Adaptations for transport: animals

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What is an example that has an open circulatory system
Insect
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Where is fluid pumped in an insect

HINT: what shape is the heart
Relatively low pressure from one main long dorsal (top) tube shaped heart running length of body
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What is the fluid, haemolymph, in insects used for

Where does the haemolymph go when the heart relaxes
-Bathes tissues directly enabling exchange of substances
-Flows freely through body cavity

-Sucked slowly back to heart
-Low pressure + no control over direction of circulation
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Why is there no respiratory pigment in the insect haemolymph
Oxygen diffuses directly to respiring cells through tracheal system
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What are three examples of animals with a closed circulatory system
Mammals

Fish

Earthworms
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In mammals and fish, what does the blood circulate in

What kind of pump is the heart and what two things does it push blood at
Fully enclosed system of tubes (blood vessels)

Muscular pump
High pressure and rapid flow rate
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In mammals and fish are the organs in direct contact with the blood

Does the blood contain a respiratory pigment
No - are bathed in tissue fluid

Yes - carries oxygen(haemoglobin)
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In an earthworm, what two vessels run the length of the body

What hearts are in an earthworm

Do earthworms contain a respiratory pigment
Dorsal(above) and ventral(below)

5 pairs of pseudo(false)hearts

Yes - carries oxygen
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What is the blood pressure in both circulatory systems

Is there direct contact with the organs in both
OPEN: low pressure as not in vessels
CLOSED: high pressure as in vessels

OPEN: haemolymph bathes directly as it leaves circulatory system
CLOSED: blood in the blood vessels so never has direct contact with organs
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Where is blood contained in both systems
OPEN: pumped from long dorsal tubular shaped heart into spaces in the body cavity
CLOSED: blood always within vessels including arteries, veins, capillaries
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What is the respiratory pigment in both systems
OPEN: o2 reaches gas exchange surface via tracheal system so no pigment is needed to carry oxygen round body
CLOSED: o2 diffuses into blood and carried round body in blood bound to the hb(pigment)
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Where is oxygen transported in both systems
OPEN: o2 transported directly to tissues
CLOSED: o2 transported from lungs to heart and then to capillaries in body tissues
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What is an example of an animal with a single closed circulatory system

What does this mean
fish

Blood passes through heart once in one complete circulation
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What is an example of an animal with a double closed circulatory system

What does this mean
mammal

Blood passes through heart twice in one complete circulation

Has to move blood at same rate to pulmonary(closer to heart) as the systemic circulation (further from heart)
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What are the two circuits in a double closed circulation
Pulmonary-lungs and closer to heart
{all blood vessels involved in transporting blood between heart + lungs}

Systemic-body and further from heart
{all blood vessels involved in transporting blood from heart to rest of the body and back to heart excluding
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What are some advantages of double circulation over single circulation
Maintains high blood pressure in systemic circulation-increased rate of flow to tissues=increased oxygen supply for aerobic respiration

Lower pressure in pulmonary circulation-decreases flow rate to lungs reducing build up of tissue fluid in lungs reduci
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What are more advantages
Rapid circulation in systemic-in order to move blood large distance the left side of the heart requires thick muscle to generate high pressure and a faster circulation
Thinner muscle on right side pumps blood a shorter distance from heart to lungs
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Final advantage
Oxygenated and deoxygenated blood kept seperate - maintains steep conc gradient for 02 at tissues + co2 in lungs for efficient gas exchange
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What is an artery

What is a vein

What is a capillary
Transports blood away from heart - oxygenated excluding pulmonary

Transport blood to heart - deoxygenated excluding pulmonary

Smallest vessels allowing exchange of substances with body cells
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What do arterioles require

What is the role of the valves
thick layer of smooth muscle to regulate blood flow in vasoconstiction(less bloodflow) and vasodilation(more bloodflow)

prevent backflow of blood contractions of skeletal muscles + help return blood to heart
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Structure of artery
Thick outer layer of collagen fibres

