transport in animals Flashcards
why do large organisms require a transport system
size-In single-celled organisms, cytoplasm v close to its environment. Diffusion will supply enough O2 and nutrients to keep the cells alive and active. multicellular organisms have several layers of cells, so there’s a longer diffusion pathway. Diffusion is too slow to enable a sufficient supply to the innermost cells
SA:V-When organisms have a large SA:V their SA is large enough to supply all the cells with sufficient O2
V increases more quickly than SA so the SA:V is smaller in larger organisms so less SA available for exchange of materials/ROD too slow as DD too great.
metabolic activiy-multicellular org are more Metabolically active so they use up glucose+ o2 faster +organisms need good supplies of O2 and nutrients to supply energy for movement + warmth n co2 from resp removed as quickly so the exchange of substances need to be efficient
Why does a greater level of activity in an organism increase demand for glucose and oxygen?
more activity requires more energy
more energy requires more aerobic respiration
which requires more reactants (oxygen and glucose)
Why does a greater volume of an organism mean a greater demand?
greater volume means greater number of cells
each cell requires energy
so demand for energy/glucose/oxygen increases
what’s circulatory system n what’s the diff types
organ system that permits blood to circulate.
open, closed,single,double
what’s open n closed circulatory system?
open=a transport system with a heart but with few vessels to contain the transport medium-blood can diffuse out of vessels n flow freely thru body cavity eg insects
closed=the transport medium/blood is enclosed n confined in vessels and does not come into contact with the cells of the body eg fish+mammals
what’s single and double circulatory system,
a circulatory system where the blood flows through the heart once during a complete circuit of the body
a circulatory system where the blood flows through the heart twice during a complete circuit of the body
What is the transport medium in insects called?
haemolymph
What does haemolymph carry and what does it not carry?
Carries food and waste products, does not carry oxygen or carbon dioxide
What are some disadvantages of an open circulatory system?
Why is the single circulatory system inefficient?
Why are double closed circulatory systems very efficient?
Inefficient, cannot be controlled well
making it harder to direct blood to specific areas when needed.
Lower Bp=: Blood doesn’t flow as quickly, = less efficient at delivering O2 and nutrients.
Oxygen may not be delivered as efficiently to tissues,
as blood is not fully contained in vessels, it can leak into body cavities, reducing efficiency.
Blood pressure drops sharply after it leaves gills, directly to the body, = reduces pressure and slows down blood flow, making it harder to deliver oxygen and nutrients effectively.
The closed circulatory system = blood doesn’t leak into tissues, so efficient delivery of nutrients and removal of metabolic waste.
blood circulates faster = the circuits are specialized for particular tasks (oxygenating the blood or distributing it to tissues), = more efficient transport of gases+nutrients,
seperates oxygenated n deoxygenated this separation = higher level of O2 to tissues, works at higher pressure, allowing blood to move faster + effectively through body.
How is blood pumped around the body in insects?
Heart is a tube-like structure travelling along the length of the body, with a series of valves along it. It pumps blood to the head, after which it flows back towards the rest of the body and drains back into the heart
What is an example of an animal with a closed single circulatory system? (one where blood passes through heart once on each circuit of the body)
Fish n annelid worms
What is an example of an animal with a closed double circulatory system?
birds n mammals
ow is blood pumped around a fish’s body?
Deoxygenated blood from the body enters the heart’s one atrium, then moves into ventricle. It is then pumped to gills, becomes oxygenated, then completes circuit of body before returning to heart
How do fish counteract the problem of having low blood pressure once blood leaves the gills?
By having their heart placed near their gills
Why are fish able to be highly active despite having a single closed circulatory system?
overall energy needs are lower compared to mammals or birds,
they continually move water over their gills =ensures a steady supply of oxygen-rich blood
it has highly specialized gills that extract O2 efficiently from water. This allows them to oxygenate their blood, even with lower bp.
function of arteries,veins n capillaries
To carry blood away from the heart under high pressure
To carry blood back to the heart under low pressure
To allow substances to be exchanged between blood and tissue fluid
adaptations of arteries why they help
thick, elastic wall,=to help stretch and recoil as the heart beats helping maintain high pressures.
inner lining(endothelium) folded to allow it to maintain high pressure
all arteries carry oxygenated blood except pulmonary which takes DO to lungs.
smooth muscle on walls = contracts to make the artery smaller/ relaxes to make it wider,to send more blood to areas that need it, like muscles in exercise and control n withstand BP.
narrow lumen-creates more resistance to blood flow,to control it + helps push blood through the arteries at higher pressure.
