Adaptations For Transport (animals) Flashcards
1
Q
What are the features of a transport system?
A
- suitable medium for transport (blood)
- pump time move blood (heart)
- valves to maintain blood flow in one direction
Extras only in some:
- respiratory pigment like haemoglobin which increases the volume of blood
- system of vessels with a branching network to distribute the transport medium to all areas of the body
2
Q
What does it mean if an animal has an open circulatory system? Give an example of an animal with one.
A
The blood does not move around the body in vessels but it bathes the tissue directly while held in a cavity called the haemocoel. For example, insects
3
Q
Describe the open circulatory system of an insect.
A
- open circulation system
- long dorsal (top) tube shaped heart running the length of the body. Pumps blood at low pressure into haemocoel where materials are exchanged between blood and body cells. Blood returns slowly to the heart and the circulation starts again.
- oxygen diffuses directly to the tissues from the tracheae so the blood doesn’t transport oxygen and has no respiratory pigment.
4
Q
Why does the blood of an insect have not respiratory pigment?
A
-oxygen diffuses directly to the tissues from the tracheae so the blood doesn’t transport oxygen and has no respiratory pigment.
5
Q
Describe a closed circulatory system for SINGLE circulation. Give an example animal.
A
The blood moves through the heart once in it’s passage around the body. For example the earthworm.
6
Q
Describe the circulation of an earthworm
A
- Single circulation in a closed system.
- blood moves in vessels and blood is under pressure.
- vascularised
- organs are not in direct contact with blood
- respiratory gases as transported in the blood.
7
Q
How is blood transported around an earthworm?
A
- blood moves forward in the dorsal vessel and back in the ventral vessel.
- five pairs of pseudohearts, thickened, muscular blood vessels pump the blood from the dorsal to the ventral vessel and keep it moving.
8
Q
Describe the single circulation of blood in fish.
A
- the ventricle of the heart pumps deoxygenated blood to the gills where it’s pressure falls
- oxygenate blood returns to the atrium of the heart
- blood moves to the ventricle and the circulation starts again.
9
Q
Describe what double circulation is.
A
- The blood passes through the heart twice during its circuit around the body
- mammals have a closed circulation system
- blood is pumped by a muscular heart at high pressure for rapid flow rate through blood vessels.
- organs not in direct contact with blood but bathed in tissue fluid.
- haemoglobin carries oxygen
- blood pressure reduced in lungs so blood then returns to the heart so pressure increases again and then pumped to the rest of the body so materials are delivered more quickly.
10
Q
What are the two parts of double circulation in mammals?
A
- pulmonary circulation
- systematic circulation
11
Q
Describe pulmonary circulation
A
- first half of double circulation
- supplies the LUNGS
- right side of the heart (right ventricle) pumps deoxygenated blood through the pulmonary artery to lungs
- oxygenated blood becomes so at the lungs.
- this blood then returns to the heart through the pulmonary vein into the left atrium.
12
Q
Describe systematic circulation
A
- second half of double circulation system.
- supplies the rest of the BODY
- left side of the heart (left ventricle) pumps oxygenated blood out of heart through the aorta to the rest of the body tissues.
- this blood becomes deoxygenated
- this blood then returns to the right atrium through the inferior vena cava.
13
Q
Why is double circulation more efficient than single?
A
Oxygenated blood is pumped at higher pressure.
14
Q
What are the three types of blood vessel?
A
Artery
Capillary
Vein
15
Q
Arteries and veins have the same basic structure bus in different proportions. Describe the structure
A
- innermost layer is the endothelium
- middle layer is tunica media.
- outer layer is tunica externa
16
Q
Describe the endothelium layer in veins and arteries.
A
-one cell thick smooth lining reducing friction with a minimum resistance to blood flow
17
Q
Describe the tunica externa structure for veins and arteries
A
contain collagen fibres with resist over stretching
18
Q
Describe the basic structure of tunica media
A
- Contains elastic fibres and smooth muscle.
- Contraction of the smooth muscle regulates blood flow and maintains blood pressure as it’s transported further away from the heart
- thicker in arteries than in veins
19
Q
Describe the structure of tunica media for arteries
A
- elastic fibres allow stretching to accommodate changes in the blood flow and pressure as blood is pumped from the heart
- at a certain point, stretched elastic fibres recoil pushing blood through the artery
- this is felt as a pulse and maintains blood pressure
20
Q
Describe an artery
A
- carries blood away from the heart
- thick muscular wall withstands bloods high pressure derived from the heart
- branch into smaller vessels called arterioles which further divide into capillaries.
