Adaptions for transport in animals

Question 1

open circulatory systems

Answer 1

blood does not move around the body in blood vessels but it bathes the tissues directly while held in a cavity the haemocoel

Question 2

insects-open blood system

Answer 2

long dorsal (top) tube shaped heart, running the length of the body.
pumps blood out at low pressure into the haemocoel, where materials are exchanged between the blood and body cells
blood returns slowly to the heart and the open circulation starts again

Question 3

oxygen- open blood system in insects

Answer 3

oxygen diffuses to the tissues from the tracheoles so the blood does not transport oxygen and has no respiratory pigment

Question 4

closed circulatory systems

Answer 4

the blood move in blood vessels
single circulation
double circulation

Question 5

single circulation

Answer 5

the blood moves through the heart once in its passage around the body

Question 6

single circulation in fish

Answer 6

ventricle of the heart pumps deoxygenated blood to the gills, where the well developed capillary network reduces its pressure.
oxygenated blood is carried to the tissues and from there, deoxygenated blood returns to the atrium of the heart
blood moves to the ventricle and the circulation starts again

Question 7

single circulation- earthworm
blood moves forward

Answer 7

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

Question 8

double circulation

Answer 8

blood passes through the heart twice in its circuit around the body eg. mammals

Question 9

double circulation in mammals

Answer 9

blood is pumped by a muscular heart at high pressure , giving rapid flow through blood vessels
blood pressure is reduced in the capilliaries of the lungs and and its pressure would be too low to make the circulation effiicent in the rest of the body
instead blood is returned to the heart, which raises its pressure again, to pump it tii the rest of the body
materials are then delivered quickly to the body cells

Question 10

insect
earthworm
fish
mammal

Answer 10

circulation type
closed
closed, single
closed, single
closed,double

respiratory pigment
none
yes
yes
yes

heart
Dorsal tube shaped
Pseudohearts
1 atrium and 1 ventricle
2 atria and 2 ventircles

Question 11

pulmonary circulation

Answer 11

serves the lungs
right side of hearty pumps deoxygenated blood to the lungs
oxygenated blood returns from the lungs to the left side of the heart

Question 12

systemic circulation

Answer 12

serves the body tissues
left side of the heart pumps the oxygentaed blood to the tissues
deoxygentaed blood from the body returns to the right side of the heart

Question 13

in each circuit

Answer 13

the blood passes through heart twice, once through the right side and once through the left side
double circulation of mammal is more efficient than the single circulation of a fish as the oxygenated blood can be pumped around the body at a higher pressure

Question 14

blood contents

Answer 14

made up of cells (45%)
and plasma (55%)

Question 15

plasma

Answer 15

pale yellow liquid
fluid component of the blood comprising water and solutes
blood - cells

Question 16

affinity

Answer 16

degree to which two molecules are attracted to each other

Question 17

cooperative binding
allows to

Answer 17

the increasing ease with which heamoglobin binds its second and third oxygen molecules, as the conformation of the heamogloblin molecule changes
allows haemogoblin to pick up oxygen very rapidly in the lungs

Question 18

oxygen dissociation curve

Hb binds

Answer 18

haemoglobin binds oxygen in the lungs, and realeases it in the respiring tissue
Oxygen + Haemoglobin = oxyhaemoglobin
4O2 + Hb = HbO8

Question 19

red blood cells

Answer 19

Erythocytes
red- contain pigment called haemoglobin
transports oxygen from the lungs to the respiring tissue
made in bone marrow, destroyed in the liver

Question 20

red blood cells- structure

Answer 20

biconcave discs- surface area is larger so more oxygen diffuses across the membrane
thin centre makes them look paler in the middle- reduces the diffusion distance making gas exchange faster

Question 21

red blood cells- no nucleus

Answer 21

more room for haemoglobin, maximising oxygen that can be carried

Question 22

to transport oxygen efficiently
associate and dissacssociate

Answer 22

haemoglobin must associate readily with oxygen where gas exchange takes place eg. alveoli and readily disassociate with oxygen at the respiring tissues eg. muscle

Question 23

haemogoblin- 4 haem groups
pp

Answer 23

each haem contains an ion of iron (Fe2+)
one oxygen can bind to each iron
first oxygen molecule that attaches changes the shape of Hb molecule- easier for the second molecules to attach
2nd oxygen molecule attaching changes shape again - easier 3rd
cooperative binding
3rd molecule doesnt change shape so it takes up a large increase in oxygen partial pressure to bind the fourth oxygen molecule.

