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A Level Biology Me > Chapter 8transport > Flashcards

Chapter 8transport Flashcards

1
Q

Why do animaks need a TRANSPORT SYSTEM? (4-5)

A
  • big diffusion distances mean they wont be able to transport moleculed from deep cells to outer membrane fast enough to survive
  • SA:V so low that this rate of diffusion would not even be able to happen at a fast enough rate to survive
  • food figested in one part of an animal contents need to be transported to cells all over
  • hormones made in one part needs to be transported all over
  • waste products from metabolism need ti be transported to wn excreteoy organ
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2
Q

Most animals use a circulatory system to transport . What consists of a circulatory sydtem? (3)

What does human ciculatory system transport ?

A
  • have a liquid transport medium that circulated around body (blood(
  • have vessels that carry the transport medium
  • they have a pumping mechanism to move the fluid around

2) carbon dioxide waste, oxygen glucose amino caids anti bodies platelets etc

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3
Q

Describe an OPEN circulatory system with an example
What is it
Path of blood and way back
What do they transport

A
  • AN OPEN circulatory system is where sll thr blood is not contained in vessles all the time, but instead flows freely in the BODY CAVITY (haemocel ) with only few vessels

Happens in invertabrates like insect

  • the fragmented heart lumps blood along a main artery, where blood then goes to the body cavity
  • these then in direct contact with tissues and cells
  • transports food and nitrognous waste, cells needed for diseas, not oxygen or co2 as thats TRACHEAL SYSTEM
  • then blood flows back under low pressure into heart in an open vessel or valve
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4
Q

What is blood in insect called

A

Haemolyph

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5
Q

What are disadvantages to insect open ciceukatory system (3)

A
  • under low pressures (not efficient)
  • steep conentratioj gradient cant be maintained ( not effienct diffusion)
  • amount of haemolymph cant be vaired due to changing conditions
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6
Q

Describe a closed circulatory system

What uses

A

Here all thr blood is CONTAINED IN BLOOD VESSELS

  • heart pumps blood in high pressured through artieries , subsatsnces trsnsported diffuse out into celld , but blood stays inside a vessel at all time snd then return to heart
  • amount if blood going in can be adjusted by widening / narrowing
  • most use a pigment to carry

2) all mammals, and some sea creatures

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7
Q

What is the difference between a single (closed) circulatory and s double

A

Single the blood travels only onfe through the heart for each complete circulation

Double = blood trwvele twice through the heart for each complete circulation

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8
Q

What is the path of blood in single ciruclatory dydtem and why bad

A
  • blood pumped through heart
  • goes to lungs and gas exchanges
  • then goes to rest of organs and exchanges with cells

2) as a result of passing through all vessles pressure drops, so return to heart slowly = not as efficeint and not as suitable for active animals

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9
Q

Why can a fish be active yet still have a single circulatory system (3)

A

a lot of metabolic demands are lessened:
- bidy weight supported by upthrust of water
- dont maintain own body temperture
And on top fish have a very effiecent gas exchange system

This means for low metbsolic demand and good exchange a single is enough snd better as they can still be really active

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10
Q

Describe flow of blood in a double circulatory system

A
  • blood pumped from heart to lungs, where gas exchange takes place
  • returns to heart, and pumped again to rest of body under HIGH PRESSURE
  • exchange takes place between cells and blood
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11
Q

Why is doubke more efficent then single

What are differences

A
  • pumped st higher pressures, so returns to heart quicker, allowing organisms to be more active and meet higher metabolic demands including body temp maintain
    Means more oxygen delivered so meets demand

2) pressure
- 4 chambered heart for double vs 2 for single
- oxugenated snd doxygenated always kept separate , allows for maximum loading

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12
Q

Why is closed better than open

A

Blood and bodily fluods kept separate, means blood is transported easier

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13
Q

What do all vessels have in different proportions

A

Collagen
Smooth muscle
Elsstic fibres

Endothemium and lumen

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14
Q

Some conditions to help remember proportions of materials

A

If extreme pressure = more elastic fibre

If need to dilate blood = more smooth muscle

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15
Q

Structure due to function of arteries?

Function of elastin and collagen

A

Arteries carry oxygenated blood in most case at HUGE PRESSURES
As a result
- they have high elastic fibre ( maintain pressure)
- high collagen (withstand pressure)
- low amounts of smooth muscle

Elsstic fibre will stretch and take a larger volume on contraction, however in between contractions of heart the elastic fibre will recoil and push blood along
- this helps even out heart surge of blood and makes it CONTINOUS FLOW

the collagen ensured this is done within limits (dont deform), withstanding pressure

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16
Q

Structure due to function of arterioles?

