transport in animals Flashcards
1
Q
how does the level of activity of an organism, affect it’s need for a transport system
A
- active animals, need more energy and therefore, a faster rate of respiration
2
Q
state 4 characteristics of a small simple organism
A
- large SA:VOL ratio
- rely on simple diffusion
- unicellular
- low metabolic rate
3
Q
state 3 characteristics of a multicellular organisms
A
- more cells, so have a higher metabolic rate
- smaller SA:VOL ratio
- have a specialised transport system, due to large diffusion distances
4
Q
Why do large multicellular organism need a transport system?
A
- Supplies all cells with oxygen and glucose.
- Remove metabolic waste, e.g., carbon dioxide, urea, etc.
5
Q
why do small animals not need transport systems
A
due to short diffusion distances meaning that they can rely on simple diffusion.
6
Q
why do larger animals, need transport systems
A
due to large diffusion distance and small surface area to volume ratio.
7
Q
what are the basic components, of a circulatory system
(state 6)
A
- circulating fluid
- pumping device
- blood vessels
- valves
- input from an exchange surface
- circuits
8
Q
what do most organism have
A
most organism have blood, and insects have haemolymph, to carry key ions (glucose, oxygen, etc)
9
Q
a closed system
A
is where blood, is enclosed in vessels at all times
10
Q
what is an open circulatory system
A
is where fluid is not enclosed in blood vessels and slowly moves at a low pressure in the cavity
11
Q
open and closed system, similarities and differences
A
12
Q
what organism are closed systems found in
A
fish, birds, mammals, amphibians
13
Q
what organisms are open systems found in
A
in insects
14
Q
what is single circulation
A
where blood is passing through the heart once
15
Q
what is a double circulation
A
where blood is passing through the heart twice
16
Q
The disadvantages of single circulation in fish, are that
A
pressure drops
17
Q
Advantage of double circulation in mammals are
A
- maintains high blood pressure
- different pressure created, in different body parts, allowing high metabolic demands to be met
18
Q
do all arteries contain oxygenated blood
A
false (PULMONARY)
19
Q
which vessel, supplies the cardiac muscle with oxygenated blood
A
left coronary artery
20
Q
all veins lead into the heart
A
true
21
Q
systemic circulation transports blood between the heart and the lungs
A
false (pulmonary)
22
Q
in a double circulatory system, blood flows though the heart twice in every complete circuit of the body
A
true
23
Q
birds have a single circulatory system
A
False
24
Q
what is the structure of the heart
A
- 4 chambers
- 2 thin walled atria
- 2 thick walled ventricles
- the heart is formed of mainly cardiac muscle myocardium
- the heart has an inner epithelial lining called the endocardium and an outer covering called the pericardium
25
what is the role of atrioventricular valves (tricuspid and bicuspid)
prevents backflow. The valve, tendons and papillary muscle, prevent the valves turning inside out.
26
what happens during diastole
- blood under low pressure enters the left and right atria from the pulmonary and vena cava respectively. the atria fill with blood and gradually become distended
- initially the bi/tricuspid valves are shut but as the atria fill with blood the pressure in the atria increase and eventually exceeds that of the ventricles and causes the valves to open
27
what happens in atrial systole
- the atria contract simultaneously, pressure in the atria rises and so more blood flows from the atria to the ventricles. Contraction of the atrial walls also has the effect of sealing off the vena cava and pulmonary veins ->
- this stops backflow, into the veins, as the pressure in the atria increases, the atria only have thin walls, as they only need to create enough pressure, to pump blood a short distance to the ventricles
28
ventricular systole
- atria relax. ventricles contract and the pressure increases and soon exceeds the pressure, in the aorta and pulmonary artery. so the semilunar valves are forced open.
- pressure in the ventricles is higher than in the atria and so the AV valves close (lub sound) and back flow is prevented, then blood is expelled though the aorta and pulmonary arteries
29
why is the heart considered to be myogenic
cardiac muscle is self sustaining i.e. it initiates its own heart beat
30
ventricular and atrial diastole
- high pressure develops, in both arteries and this forces blood back towards the ventricles - the semi lunar valves close, preventing backflow and (dub sound) then they start filling again.
31
heart rate
32
heart rate
the number of times the heart beats per minute
33
stroke volume
the volume of blood pumped by each ventricle with each heart beat ( averaging 70ml per beat in adults at rest )
34
cardiac output
the volume of blood, ejected from the left or right ventricle into aorta or pulmonary artery per minute.
35
1. The sinoatrial node, acts as a pacemaker for the heart
the SAN, consists of a small number of specialised cardiac fibres.
- initiates a wave of excitation
- wave of excitation spreads across atrial walls, causing simultaneous contraction
36
2. wave of excitation reaches the atrioventricular node (AVN) which is a second group of specialised cells near the base of the atria.
