The Heart and Health Flashcards
what colour is oxygenated and deoxygenated blood
oxygenated = bright red, deoxygenated = dark red almost purple
what is a double circulatory system
blood goes through heart twice for every circuit of the body
why do mammals have a double circulatory system
to generate enough pressure to keep the blood moving - pressure is lost as blood flows through capillaries inside organs and tissues
types of veins/arteries for liver
hepatic
types of veins/arteries for kidneys
renal
types of veins/arteries for legs
femoral
types of veins/arteries for lungs
pulmonary
types of veins/arteries for neck
jugular
function of pulmonary artery
sends blood to lungs
function of vena carva
brings blood back from body
function of right atrium
pushes blood into right ventricle
function of septum
separates two sides
function of aorta
sends blood around body
function of pulmonary vein
receives blood from lungs - sends to left atrium
function of left atrium
sends blood to left ventricle
function of valves
control blood movement from atrium to ventricles and out of body
function of left ventricle
sends blood to aorta
function of muscle in the heart
contracts to provide pressure
flow of blood through heart
- deoxygenated blood enters right atrium via vena carva
- right atrium contracts - blood forced into ventricle through AV valve
- right ventricle contracts - blood pumped through valve into pulmonary artery
- blood transported to lungs
- blood returns to heart via pulmonary vein - enters left atrium
- left atrium contracts - blood forced into left ventricle through AV valves
what is the sino-atrial node and where is it located
natural pacemaker which controls heart rate in the right atrium
medical intervention for irregular heartbeat
can have an artificial pacemaker fitted, which sends electrical signals to the SAN
how to calculate heart rate
60 / time for 1 heart beat … measure distance/time between each peak to find time for one heart beat
do veins or arteries carry pressurised blood
arteries carry pressurised - veins carry depressurised
parts and description of an artery
lumen, endothelium, muscle & elastic tissue, outer coat - carry oxygenated, high pressure blood away from heart (except pulmonary which carries deoxygenated) - muscle pushes blood around body (creates pulse) - elastic provides stretch for increased blood flow
parts and description of a vein
lumen, endothelium, muscle & elastic tissue, outer coat - less muscle & elastic than artery - carries depressurised, deoxygenated blood back to heart (except pulmonary which carries oxygenated) - muscle prevents backflow - elastic provides stretch for increased blood flow - have valves; when pressure falls behind the valve, pockets fill & close the valve; when pressure builds valve is pushed open & blood flows through
parts and description of a capillary
lumen, epithelial cells - no muscle/elastic - 1 cell thick (short diffusion path) - where exchange of materials occurs
define breathing
a physical process involving a contraction of muscles to move air in and out of body
define respiration
a chemical process inside cells to release energy
parts of respiratory system
larynx - trachea (surrounded by rings of cartilage) - bronchus - bronchioles - alveoli - lungs surrounded by pleural membrane, & internal/external intercostal muscles - diaphragm
movement of muscles, ribcage, diaphragm & volume/movement of air/pressure in inhalation
muscles contract - ribs spread out & move up - diaphragm contracts, flattens and moves down - pressure decreases - volume increases - air moves into lungs to equalise pressure
movement of muscles, ribcage, diaphragm & volume/movement of air/pressure in exhalation
muscles relax - ribs get closer together & move in - diaphragm relaxes & returns to domed position - volume decreases - pressure increases - air moves out of lungs to equalise pressure
good features of bell jar model for breathing
shows effect of pressure on lungs - represents thorax (lungs, diaphragm, trachea, bronchi) - shows how lungs move (inflate/deflate) - diaphragm contracts & moves to change volume & pressure
limitations of bell jar model for breathing
no ribs to move - walls of jar dont move so doesn’t represent ribs & muscles well
adaptations of alveoli for gas exchange
large sa - millions of capillaries & alveoli; alveoli highly folded and rounded
steep conc grad - constantly breathing (new supply of o2 and taking away co2); good blood supply (constantly takes o2 away & brings co2 lungs); moist cells
short diff path - only pass through 2 cells (1 cell in alveoli wall, 1 in capillary)
adaptations of capillary in leg muscle for gas exchange
large sa - millions of capillaries in 1 capillary bed
steep conc grad - aerobic respiration (uses lots of o2); lots of capillaries (constantly moving blood)
short diff path - walls only 1 cell thick; thin permeable walls
adaptations of plant leaf for gas exchange
large sa - flat & large
steep conc grad - many stomata (easier for co2 to diffuse); spongy mesophyll provide air spaces; moist cells & air
short diff path - thin leaves; thin cell walls
adaptations of fish gills for gas exchange
large sa - each gill filament has many capillaries; lamellae provide large sa
steep conc grad - counter-current flow principle (more effective); o2 can move into blood along entire length of gill
short diff path - 1 cell thick between outer layer of gill filaments & capillary walls
components of blood
plasma, rbc, wbc, platelets
what is plasma & its function
yellow liquid - carries rbc and wbc
what is a platelet & its function
small fragment of cell - has an important job in blood clotting
arguments for use of blood products
plasma - universal; will not harm people - prevent heart attack by maintaining blood volume
blood - prevent death by providing rbc to carry o2
arguments against use of blood products
plasma - does not contain rbc; does not help move o2
blood - religious reasons; receiving cells from another person; not natural - HIV, hepatitis; worried about infections
function & specialisations of rbc
transports o2 around body in haemoglobin - no nucleus (more space for haemoglobin - more o2) - biconcave (can be squashed to fit through capillaries and increase sa)