Why have smooth muscle and less elastic

A

Arterioles link arteries to cappilaey bed

  • less pressure = less elastic fibre (but still a lot ) and LESS COLLAGEN
  • however more smooth muscle

Arterioles have high propritions of smooth muscle meaning thry can contrsct snd relax this to change blood flow going to capilaries, contarscting reduces snd called vasoconstriction and releaxing increases called vasodilatioj

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17
Q

Structure of capilaries and 2)how it adoated helps function (3)
Why slow

A

Capilaires are site of exchnage .

  • they have holes called FENOSTRATIONS so substances cab pass in and out to cells (escept in nerves where tight)
  • lumen big so pressure low and slow down

Adapted

  • endotheliul tissue inly ONE cell thick = short distance = better diffusion
  • large surface area = better diffusion of substance
  • surface area greater than arteriole = FORCES BLOOD TO SLOW DOWN , and pressure drop, thus there is actual time for blood to trandport substances
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18
Q

Sturture of venules and veins and function

A

Veins carry deoxygenated blood back to heart except for few

Venules link capillaries to veins , which end up superior and inferior vena cava

  • blood pressure very low in veins so not much elastic tissue needed
  • small amounts of muscke
  • large amount of collagen
  • bugger veins have VALVES so no backflow and blood goes
  • wide lumen to hold more oxygen
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19
Q

How do veins ensure blood goes against gravity etc (3)

A

1) valves
2) big veins are betwen very active muscles like legs, when they cintract this saueezes veins and pushes some blood up, when relax valves snsure blood dont fall back
3) even breathing expansion if chest acts as a oumo for abdominal veins etc

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20
Q

What is actually blood consist of

What does plasma carry?

A
  • yellow liquid plasma
  • red blood cells
  • white blood cells
  • platelets

2) plasma carries:
- water
- glucose
- hormones
- amino acid
- albumin for osmotic pressure
- fibrinogen for clotting
- globulins for immune

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21
Q

Functions of blood for transport (same to what plasma carried but mor)

A
  • transporting oxygen co2
  • digested food from small intestine
  • nitrogenous waste to excretory organs
  • hormones
  • food molcuels from storage compounds
  • platelets to damsged areas
  • cells and antibodies
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22
Q

How is tissue fluid formed (what moves , ocnotic? Hydroststic ?)

What happens after ?

A
  • as substances in blood pass through capilaries, they can fit through thE FENESTRATIONS and escape into tissue, except PLASMA PROTEINS especially albumin and also red blood cells
  • plasma proteins including albumin are constant and thus lower the water potential here, causing water to move inti the blood by osmosis. The pressure as anresult, the tendency for water to move in to the gloodnas a resukt of this is termed ONCOTIC PRESSURE

2) now oncotic pressure quite high, but at the artery end of capilary blood is still UNDER PRESSURE from surge of blood from heart, giving it a HYDROSTATIC PRESSURE , forcing fluid out.
- as this hydrostatic pressure > then oncotic pressure, net movement due to orrssure is OUT OF THE BLOOD capilaires and into the tissues . This is tissue fluid and is plasma without plasma and red blood cells.

Diffusion takes place between tissue fluid and cells for exchange…

2) now as fluid has moved out the hydrostatic pressure has decreased . Towards venous end, the oncotic pressure (which stays CONSTANT) now higher then hyrostatic, so by pressure fluid moves in by osmosis .
- by the time it reahed veins, 90% of all TISSUE FLUID HAS NOW RETURNED !!

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23
Q

What leaves the cappilaries and what doesnr

A

Everything but red blood cells snd plasma proteins as too big

White blood cells big but multi lobed means it csn fit

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24
Q

What happens to the extra 10% left behind not reabsorbed left as tissue fluid?
What is it , and how returns to heart

A

This is excess that couldnt return but needs to be collected to avoid swellijtn- lymph
- this is drained into series of lymph capilaires

Lymph consists if everything plasma had but with a few less nutrients, and also fatty scids from small intestinte

  • lymph vessles join ti form larger vesslee, and fluid is transported through by SQUEEZING OF BODY MUSCLES and also VALVES . They end up at heart
25
Q

What are lymph nodes and lympocyted
Why role in defence
Why check for swollen lymoh node?