Question 24

partial pressure of a gas

Answer 24

the pressure it would exert if it were only one present

Question 25

oxygen dissociation curve shows

Answer 25

- O2 affinity of haemogoblin is high at high partial pressures of oxygen and oxyhaemogoblin does not release its oxygen - oxygen affinity reduces as the partial ;pressure of oxygen decreases, and oxygen is readily released, meeting respiratory demands very small decrease in the oxygen partial pressure leads to lot of oxygen dissociating from haemogoblin

Question 26

if relationship between oxygen partial pressure and % saturation of haemogoblin with oxygen were linear HIGHER

Answer 26

At higher partial pressure of oxygen, haemogoblin oxygen affinity would be too low and so oxygen would be readily released and would not reach the respiring tissues

Question 27

if relationship between oxygen partial pressure and % saturation of haemogoblin with oxygen were linear LOWER

Answer 27

at lower partial pressure of oxygen, haemogoblins oxygen affinity would be too high and oxygen would not be released in respiring tissues, even at a low oxygen partial pressure

Question 28

Disassociation in the tissues

Answer 28

In the tissues the partial pressure of oxygen is about 2~4 kPa. At these low partial pressures of oxygen, haemoglobin has a lower affinity for oxygen. The haemoglobin offloads oxygen to the tissues.

Question 29

Dissociation in the lungs

Answer 29

In the lungs the partial pressure of oxygen is about 11 kPa. At these high partial pressures of oxygen, haemoglobin has a higher affinity for oxygen. The haemoglobin becomes saturated with oxygen.

Question 30

Disassociation of mother placental tissues

Answer 30

In the placental tissues the partial pressure of oxygen is about 2~4 kPa. The mothers haemoglobin has a low affinity for oxygen. The haemoglobin more readily offloads oxygen to the tissues.

Question 31

Disassociation of foetus

Answer 31

At the same partial pressure of oxygen, about 2~4 kPa. The fetal haemoglobin has a higher affinity for oxygen. The fetal haemoglobin picks up the oxygen offloaded by the mother.

Question 32

Transport of oxygen in other animals

Answer 32

Dissociation curve is to the left of an adults The haemoglobin has a higher affinity for oxygen than adult human. This means it loads or saturates with oxygen very readily at very low partial pressures of oxygen. They then release the oxygen as extremely low p.p. of oxygen.

Question 33

lugworm

Answer 33

In the sand the partial pressure of oxygen is very low, about 2~4 kPa. The lugworm has haemoglobin/mogloblin which has an even higher affinity for oxygen than normal human haemoglobin. The haemoglobin more readily saturates with oxygen to the tissues.

Question 34

llama

Answer 34

lives in an area of high altitude of 2-4kPa where the O2 partial pressure is very low It's haemoglobin has a high affinity for oxygen at all oxygen partial pressure than humans loads oxygen more readily in the lungs and releases oxygen when oxygen partial pressure is low

Question 35

Bohr effect

Answer 35

The movement of oxygen dissociation curve to the right at a higher partial pressure of carbon dioxide, because at a given oxygen partial pressure, haemoglobin has a lower affinity for oxygen Accounts for the unloading of oxygen from oxyhemoglobin in respiring tissues where partial pressure carbon dioxide is high and oxygen is needed

Question 36

Effects of carbon dioxide concentration

Answer 36

If the carbon dioxide concentration increases, haemoglobin releases oxygen more readily At any oxygen partial pressure the haemoglobin is less saturated with oxygen so the data points on the dissociation curve are lower

Question 37

CO2 curve- tissues

Answer 37

In the tissues the partial pressure of oxygen is about 2~4 kPa. The p.p. of carbon dioxide is high due to tissue respiration. The haemoglobin more readily offloads oxygen to the tissues.

