Flashcards
human transport
Cards in this deck (78)
- 1whether or not there's a specialised transport medium or whether or not it's circulated by a pump depends on two factors...-surface area to volume ratio
-how active the organism is - 2what are arteries/arterioles/capillaries/venules/veins and what is their job?-arteries carry high pressure blood away from hear and into arterioles
-arterioles are narrower arteries that control blood flow from arteries into capillaries
-capillaries are tiny vessels that link arterioles to venules and is where gas exchange takes place in cells
-venules are small veins that connect capillaries to veins
-veins carry low pressure blood from capillaries back to heart - 3role of the coronary artery?takes blood to the heart tissue
- 4role of the pulmonary artery?takes blood away from heart towards lungs
- 5role of pulmonary vein?takes blood from lungs to heart
- 6role of aorta?-the main artery
-takes blood away from heart - 7role of vena cava?-main vein
-takes blood black to heart - 8role of hepatic artery?takes blood away from heart to the liver
- 9role of hepatic vein?takes blood away from liver back to the heart
- 10role of renal artery?takes blood to kidneys away from heart
- 11role of the renal vein?takes blood away from the kidneys back towards the heart
- 12structure of general blood cells?-tough outer layer (resists pressure changes from within and outside)
-muscle layer (contract +control blood flow)
-elastic layer (maintains blood pressure by stretching/recoiling)
-thin inner lining/endothelium (smooth=prevent friction, thin=allow diffusion)
-lumen (allow blood flow) - 13structure/function of artery?-thick muscle layer (maintain pressure)
-elastic layer (maintain pressure, stretch and recoil)
-thick walls (large to resist vessels bursting+maintain high pressure)
-no valves (except in arteries leaving the heart) as blood is under high pressure so doesn't flow backwards
-flat endothelial layer (smooth to reduce friction) - 14why do arteries have an elastic layer that's relatively thick compared to veins?-high pressure so blood reaches extremities of body
-elastic wall stretches at each heart beat (systole) + springs back when heart relaxes (diastole)
-helps maintain high blood pressure + smooth pressure surges created by heart beat - 15arteriole structure/function?-carry blood under lower pressure than arteries
-control flow of blood between arteries and capillaries
-muscle layer thicker than arteries (contraction of muscles allows constriction of lumen=restricts blood flow+controls movement into capillaries that supplies tissues with blood)
-elastic layer is thinner than arteries (blood pressure is lower) - 16veins/venuoles structure?-thinner muscle layer than arteries
-relatively thin elastic layer
-less thick walls compared to arteries
-valves - 17why have veins/venuoles got thinner muscle layer than arteries?-veins carry blood away from tissues (constriction and dilation cannot control flow of blood to tissues)
- 18why is the elastic layer in veins/venuoles thinner compared to arteries?-low pressure of blood in veins won't cause them to burst
-pressure is too low for them to create a recoil action - 19why are veins/venuoles walls less thick than arteries?-no need for thick wall since the pressure of the blood is too low to create any risk of bursting
-allows them to flatten easily, aiding the flow of blood within them + makes lumen wider (reduces friction in blood flow + ease blood flow) - 20why are there valves through out veins/venuoles?-prevent backflow of blood
-blood may flow backwards cus of the low pressure
-veins compress when body muscles contract + pressurises the blood within them
-valves ensure pressure directs blood towards the heart only - 21capillaries structure/function?-wall only consists of one cell thick endothelial lining (thin so diffusion distance is short)
-branched (large surface area for diffusion
-narrow diameter (allow them to permeate tissues so no cell is far from a capillary, keeping diffusion distance short)
-narrow lumen (red blood cells squeezed flat against side of capillary+brings them even closer to the cells that they supply oxygen with, reduces diffusion distance+slows rate of flow allowing more time for diffusion)
-spaces between lining cells that allow white blood cells to escape in order to deal with infections in tissues - 22what is tissue fluid/lymph?-watery liquid
-supplies cells with; glucose, amino acids, fatty acids, salt, O2
-also supplies cells with wastes it receives (CO2)
-bathes all cells/forms the environment in which they live
-formed from blood plasma
-constant environment
-doesn't contain proteins - 23describe hydrostatic pressure?-a pressure created at the arterial end of capillaries by the blood being pumped along arteries, then narrower arterioles, then narrower capillaries
-forces plasma out of capillary to create tissue fluid - 24what two factors opposes the hydrostatic pressure?-osmotic pressure
(blood has lower water potential due to plasma proteins which aren't in lymph
+ tends to draws water back into capillaries)
-hydrostatic pressure
(-causes net movement of plasma from capillaries) - 25what is ultrafiltration?-filtration under pressure
-when the hydrostatic pressure causes a net movement of plasma from capillaries