Thick inner layer of muscle + elastin

Endothelium (one cell thick)

Narrow lumen

1-25mm
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Structure of vein
Collagen fibres

Elastic fibres + smooth muscle

Endothelium

Wide lumen

1-15mm
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Structure of capillary
Endothelium

5-10um
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What is the endothelium

Why is it an important feature
Most innermost layer and provides smooth lining

Reduces friction to reduce resistance to blood flow

Provides short diffusion distance (one cell thick in capillaries)
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What is the elastic fibres and smooth muscle

Smooth muscle function in arteries

Elastic fibre function in arteries
Middle layer, in arteries the layer is much thicker than in veins

withstands high blood pressure produced by hearts pumping action and can contract/relax directing bloodflow

Stretch+recoil maintaining high blood pressure
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What are collagen fibres and what are they resistant to
Outer layer of vessels and are resistant to over stretching
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What does the veins wide diameter lumen mean for the delivery of blood

Why do veins have thin walls

What does the thin muscle layer being able to be compressed easily allow
can deliver large volumes of blood back to heart

pressure inside lower due to further distance from heart

contracting skeletal muscles to squeeze veins and push blood up towards heart
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What do pocket valves ensure

How do these work

Why do veins above heart have no valves
Blood flows in one direction - to heart

-blood tries to flow back
-blood fills pocket above valve
-forces valve shut

gravity draws blood down to heart
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Why do arteries have thick layer of smooth muscle

Why do arteries have thick layer of elastic fibres

What does the arterioles being able to adjust their diameter mean
withstand high blood pressure

maintain high blood pressure

vary blood supply to capillary bed
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What is the one thing capillaries consist of

What are the capillary walls permeable to and what do the thin walls allow for

What does the narrow lumen restrict and what does thus allow more time for
endothelium and one cell thick

water+dissolved substances e.g 02 and allow for efficient exchange of materials and gases as shorter diffusion path and larger cross sectional area

restricts blood flow =more time for exchange of materials at tissues
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What is the function of the tendinous chords in the heart
When the ventricles contract the increases blood pressure causes the atrioventricular valves to close simultaenously preventing backflow of blood into atria

prevent valves inverting into the atria
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what two ways can ethical issues be considered when using animals for dissection
treated humanely

ensure no animals are killed needlessly
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what is function of aorta

function of vena cavae

function of pulmonary artery
largest artery, transports blood from heart to body

two veins that carry deoxygenated blood to heart from upper and lower parts of body

transport deoxygenated blood from heart to lungs for gas exchange
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function of pulonary veins

function of coronary arteries

function of coronary veins
transport oxygenated blood from lungs back to heart

supply heart cells with oxygenated blood and glucose

remove deoxygenated blood from cardiac muscle
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what happens in the first stage of the cardiac cycle : atrial systole (contraction)
both atria contract at the same time forcing tricuspid valve and picuspid valves open.

blood flows from atria(high pressure) into ventricle(lower pressure)

blood backflow into veins prevented by closure of valves in veins
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what happens in the second stage of the cardiac cycle : ventricular systole
(contraction)
ventricles contract at same time forcing blood up+out heart(high pressure) into arteries(low pressure)

bicuspid+tricuspid valves close due to pressure from blood in ventricles preventing blood backflow into atria

semilunar valves in aorta and pulonary a
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what happens in third stage of cardiac cycle: diastole (relaxation)
atria+ventricles relax making low pressure in heart

semilunar valves close due to blood in aorta(high pressure) trying to flow backwards into ventricles(low pressure)

blood flows from veins(high pressure)through atria into ventricles
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why does the left ventricle have a thicker muscular wall than the right ventricle
produces higher pressure as left ventricle pumps blood to body

to move blood such large distance, right ventricle pumps blood to lungs which is a shorter distance from heart so needs lower pressure
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when do the atrio ventricular valves
(tri+bi cuspid valves) open

when do they close
pressure of blood in atria is greater than in ventricles

pressure of blood in ventrcles greater than in atria
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when do semi lunar valves open

when do they close
pressure in ventricles is greater than aorta and pulmonary artery

pressure in arteries greater than ventricles and blood tries to flow backwards
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In arteries where does the highest pressure occur