Question 38

summary of CO2 curve

Answer 38

When the partial pressure of carbon dioxide is high haemoglobin has a lower affinity for oxygen so it is less efficient at loading oxygen and more efficient at unloading it

Question 39

transport of Carbon dioxide

Answer 39

Transported in: - in solution in the plasma (aprox 5 percent) - in HCO3- (aprox 85) - Bound to haemoglobin as carbamino haemoglobin (aprox 10)

Question 40

Reactions in red blood cell 1- transport of CO2

Answer 40

Carbon dioxide in the blood diffuses into the red blood cell

Question 41

Reactions in red blood cell 2- transport of CO2

Answer 41

Carbonic anhydrase catalyses the combination of carbon dioxide with water, making carbonic acid

Question 42

Reactions in blood cell 3- transport of CO2

Answer 42

Carbonic acid dissociates into H + and HCO3- io s

Question 43

reactions in red blood cell 4- transport of CO2

Answer 43

HC03- ions diffuse out of blood cell into the plasma

Question 44

reactions in red blood cell 5- transport of CO2

Answer 44

To balance the outflow of negative ions and maintain electrochemical neutrality, chloride ions diffuse into the red blood cell from the plasma Chloride shift

Question 45

chloride shift

Answer 45

Diffusion of chloride ions from the plasma into the red blood cell, preserve an electrical neutrality

Question 46

reactions in red blood cell 6- transport of CO2

Answer 46

H plus ions cause oxyhemoglobin to dissociate into oxygen and haemoglobin The H plus ions combined with the haemoglobin to make hemoglobinic acid HHb Removes hydrogen ions and so pH of red blood cell doesn't fall

Question 47

Reactions in red blood cell 7- transport of CO2

Answer 47

Oxygen diffuses out of the red blood cell into the tissues

Question 48

more respiration

Answer 48

means more carbon dioxide is present so more oxyhemoglobin dissociates and provides oxygen to respiring cells

Question 49

tunica initima

Answer 49

innermost layer, single layer of endothelium in some arteries, it is supported by elastin-rich collagen smooth lining, reducing friction and produces minimal resistance to blood flow

Question 50

tunica media

Answer 50

middle layer contains elastic fibres and smooth muscle thicker in arteries- elastic fibres allow stretching to accommodate changes in blood flow and pressure as blood is pumped from the heart At a certain point, stretched elastic fibres recoil, pushing blood on through the artery: felt as a pulse, maintains blood pressure Contraction of smooth muscle regulates blood flow and maintains blood pressure as blood is transported further from the heart

Question 51

tunica externa

Answer 51

outer layer Contains collagen fibres and elastic fibres Resist overstretching and provide strength

Question 52

Arteries

Answer 52

Carry blood away from the heart Thick muscular wars withstand blood's high pressure derived from the heart Arteries branch into smaller vessels called Arterioles that fever subdivide into capillaries

Question 53

capillaries

Answer 53

Form a vast network that penetrates all the tissues and organs of the body Blood from capillaries collect into venules which takes blood into the veins, who h return it to the heart

Question 54

Veins

Answer 54

larger diameter lumen and thinner walls with less muscle than arteries- Blood pressure and flow rate are lower Veins above the heart, blood returns to the heart by gravity - moves through other veins by pressure from surrounding muscles

Question 55

semi lunar valves

Answer 55

Veins have these along their length ensuring flow in one direction and preventing back flow;

Question 56

cappilaries- thin walls

Answer 56

Only one layer of endothelium on a basement membrane Pores between the cells can make the capillary walls permeable to water and solutes So exchange of materials between the blood and tissues takes place

Question 57

Capillaries - small diameter

Answer 57

Rate of blood flow slows down Many capillaries in a capillary bed which reduces the rate of blood flow so that there is plenty of time for the exchange of materials with the surrounding tissue fluid

Question 58

Myogenic contraction

Answer 58

The heartbeat is initiated within the muscle cells themselves, and is not dependent on nervous or hormonal simulation

Question 59

The heart

Answer 59

Two pumps - oxygenated blood and deoxygenated blood Atria and ventricles seperate oxygenated and deoxygenated blood

Question 60

Heart- cardiac muscle

Answer 60

Cardiac muscle is a specialised tissue with myogenic contraction Means it can contract and relax rhythmically of its own accord

Question 61

Pumping blood

Answer 61

1. The oxygenated blood enters the right atrium through superior and inferior vena cava 2. atria contract and this forces the atrio-ventricular valves open and blood flows into the right ventricles. 3. contraction of the ventricles causes the atrio-ventricular valves to close and semi-lunar valves to open thus allowing blood to leave the right ventricle through the left pulmonary artery to lungs. 4. Oxygenated blood enters the left atrium through the left pulminary veins 5. Atrium contracts and left atrial ventricular valve opens allowing blood into the left ventricle 6. Contraction of the septum closes valves and open semi lunar valves to let the blood up and out of the aorta to the rest of the body