-forces small molecules (not cells/proteins) out of blood in capillaries - 26what happens once tissue fluid has exchanged metabolic materials with the cells it bathes?-it must return to the blood plasma via capillaries
-most tissue fluid returns to the blood plasma at the venous end of capillaries - 27how is the tissue fluid returned back to the circulatory system?1)the loss of tissue fluid from capillaries reduces the inside hydrostatic pressure
+ hydrostatic pressure is less than the tissue fluid
2)osmotic pressure resulting from low water potential inside the capillary draws water back into the capillaries
3) tissue fluid is forced back into the capillaries by the higher hydrostatic pressure at the venous end - 28what happens to the remaining tissue fluid?-returned to blood via lymphatic system
-flows into tiny lymphatics through tiny valves - 29what does the lymphatic system consist of?-tiny bind-ended vessels (lymphatics)
-found in nearly all tissues of the body
-lymphatics join up to form larger lymph vessels which gradually transport the lymph back to the large veins which run under the collar bones (subclavian veins) - 30describe valves in the lymphatics + oedema?- allow tissue fluid to flow in but not out
-wide enough to allow large molecules in
-proteins produced by cells cannot build up in the tissue fluid as it will cause a build up of tissue fluid (oedema) + causes death within 24 hours - 31how is the fluid in the lymphatic system moved by?-hydrostatic pressure- of tissue fluid that's left in capillaries
-contraction of body muscles- that squeeze the lymph vessels (valves in the lymph vessels ensure the fluid moves towards the heart) - 32what is haemoglobin?-globular protein
-Quaternary structure (more than one polypeptide chain joined together)
-iron 2+ ions
-2 alpha
-2 beta - 33primary structure of protein?-four polypeptide chains
-specific amino acid sequence
-each amino acid has an R group (determines protein shape) - 34secondary structure of protein?each polypeptide chain is collected into a helix (no beta sheets)
- 35tertiary structure-polypeptide chains folded into a precise shape held together by disuphide/ionic/hydrogen bonds between R groups
- 36Quaternary structure of proteins?-all 4 polypeptides are linked together by the same bonds holding protein in its tertiary structure to form spherical molecule
-each polypeptide is associated with a haem group (contaisn fe2+ ions) - 37role of haemoglobin?-transport 02 between lungs and respiring tissues
-each fe2+ ion within each haem group can combine with a single 02 molecule, meaning each human haemoglobin can carry four 02 molecules and become oxyhaemoglobin - 38where does oxygen loading occur?-lungs
-where partial pressure of O2 is high
-O2 diffuses from alveoli into red blood cells, where it combines with haemoglobin = oxyhaemoglobin
-high affinity
-high saturation percentage - 39where does O2 unloading occur?-red blood cells transport O2 around body, unloading at tissues where partial pressure of O2 is low
-low affinity
-low saturation percentage - 40to be efficient at transporting O2 between lungs and respiring tissues it must be able to:???-readily associate/bind with O2 at the surface where gas exchange takes place (lungs)
-haemoglobin which readily associates has a high affinity for O2
-readily dissociate O2 at the tissues requiring it
-haemoglobin which readily dissociates has a low affinity for O2 - 41what is meant by haemoglobin being saturated?-when 100% of O2 combinds with haemoglobin in a blood sample
- 42why isn't the oxygen dissociation curve not straight?-haemoglobin doesn't absorb oxygen evenly
-affinity of haemoglobin for oxygen changes as the partial pressure changes - 43when ppO is low, what is the saturation?-less haemoglobin is saturated
-haemoglobin has low affinity for O2 so does not readily associate with O2
-because the four polypeptide chains of haemoglobin are close together so is difficult for O2 to associate - 44when the ppO is high...-more haemoglobin is saturated
-haemo has high affinity for O2 so associates with O2 easily
-because one molecule of O2 has bound to one haem groups + polypeptide changes shape + loads the remaining three O2 easily (affinity increases) - 45why does the oxygen dissociation graph tails off at high concentrations?because the haemoglobin is almost saturated with O2
- 46Why is the ability of haemoglobin to change its affinity for O2 useful?-at the lungs where the ppO is high more haemoglobin is saturated
-this prevents blood moving around body where red blood cells aren't carrying max amount of O2
-at the cells where ppO is low, less haemoglobin is saturated
-this prevents blood moving back to lungs which is still loaded with O2 - 47the affinity of haemoglobin for oxygen reduces when...-PPO is low
-CO2 is present - 48what affect does an increased concentration of CO2 have on haemoglobin?-lower affinity
-haemoglobin more readily releases O2 - 49what is the bohr effect?-when a greater concentration of CO2 causes the haemoglobin to have a lower affinity to O2 and more readily releases its O2
-CO2 causes low PH
-the curve on a graph shifts to the right
-O2 is more readily released to respiring tissues
-shows less O2 is bound to haemoglobin - 50explain why CO2 reducing the affinity of haemoglobin for O2 useful at respiring tissues?-useful in rapidly respiring tissues as levels of CO2 is high