It has collagen to provide structure and support limiting stretch
what do arteries branch into
arterioles-much smaller, have smooth muscle layer tootles elastic tissue.smooth muscle =same function as arteries
what do arterioles branch into
capillaries
adaptations of capillaries why they help
Very thin walls (up to 1 cell thick)= allows for quick diffusion of gases w short diffusion distance between the blood + surrounding tissues.
narrow lumen-= resistance to blood slowing down blood flow for exchange of gases
very branched=inc SA =helps inc gaseous exchange and ensures that every cell gets what it needs.
what do capillaries connect to
venues-have v thin walls w muscle cells and they join tg to form veins
adaptations of veins why they help
Wide lumen=bp in veins much slower so don’t need to control blood flow. thin walls, =blood low bp=don’t need thick, strong walls to withstand high pressure. more flexible and can expand to store more blood. acts as a blood reservoir, holding a larger vol of blood when needed.(collagen helps support this)
Elastic fibres (allow veins to able to stretch), =easier for blood to flow back to heart, w aid of muscle contractions n valves that prevent backflow.
veins carry DO blood(o2 used up in body cells)except for pulmonary =takes OB to heart from lungs
order for blood flow through blood vessels in?
Artery—>Arteriole—>Capillaries—>Venules—>Veins
what is blood
tissue that transports many vital components around organism=
-o2+co2 to n from cells and lungs
-Nitrogenous waste from cells to excretory organs
-hormones
-cells n antibodies involved in immune response
-platelets to damaged areas
-nutrients(AA+electrolytes)
How is blood helped to keep flowing in veins?
muscle contraction(skeletal) and valves to prevent back flow of blood
What percentage of blood is made up of plasma?what’s the rest made up of
55%
erythrocytes,platelets and white blood cells(leukocytes)
functions of blood other than as a transport medium
maintains homeostasis=body temp n acts as a buffer to minimise pH changes
what’s tissue fluid
fluid that surrounds cells in tissues=made from substances that leave blood plasma(o2,h20 n nutrients)
cells take in o2 and nutrients from tissue fluid and release metabolic waste into it.
in a capillary bed,substnaces move out of capillaries into tissue fluid by pressure filtration.
why doesn’t tissue fluid contain red blood cells or big proteins
too large to be pushed out through capillary walls
how does pressure filtration work?(how is tissue fluid formed first) (1)
at start of capillary bed, nearest arteries, hydrostatic pressure(from blood flowing in w small diameter) inside capillaries is greater than hydrostatic pressure in tissue fluid. difference in hydrostatic pressure forces fluid out of capillaries(three small gaps in C walls) into the space around cells forming tissue fluid.
how does pressure filtration work?(how is tissue fluid formed first)
as fluid leaves, HS pressure reduces in capillaries, so HS pressure is much lower at end of capillary bed nearest to venules.
As water leaves the capillaries conc of plasma proteins n rbc’s in capillaries inc(too large to leave so they stay) = water potential decreases.
Plasma proteins in capillaries generate oncotic pressure-at venule end of capillary bed there’s a high oncotic pressure and a low water potential.As water potential in capillaries lower than water potential in tissue fluid, water re-enters capillaries (by osmosis down water potential gradient) at venule end by osmosis.
no more water forced out as HS pressure dropped too low as sm water pushed out. waste products (cells released) dissolved in water are reabsorbed back into blood -to be excreted by body.
what are some of the waste products reabsorbed
co2 n urea
does all of tissue fluid re enter capillaries at venue end
no some excess fluid left.
this gets returned to blood via lymphatic system.(drainage system made up of lymph cells) smallest lymph vessels=capillaries.
fluid enters lymph vessels.once inside its called lymph.
valves in lymph vessels stop lymph from going backwards and contraction of nearby skeletal muscles help Lymph gradually moves towards main lymph vessels in thorax where its returned to blood near heart.
why is there excess fluid left
equilibriums reached in capillaries (as osmosis is movement of water particles from an area of high WP to low WP) which Is. reached hone water moves back
how is hydrostatic pressure and oncotic pressure exerted
pressure fluid exerts on wall of its container(blood on capillary=higher at arteriole end than venule
oncotic=water leaving capillary via osmosis whilst proteins stay in Changing water potential.
what do lymph nodes contain
lymphocytes-help immune system
what does tissue fluid contain when it becomes lymph
little o2,glucose/proteins,some co2
where red blood cells found where are platelets found where are wbcs found
where are water n dissolved solutes found
Blood only as they are too large to pass through gaps in capillary walls
found in blood, too large to pass thru gaps in capillary walls
in lymph nodes which help immune system
blood plasma, interstitial fluid, and inside cells throughout the body.