21
Q
Describe capillaries
A
- form a vast network that penetrates all tissue and organs of the body.
- blood from capillaries collects into venules which take blood to veins.
- thin walls which are one layer of endothelium on a basement membrane
- pores between cells make walls permeable to water and solutes for exchange between blood and tissue
- small diameter and slow flow rate of blood for time for exchange of materials.
22
Q
Describe veins
A
- large diameter lumen
- thinner walls with less muscle than arteries.
- so, blood pressure and flow rate are lower.
- veins above heart don’t contain calves as blood returns by gravity
- contain semi lunar valves along their length ensuring blood flows in one direction.
23
Q
What can be caused by faulty valves in veins?
A
Varicose veins and heart failure.
24
Q
Which side of the heart is oxygenated?
A
Left
25
What are the four chambers of the heart?
Left and right atria and left and right ventricle
26
Which veins enter the heart?
Pulmonary vein on the left
| superior and inferior vena cava on the right
27
What does SAN stand for?
Sino atrial node
28
What does the sinoatrial node do?
Provide electric stimulation to act as a peacemaker for the heart contractions
29
What type of valves are in the arteries leaving the heart?
Semi lunar valves
30
What are the stages of the heart cycle?
Atrial systole, ventricular systole, diastole
31
Describe atrial systole
- walls of atrium contract/walls of ventricle relaxed
- pressure of atrium increasing/pressure in ventricle is low
- atrioventricular valves/semilunar valves closed
32
Describe ventricular systole
- walls of atrium relaxed/walls of ventricle contract
- pressure in atrium low/pressure in ventricle increases
- atrioventricular valves closed/semi lunar valves open.
33
Describe diastole
- Walls of atrium and ventricle is relaxed
- pressure in atria and ventricle is low
- Atrioventricular valves open/semilunar valves closed
34
Which is the longest period in the cardiac cycle?
Diastole
35
What does AVN stand for
Atrioventricular node
36
What does the atrioventricular node do?
The only conducting area of tissue in the wall of the heart between the atria and ventricles, through which electrical excitation passes from the atria to conducting tissue in the walls of the ventricles
37
What does neurogenic mean?
Origin of stimulus like a nerve impulse.
38
What does myogenic mean?
Origin of stimulus= muscle no nerve needed cardio muscle cardiac muscle is myogenic so no nerve supply needed
39
What type of valves are found at the base of the aorta and pulmonary artery
Semilunar valves and atrioventricular valves
40
What do valves do?
Prevent the back flow of blood
41
What are the two types of reflex action?
Neurogenic and myogenic
42
What is the blood made of?
55% plasma 45% cells
43
What is found in blood plasma?
90% water, plasma proteins, mineral irons, glucose, amino acid, waste products, vitamins
44
What type of cells are found in the blood?
1% white blood cells with different sized nuclei (phagocytosing) and red blood cells (ERYTHROCYTES)
45
Describe red blood cells
- erythrocytes
- no nucleus
- 7 um diameter
- contain haemoglobin
- flat for large surface area
- bioconcave shape.
46
Where is blood pressure highest?
The aorta and large arteries
47
What affect does ventricular contraction have on the blood?
Blood pressure will rise and fall rhythmically.
48
What causes blood pressure to drop in arterioles despite the narrow lumen?
- friction between the blood and vessel walls
| - although it does depend on whether the vessel is dilated or constricted.
49
Why does the extensive capillary network have a reduced blood pressure?
Fluid leaks from the capillaries into the tissues
50
Describe the relationship between blood pressure and blood flow in arteries and capillaries.
The higher the blood pressure the faster the blood flows so both pressure and speed falls as the distance from the heart increases
51
Why do veins have low blood pressure which doesn’t change.
Due to the contractions of the ventricles
52
Despite the lower blood pressure why do veins have a faster bloodflow than in capillaries?
Veins have a larger diameter lumin
53
How does blood return to the heart?
Rhythmically by the massaging effects of the muscles surrounding the veins
54
What is an electrocardiogram (ECG)
A trace of the voltage changes produced by the heart detected by electrodes in the skin.
55
What is the P-wave in an electrocardiogram?
The P-wave is the first part of the trace and shows the voltage change generated by the SAN associated with the contraction of the atria. Atria have much less muscles than in the ventricles so the P-waves are small.
56
What does the P-wave show in an electrocardiogram?
Atrial depolarisation
57
In an electrocardiogram what shows the atrium relaxing
The time at the start of the P-wave and start of the QRS complex
58
What is the PR interval in an electrocardiogram?
