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IGCSE Science > 7 Biology - Transport In Humans > Flashcards

7 Biology - Transport In Humans Flashcards

1
Q

what is the role of transport system?

A

it provides the body with substances

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2
Q

what are components of circulatory system?

A

heart
blood
blood vessels

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3
Q

what are the blood contents and their functions?

A

55% - plasma

45% - red blood cells - transport oxygen

1% - white blood cells (help fight disease) and platelets (help blood clot)

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4
Q

how are red blood cells adapted?

A

they contain haemoglobin to carry oxygen

they don’t have a nucleus to allow for more space for oxygen

donut-like shape increases surface area

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5
Q

what are the two types of white blood cells?

A

phagocytes

lymphocytes

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6
Q

what do phagocytes do?

A

they engulf pathogens and destroy them with digestive enzymes

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7
Q

what do lymphocytes B and T lymphocytes) do?

A

B lymphocytes - produce antibodies

T lymphocytes - attack pathogens directly OR produce chemicals which control activity of all cells in immune system

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8
Q

what are antibodies?

A

proteins that recognise and destroy pathogens

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9
Q

what are antigens?

A

at surface of pathogen

provokes the immune system

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10
Q

what are chemical defences in our bodies that help fight against diseases?

A

ears are protected by bacteria killing wax

eyes have lysozyme - destroy bacteria in tears

hydrochloric acid in stomach

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11
Q

what are physical defences in our bodies that help fight against diseases?

A

skin
mucus
cillia

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12
Q

what is meant by double circulation?

A

blood passes through the body twice in each complete circuit

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13
Q

Explain the flow of blood through the heart

A

deoxygenated blood from the body enters the atrium through the vena cava

goes through the valves into the ventricle which contracts, making blood pass through valves to lungs via pulmonary artery where it becomes oxygenated

Oxygenated bllod re-enters left atrium through pulmonary vein

passes through valves to left ventricle

goes to body through aorta

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14
Q

explain each the role of each vein/artery

A

pulmonary artery: oxygenated blood from heart to lungs
pulmonary vein: oxygenated blood from lungs to heart

vena cava: main vein, deoxygenated blood from organs to heart
aorta: main artery, oxygenated blood to body

hepatic portal vein: blood from digestive system to liver
hepatic vein: blood with food substances away from liver

renal artery: oxygenated blood to kidneys
renal vein: oxygenated blood away from kidneys

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15
Q

function and structure
vein
artery
capillary

A

artery: blood to heart at low pressure
vein: blood from heart at high pressure
capillaries: exchange of materials between blood & tissue

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16
Q

what controls beating of heart?

A

the pacemaker, located in the wall of right atrium

17
Q

how does exercise affect breathing heart and blood pressure?

A

exercise uses energy and nutrients

so more nutrients and energy are needed

breathe more often and deeper and hearts beats faster to get nutrients and oxygen needed to make that extra energy that you need

18
Q

what causes coronary heart disease?

what causes a heart attack?

A

poor diet - too much cholesterol and fatty acids

poor lifestyle - smoking, lack of exercise

genetic factors

the build up of plague in the artery which stops blood flow

19
Q

what is respiration?

A

energy producing reaction which releases energy

happens in living organisms

20
Q

what is aerobic respiration?

A

respiration including oxygen

21
Q

equation for aerobic respiration

A

glucose + oxygen –> carbon dioxide + water –energy

C6H12O6 + 6O2 –> 6CO2 + 6H2O

22
Q

what is anaerobic respiration?

A

no involvement of oxygen, glucose is still broken down into CO2 with the release of energy and alcohol(ethanol)

23
Q

what are the two types of anaerobic respiration

A

fermentation

in muscles

24
Q

explain anaerobic respiration in muscles?

A

happens in muscles when there is not enough supply of oxygen, usually during exercise
only produces low amounts of energy
releases lactic acid

25
Q

what is lactic acid? why is it bad? what happens if there’s too much of it?

A

it is harmful and poisonous
if it builds up in cells it inhibits muscular contraction
may lead to fatigue and eventually death

26
Q

equation for muscle anaerobic respiration

A

C6H12O6 –> energy + 2C3H6O3 (lactic acid)

27
Q

what is anaerobic respiration - fermentation?

A

respiration in bacteria and yeast

used to make alcohol and bread

28
Q

equation for fermentation

A

C6H12O6 –> 2C2H5OH (alcohol) + 2CO2

29
Q

what are the properties of the gas exchange system?

A

thin - short distance to diffuse

large surface area - lots of diffusion at same time

moist - cells don’t die

well ventilated - concentration gradients of O2 and CO2 are kept by regular fresh supplies of air

close to blood supply - gases can be transported

30
Q

label the respiratory system

A

http://a.files.bbci.co.uk/bam/live/content/z6qfcdm/large

31
Q 
function
of each part in respiratory system
A

larynx: air passes through breathing. vocal chords vibrate - voice
trachea: carries air towards lungs. C-shaped rings (cartilage) prevent it from collapsing
bronchus: branch from trachea, one for each lung
bronchiole: very fine branches leading to alveolus
alveolus: where gas exchange takes place. Lined by membranes. Thin & enormous surface
diaphragm: muscle that relaxes/contracts to increase/decrease volume so that air comes in or out

32
Q

how does gas exchange happen in the alveoli

A

http://internationalgcsebiology.wikispaces.com/file/view/alv.GIF/399205632/359x277/alv.GIF

33
Q

what is in air when we breath in/out?

A

in: 20% oxygen 0.04& CO2 78& nitrogen
out: 16% oxygen 4% CO2 78% nitrogen

34
Q

what is breathing?

A

muscular movements that give fresh supply of fresh air

intercostal muscles and diaphragm contract so that the lung volume increases and pressure falls and air rushes in

35
Q

why is smoking bad?

A

nicotine causes addiction

cilia destroyed

cancer risk increases - lung, mouth, larynx, stomach, pancreas, bladder

increases risk of coronary heart disease

36
Q

why are the heart valves important?

A

they prevent blood back flow

IGCSE Science (13 decks)

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