9. Transport in Animals Flashcards
1
Q
Circulatory system definition
A
The circulatory system is a system of blood vessels with a pump and valves to ensure one-way flow of blood
2
Q
What type of circulatory system do fish have?
A
Fish have a two-chambered heart and a single circulation
3
Q
What does single circulation mean?
A
This means that for every one circuit of the body, the blood passes through the heart once
4
Q
What type of circulatory system do mammals have?
A
Mammals have a four-chambered heart and a double circulation
5
Q
What does double circulation mean?
A
This means that for every one circuit of the body, the blood passes through the heart twice
6
Q
What does the right side of the heart do?
A
The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs
7
Q
What is the blood flowing in the lungs called?
A
Pulmonary circulation
8
Q
What does the left side of the heart do?
A
The left side of the heart receives oxygenated blood from the lungs and pumps it to the body
9
Q
What is the blood flowing through the body called?
A
Systemic circulation
10
Q
What is the advantage of a double circulatory system?
A
Blood travelling through the small capillaries in the lungs loses a lot of pressure that was given to it by the pumping of the heart, meaning it cannot travel as fast
By returning the blood to the heart after going through the lungs its pressure can be raised again before sending it to the body, meaning cells can be supplied with the oxygen and glucose they need for respiration faster and more frequently
11
Q
In what direction do veins carry blood?
A
Blood is pumped towards the heart in veins
12
Q
In what direction do arteries carry blood?
A
Blood is pumped away from the heart in arteries
13
Q
What separates the two sides of the heart?
A
The two sides of the heart are separated by a muscle wall called the septum
14
Q
What is the heart made of?
A
The heart is made of muscle tissue
15
Q
What supplies the heart muscle with blood?
A
supplied with blood by the coronary arteries
16
Q
Do ventricles or atria have thicker muscle walls? Why?
A
VENTRICLES
The ventricles have thicker muscle walls than the atria as they are pumping blood out of the heart and so need to generate a higher pressure
17
Q
Does the left ventricle or the right ventricle have a thicker muscle wall? Why?
A
The left ventricle has a thicker muscle wall than the right ventricle as it has to pump blood at high pressure around the entire body, whereas the right ventricle is pumping blood at lower pressure to the lungs
18
Q
What is the role of the septum?
A
The septum separates the two sides of the heart and so prevents mixing of oxygenated and deoxygenated blood
19
Q
What is the basic function of valves?
A
The basic function of all valves is to prevent blood flowing backwards
20
Q
What are the 2 sets of valves in the heart?
A
- atrioventricular (bi and tricuspid)
- semilunar valves
21
Q
What do the atrioventricular valves separate?
A
The atrioventricular valves separate the atria from the ventricles
22
Q
What is the valve in the right side of the heart called?
A
Tricuspid valve
23
Q
What is the valve in the left side of the heart called?
A
Bicuspid valve
24
Q
When are the atrioventricular valves opened and closed?
A
These valves are pushed open when the atria contract but when the ventricles contract they are pushed shut to prevent blood flowing back into the atria
25
Where are the semilunar valves found?
The semilunar valves are found in the two blood arteries that come out of the top of the heart
26
What is unusual about the semilunar valves?
They are unusual in that they are the only two arteries in the body that contain valves
27
When do the semilunar valves open and close?
These valves open when the ventricles contract so blood squeezes past them out of the heart, but then shut to avoid blood flowing back into the heart
28
1. What type of blood comes from the body and where does it go?
Deoxygenated blood coming from the body flows into the right atrium via the vena cava
29
2. What happens once the right atrium has filled with blood?
Once the right atrium has filled with blood the heart gives a little beat and the blood is pushed through the tricuspid (atrioventricular) valve into the right ventricle
30
3. What happens when the blood enters the right ventricle?
The walls of the ventricle contract and the blood is pushed into the pulmonary artery through the semilunar valve which prevents blood flowing backwards into the heart
31
4. Where does the blood go when it's pushed through the pulmonary artery? What happens here and what process occurs?
The blood travels to the lungs and moves through the capillaries past the alveoli where GAS EXCHANGE takes place
32
5. Why does there have to be a low pressure on the right side of the heart?
blood is going directly to capillaries which would burst under higher pressure
33
6. What happens to the blood which has travelled from the lungs?
Oxygen-rich blood returns to the left atrium via the pulmonary vein
34
7. What happens to the blood once it enters the left atrium?
It passes through the bicuspid (atrioventricular) valve into the left ventricle
35
8. How is the blood transported around the body from the left ventricle?
The thicker muscle walls of the ventricle contract strongly to push the blood forcefully into the aorta and all the way around the body
36
9. What prevents the blood from flowing back into the heart?
The semilunar valve in the aorta prevents the blood flowing back down into the heart
37
How can heart activity be monitored?