The interval for the excitation to spread from the atria to the ventricles through the AVN
59
In an electrocardiogram what is the QRS complex show?
Ventricular depolarisation
60
In an electrocardiogram what’s the T wave show?
The repolarisation of the ventricle muscle
61
In an electrocardiogram what is the isoelectric line?
The baseline of the trace
62
How can a heart rate be calculated in electrocardiogram?
The distance between the peaks of the QRS waves
63
What would an electrocardiogram look like for somebody who is suffering from atrial fibrillation?
There would be no P-wave and irregular or no atrial depolarisation
64
What would an electrocardiogram of someone suffering from a heart attack look like?
Wide QRS complex
65
What would an electrocardiogram of someone suffering from enlarged ventricles look like?
The QRS shows greater voltage change
66
What would an electrocardiogram of someone suffering from insufficient blood to heart look like?
Height of the ST segment and the T-wave change
67
Describe haemoglobin
It is a protein with a Quaternary structure.
The shape varies in different organisms, depending on the organisms metabolic rate and living environment
Four polypeptide chains to alpha chains and two beta chains
Each of the four chains have a haem group
68
What determines the shape of the protein?
The DNA code Which codes for sequence of amino acids
69
What is the role of haemoglobin?
To transport oxygen
70
How does haemoglobin transport oxygen?
Haemoglobin binds to the oxygen in the lungs then The blood transports it around the body and releases it into respiring tissues in the lungs oxygen plus haemoglobin binds to make up oxyhaemoglobin
71
How does haemoglobin efficiently transport oxygen?
Haemoglobin will associate with oxygen at the gas exchange surface (like the alveoli) in capillaries surrounding the lungs.
72
What do we call the substance when haemoglobin is fully loaded with oxygen?
Oxyhaemoglobin
73
What happens to Oxy haemoglobin when the blood has reached the respiring tissues?
The Oxy haemoglobin will dissociate to make oxygen and haemoglobin separately and the oxygen will diffuse into the tissue.
74
What will change haemoglobins affinity for oxygen?
The shape of the haemoglobin.
75
What is the definition for affinity?
How strongly to molecules are attracted to each other
76
How can affinity be shown?
On an affinity curve
77
What would an affinity curve look like for haemoglobin that has high affinity for oxygen?
Further left so the higher the haemoglobins oxygen affinity so takes oxygen more readily but release is it less easily
78
What would the oxygen dissociation curve look like for haemoglobin with a lower affinity for oxygen?
The curve would be further right
79
What factors determine the shape of haemoglobin?
Where the organism lives.
Size of the organism and its metabolic rate.
Activity levels of the organism.
80
How many oxygen molecules can bind to one haemoglobin and why?
Four molecules of oxygen can bind to one haemoglobin because each haemoglobin has for haem groups which each contain one ion of iron
81
What happens to the haemoglobin when the first oxygen molecule binds to it?
The haemoglobin molecule changes shape making it easier for the second molecule to attach
82
What is cooperative binding?
On haemoglobin molecule when one binding oxygen makes it easier for the next oxygen to bind because there is a change of shape in the haemoglobin
83
What must occur for the fourth oxygen to bind to the haemoglobin when there is not a change of shape after the third oxygen binding?
A large change in partial pressure
84
What is partial pressure
The pressure a gas would exert if it was the only one present
85
What causes the dissociation curve to have a sigmoid shape (S)?
Oxygen is not absorbed evenly due to the increasing partial pressure from cooperative binding
86
What will very low oxygen partial pressure cause?
It would make it harder for haemoglobin to associate with oxygen
87
What would oxygen saturation be like at high oxygen partial pressure?
The percentage saturation of oxygen would be high
88
On an oxygen dissociation curve what would it mean when the line has reached 100%?
It is all oxyhaemoglobin
89
How do you red blood cells transport oxygen to tissues?
Red blood cells load oxygen in the lungs, whether oxygen partial pressure is high, so haemoglobin become saturated with oxygen.
The cells carry the oxygen as Oxy haemoglobin to respiring tissues like muscle.
In muscles there is low oxygen partial pressure because oxygen is being used for respiration.
Haemoglobin will then dissociate with oxygen.
90
In comparison to human haemoglobin on a dissociation curve what would a curve look like for an animal with a higher affinity for haemoglobin for oxygen?
Further left
91
The father left on the dissociation curve what is the relationship like between oxygen and haemoglobin?
The haemoglobin associated with oxygen more easily but dissociate less easily
92
On a dissociation curve what can be found left of a human?
Fetus.
Llama.
Lugworm.