What does the rythmic rise and fall correspond to

What maintains this pressure

Why does the pressure here never fall to 0
aorta/arteries closest to heart

ventricular contraction and relaxation

elastic fibres

semi lunar valves close
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in arterioles what is the friction with that causes a progressive drop in pressure

what two feautures do arterioles have causing this drop

what does the pressure depend on
friction with vessel walls

large total cross sectional area
relatively narrow lumen

dilated or constricted
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what two things reduce the flow rate and decrease pressure in the capillaries

what is forced out into tissues to further this

why is the mean pressure in lung capillary lower than muscle capillary
small diamater, friciton with walls

some fluid

reduced flow rate allowing more time for gas exchange
less tissue fluid produced
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why is the return flow to the heart in veins non-rythmic

why does the low pressure here not fall to zero
veins too far from heart to be affected by contraction and reelaxation

massaging effect of skeletal muscles
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what does the heart muscle being myogenic mean
heartbeat initiated from within muscle itself and not due to external stimulation
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1) in controlling heartbeat,
-where is the sino atriul node (SAN)
-what is it made of
-what does it act as
wall of right atrium

region of specialised cardiac fibres

pacemaker
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2) where does the wave of depolarisation arise

what kind of impulse is this

what happens once this impulse has arrised
at the SAN

electrical

nerve impulses spread over the two atria causing them to contract simultaneously - right then left
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3) what prevents the electrical stimulation spreading to the ventricles

what does this act as

what musnt the muscles of the venticles start to do until the muscles of the atria have finished contracting
thin layer of connective tissue

layer of electrical insulation

start to contract
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4) what does the short delay allow for

where does the nerve impulse reach after the short delay

where does the lie

where does this pass the impulse to
time for ventricles to fill up with blood

atrio ventricular node (AVN)

between two atria

ventricles
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5) where is the impulse passed from the AVN

what does the bundle branch into

where are these located

where do they carry the wave of depolirisation
down bundle of his to apex of heart

purkinje fibres

ventricular walls

upwards through ventricle muscle
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6) what does the impulse cause the cardiac muscle in each ventricle to do

where does this force blood
contract simultaneously from apex upwards

up and out of the heart
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what is an ECG

what do electrodes placed on the skin detect

where are these electrical signals then shown

what is the record produced by this
electrocardiogram

electrical activity that spreads through heart during cardiac cycle

cathode ray osccilloscope/chart recorder

ECG
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What does the P wave on an ECG show

What does QRS wave show

What does t wave represent
first part of trace shows depolirisation of atria in atrial systole

spread of depolirisation through ventricles = ventricular systole

relaxation + repolirisation of ventricular muscle in ventricular diastole
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What does the length of a PR interval on an ECG indicate

Why is the QRS wave bigger than the P wave
transit time for the electrical signal to travel from the SAN to the ventricles

ventricles have more muscle than the atria so amplitude is bigger than the P wave
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How do you calculate heart rate from an ECG

How do you calculate cardiac output
length of cycle = time taken between equivalent points on the trace

heart rate x stroke volume
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Other cards in this set

Card 2

Front

Where is fluid pumped in an insect

HINT: what shape is the heart

Back

Relatively low pressure from one main long dorsal (top) tube shaped heart running length of body

Card 3

Front

What is the fluid, haemolymph, in insects used for

Where does the haemolymph go when the heart relaxes

Back

Preview of the front of card 3

Card 4

Front

Why is there no respiratory pigment in the insect haemolymph

Back

Preview of the front of card 4

Card 5

Front

What are three examples of animals with a closed circulatory system

Back

Preview of the front of card 5
View more cards

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