Heart activity can be monitored by using:
- an ECG,
- measuring pulse rate - listening to the sounds of valves closing using a stethoscope
38
What is heart rate measured in?
Immediately after they do some exercise, record the pulse rate every minute until it returns to the resting rate
39
How can you investigate the effects of exercise on heart rate?
To investigate the effects of exercise on heart rate, record the pulse rate at rest for a minute
Immediately after they do some exercise, record the pulse rate every minute until it returns to the resting rate
40
What should this experiment show? (investigating the effects of exercise on heart rate)
This experiment will show that during exercise the heart rate increases and may take several minutes to return to normal
41
Why, (generally), does heart rate increase during exercise?
So that sufficient blood is taken to the working muscles to provide them with enough nutrients and oxygen for increased respiration
42
What does an increased heart rate allow the removal of?
An increase in heart rate also allows for waste products to be removed at a faster rate
- Following exercise, the heart continues to beat faster for a while to ensure that all excess waste products are removed from muscle cells
43
In what way will muscles likely have been respiring? What does this cause?
It is also likely that muscle cells have been respiring anaerobically during exercise and so have built up an oxygen debt
44
How can an oxygen debt be "repaid"?
This needs to be ‘repaid’ following exercise and so the heart continues to beat faster to ensure that extra oxygen is still being delivered to muscle cells
45
What is the extra oxygen produced by the rapid beating of the heart also used for?
The extra oxygen is used to break down the lactic acid that has been built up in cells as a result of anaerobic respiration
46
What can happen to coronary arteries if a person has a diet high in saturated fats/cholesterol?
A coronary artery becomes partially or completely blocked by fatty deposits called ‘plaques’/ atheromas (mainly formed from cholesterol),
47
Why are atheromas harmful?
the arteries are not as elastic as they should be and therefore cannot stretch to accommodate the blood which is being forced through them – leading to coronary heart disease
48
What does partial blockage of the coronary arteries cause? What is this called?
Partial blockage of the coronary arteries creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
49
What does complete blockage of the coronary arteries cause? What is this called?
Complete blockage means cells in that area of the heart will not be able to respire and can no longer contract, leading to a heart attack
50
How does a poor diet affect your chance of developing coronary heart disease?
eating more saturated fat increases cholesterol levels, increasing the chance of the buildup of fatty plaques
51
How does stress affect your chance of developing coronary heart disease?
when under stress, hormones produced can increase blood pressure, increasing the chance of a blockage in the coronary arteries
52
How does genetic predisposition affect your chance of developing coronary heart disease?
studies show that people with a history of coronary heart disease in their family are more likely to develop it themselves, suggesting it partly has a genetic basis
53
How does smoking affect your chance of developing coronary heart disease?
nicotine in cigarettes will cause blood vessels to become narrower, increasing blood pressure which will cause the buildup of fat globules. if this occurs in the coronary artery, this will cause coronary heart disease
54
How does age affect your chance of developing coronary heart disease?
the risk of developing coronary heart disease increases as you get older
55
How does gender affect your chance of developing coronary heart disease?
males are more likely to develop coronary heart disease than females
56
What factors can effect your chance of developing coronary heart disease? (6)
- a poor diet
- stress
- genetic predisposition
- smoking
- gender
- age
57
In what 3 ways can you reduce the risk of developing coronary heart disease?
Quit smoking
Reduce animal fats in diet and eat more fruits and vegetables
Exercise regularly
58
How does reducing animal fats help to reduce the risk of developing coronary heart disease?
this will reduce cholesterol levels in the blood and help with weight loss if overweight
59
How does exercising regularly help to reduce the risk of developing coronary heart disease?
this will help with weight loss, decrease blood pressure and cholesterol levels and help reduce stress
60
In what ways can coronary heart disease be treated?