-affinity for O2 is reduced + low 02 concentration= O2 is readily unloaded from the haemoglobin into haemoglobin into the muscle cells
-therefore the max amount of O2 is unloaded at cells - 51explain why CO2 reducing the affinity of haemoglobin for O2 at the lungs useful?-CO2 is low because it diffuses across the alveolar surface and is exhaled
-affinity for O2 is increased + high conc of O2 = O2 is readily loaded by haemoglobin
-so max amount of O2 is loaded at lungs - 52levels of CO2, O2, affinity at respiring tissues?-high CO2
-low O2
-low affinity for O2
-O2 released - 53levels of CO2, O2, affinity at lungs?-low CO2
-high O2
-high affinity for O2
-O2 attached - 54how does high PP of CO2 reduce affinity of O2?because dissolved CO2 is acidic, and the low PH causes haemoglobin to change shape
- 55what occurs in the lungs in relation to haemoglobin?-CO2 constantly exhaled
-PH is raised due to low level of CO2
-the higher PH changes the shape of haemo + so its affinity for O2 increases
-haemoglobin associates with O2 to form oxyhaemoglobin - 56what occurs in the respiring tissues in relation to haemoglobin?-CO2 is produced by respiring cells
-CO2 is acidic in solution so lowers the PH of the blood in tissues
-the lower PH changes the shape of the haemo + so its affinity for O2 decreases
-oxyhaemoglobin releases O2 into respiring tissues to form haemoglobin - 57the more active a tissue is, the...?-more O2 is unloaded
-the lower the saturation of the haemoglobin when the blood returns to the heart - 58what part of the body does human haemoglobin become most saturated?-when it passes through the lungs
-carries 4 O2 molecules here - 59why will only 1 O2 molecule be released at a tissue with low respiration rate?because the O2 will not be used quickly in respiration, therefore the concentration will remain fairly high
- 60what will blood coming from tissues of a low respiratory rate consist of?-haemoglobin 75% saturated with O2
- 61how does CO2 change shape of haemoglobin?1) high respiration rate
2) tissues produce lots of CO2
3) pH lowered significantly
3) haemoglobin shape changed significantly
4) O2 unloaded readily + lower affinity for O2
5) more O2 available for respiration - 62characteristics of foetal haemoglobin?-high affinity for O2
-the curve is more to the left
-blood is more saturated
-combines to O2 more readily - 63why is the ppO fairly low in blood vessels of the placenta?-foetus is respiring to create energy it needs to make proteins+grow
-so mothers haemoglobin releases some of its O2 into placenta - 64describe conformational change?-1st O2 hard to pick up (slow increase on graph)
-shape is changed which makes haemoglobin easily pick up 2nd+3rd
-harder to pick up fourth (levels off on graph) - 65what happens to oxyhaemoglobin at low pp's?-breaks down
-releases O2 in solution
-this rapidly diffuses into surrounding tissues - 66why does foetal haemoglobin have a high affinity?-in the placenta maternal and foetal blood are close + there's a low oxygen pp
-so foetal haemoglobin has to have a higher affinity for O2 otherwise maternal oxyhaemoglobin wouldn't dissolve - 67what is the two correlations about types of haemoglobin?-environment of organism
-metabolic rate - 68why causes organisms to have a high metabolic rate?-organisms with large surface area to volume ratio
-maintaining constant body temp
-organisms who carry energy demanding processes - 69why does having a large surface area to volume ratio mean a high metabolic rate is required?-lose heat rapidly when environment temp is lower than their body temp
-to compensate for this they have a high metabolic rate that generates heat
-a high metabolic rate means high amounts of respiratory tissues have high O2 demands - 70how does organisms carrying out energy demanding processes cause organisms to have a high respiratory rate? birds? fish?-requires a lot of O2 to be able to respire at a rate to keep the body moving
-birds must use a a lot of energy opposing gravity + need to maintain a constant body temp higher than surroundings
-fish expend considerable amounts of energy swimming through a dense medium - 71what type of haemoglobin is required for organisms with high metabolic rates?-haemoglobin which releases O2 more readily than it takes it up
-low affinity for O2 - 72characteristics of haemoglobin of organisms living at high altitudes?-binds to O2 readily
-high affinity for O2
-readily combinds with O2 more easily than it releases it - 73what is myoglobin?-protein
-found in muscle cells
-combines reversibly with O2
-acts as an oxygen store as it picks up O2 released by haemoglobin at normal ppo
-only releases O2 if O2 pressure gets very low + acts as a reserve - 74structure of myoglobin?-one polypeptide rather than four
-one haem group - 75Myoglobin + oxyhaemoglobin?-one O2 molecule combines with the one haem group to produce oxyhaemoglobin
-once combined, the oxyhaemoglobin is very stable and won't release O2 unless the ppO is very low - 76haemoglobin of llamas?-live at high altitude (little O2)
-low metabolic rate
-haemoglobin binds to O2 more readily than it releases it - 77haemoglobin of lug worms?-low ppO
-needs to extract as much O2 a possible
-haemoglobin associates with more O2 - 78—
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- - biology Flashcards on human transport, created by hanna akhrass on 04/03/2016.
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