draw a diagram of human heart including names of chambers valves n vessels
Phone
1)what is the valve between aorta n left ventricle
2)what’s valve between pulmonary vein and left ventricle
3)what’s the valve between pulmonary artery n right ventricle
4)valve between right atrium and right ventricle
SL valve
av valve
SL valve
av valve
compare left v and right v
The left ventricle pumps oxygenated blood through the aorta and into the systemic circulation, = needs to travel a longer distance and reach all the tissues in the body. = requires higher pressure to overcome the resistance in the arteries
+ to contract with more force. walls help w pressure.
the right ventricle pumps blood to the lungs, which is a shorter distance and much lower pressure, so it doesn’t need to be as thick or muscular.
what do the atrioventricular valves n SL valves do?
link atria to ventricles and
link ventricles to pulmonary artery=all stop backflow of blood.
they only open one way(if they’re open or closed depends on pressure of chambers)if there’s higher pressure behind valve its forced open but if pressure higher in front of valve its forced shut.flow of blood is undirectional.
how to dissect a heart
1)wear apron and gloves
2)place heart on dissecting tray
3)look on outside and identify 4) main vessels attached to it, feel inside.arteries thicker than veins
5)use clean scalpel and cut along lines to look inside each ventricle.measure n record thickness of each ventricle wall.
6.cut open atria and look inside and see if their walls are thicker than ventricle walls.
7.find av valves then sl valves.look at structure and see how they only open way.draw sketch of valves n insides of atria n ventricles
8)wash hands n disinfect after
what is the cardiac cycle
Consists of dytoles and systoles that keeps blood circulating.voljmes of an and v change as contract n relax altering pressure. Causes valves to open n close . Lub sound caused by AV valves closing . Dub sound caused by SL valves closing
first two steps of cardiac cycle
1)ATRIAL SYSTOLE=ventricles are relaxed.atria contract, decreasing vol of chambers and inc pressure inside chambers.this pressure behind av valves pushes them open pushing blood blood into ventricles thru em.slight inc in ventricular pressure and chamber volume as ventricle receive the ejected blood from contracting atria
2)VENTRICULAR SYSTOLE
=atria relax.ventricles contract(dec their vol) inc their pressure.pressure becomes higher in the ventricles than the atria which forces AV valves shut to prevent back flow.pressure in ventricles also higher than in aorta and pulmonary artery which forces open SL valves and bloods forced out of arteries.
what happens in the last part of cardiac cycle
CARDIAC DIASTOLE- The ventricles and the atria both relax. The higher pressure in the pulmonary artery and aorta closes the SL valves to prevent back-flow into the ventricles.
Blood returns to the heart and the
atria fill again due to the higher
pressure in the vena cava and pulmonary vein. In turn this starts
to increase the pressure of the
atria. As the ventricles continue to relax, their pressure falls below the pressure of the atria and so the AV valves open. This allows blood to flow passively (without being pushed by atrial contraction) into the ventricles from the atria.
The atria contract, and the whole
AV valves forced open n process begins again.
explain this pressure graph
(see phone)
at x=
at y=
at w =
at z=
what does diastole and systole mean and givehen order left atrium and ventricle go through it
Diastole: phase when the heart muscle relaxes. the heart chambers (a + v) fill with blood in prep for next contraction.
Systole: This is the phase when the heart muscle contracts. During systole, the ventricles contract to pump blood out of the heart
left a-systole,diastole diastole
left v-diastole systole diastole
what separates deoxygenated and oxygenated blood?
septum
What order does blood flow through the heart in?
DO blood enters the right atrium from the body through the superior and inferior vena cava.
Blood flows from the right atrium into the right V through the tricuspid valve.
The right v pumps the DO blood through the pulmonary valve into the pulmonary artery, + carries to the lungs for oxygenation.
OXY blood returns from the lungs through the pulm veins into the left A.
Blood flows from the left a into the left v through the bicuspid (mitral) valve.
The left v then pumps the oxy blood through the aortic valve into aorta, distributes it throughout the body.
what are arteries on surface of heart called
the coronary arteries. They supply oxy blood to heart muscle (myocardium), ensuring that the heart itself gets the oxygen and nutrients it needs to function effectively. The two main coronary arteries are:
what are tendinous cord
white stringy inelastic cords that attach av valves to papillary muscles within ventricle preventing from collapsing into atria during ventricular contraction
what’s apex
pushing blood out of the LV into aorta to the rest of the body.
name for minimum blood pressure
diastolic blood pressure. This shows lowest pressure in the arteries, which happens when the heart is not contracting and blood flow is more steady.
what’s systolic pressure
occurs during systole happens when the LV contracts + pumps blood into the aorta and rest of the body. contraction generates the highest pressure in the arteries,
how to calculate cardiac output
HR x SV
hr=no of beats per min
sv=vol of blood pumped during each heartbeat in cm3
cO
sv. HR
cardiac muscle is myogenic what’s this mean
it can contract n relax without receiving signals from nerves.this patterns of contractions controls the regular heartbeat.
how does the control of heartbeat work
1)sinoatrialnode(pacemaker setting rhythm of cardiac cycle) initiates a wave of excitation
2)wave of excitation spreads across atria which becomes depolarised-causing a contraction-atrial systole.