- Aspirin can be taken daily to reduce the risk of blood clots forming in arteries
- surgical methods such as angioplasty or a coronary bypass
61
1. During angioplasty, what is inserted and where?
A narrow catheter (tube) is threaded through the groin up to the blocked vessel
62
2. What is in the catheter and what does this do?
| angioplasty
A tiny balloon inserted into the catheter is pushed up to the blocked vessel and then inflated
This flattens the plaque against the wall of the artery, clearing the blockage
63
3. What is inserted to keep the artery clear?
| angioplasty
To keep the artery clear, a stent (piece of metal / plastic mesh) is also inserted which pushes against the wall of the artery
64
4. What may the stent be coated in?
| angioplasty
Sometimes the stent is coated with a drug that slowly releases medication to prevent further build-up of plaque
65
How is a coronary bypass surgery carried out?
A piece of blood vessel is taken from the patient’s leg, arm, or chest and used to create a new passage for the flow of blood to the cardiac muscle, bypassing the blocked area
66
What gives rise to the name of the surgery?
| coronary bypass surgery
The number of bypass grafts gives rise to the name of the surgery, so a ‘triple heart bypass’ would mean three new bypass grafts being attached
67
What is the difference between the pressure and direction of the blood carried by veins and arteries?
A- Carry blood at high pressure away from the heart
| V - Carry blood at low pressure towards the heart
68
What is the difference between the type of blood carried by veins and arteries?
A - Carry oxygenated blood (other than the pulmonary artery)
| V - Carry deoxygenated blood (other than the pulmonary vein)
69
What is the difference between the walls of veins and arteries?
A - Have thick muscular walls containing elastic fibres
| V - Have thin walls
70
What is the difference between the lumen of veins and arteries?
A - Have a narrow lumen
| V - Have a large lumen
71
What is the difference between the flow of blood carried by veins and arteries?
A - Speed of flow is fast
| V - Speed of flow is slow
72
What is one feature that veins have that arteries do not?
VALVES
73
What are 5 features of capillaries?
Carry blood at low pressure within tissues
Carry both oxygenated and deoxygenated blood
Have walls that are one cell thick
Have ‘leaky’ walls
Speed of flow is slow
74
How is an artery adapted to its function?
Have thick muscular walls containing elastic fibres to withstand high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
Have a narrow lumen to maintain high pressure
75
How is a vein adapted to its function?
Have a large lumen as blood pressure is low
| Contain valves to prevent the back-flow of blood as it is under low pressure
76
How is a capillary adapted to its function?
Have walls that are one cell thick so that substances can easily diffuse in and out of them
Have ‘leaky’ walls so that blood plasma can leak out and form tissue fluid surrounding cells
77
What happens to arteries as they get further away from the heart?
As arteries divide more as they get further away from the heart, they get narrower
78
What are arterioles?
The narrow vessels that connect arteries to capillaries are called arterioles
79
What happens to veins as they get further away from the heart?
Veins also get narrower the further away they are from the heart
80
What are venules?
The narrow vessels that connect capillaries to veins are called venules
81
What does the cardiovascular system sometimes need to do during exercise or when we are hot?
Sometimes the cardiovascular system needs to redistribute the blood to specific areas of the body
82
Why does the cardiovascular system needs to redistribute the blood to specific areas of the body during exercise?
More of it goes to the working muscles and less of it goes to other body organs such as the digestive system
83
Why does the cardiovascular system needs to redistribute the blood to specific areas of the body when we are hot?
When we are hot, more blood flows through the surface of the skin and when we are cold less blood flows through the surface of the skin
84
What is the redirection of blood flow caused by?
This redirection of blood flow is caused by the use of a vascular shunt vessel
85
What can shunt vessels do?
The shunt vessels can open or close to control the amount of blood flowing to a specific area
86
What is the vein carrying blood from the lungs to the heart called?
Pulmonary vein
87
What is the artery carrying blood from the heart to the body called?
aorta
88
What is the artery carrying blood from the heart to the liver called?
hepatic artery
89
What is the artery carrying blood from the heart to the gut (intestines) called?