A

Along lymph vessles are lymph nodes, where LYMPHOCYTES BUILD UP HERE when necessary and proeuce antibodies , which pass into blood.
- lymoh nodes intercept bacteria in lymph , ingested by phagocytes. As a result lymph syste, plays big role im defence

2) doctrod check for enlarged lymoh nodes as if swollen it means a lot of lympocytes there to FIGHT OFF PATHOGEN. Thats how they can tell there is some sorr of infection, and they check lymoh glands as a redult

26
Q

Do all proteins stay in blood ? Any in tissue fluid or lymoh?

A

No only big ones, small ones go to tissue fluid and ANTIBODIES are in lymph

27
Q

What is odema

A

Too pressure means stress so blood pressure goes uo meaning not enough reabsorbtion meaning swelligm snd reabsorbtion not enough and shows in urine

28
Q

Fewtures of heart

What type of muscle is heart and how not fatigue

A

Caridad muscle, can contract without nerve impulse and dowsnt get fatigued due to constant blood supply from coronary arteires

  • blood enters right atrium frim superior snd inferior vena cava, lumped to right ventricle pumpled to lungs brought back to left atroum pumoed tk ventricke and then rest of body through aorta

Left side more thicn

29
Q

Describe basic motion of blood through heart

A

1) deoxygenated blood enters from superior and inferiro vena cava and fills right atroum. As blood flows in slight pressure there forces some blood through tricuspid valve and to the right ventricle. When both fill, atrium contract forcing all blood in ventricle
2) more pressure ventricle = tricuspid vslve close , ventricle contracts and blood pushed through semilunar and pulmonary artery to lungs. Semilunar close
3) AT THE SAME TIME blood from lungs return to left atrium and pressure build bicuspid open snd fill ventricle. Atroum contract forcing all into ventricle
3) ventricle contrsct stormger go throigh aorta and semiounar

30
Q

What is septum?

A

Middle dividing wall of heart which prevents mixing if ixygenated snd deoxygenated

31
Q

What happens in systole and diastole?

A
  • diastole heart relaxes, the atria and ventricles are both relaxed and as higher pressure in atria AV valves open, but as higher pressure in arteries SL are closed. Here the heart fills with blood
  • at systole first atria contract while ventricle relax, causing blood to be pushed here, and then ventricular systole the atria relax and ventricles relax, forcing blood all over the body .

Finally at the end back to beginning. Pressure at arteries maximum but ptrssure in heart 0.

32
Q

When is lub dub sounds made

A

Lub = is when av valve close and dub is SL valve

So lub heard after atria systole and venreicles contracting and dub after venrticukar systole ( ventricles relax then) , slightly delayed

33
Q

Caridac muscle is myogenic , but what dies this mean

A

The muscle has its own intrinsic rhythm and controls own contractions by intiating own electrical impulses

34
Q

Basically describe what happens for the heart to contract

A

There are two nodes, the SINO ATRIAL NODE and ATRIO VENTRICULAR NODE

  • first the SAN initaites a wave of ELECTRICAL EXCITITATION (depolarisation) here, and this causes the atria to contract in sysotele
  • non conducting tissue ensures ventricles not stimukated
  • the AVN is next to the SAN but when it picks up the signal, it causes a DELAY (important)
  • then thr AVN stimukated the bundle of hiss, which are CONDUCTING TISSUE made up of PURKINJE fibres that carry the electrical wave of excitation DOWN THE SEPTUM . Here non conducting tissue ensured the ventricles are not stimulated yet
  • finally at the APEX purkinje fibree sprewd out thr walls of the ventricles on both sides starting at the apex (important). The ventricles then contract in systole from down up

When relaxing, heart then repolarises to restart

35
Q

Why does AVN impose a delay

Why limg through bundle of his to bottom

A

1) a dekay is crucial so that sll thr blood can enter the ventricles first fully before they contract, if it happened sake time, barely any blood would lewve hewrt, to inefficent
2) excitation and depolarisation needs to happend from the bottom down so that sll can be squeezed UPWARDS AND LEAVE

36
Q

How is the electrical activity if heart measured and what do these produce?

Why is making these diagram usefuk

A

Electrical differences are produced in YOUR SKIN as a result of electrical activity from hewrt. This way by sticking electrodes, heart activity can be detected and an ELECTROCARDIODIAGRAM could be made

2) can help detect abnormalities and thus diagnose potential problems like in heatt attack

37
Q

What are the different sections on ECG

A

Three different times electrical activity increases. One for atrial systole, then ventricular and finally repolarisation when diastole happens

P= atrial systole (first peak)
QRS complex = ventricukar systole (second peak)
T = repolarisation (last peak )

38
Q

QT interval? TP?