Question 62

atrial systole

Answer 62

Atrium walls contract and blood pressure in the atria increases pushing blood through the left and right atrial ventricular valves down into the ventricles which are relaxed

Question 63

Ventricular systole

Answer 63

Ventricle walls contract and increase blood pressure in the ventricles Forces blood up through semi lunar valves out of the heart into pulmonary artery and aorta Blood cannot flow back from ventricles into atria because atria ventricular valves are closed by the rise in ventricular pressure Pulmonary artery carries deoxygenated blood to the lungs and the aorta carries oxygenated blood to the rest of the body

Question 64

Diastole

Answer 64

atria and ventricles relax, elastic recoil of the heart lowers the pressure inside the heart chambers and blood is drawn from the arteries and veins thus causing semilunar valves in the aorta and pulmonary arteries to close, preventing backflow of blood.

Question 65

heartbeat

Answer 65

Two sides of the heart work together - atria contract at the same time followed by ventricles contracting together. Contraction and relaxation of the whole heart is a heartbeat

Question 66

when a chamber contracts

Answer 66

It is emptied of blood, when it relaxes it fills with blood again

Question 67

atria walls

Answer 67

They have little muscle as blood only has to go to the ventricles Ventricle walls contain more muscle and generate more pressure as they have to send the blood further, either to the lungs or body

Question 68

left ventricle- thicker muscular wall

Answer 68

Than right ventricle as it has to pump the blood all round the body whereas right ventricle only has the pump blood to the lungs

Question 69

valves

Answer 69

Valves prevent backflow of blood Atrio-ventricular valves, Semi Lunar valves at the base of the aorta and pulmonary artery and semi lunar valves in veins all operate by closing under high blood pressure prevent him blood flowing backwards

Question 70

Adaptation of capillaries for the exchange of materials

Answer 70

Exchange between blood and body cells happen in the capillaries - Thin permeable walls - Provide a large service area for exchange of materials - Blood flows vary slowly through capillaries allowing time for exchange of materials

Question 71

tissue fluid

Answer 71

Fluid from the plasma is forced through the capillary walls and (as tissue fluid) bathes the cells supplying them with solutes Tissue fluid removes waste made by cells Diffusion of solutes in and out of capillaries relates to blood hydrostatic pressure and solid pressure

Question 72

Atrial end of capillary bed 1 blood is under pressure

Answer 72

1. Blood is under pressure from pumping of heart and muscle contraction in artery and arteriole walls. High hydrostatic pressure pushes liquid outwards from capillary to spaces between surrounding cells

Question 73

Atrial end of capillary bed 2 plasma

Answer 73

2. Plasma is a solution and its low solute potential ( Due to colloidal proteins) tends to pull water back into capillary by osmosis

Question 74

Atrial end of cappillary bed 3 H>O

Answer 74

Hydrostatic pressure is greater than plasma-solute potential so water and solutes are forced out thru cappilary walls to the spaces between cells

Question 75

Atrial end of cappillary bed 4

Answer 75

Solutes are used during cell metabolism so the concentrations in and around the cell is low but in blood is higher. This favours the fusion from the capillaries to the tissue fluid.

Question 76

At the venous end of capillary bed 1 H<

Answer 76

1. Blood hydrostatic pressure is lower than at the arterial end because its volume has been reduced by fluid loss and because friction with capillary wars resist its flow

Question 77

At the venous end of capillary bed 2 plasma proteins

Answer 77

2. Plasma proteins are more concentrated in blood because so much water has been lost. Solute potential of remaining plasma is more negative. Osmotic force pulling water inwards is greater than hydrostatic force pushing water outwards so water passes back into capillaries by osmosis

Question 78

At the venous end of capillary bed 3 co2 and wastes

Answer 78

3. Tissue fluid surrounding cells pick up carbon dioxide and other wastes, which diffuses down a concentration gradient from cells and into capillaries where they are less concentrated

Question 79

At the venous end of capillary bed 4

Answer 79

4. Not all fluid passes back into capillaries. 10% drains into blindly ending lymph capillaries of lymphatic system. Most of lymph fluid eventually returns to venous system through thoracic duct which empties into the left subclavian vein above the heart