Myoglobin.
93
Why does Foetal haemoglobin have a higher affinity for oxygen?
A fetus must absorb oxygen from the maternal haemoglobin at the placenta so it has a higher affinity for oxygen because it has two different polypeptide chains from adult haemoglobin
94
Why does the lugworm have a higher affinity for oxygen?
It lives in sand which means it is in a low oxygen environment
It has a low metabolic rate
95
Why does A lama have a high affinity for oxygen?
Because it lives in areas of high altitude so there is a low oxygen partial pressure this means oxygen associates in lungs rapidly and releases oxygen when oxygen partial pressure is low and it’s respiring tissues
96
What is myglobin?
A muscle tissue with a high oxygen affinity
97
What forms when myglobin binds with oxygen?
Oxymyoglobin is formed
98
How can you tell the bohr affect is present on a dissociation curve?
The movement of the oxygen dissociation curve is moved to the right at higher partial pressure of carbon dioxide because haemoglobin has a lower affinity for oxygen.
99
If there is high concentrations of carbon dioxide what happens to the Oxy haemoglobin?
Oxyhaemoglobin dissociates more readily
100
What makes the haemoglobin more efficient at dissociation?
When the partial pressure of carbon dioxide is high haemoglobin will have a lower affinity for oxygen
101
What happens in the muscles to make sure that the muscles receive increase supply of oxygen during exercise?
There is more carpenters dioxide in muscles so more Oxy haemoglobin will dissociate oxygen more easily when carbon dioxide is high in muscles which are respiring during exercise
102
What are the ways in which carbon dioxide is transported?
- In solution in the blood plasma (5%).
- As the hydrogen carbonate ions HCO3 brackets (85%)
- Bound to haemoglobin as carbamino-haemoglobin (10%).
103
Describe how carbon dioxide is transported in red blood cells around the body.
1) CO2 in blood diffuses into the red blood cells
2) Carbonic anhydrase catalyses carbon dioxide+water => carbonic acid
3) carbonic acid dissociates HCO3- and hydrogen ions
4) HCO3- ions diffuse OUT of red blood cell into plasma
5) chloride ions diffuses into red blood cell
6) H+ ion causes oxyhaemoglobin to dissociate into 4o2 and Hb. H+ ion combines with haemoglobin to form HHb to remove H+ ions so PH of red blood cell doesn’t fall.
7) oxygen diffuses out of red blood cell into tissues
104
What does blood Plasma transport?
```
Digested food products
Hormones
Proteins
Albumin
Fibrinogen
Antibodies
Ions
Distributes heat
```
105
Where does exchange of materials between blood and body cells happened?
In the blood capillaries
106
What move from the blood capillaries to the cells?
Plasma, solutes and oxygen
107
What moves from the cells into the blood capillaries?
Waste products from the cell like carbon dioxide and uria
108
How are blood capillaries well adapted for material exchange?
Thin permeable walls
Large surface area for exchange of materials
Blood flows very slowly through the capillaries allowing time for exchange of materials.
109
Why is tissue fluid (fluid from the plasma) forced through capillary walls?
To surround cells to provide solid like glucose, amino acids, fatty acids, salt, hormones and oxygen
110
What does tissue fluid do?
Removes waste made by cells
111
What does the diffusion of salt in and out of the capillaries relate to?
The blood is hydrostatic pressure and solute potential
112
What type of muscles surround arterioles?
Splincter muscles
113
Which system also surrounds capillaries and body cells?
The lymphatic system to carry away waste water
114
What means that tissue fluid is lost from the bloodstream?
Hydrostatic pressure is greater than osmotic pressure in blood capillaries
115
What do you live vessels do surrounding body cells and blood capillaries?
Collect excess tissue fluid.
116
Name different types of blood vessels and how they connect
Artery, arterial, capillaries, Venuole, vein
117
How does water move back into the capillary from surrounding the Tissue cells?
Plasma has low solute potential due to colloidal plasma proteins which tends to pour water back into capillary by osmosis
118
How come water and it’s so late are forced out of blood capillaries walls?
Hydrostatic pressure is greater than plasma solute potential
119
Where does blood plasma go when it is forced out of capillary walls?
The space surrounding the cells
120
Why does tell you to leave blood capillaries?
The concentration outside of the cell is low and the concentration in the blood is high favouring diffusion from capillaries into tissue fluid down the concentration gradient this is because solutes are used during cell metabolism
121
Where there is about 10% of fluid drained to from outside of the cells instead of going back into the blood capillaries?
Into lymph capillaries which connect to the lymphatic system