function & specialisations of wbc
fight diseases - large nucleus (more dna - high level of control within cell - dna instructs ribosomes how to make antibodies (proteins))
what causes chd
layers of fatty material (atheroma) building up inside coronary arteries, which narrows them and restricts blood flow
what happens when blood flow TO HEART is restricted
the flow of blood to the heart muscle is reduced - receives less oxygen and glucose for respiration - less energy released for contraction of hearts muscle
symptoms of reduced blood flow
breathlessness - harder to do exercise - pain (cell distress signals from lack of o2) - lethargy - higher heart rate and bp
risk factors for chd that cant be modified
genetic predisposition - inheriting genes that increase the risk of chd
modifiable risk factors for chd
stress (lower work load) - fatty/sugary diet (change diet) - lack of exercise - smoking
treatments for chd
statins, valve replacement, heart transplant, stents
what drug is used to treat chd, what do they do, how does this help, pros and cons
statins - tablets taken 1 per day - reduce production of cholesterol in liver - lower levels in blood -PRO - prevents formulation of plaques (prevents blocking of arteries - heart attacks) - easy to take CON - continues for life (dangerous to forget) - interacts with other medicines (may not be fit for everyone) - unpleasant side effects (muscle damage - might no be viable option)
pros and cons of mechanical and biological valves
MECHANICAL - PRO - not biological tissue (less religious objections) - durable (last longer) CONS - tendency for blood clots to form metal surface (heart attacks) - may not work as effectively
BIOLOGICAL - PRO - work naturally (no blood thinning needed) - CONS - less durable - religious objections - immunosupressents (may get rejected)
how does hart valve replacement work, pros, cons
removing a damaged valve in surgery under anaesthetic and replacing it with a new one - PROS - can prevent heart failure (stops backflow of blood/leaky valves - heart beats efficiently to supply blood to cells) - no alternatives (no medicines to treat aortic valve problems) CONS - anaesthetic (dangerous - allergic reaction - potentially fatal) - surgery (potential for infection)
how does heart transplant work, pros, cons
surgery under general anaesthetic - use a heart-lung bypass machine - remove own heart and replace it with a donor PROS - survive (new heart - work more efficiently) CONS - long recovery period - immunosuppressants for rest of life (side effects - vulnerability to disease, weight gain, kidney problems) - complications (rejection, heart failure, narrowing of arteries), surgery (infection - allergic reaction)
how do stents work, pros, cons
stent placed in artery (guided round body using x-ray) - inflated via balloon - flattens fatty deposits against artery wall - widens artery PROS - decreases risk of heart attack (greater blood flow - easier to supply blood to body) CONS - open wound (risk of infection) - anaesthetic - can cause an aneurysm (cause bulge - rupture - internal bleeding)
explain how chd can cause a heart attack
coronary arteries on surface of heart - tiny deposit of fat & cholesterol (plaque) - grows & reduces flow of blood
if 1 coronary artery is blocked - can starve a patch of heart cells of o2 - new arteries can grow to fill gap and feed struggling cells - natural bypass - at least 2 days to grow
high blood pressure - rbc smash against plaques - damaged - plaques open - rbc stick to damaged plaque - creates clot
body releases adrenaline to make heart pump faster to get more o2 - clot gets bigger - less rbc to heart
some cells starved of o2 - stop beating/contracting - not enough energy to keep cells in 1 piece - cells die/disintegrate
lungs fill with fluid as blood backs up near lungs and pressure build so fluid leaks - cant breathe
lack of o2 - affects brain - dizzy disoriented confused
medical intervention for heart attacks
ecg to locate dying patch of cells & blocked artery
TPA medicine - clot-busting drug - destroys plaque/blockage to return blood flow to normal - only works once
cell may beat out of sync - create own electrical signals - clashes with SAN - defibrillator shocks heart - stops beating - makes it reset
the body after a heart attack
ruptured membrane of plaque heals, but plaque remains
blood thinners to stop new plaques forming & arteries blocking - less cells - harder to get o2 - gentle exercise, no stress
heart cells cannot replenish - permanent damage
define health
a state of complete physical, social and mental wellbeing - not merely the absence of disease or infirmity
communicable disease
a disease that can be spread between organisms - flu, cold, HPV
non-communicable disease
a disease that cannot be spread between organisms - cirrhosis, diabetes, cancers, scurvy
what can immune reactions caused by pathogens also cause
can trigger allergies ie skin rash, asthma
what can viruses in cells be the trigger for
certain cancers
what can severe physical ill health lead to
depression and other mental illness
risk factors for type 2 diabetes & why
obesity - more fatty acids in blood - insulin resistance causes beta cell dysfunction - body loses sensitivity to insulin (as body cannot use the insulin as it should, blood sugar levels can increase)
risk factors for liver/brain damage & why
excessive alcohol consumption - liver becomes scarred & can’t process alcohol - liver cirrhosis develops - inability to process leads to brain damage
risk factors for lung diseases & why
smoking - inflame airways - less room for air - tar coats alveoli - other particles also irritate lung tissue - scarring
risk factors for skin cancer & why
UV radiation (a carcingoen) - can damage DNA in skin cells via absorption of photons - causes cells to grow out of control
risk factors for low birth weight in babies & why
smoking whilst pregnant - nicotine causes lower maternal weight sot he baby can’t get all the needed nurtrients
risk factors for brain damage in babies & why
not enough o2 - ie umbilical cord complications, anaemic mother’s blood, smoking - not enough o2 cant be healthy
