materials with the tissues.
60
What is the walls of Arteries and Arterioles like?
Thick walls to resist high pressured blood
61
What is the size of the lumen like in arteries and arterioles ?
Narrow lumen to maintain high pressure
62
Why do arteries and arterioles have lots of elastic fibres/ tissue in its walls?
Allows it to stretch to accommodate surge of blood from ventricles and recoil to maintain pressure.
63
How do arterioles adjust the amount of blood delivered to certain areas of the body?
They adjust their diameter by contracting or relaxing smooth muscle
64
What is the tissue on the inside of arterioles/ arteries, why is it this tissue?
Smooth endothelium to reduce friction
65
What is the structure of a capillary?
A single layer of cells in the wall (endothelium) no elastic tissue
66
What slows the flow of blood in the capillaries?
The small diameter of lumen which causes friction with walls and slows the flow of blood.
67
Why is it important that the blood flow in capillaries is slow?
Low speed of flow enhances the ability to exchange materials with the surrounding tissue by diffusion
68
What in the capillaries allows solutes and ions to leak out?
GAPS NOT PORES
69
What is the outer layer of veins made of and why?
Collagen
70
What is the structure of the vein?
Thinner wall as the pressure of blood is reduced, wider lumen, little elastic tissue in wall (no stretch and recoil), valves to prevent backflow of blood.
71
What is the blood flow in the veins like?
Blood in the vein is no longer influenced by the contractions of the heart and is under very low pressure
72
How does blood from organs above the heart get back?
Gravity
73
How is the pressure maintained in the arteries ?
The pressure is maintained due to the elastic tissue of the arteries
74
What is the pattern of pressure in the arteries?
Rhythmical rise and fall in pressure due top ventricular contraction and relaxation
75
What causes a small decrease in the pressure in the arteries?
Friction with blood vessel walls, leads to a small decrease in pressure
76
What is the pressure like in the Arterioles ?
Blood is at a lower pressure as it is further away from the heart
77
Why does a larger pressure drop occur in the arterioles?
Arterioles have a larger total surface area and narrower lumen therefore a large drop in pressure occurs here.
78
What causes a decrease in the pressure in the arterioles?
Pressure drop is greater if the arterioles are constricted
79
Why do capillaries have a large drop in pressure?
Capillaries have a larger total cross sectional area therefore even greater resistance to blood flow and a further drop in pressure
80
Why do capillaries have a large drop in pressure?
Capillaries have a larger total cross sectional area therefore even greater resistance to blood flow and a further drop in pressure
.Leakage from capillaries
81
What is the function of skeletal muscle in the return of the blood back to the heart?
Skeletal muscles are used to massage the veins and help return blood to the heart
82
How are capillaries well adapted to be an exchange site between blood and body cells?
They are well adapted as they have thin, permeable walls, they provide a large total surface area and blood flows slowly through them.
83
What can pass in and out of the capillaries?
Blood is contained within the vessels, but fluid from the plasma is able to escape into the tissues - tissue fluid.
84
What does tissue fluid provide the cells with when it bathes them?
```
.Glucose
.Amino Acids
.Fatty acids
.Mineral Ions
.Oxygen
```
85
What does tissue fluid remove?
Toxic Waste
86
Why do the arterioles have high pressure?
High pressure is due to the pumping action of the heart and the resistance to blood flow in the capillaries
87
What forces the fluid part of the blood out od the vessels and into the tissue?
Hydrostatic pressure
88
What opposes the outward flow of the tissue fluid?
The reduced water potential of the blood (due to plasma proteins)
89
What causes a net flow movement of tissue fluid out of the capillary?
The hydrostatic pressure is greater than the osmotic force therefore there is a net flow of fluid out taking glucose, oxygen, and ions into the tissue.
90
Why is there a net movement of tissue fluid back into the venules?
Blood pressure is reduced here so the Hydrostatic Pressure is now less than the reduced water potential of the blood due to the plasma proteins. There is a net flow of fluid back into the capillaries taking CO2 and urea from the tissues.
91
Where does the left over tissue fluid drain into?
Some of the tissue fluid drains into the lymphatic system and is returned to the venous system through the thoracic duct near the heart.
92
What is the function of digested food products in the blood?
Supply each cell with nutrients
93
What is the function of hormone in the blood?
To take hormone from glands to all cells in the body
94
What is the function of Proteins - albumin/ fibrinogen in the blood?
Fibrinogen for blood clotting. Maintains water potential gradient of blood
95
What is the function of antibodies in the blood?
Fight Infection
96
What is the function of Ions in the blood?
Function specific to each ion e.g. blood clotting and bone formation.
97
What are the 5 Key roles of blood?
1. Transport
2. Distributes Heat
3. Buffer
4. Defence
5. Provides pressure for some organ function
98
What is the carriage of oxygen in water at body temperature?
The solubility of oxygen is 0.025cm3 per cm3 of water therefore per dm3 of H2O = 25cm3 of O2
99
What is the carriage of oxygen by haemoglobin at body temperature?