A

QT is the interval between ventricular systole and repolaridstion so time taken for ventricles to contract,

TP is time taken to fill up again

39
Q

Stroke volume, heart rate and cardiac output?

2) how to find heart rate from ECG

A

Cardiac output is the amount of blood leaving ventricle in one minute
Hear rate is beats per minute
Stroke volume amount if blood leaving a ventricle in a heeart beat

So cardiacr = stroke times heart

2) find out by doung 60/ time for one heart beat to find out heart rate then * by stroke volume

40
Q

What is average cardiac output

What is AVERAGE HEART RATE AT REST

A

4-6 litres, if more or less could be wring

2) 60 to 100, but check the cardiac volume as athelets will have lower

41
Q

Four types of abnormalities wnd how they look on graph

A

1) TACHYCARDIA = TOO FAST ( maybe fever etc)
2) BRACHYCARDIA = TOO SLOW (normally athelets have if really low then concern )
3) ECTOPIC HEARTBEAT = irrgular rhythm (either extra or one less)
- you will see a fraud p wave, or maybe a taller and wider QRS , maybe without P wave, something weird

4) atrial fibrillation
- just looks all over the place with no real atrial rhthym, a lot of mini atrials

42
Q

What causes four abnormalities

A

1) tachy = maybe fever, if bad treated with surgery
2) brachy = typically athletes ( but if really bad, ARTIFICIAL PACEMAKER NEEDED)
3) ECTOPIC = happens to everyone a day, but could be serious if frequent. Caused by previous atria electricity or just ventricles contacting earlier without p
4) artifical fibrillation = caused by wtria cintacting sommuch and not properly not sllngoung to ventricles and just really inefficent = death chest pain fainting

43
Q

What makes a red blood cell specikaised for its function (4)

A

Red blood cells rransport oxygen all around body

1) Biconcave disc shape = increases surface area to volume ratio for efficent diffusion
2) lots og haemoglobin, combines with oxygen to oxy haemoglobin which allows it to carry it arround
3) loses NUCLEUS WHEN MATURE= can fit more haemoglobin = more oxygen
4) thin membrane = efficent diffusion

44
Q

What was haemoglobin structure and features again? (Type of proetein steucure etc)

How shale changes!

A
  • globular protein= spherical in shape
    = made up of a quaternary structure of 4 polypetide units , 2 alpha and 2 beta
  • each polypeptide unit contains a prosthetic non protein HAEM GROUP, which contains iron ion, which oxygen binds to
  • each hameoglobin molcule bind to 4 oxygen molecules, and there are millions of haemoglobin in ixygen

2) shape changes making it easier for more o2 to join, or more to leave

45
Q

What is equation between oxygen and haemoglobin

How strongly, (why revrsible)

A

Oxygen +haemoglobin = oxyheamoglobin reverisbke as bind LOOSELY, as it needs ti be revseible to DROP OFF OXYGEN TOO

4O2 + HB —> Hb(O2)4

46
Q

How do oxygen join with the erthyrocyted then?
Why is this essier as more join
What happens to conc now
and how oxugen leave

A

At lungd erthryrocyted have lowest oxygen conc, and lung high, so by diffusion oxygen moves inti red blood cell snd binds with haemoglobin

1) when one haem group is binded to oxygen, it makes it EASIER FORNTHE SECOND TO BIND ON, AND THIRD AND FOURTH.
= fhis is called POSITIVE COOPERITIVITY
2) as the oxygen is now bound ti hsemoglobin, FREE oxygen conc in red blood cell stays low, and so more can keep ciming in until all hameoglobin is SATURATED

3) when blood resches tissues, which have low conc, oxygen moves out from haemoglobin down a conc gradient
- once firsr molecule releasedm it becomes even essied for second and third and fourth, as shape if hameoglobin changes ti allow it to happane similaer to before..

47
Q

Oxygen dissocatioon curve

Explain shape

A

Shape is of a sigmoid curve

  • at low partial pressures of o2, only a few haem groups are attached to oxygen so low % saturation
  • as you increase partial pressure, this % increases very quickly as introduction of a few oxygen bound haemoglobin makes it EASIER for more to be attached
  • as you further increase, the graph levels off as all hameoglobin begins ro be saturated, making it harder to join more, thats why middle best
48
Q

What does the shape of oxygen dissociation curve mean (at lungd and at respiring tissue) in terms of affinity

A
  • at high partisl pressures, such as in lungs, oxygen loaded rapidly, hameoglobin high affinity
  • a drop in partial pressue such as respiringntissue means oxygen leaves rapidly too (which is good) haemoglobin has a low affinity
49
Q

Affintiy?