3)the wave of excitation can’t spread down to the ventricles due to collagen layer which is non conducting.
4)av node detects + delays wave of excitation+conducts it down bundle of his to apex of heart.
TIME DELAY BETWEEN 3 + 4 =allows atria to fully empty the ventricles to fill up before contracting=max pressure=inc efficiency
5)bundle of hiss(in septum)separates into purkyne fibres, the waves of excitation spread upwards causing depolarisation of ventricles(vent systole) from bottom up.ensures all blood ejected into arteries.
Why can’t signals from the SAN pass directly to the ventricles?
due to collagen layer which is non conducting
what can electrical activity be captured on and how could a doctor check someones heart function?
electrocardiographs=records when heart muscle depolarises and polarises using electrodes placed on chest.
what does a normal ecg look like?
describe the points
p caused by contraction(depolarisation)of the atria.
qrs complex-contraction(depolarisation)of ventricles.
T wave is due to relaxation(repolarisation) of the ventricles
height indicates how much electrical charge is passing through the heart-bigger wave=more electrical charge=stronger contractions
how to calculate heart rate
60/time taken for 1 heartbeat
if someone has tachycardia what that mean
if someone has bradycardia what that mean
and what these look like
heart beat too fast-120bpm=shows heart isn’t pumping blood efficiently
heatbeat too slow-50bpm.below 60 is bad gng.
in trained athletes might be normal but others =electrical activity gone wrong(smth preventing impulses from SAN from being passed on properly)
PHONE
what’s an ectopic heartbeat
extra heartbeat that interrupts regular rhythmn
caused by earlier contraction of atria than in previous he’s(p wave earlier)can be caused by early contraction of v too=you would see taller n wider qrs complex sometimes w out p wave.
occasionally it wouldn’t affect healthy person
what’s fibrillation
really irregular heartbeat.A+V completely lose rhyme n stop contracting properly.can result in chest pain, fainting,lack of pulse, and death xx
describe role of haemoglobin
Carries 02 around body in rbc.
It’s a conjugated protein so it has a protein with a prosthetic group.
Each of the 4 polypeptide( 2 alpha and 2 beta) chains in each chain has a prosthetic group called haem.
Haem group contains iron which oxygen binds to (gives haemoglobin its red colour) and bindings easier due to tertiary structure changing.
Water soluble so dissolved in plasma.
each molecule of haemoglobin can carry 4 o2 molecules.
how is oxyhemoglobin formed
in the lungs o2 joins to iron in haemoglobin=to form oxyhemoglobin.reversible reaction as near the body cells o2 leaves oxyhemoglobin and it turns back to haemoglobin.when o2 molecule joins to haemoglobin=association/loading.when o2 leaves oxyhemoglobin=dissasociation/unloading.
equation for association and disassociation for o2 and po2
load
Hb+4O2———->HbO8
<———-
unload
Do oxygen molecules bind to haemoglobin loosely or tightly?
This allows hemoglobin to pick up oxygen in the lungs, where oxygen levels are high, and release it in tissues, where oxygen levels are low.
What is positive cooperativity?
When the first o2 molecule binds to hemoglobin, it causes a conformational change in protein, making it easier for the next o2 molecule to bind.
As more o2 molecules bind, the affinity of hemoglobin for o2 increases, allowing it to pick up oxygen more readily in the lungs.
describe haemoglobin affinity of o2
haemoglobin affinity for o2 varies depending on conditions in-one condition is partial pressure of o2.(po2)
What occurs at high partial pressures of oxygen?
the greater the conc of dissolved oxygen in cells, the higher the partial pressure.As PO2 increases haemoglobin affinity for o2 inc too:oxygen loads onto haemoglobin to form oxyhemoglobin where there’s a high conc of o2
What occurs at low partial pressures of oxygen?
the lower the conc of dissolved o2 in cells the lower the PO2.As PO2 decreases haemoglobin affinity for o2 dec too:oxyhaemoglobin unloads its o2 where there’s a lower po2.