Mesenteric artery
90
What is the artery carrying blood from the heart to the kidneys called?
renal artery
91
What is the vein carrying blood from the kidneys to the heart called?
renal vein
92
What is the vein carrying blood from the liver to the heart called?
hepatic vein
93
What is the vein carrying blood from the body to the heart called?
vena cava
94
What is the vein carrying blood from the gut (intestines) to the liver called?
Hepatic portal vein
95
What is the artery carrying blood from the heart to the lungs called?
pulmonary artery
96
What can happen as a result of the capillary walls being so thin?
The walls of the capillaries are so thin that water, dissolved solutes and dissolved gases easily leak out of them / pass through the walls from the plasma into the tissue fluid surrounding the cells
97
What is the purpose of the tissue fluid?
Cells exchange materials (such as water, oxygen, glucose, carbon dioxide, mineral ions) across their cell membranes with the tissue fluid surrounding them by diffusion, osmosis or active transport
98
What happens to the excess fluid surrounding the capillaries?
More fluid leaks out of the capillaries than is returned to them, and this excess of leaked fluid surrounding the capillaries then passes into the lymphatic system, becoming lymph fluid
99
What is the lymphatic system?
The lymphatic system is formed from a series of tubes which flow from tissues back to the heart
100
What does the lymph system connect with? Why?
It connects with the blood system near to the heart, where lymph fluid is returned to the blood plasma
101
What are lymph nodes?
Lymph nodes are small clusters of lymphatic tissue found throughout the lymphatic system, especially in the neck and armpits
102
What is found in lymph nodes?
Large numbers of lymphocytes are found in lymph nodes
103
What produces lymphocytes?
Tissues associated with the lymphatic system, such as bone marrow, produce these lymphocytes
104
What is the role of lymphocytes?
Lymphocytes play an important role in defending the body against infection
105
What does blood contain? (4)
Blood consists of red blood cells, white blood cells, platelets and plasma
106
What is the structure of red blood cells?
Biconcave discs containing no nucleus but plenty of the protein haemoglobin
107
What is the structure of white blood cells?
Large cells containing a big nucleus, different types have slightly different structures and functions
108
What is the structure of platelets?
Fragments of cells
109
What is the structure of plasma?
straw coloured liquid
110
What is the role of white blood cells?
White blood cells are part of the body’s immune system, defending against infection by pathogenic microorganisms
111
What are the two main types of white blood cells?
There are two main types, phagocytes and lymphocytes
112
What do phagocytes do?
Carry out phagocytosis by engulfing and digesting pathogens
113
1. How do phagocytes detect pathogens?
Phagocytes have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
114
2. What do phagocytes do once they encounter a pathogenic cell?
Once they encounter the pathogenic cell, they will engulf it and release digestive enzymes to digest it
115
How can phagocytes be recognised? (using a microscope)
They can be easily recognised under the microscope by their multi-lobed nucleus and their granular cytoplasm
116
What do lymphocytes do?
Produce antibodies to destroy pathogenic cells and antitoxins to neutralise toxins released by pathogens
117
How can lymphocytes be recognised? (using a microscope)
They can easily be recognised under the microscope by their large round nucleus which takes up nearly the whole cell and their clear, non-granular cytoplasm
118
Why is plasma important?
Plasma is important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
119
What is the role of red blood cells?
Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
120
In what form do red blood cells transport oxygen?
They carry the oxygen in the form of oxyhaemoglobin
121
What is the role of white blood cells?
White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production
122
What is the role of platelets?
Platelets are fragments of cells which are involved in blood clotting and forming scabs where skin has been cut or punctured
123
Why is blood clotting important?
Blood clotting prevents continued / significant blood loss from wounds
124
Why is scab formation important?
Scab formation seals the wound with an insoluble patch that prevents entry of microorganisms that could cause infection
125
For how long do scabs remain?
It remains in place until new skin has grown underneath it, sealing the skin again
126
1. What happens when the skin is broken?
| blood clotting
When the skin is broken (i.e. there is a wound) platelets arrive to stop the bleeding
127
2. Where do the series of reactions involved in blood clotting take place?
A series of reactions occur within the blood plasma
128
3. What types of chemicals do platelets release? What do these chemicals do?
Platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin and form an insoluble mesh across the wound, trapping red blood cells and therefore forming a clot
129
4. What happens to the clot once the process is over?
The clot eventually dries and develops into a scab to protect the wound from bacteria entering
