3.2 transport in animals Flashcards

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1
Q

Define tachycardia

A

heart beats too fast

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2
Q

Define bradycardia

A

heart beats too slow

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3
Q

Define ectopic

A

heart skips a beat or extra beat is added

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4
Q

Define fibrilliation

A

heart contracts at an irregular way

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5
Q

Define systole

A

ventricles are contracted

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6
Q

Define diastole

A

ventricles are relaxed

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7
Q

What is the tunica intima made up of in an artery

A

endothelial layer, connective tissue layer, elastic fibres

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8
Q

Function of the tunica intima in the artery

A

reduce friction

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9
Q

What is the tunica media made out of in the artery

A

elastic lamellae, connective tissue, smooth muscle

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10
Q

Why is the tunica media layer thick in the artery

A
  • withstand high pressures
  • contract and narrow lumen for reduced blood flow
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11
Q

Function of elastic tissues in the tunica media in the artery

A

recoil and change blood pressures

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12
Q

What is the tunica adventita made out of in the artery

A

collagen

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13
Q

Function of collagen in the tunica adventita in the artery

A

protects blood vessels from over stretching

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14
Q

Function of a larger lumen in a vein

A
  • ensures blood returns to the heart
  • reduces friction between the blood and endothelial layer
  • more volume of blood carried
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15
Q

Why is the tunic media poorly developed

A

do not need to withstand high pressures

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16
Q

Where is the bicuspid valve found

A

between the left atrium and left ventricle

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17
Q

Where is the tricuspid valve found

A

between the right atrium and right ventricle

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18
Q

Where is the aortic valve found

A

between the left ventricle and aorta

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19
Q

Where is the pulmonary valve found

A

between the right ventricle and pulmonary valve

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20
Q

What happens during atrial systole

A
  • the walls of the atria contract
  • atrial volume decreases = artial pressure increases
  • pressure in the atria rises above the ventricles forcing the AV valve open
  • blood moves into the ventricles
21
Q

What happens during ventricular systole

A
  • walls of the ventricles contract
  • ventricular volume decreases = ventricular pressure increases
  • pressure in the ventricles rises above artia
  • AV valves close
  • pressure in the ventricles rises above the aorta and pulmonary artery
  • SL valves open so blood is forced out
22
Q

What happens during diastole

A
  • both the atria and ventricles are relaxed
  • pressure in the ventricles drop below aorta and pulmonary artery so SL valves close
  • atria fills with blood
  • pressure rises in the atria and the AV valves open
  • cycle is repeated
23
Q
A
23
Q

Cardiac output

A

heart rate x stroke volume

24
Q

Define myogenic

A

heart beats without any help of an external stimulus

25
Q

What does the SAN do

A

initiates a wave of depolarisation that causes the atria to contract

26
Q

What does the AVN do

A

causes a delay so the ventricles contract after the atria

27
Q

What do the purkyne fibres do

A

initiate depolarisation of the ventricles from the apex (bottom)

28
Q

What is the P wave on an electrocardiogram

A

causes by the depolarisation of the atria, resulting in atrial systole

29
Q

What is the QRS complex on an electrocardiogram

A

causes by the depolarisation of the ventricles, resulting in ventricular systole

30
Q

What is the T wave on an electrocardiogram

A

causes by the repolarisation of the ventricles, resulting in ventricular diastole

31
Q

What happens when oxygen binds to haemoglobin

A

forms oxyhaemoglobin

32
Q

What is cooperative binding

A

when an oxygen molecule can bind more easily to the iron in the haem group

33
Q

How are hydrogen carbonate ions formed

A
  • carbon dioxide diffuses into the erythrocyte to combine with water
  • red blood cells contain carbonic anhydrase - catalyses a reaction between carbon dioxide and water to form carbonic acid
  • this readily disassociates into hydrogen (H+) and biocarbonate ions (HCO3-)
  • biocarbonate ions are pumped out of the cell in exchnage with chlorine ions
34
Q

What is the purpose of haemoglobin in the carriage of carbon dioxide

A

act as a buffer

35
Q

What do H+ ions do in the carriage of carbon dioxide

A
  • bind to haemolgobin to form haemoglobinc acid (prevents H+ ions changing the pH of the erythrocyte)
36
Q

What happens in the chloride shift

A
  • hydrogen carbonate ions are moved out from the red blood cell via a transport protein in the membrane
  • negatively charged chloride ions are transported into the red blood cells (prevent electrical inbalance)
37
Q

What does a shift to the left on a carriage of oxygen graph mean

A

increased affinity of oxygen

38
Q

What does a shift to the right mean on a carriage of oxygen graph

A

decreased affinity of oxygen

39
Q

Define affinity

A

strength of which two molecules bind to each other

40
Q

When is haemoglobin considered saturated

A

when all four of its binding sites are taken up with oxygen

41
Q

Process of oxygen association to haemoglobin

A
  • due to the shape of the haemoglobin molecule it is difficult for the first molecule to bind therefore it takes longer
  • the first oxygen changes the shape so it is easier for the next oxygen to bind
  • as it approaches saturation it takes longer as there is a shortage of binding sites
42
Q

Why does foetal haemoglobin have a higher affinity

A
  • the placenta has a low pO2 so the mothers haemoglobin dissociates quicker
  • higher affinity means the foetus can pick up the oxygen at lower pO2
43
Q

Define hydrostatic pressure

A

pressure exerted by a fluid

44
Q

Define oncotic pressure

A

osmotic pressure exerted by plasma proteins within a blood vessel

45
Q

What happens at the ateriole end of the capillary

A
  • hydrostatic pressure is greater than the oncotic pressure so fluid is forced out
46
Q

What happens at the venule end of a capillary

A
  • hydrostatic pressure is lower than the oncotic pressure so fluid is forced into the blood
47
Q

Define odema

A

when too much fluid is pushed outside so it accumlates around the capillary

48
Q

What does the lymphatic system do

A

maintains correct pressure gradient for the movement of tissue fluid