AVN - delays contraction of the ventricles by 0.1 (seconds), which allows atria to finish contracting -> provides a route for transmission of electrical impulse from the atria to the ventricles
37
3. The AV node is continuous with the bundle of his which are modified cardiac fibres running down the (interventricular) septum. They fan out over the wall of the ventricles forming a network of fibres called Purkinje fibres.
impulses are spread and conducted by the Purkinje fibres, from the apex of the heart + over the ventricles. ventricles contract from apex up -> forces blood, up + out of the heart.
38
what are the 3 advantages of co - ordinating the heart beat
1. ensures that systole of the atria, followed by the ventricles.
2. allows blood to pass through the heart at at regular rate.
3. ensure, that ventricular systole does not occur, until the atria have finished contracting -> 0.1 (second) delay.
39
what is an Electrocardiogram (state 2 possible explanations)
- Electrocardiography can be used to monitor and investigate the electrical activity of the heart
- Electrodes that are capable of detecting electric signals are placed on the skin
- These electrodes produce an electrocardiogram (ECG)
- An ECG shows a number of distinctive electrical waves produced by the activity of the heart
- A healthy heart produces a distinctive shape in an ECG
40
what is the P wave
Caused by the depolarisation of the atria, which results in atrial contraction (systole)
41
what is the QRS complex
- Caused by the depolarisation of the ventricles, which results in ventricular contraction (systole)
- This is the largest wave because the ventricles have the largest muscle mass
42
what is the T wave
Caused by the repolarisation of the ventricles, which results in ventricular relaxation (diastole)
43
what is the Q - T interval
the contraction time of the ventricles
44
what is the T - P interval
filling time i.e. the time between the end of one cardiac cycle and the beginning of the next
45
why is it, that when the SAN sends out a electrical impulse, that contraction does not occur in the ventricles
- due to the deep tissue, at the bottom of the atria, stopping the impulse reaching the ventricles, otherwise it would cause a decrease in stroke volume, because atria wouldn't be fully emptied in time.
46
what is bradycardia
- this is where there is a normal PQRST phase, but there is a large T-P phase (filling time)
- it is where a person has a resting heart rate that is below 60BPM
47
what is tachycardiac
- an increase in hr, which can be normal when stressed or exercising
- tachycardiac, is a medical issue, where HR rises to 120 BPM without a reason.
the T-P interval (filling time) is know much shorter due to the heart pumping more frequently but it is pumping the same volume of blood.
48
what is atrial fibrillation
- normal QRS complex, but many small peaks in between QRS complex, showing atrial fibrillation
- usually HR of around 100- 175 BPM
- beat is erratic
- increased risk of heart attacks, + strokes
49
what is ventricular fibrillation
- heart beat is unregulated + uncoordinated
- no distinct PQRST peaks
- ventricles contracting, but they are not filled, so very low volume of blood is pumped
- treatment = defibrillation
50
what is an epitonic heart beat
- heart beats too early followed by a pause
- extra beats out of normal rhythm, followed by a longer gap
51
know the table on page 37 of the exchange and transport booklet 2
52
know the blood flow graph
53
what are the 4 ways to maintain blood flow
- pumping action of the heart
- contraction of skeletal muscles during normal movements squeezes on the thin walled veins. This increases the pressure of the blood inside.
- valves ensure that this pressure directs the blood back to the heart.
- inspiratory movements (breathing in) reduces pressure in the thorax, this helps to create a pressure gradient to draw the blood towards the heart which is in the thorax. expiratory pressure changes mean pressure increases in veins outside the heart speeding blood flow into the heart.
54
know the blood mind map, that is in the booklet (transport and exchange 2)
55
what is hydrostatic pressure
blood pressure inside the capillaries, caused by fluid pushing against the sides of the vessels
56
what is oncotic pressure
the net pressure that drives reabsorption - the movement of fluid from the tissue fluid back into the capillaries - is called osmotic pressure (sometimes referred to as oncotic pressure). it is due to the presence of plasma proteins in the blood and the absence of these in the tissue fluid.
57
what is the purpose of blood transport
- oxygen to respiring cells and carbon dioxide from respiring cells.
- digested food from the small intestine
- chemical messages (hormones)
- cells and antibodies involved in immunity
58
how is the tissue fluid formed
1. Blood flows into the capillary at high hydrostatic pressure in the arteriole end.
2. The high pressure forces fluid through the gaps in the cells of the capillary where nutrients and oxygen dissolve into it.
3. This fluid with the dissolved oxygen and nutrients seep in between the cells of the tissue — it is now tissues fluid.
59
How does fluid return to the blood? [3 MARKS]
1. The hydrostatic pressure of the blood is pushed back by the hydrostatic pressure of the fluid which pushes the fluid back into the capillaries.