.In 1dm3 of blood there is 150g of haemoglobin
.1g of haemoglobin can combine with 1.3cm3 of oxygen
.Per dm3 of blood = 195 cm3 of oxygen
100
Why is the beginning of the oxygen dissociation curve not very steep?
The deoxyhaemoglobin has a 'tense' tight structure. It is hard for the first oxygen molecule to combine to a haem group
101
Why does the oxygen dissociation curve suddenly increase in gradient?
Once the first haem group has bonded the structure of the haemoglobin is disturbed making it easier for the second oxygen molecule to combine.
102
Why does the oxygen dissociation graph plateau at the end ?
When the fourth oxygen molecule is attached it is described as oxyhaemoglobin and the graph plateaus.
103
What is the shape of the oxygen dissociation curve?
Sigmoid Shaped ('S' shaped)
104
What is the structure of Haemoglobin?
.4 polypeptide chains (2X alpha and 2X beta)
.4 Haem groups (prosthetic groups)
.4 O2 molecules that can attach when haemoglobin is fully saturated to oxyhaemoglobin
105
What pO2 is typical of respiring tissues?
Almost complete dissociation of O2
106
What does the steepness of the oxygen dissociation curve correlate to?
Corresponds to the easy dissociation of oxyhaemoglobin. Typical of blood in capillaries.
107
What is the typical pO2 of the lungs, pulmonary veins and systemic arteries? Why?
Little dissociation of O2, ideal for the transport of oxygen.
108
What are the two 'other' (minor) ways in which Carbon Dioxide is transported?
.Plasma (5%)
| .Combines with haemoglobin to form CARBAMINO-HAEMOGLOBIN (10%)
109
What is the main way carbon dioxide is transported?
Most is converted in the red blood cells to carbonic acid (bicarbonates)
110
What happens to the carbonic acid?
Dissociates into hydrogen and hydrogen carbonate ions
111
What causes the oxyhaemoglobin to dissociate into oxygen and haemoglobin?
The hydrogen ions that were created from the carbonic acid
112
What is produced when hydrogen ions are buffered by the haemoglobin?
Haemoglobinic acid
113
What are the 6 steps to the transport of Carbon Dioxide?
1. Diffusion of CO2 into the red blood cell
2. Carbonic anhydrase catalyses the conversion of CO2 and water into carbonic acid
3. Carbonic acid dissociates into hydrogen and hydrogen carbonate ions
4. Hydrogen carbonate ions diffuse into the blood plasma, and chloride ions diffuse into the red blood cells to preserve electrical neutrality
5. Hydrogen ions attach to the haemoglobin to form Haemoglobinic acid and displaces the oxygen
6. Oxygen diffuses out of the red blood cells into the plasma and tissues.
114
What is the function of chloride ions in the transport of CO2?
Preserve electrical neutrality
115
What is formed when hydrogen ions bond with haemoglobin?
Haemoglobinic acid
116
What catalyses CO2 and water into carbonic acid?
Carbonic Anhydrase
117
What is the Bohr Effect?
This is the theory that as the pCO2 increases the percentage saturation of haemoglobin at the same pO2 decreases
118
What effect does the Bohr Effect have on a graph?
The curve shifts to the right
119
How does the concentration of Carbon Dioxide effect the H+ production?
The more carbon dioxide around the more H+ produced (from carbonic acid)
120
What is the role of H+ ions in the displacement of oxygen?
The H+ displace the oxygen from the oxyhaemoglobin and the less saturated it becomes at the same partial pressure of 02.
121
When is the Bohr Effect observed?
This effect is observed in muscles during exercise and is responsible for the release of oxygen from capillaries to these highly respiring tissues.
122
What four factors effect the shifting of the oxygen dissociation curve to the right?
.Decrease in pH
.Increase in temperature
.Increase pCO2
.Increase in 2,3-BPG
123
What is the shape of the oxygen dissociation curve for myoglobin like?
.No 's' shape
.Graph in linear
.Steep incline
124
What are the differences between myoglobin and haemoglobin ?
.Myoglobin has a high affinity for O2
.Becomes fully saturated with O2 at lower pO2
.Myoglobin acts as an O2 store in the muscles
.Myoglobin provides O2 to muscles during extreme aerobic respiration.
125
What are the structural differences between foetal and adult haemoglobin?
Adult - 2 alpha and 2 beta chains
| Foetal - 2 alpha and 2 delta chains
126
What are the difference in characteristics between foetal and adult haemoglobin?
Foetal haemoglobin has a higher affinity for oxygen
127
What are the three characteristics of lugworms?
.Adapted to live in environments with low O2
.Low metabolic rate
.Lugworms pumps sea water through its burrow, giving access to the limited amount of O2 present.
128
What happens to humans blood at high altitude?
EPO is released which increases the production of red blood cells
129
How does a llamas affinity for oxygen compare to a low land animals affinity?
The lama has a higher affinity due to its high altitude environment.
