7 Biology - Transport In Humans Flashcards
what is the role of transport system?
it provides the body with substances
what are components of circulatory system?
heart
blood
blood vessels
what are the blood contents and their functions?
55% - plasma
45% - red blood cells - transport oxygen
1% - white blood cells (help fight disease) and platelets (help blood clot)
how are red blood cells adapted?
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
what are the two types of white blood cells?
phagocytes
lymphocytes
what do phagocytes do?
they engulf pathogens and destroy them with digestive enzymes
what do lymphocytes B and T lymphocytes) do?
B lymphocytes - produce antibodies
T lymphocytes - attack pathogens directly OR produce chemicals which control activity of all cells in immune system
what are antibodies?
proteins that recognise and destroy pathogens
what are antigens?
at surface of pathogen
provokes the immune system
what are chemical defences in our bodies that help fight against diseases?
ears are protected by bacteria killing wax
eyes have lysozyme - destroy bacteria in tears
hydrochloric acid in stomach
what are physical defences in our bodies that help fight against diseases?
skin
mucus
cillia
what is meant by double circulation?
blood passes through the body twice in each complete circuit
Explain the flow of blood through the heart
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
explain each the role of each vein/artery
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
function and structure
vein
artery
capillary
artery: blood to heart at low pressure
vein: blood from heart at high pressure
capillaries: exchange of materials between blood & tissue
what controls beating of heart?
the pacemaker, located in the wall of right atrium
how does exercise affect breathing heart and blood pressure?
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
what causes coronary heart disease?
what causes a heart attack?
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
what is respiration?
energy producing reaction which releases energy
happens in living organisms
what is aerobic respiration?
respiration including oxygen
equation for aerobic respiration
glucose + oxygen –> carbon dioxide + water –energy
C6H12O6 + 6O2 –> 6CO2 + 6H2O
what is anaerobic respiration?
no involvement of oxygen, glucose is still broken down into CO2 with the release of energy and alcohol(ethanol)
what are the two types of anaerobic respiration
fermentation
in muscles
explain anaerobic respiration in muscles?
happens in muscles when there is not enough supply of oxygen, usually during exercise
only produces low amounts of energy
releases lactic acid
what is lactic acid? why is it bad? what happens if there’s too much of it?
it is harmful and poisonous
if it builds up in cells it inhibits muscular contraction
may lead to fatigue and eventually death
equation for muscle anaerobic respiration
C6H12O6 –> energy + 2C3H6O3 (lactic acid)
what is anaerobic respiration - fermentation?
respiration in bacteria and yeast
used to make alcohol and bread
equation for fermentation
C6H12O6 –> 2C2H5OH (alcohol) + 2CO2
what are the properties of the gas exchange system?
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
label the respiratory system
http://a.files.bbci.co.uk/bam/live/content/z6qfcdm/large
function of each part in respiratory system
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
how does gas exchange happen in the alveoli
http://internationalgcsebiology.wikispaces.com/file/view/alv.GIF/399205632/359x277/alv.GIF
what is in air when we breath in/out?
in: 20% oxygen 0.04& CO2 78& nitrogen
out: 16% oxygen 4% CO2 78% nitrogen
what is breathing?
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
why is smoking bad?
nicotine causes addiction
cilia destroyed
cancer risk increases - lung, mouth, larynx, stomach, pancreas, bladder
increases risk of coronary heart disease
why are the heart valves important?
they prevent blood back flow