Question 80

Features of plasma site Associated cells Respiratory gases Nutrients protein molecules Water potential

Answer 80

site- blood vessels Associated cells- erythrocytes, granulocytes, lymphocytes Respiratory gases- more O2, less CO2 Nutrients- more Have Large protein molecules Water potential- lower

Question 81

Feature of tissue fluid and lymph site Associated cells Respiratory gases Nutrients protein molecules Water potential

Answer 81

site- Surrounding body cells, lymph capillary vessel Associated cells - granulocytes, lymphocytes Respiratory gases - less O2, more CO2 Nutrients - fewer No large protein molecules Water potential - higher

Question 82

blood pressure aorta

Answer 82

The blood pressure is highest in the aorta and large arteries. It shows the greatest rhythmic fluctuation due to ventricular contractions.

Question 83

blood pressure vessel walls

Answer 83

Friction between the blood and the vessel walls, & increased total surface area of vessels reduce the pressure (and speed) of the blood passes into the arterioles.

Question 84

blood pressure cappillaries

Answer 84

The surface area increases even more into the capillaries. This also reduces the blood pressure. The effects of the ventricles contractions are lost.

Question 85

Systole definition

Answer 85

Stage in the cardiac cycle in which heart muscle contracts

Question 86

diastole definition

Answer 86

Stage in the cardiac cycle in which heart muscles relax

Question 87

sino atrial node SAN

Answer 87

an area of the heart muscle in the right atrium that initiates a wave of electrical excitation across the atria, to generate contraction of the heart muscle. called pacemaker

Question 88

atrio ventricular node AVN

Answer 88

the only conducting area of the tissue in the wall of the heart between the atria and ventricles, through which electrical excitation, passes from the atria to the conducting tissue in the walls of the ventricles.

Question 89

control of a heartbeat 1

Answer 89

- wave of electrical stimulation arises at the SAN and spreads over both of the atria so they contract together

Question 90

Control of a heartbeat 2

Answer 90

Ventricles are electrically insulated from the atria by a thin layer of connective tissue- AVN Electrical stimulation only spreads to ventricles from this point. The AVN introduces a delay in transmission of electrical impulse Muscles of the ventricles do not start to contract until muscles of atria have finished contracting

Question 91

Control of heartbeat 3

Answer 91

AVN passes the excitation down the nerves of the bundle of hiss, Left and right bundle branches and to the apex of the heart Excitation is transmitted to Purkinje fibres into the ventricle walls which carry it upwards through the muscles of the ventricle walls

Question 92

Control a heartbeat

Answer 92

4. impulses cause the cardiac muscle in each ventricle to contract simultaneously, from the apex upwards 5. This pushes the blood up to the aorta and pulmonary artery and empties ventricles completely

Question 93

Electrocardiogram

Answer 93

Trace of the voltage changes produced by the heart, detected by electrodes on the skin

Question 94

Electrocardiogram - p-wave

Answer 94

Shows voltage change generated by SAN associated with the construction of Atria atria have less muscle than ventricles so P- waves are small Repolarisation of atria and they contract

Question 95

Electrocardiogram - QRS

Answer 95

QRS complex shows depolarisation and contractions of ventricles Ventricles have more muscle than atria so amplitude is bigger than P wave

Question 96

Electrocardiogram- T wave

Answer 96

Shows repolarisation of ventricle muscles causes the relaxation of venticles ST segment lasts from the end of the S wave to beginning of T wave

Question 97

Electrocardiogram- PR Interval

Answer 97

The time between the start of the P wave and the start of the QRS complex. It is the time taken for the excitation to move from the atria to the ventricle.

Question 98

Calculating heart rate

Answer 98

60/ length of cycle Length of cycle - time between equivalent points Eg. R to R

Question 99

Abnormal traces

Answer 99

- a person with atrial fibrillation has rapid heart rate and may lack a P wave - Person who had a heart attack may have a wide QRS complex - Person with enlarged ventricle walls may have QRS complex showing greater voltage change - Changes in height of ST segment and T wave may be related to insufficient blood being delivered to heart muscle eg. Atheroclerosis

Question 100

when can pp of oxygen drop below 3kpa

Answer 100

vigorous exercise high levels of aerobic respiration when oxygen is used/needed by muscle cells