Does this change!

A

The tendence of s mocleule to bind with oxygen

Yes in different environements.. and effects like temp, ph etc

50
Q

What is the effect of carbin dioxide on curve? (How shift)
- what affinity change
- why is this good
What is this called?

A

1) At the same partial pressue of oxygen, an increase in partial pressure of carbon dioxide shifts the oxygen dissocation curve to the RIGHT
- 2) this means at the same partial pressue of oxygen , with more co2 haemolobin has a LOWER AFFINITY for oxygen , meaning it will let it go

  • 3) this is good because when partial pressue of co2 increases its typically because dons respired more , so they need more oxygen, and thus need haemoglobin to let go more do they can respire more
    4) called bohr shift
51
Q

What happens at low pCo2 then

A

Shifts to left, haemoglobin retains more oxygen at same Po2, doesnt give up as easilly

52
Q

Explanation of bohr shift
How increase co2 leads to lower affinity of oxygen?

WHAT OTHER ACID CAUSES THIS IN EXCERCISE CONDITIONS!

A

Increase co2 = increase in carbonic acid = dissociates = increase in H+ ions

  • these H+ ions need to join with Hameglobin to make Haemoglobic acid , so that PH DONT INCREASE TOO MUCH
  • as a result increase makes oxygen detach from oxyhaemoglobin more so H+ ions can me moped up = lower affinity

This all came from increase of co2

2) this also promoted by rise of LACTIC ACID when anerobic respiration (same thing), carbonic , all dissociate focing hsemoglobin to join with H+ and lowering affinity

53
Q

What else can cause a borh shift , in excerise conditiond?

A

Increase in temp makes it easier to release oxygen more

Lactic and carbonic

54
Q

Explain how dissociation curve moves for fetal heamoglobin

A
  • fetal blood doxygenated runs close ro mothers oxygenated in placenta
  • if it had same affinity for ixygen it would not be able to take any
  • so it has HIGHER AFFINITY then mother haemoglobin so it can take more
  • as a result curve shifts to the LEFT THE WHOLE WAY, this means at same partial pressure of oxygen, fetus more saturated so more affinity

(Mum already dissociating as when hit placenta it has lower po2 due to being used up

55
Q

Myoglobin ( not needed)

A

Shift left, high affinity and only dosscioates when levels very low
Found in muscles as reserve

56
Q

How is carbon dioxide transferred in % terms

A
  • 5% stays in plama
  • 10-20 % actually transported in red blood cells and combine with hb to make CARBONOHAEMOGLOBIN
  • 70- 75% is converted into carbonic acid then HCO3- ions and transported in the plasma
57
Q

What happens to 70% carbon dioxide in the red blood cells, how is that transported?
- include how acid made, what happens after, to H+ ions, electrical balance so shift, and how this affects conc gradient

A

Carbon dioxide in the red blood cell that doesnt make carbinohaemoglobin reacts slowly with water to make CARBONIC ACID

  • carbonic acid is then CATALYSED by carbonic anhydrase in the cells to dissociate into H+ ions and HCO3- ions
  • H+ ions joins with haemoglobin (forcing oxygen out loweing affinty) to make haemoglobic acid, this stops pH from increasing so it is a buffer
  • HCO3- ions then move down a concentration grsdient out of cells into plasma due to diffusion
  • but Cl- ions diffuse in to the red blood cells SO THAT THE ELECTOCHEMICAL BALANCE OF CELL IS MAINTAINED = know as CHLORIDE SHIFT
  • now the fact carbon dioxide is removed and converted into HCO3- ions means there is a low conc of co2 and so more can KEEP DIFFUSING INTO FROM RESPIRING CELLS
58
Q

What happens to HCO3- ions after transported in plasma to lungs

A

When blood reaches lung tissue , where there is lower conc of co2, CARBONIC ACID IS CATALYSED BY CARBONIC ANHYDRASE REVERSE TO MAKE CO2 AND WATER AGAIN

  • HCO3- diffuse BACK INTO THE CELLS , and join with H+ ions solit from haemoglobic acid to make even more CARBONIC ACID
  • however as HCO3 move in , cl- has to move out to ensure electrical balance is constant

Now carbin dioxide diffuses diwn a conc gradient in alveoli where it leaves in expiratioj …

59
Q

Whynis HCO3- A GOOD WAY TO TRANSPORT THE CO2

A

it is more solible in plasma being polar

A Level Biology Me (41 decks)

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