What is the partial pressure of oxygen in the alveoli?
oxygen enters blood capillaries at alveoli in lungs.alveoli has a high po2 so oxygen loads onto haemoglobin to form oxyhemoglobin. so high i2 conc,high po2,high affinity,O2 loads.
What is the partial pressure of oxygen in the respiring tissues ?
when cells respire they use up o2-lowering po2
RBC’s deliver HBO8 to respiring tissues where it unloads its o2.haemoglobin then returns to lungs to pick up more o2.
so low o2 conc.low po2,low affinity,o2 unloads
what does an oxygen dissociation curve show
how saturated the haemoglobin is with o2 at any given partial pressure.The affinity of haemoglobin for o2 affects how sat haemoglobin is
explain the graph
at high partial pressures haemoglobin will almost be completely saturated with o2 soo at high pp haemoglobin has a higher affinity for o2 so will load up lots of o2.at lower pp we only have ab 50% saturation so haemoglobin doesn’t have as high affinity so it doesn’t attract oxygen well and unload o2 in those regions.
why is it an advantage at low partial pressures there’s a lower affinity
haemoglobin unloading o2 at sites where oxygens needed(with a low po2) this would be sites which are respiring as they’re using up the o2 in resp
explain what happens at the low partial pressure
not high saturation=due to positive cooperative binding =first o2 to bind to o2,but when they do it makes it easier for others due to conformational change, that’s why its a steep curve as after first its much easier for saturation but as it becomes more saturated it gets harder for o2 molecules to join explained by shallow bits on graph.
diff between foetal haemoglobin and adult haemoglobin
foetal haemoglobin has higher affinities for o2 as its blood is better at absorbing o2 than mothers blood. =important as foetus gets o2 from mums blood across placenta, by time blood reaches placenta, saturations decreased as some o2 used up by mothers body.
Placenta has low po2 so adult oxyhemoglobin will unload its o2.so for foetus to get enough o2 to survive, it has a higher affinity to o2 than adult and becomes more saturated in lower po2 than adult
if foetal haemoglobin and adult haemolgin had same saturation what happens
blood wouldn’t be saturated enough
oxygen wouldn’t move efficiently from mother to fetus, potentially leading to inadequate oxygen supply for the developing fetus.
draw and explain foetal and adult haemoglobin graph
at low po2,in placenta foetus has high affinity for o2 so o2 loads
at low po2 in placenta adult haemoglobin has low affinity for o2 so o2 unloads.
what’s the Bohr effect
Another condition that affects haemoglobin affinity for o2.
The effect of co2.when there’s lots of co2 present=it forms carbonic acid within water in blood. so if there’s lots of respiration occuring=more co2=more acidic blood from carbonic acid =so oxyhemoglobin curve shifts to the right
if curve shifts left what does it indicate
lowest po2 of co2 in alveoli(where co2 diffuses out)increased affinity and uploads more oxygen
if curve shifts right what that mean
so haemoglobin’s affinity for oxygen decreased with higher partial pressure for co2. in respiring tissues(where co2 made, dissolving in blood so more low ph= causes
conformational change of haemoglobin causes affinitiy to decrease unloading o2 more readily.(particularly in tissues w resp as they need it)
so even at same partial pressure of o2 if you have co2 present, haemoglobin affinity for o2 decreases with a lower saturation so more o2 unloaded.
what catalyses the formation of carbonic acid when co2 from respiring tissues reacts w water in blood
carbonic anhydrase
where does the rest of the CO2 go
10% binds directly to haemoglobin and taken directly to lungs.
carbonic acid dissociates into H+ ions and HCO3- ions.increase in H ions causes oxyhemoglobin to unload its o2 thru cone change so haemoglobin can take up the h+ ions.this makes haemoglobinic acid.(this stops H= ions from inc acidity of cell).HCO3- ions diffuse out of RBC’s and transported in blood plasma.
to compensate for loss of HCO3- what happens
chloride ions diffuse into red blood cells from plasma.this is the chloride shift and it maintains the balance of charge between blood cell n plasma.
when the blood reaches the lungs the low PCO2 causes some of HCO3- ions and H+ ions to recombine into co2 n water.the CO2 then diffuses into alveoli and is breathed out.
How much carbon dioxide is converted to hydrogen carbonate (HCO3-) ions and transported in the erythrocytes’ cystoplasm?
70%
CO₂ from tissues enters the bloodstream and can be carried in three ways:
Dissolved directly in plasma
Bound to hemoglobin
Converted to bicarbonate
What is the equation for the conversion of carbon dioxide to hydrogen carbonate ions?
co2+h20——-h2co3+h++hco3-
carb anhy