2. The water potential of the tissue fluid is higher than the blood
3. Therefore water moves back into the blood from the fluid by osmosis
60
how is lymph formed (4 marks)
Lymph is formed when intersistal fluid comes into contact with the blood.
Most of the fluid leaves the blood vessels and goes into the tissue fluid however some goes into the blood vessels whilst the rest enters the lymphatic system where is transported to the veins to mix with blood and become lymph.
61
State a difference between tissue fluid and blood [2 MARKS]
Tissue fluid does not contain plasma proteins such as albumin because they're too large to pass through the capillary walls.
62
What component does tissue fluid only have a few of? [1 MARK]
White blood cells
63
what is the movement of lymph (state 5 things)
- skeletal muscle contraction
- high hydrostatic pressure
- Uni - directional movement
- valves, prevent backflow
- thin layer of smooth muscle, in the lymph vessel walls
64
state the 4 functions of the lymph
- return excess tissue fluid, (10%) back into blood circulation
- returns plasma proteins to circulation
- glycerol and fatty acids, to be absorbed into the blood stream
- prevents pathogens entering circulation
65
know the table of differences, between blood, tissue fluid and Lymph
66
what is the partial pressure of oxygen and carbon dioxide in the atmosphere
- 160 (O2)
- 0.3 (C)
67
what is the partial pressure of oxygen and carbon dioxide in alveolar air
- 104 (O2)
- 40 (C)
68
what is the partial pressure of oxygen and carbon dioxide in the pulmonary vein/systemic arteries.
- 104 (O2)
- 40 (C)
69
what is the partial pressure of oxygen and carbon dioxide in the pulmonary arteries/systemic veins
- 40 (O2)
- 45 (C)
70
what is carboxyhemoglobin
Carboxyhemoglobin (COHb) is a stable complex of carbon monoxide that forms in red blood cells when carbon monoxide is inhaled.
71
which vessel, supplies the cardiac muscle with oxygenated blood
the coronary arteries
72
why is the heart considered to be myogenic
cardiac muscle is self sustaining i.e. it initiates its own heart beat
73
why is the heart considered to be myogenic
cardiac muscle is self sustaining i.e. it initiates its own heart beat
74
why is the heart considered to be myogenic
cardiac muscle is self sustaining i.e. it initiates its own heart beat
75
why is the heart considered to be myogenic
cardiac muscle is self sustaining i.e. it initiates its own heart beat
76
how do we work out heart rate on a electrocardiogram
- by working out the distance between the P waves, then dividing 60 by that number
77
what can athletic training do
increase the stroke volume of the heart, thus meaning the body can have a lower heart rate in order to meet it's needed cardiac output
78
cardiac output equations
79
what is the partial pressure of gases definition
- the pressure, excreted by a given gas, in a mixture and is directly related, to the concentration of that gas in the mixture.
80
what is the other name for red blood cells
erythrocytes
81
what are the 3 adaptation of erythrocytes, for transporting oxygen
- a biconcave structure, to give it a large surface area to volume ratio
- contains around 300 million molecules, of the oxygen carrying protein haemoglobin
- no nucleus, to allow an increased volume of the erythrocyte to carry oxygen
82
why is Haemoglobin a conjugated protein
because its has the haem prosthetic group
83
how many molecules of oxygen, can each Fe2+ in the Haem groups combine with
- 1 molecule of oxygen per Haem group
- 4 haem groups
- meaning that 4 oxygen molecules, can bind with one molecule of Haemoglobin
84
what do we call haemoglobin when it binds with oxygen
oxyhaemoglobin
85
why do we say the partial pressure of oxygen, instead of the concentration
because it is a gas
86
what happens, once one oxygen molecule is bound
the affinity of haemoglobin for oxygen increase, making it far easier for oxygen to bind to the haemoglobin molecule
87
what percentage of carbon dioxide, is dissolved directly in the blood plasma
5%
88
what percentage of carbon dioxide is transported in the form of hydrogen carbonate ions, in the blood plasma
85%
89
what percentage of carbon dioxide, combines directly with Haemoglobin, to form carbaminohaemoglobin
10%
90
what is carboxyhaemoglobin
CO (carbon monoxide) binds with haemoglobin (irreversibly)
91
what is the chloride shift
the movement of chloride ions into red blood cells that occurs when hydrogen carbonate ions are formed. Hydrogen carbonate ions are formed by the following process. Carbon dioxide diffuses into red blood cells.
92
what do arteries branch into
arterioles
93
where do arterioles carry the blood to
the capillaries
94
what is the difference, between foetal haemoglobin and normal haemoglobin
- it has a higher affinity for oxygen, at a lower partial pressure, compared to that of adult haemoglobin
- this means that it can maximise it's uptake of oxygen from the mothers blood
