Organisation Flashcards
describe what happens in the body when inhaling.
- intercostal muscles contract
- ribs spread out and move up
- diaphragm contracts and flattens and moves down
- thoracic cavity volume increases
- pressure decreases
- air moves into lungs to equalise pressure
describe what happens in the body when exhaling.
- intercostal muscles relax
- ribs get closer together and move in
- diaphragm relaxes and returns to domed position and moves up
- thoracic cavity volume decreases
- pressure increases
- air moves out of lungs to equalise pressure
why is the bell jar a good model for human breathing?
- shows effect of pressure on lungs
- represents different aspects of thorax
- accurate diaphragm
why is the bell jar a bad model for human breathing?
doesnt accurately represent ribs and muscles - walls of the jar dont move
list the parts of the respiratory system.
- larynx
- trachea (surrounded by rings of cartilage)
- bronchus
- bronchioles
- alveoli
- lungs surrounded by pleural membrane, & internal/external intercostal muscles
- diaphragm
what enzyme breaks down carbohydrates?
carbohydrase
what are carbohydrates broken down into?
simple sugars
what enzyme breaks down starch?
amylase
what is starch broken down into?
glucose
where is amylase secreted?
- mouth - saliva from salivary glands breaks down starch into maltose
- duodenum - from pancreas breaks down starch into maltose
- ileum from ileum wall - breaks down maltose into glucose
what enzyme breaks down proteins?
proteases
what is protein broken down into?
amino acids
where is protease secreted?
- stomach - pepsin from gastric glands begins breakdown of proteins into amino acids
- duodenum - trypsin from pancreas continues breakdown of proteins into amino acids
- ileum - peptidase from ileum wall breaks peptides into amino acids
what enzyme breaks down lipids?
lipase
what are lipids broken down into?
fatty acids and glycerol
Where is lipase secreted?
duodenum - lipase from pancreas breaks lipids down into fatty acids and glycerol
where is bile produced?
the liver
where is bile stored and concentrated?
the gallbladder
what is the function of bile?
- emulsifies lipids for larger sa
- contains sodium hydrogencarbonate (alkali) - neutralises stomach acid & produces optimum pH for pancreatic enzymes
what is the food test for reducing sugars?
- benedict’s solution (bunsen burner)
- pale blue to brick red precipitate
what is the food test for starch?
- iodine
- orange to blue-black
what is the food test for proteins?
- biuret
- blue to lilac
what is the food test for lipids?
- ethanol
- clear to cloudy emulsion
what is the function of the mouth in the digestive system?
Begins chemical digestion of carbohydrates and mechanical digestion
what is the function of the stomach in the digestive system?
Begins digestion of protein; small molecules (eg alcohol) absorbed and mechanical digestion
what is the function of the duodenum in the digestive system?
Continues digestion of carbohydrates and protein; begins digestion of lipids
what is the function of the ileum in the digestive system?
completes digestion of carbohydrates & proteins into single sugars & amino acids; absorption of single sugars, amino acids & fatty acids + glycerol
what is the function of the large intestine in the digestive system?
Absorption of water; egestion of undigested food
A student investigated the effect of temperature on the activity of the enzyme amylase. Why were the starch solution and the amylase solution left for five minutes before mixing them together?
So that both solutions could reach the same temperature
A student investigated the effect of temperature on the activity of the enzyme amylase. The concentration of starch in the solution at 20 °C after 1 minute is different from the concentration at 40 °C after 1 minute. why?
The starch will be broken down slower at 20C because the molecules have less kinetic energy than at 40C so the concentration of starch in the solution will be different.
why are transport systems needed?
to distribute essential molecules efficiently
what colour is oxygenated and deoxygenated blood?
bright red and dark red almost purple
what is a double circulatory system?
where 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
what is the types of veins/arteries in the liver?
hepatic
what is the types of veins/arteries in the kidney?
renal
what is the types of veins/arteries in the legs?
femoral
what is the types of veins/arteries in the neck?
jugular
what is the types of veins/arteries in the lungs?
pulmonary
what is the function of pulmonary artery?
sends blood to lungs
what is the function of vena cava?
brings blood to heart from body
what is the function of right atrium?
pushes blood into right ventricle
what is the function of pulmonary vein?
receives blood from lungs - sends to left atrium
what is the function of left atrium?
sends blood to left ventricle
what is the function of valves?
control blood movement from atrium to ventricles and out into body
what is the function of left ventricle?
sends blood to aorta
describe the flow of blood through the heart.
- deoxygenated blood enters right atrium via vena cava
- 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?
natural pacemaker which controls heart rate in the right atrium
what is the medical intervention for irregular heartbeat?
can have an artificial pacemaker fitted, which sends electrical signals to the SAN
what is the function of septum?
separates the 2 sides of the heart
what is the function of aorta?
sends blood around the body
how do you calculate heart rate?
- 60 / time for 1 heart beat
- measure distance/time between each peak to find time for one heart beat
what kind of blood do veins and arties carry?
arteries carry pressurised blood - veins carry depressurised
list the parts of an artery
lumen, endothelium, muscle & elastic tissue, outer coat
why is muscle needed in an artey?
pushes blood around body (creates pulse)
why is elastic needed in an artery?
provides stretch for increased blood flow
list the parts of a vein
lumen, endothelium, muscle & elastic tissue, outer coat - less muscle & elastic than artery
why is muscle needed in veins?
prevents backflow
why is elastic needed in veins?
provides stretch for increased blood flow
how do vein valves work?
when pressure falls behind the valve, pockets fill & close the valve; when pressure builds valve is pushed open & blood flows through
list the parts of a capillary
lumen, epithelial cells
list the components of blood
wbc, rbc, plasma, platelets
what is plasma?
yellow liquid which carries rbc and wbc
what are platelets?
small fragments of cells which help in blood clotting
why can plasma be useful?
it is universal so will not harm people and can prevent heart attack by maintaining blood volume
why can blood be useful?
prevent death by providing rbc to carry o2
what are some reasons against using blood products?
religious reasons; receiving cells from another person; not natural - HIV, hepatitis; worried about infections
what is the function of rbc?
transports o2 around body in haemoglobin
what are the adaptations of rbc?
- no nucleus (more space for haemoglobin - more o2)
- biconcave (can be squashed to fit through capillaries and increase sa)
what is the function of wbc?
fight diseases
what are the adaptations of wbc?
large nucleus (more dna - high level of control within cell - dna instructs ribosomes how to make antibodies (proteins))
what are the adaptations of a leaf? [4]
- upper epidermis is mostly transparent to allow light to reach palisade cells
- air spaces allow for faster diffusion
- waxy cuticle prevents water loss and infection
- stomata control movement of gases
list the different cells and tissues in a leaf
- cuticle
- upper/lower epidermis
- palisade mesophyll
- spongy mesophyll
- guard cells
- stomata
what are guard cells?
specialised lower epidermis cells which control the opening and closing of stomata
what is the function of the xylem?
transports water and minerals
describe the structure of the xylem
- made of dead cells
- no end walls - less obstruction to movement of water - flows one way in hollow tube
- walls stiffened with lignin
what is the function of the phloem?
transports water and food (glucose and sucrose, fatty acids, oils, amino acids
describe the structure of the phloem
2 way flow
- cells have end walls with perforations; sieve plates
- companion cells; change flow direction; active transport; full of mitochondria
describe the process of transpiration
- osmoses from soil into root hair cell (dilute to concentration solution) - move down concentration gradient.
- moves to root cell.
- moves through xylem - transpiration stream - pulls more water up.
- moves to spongy mesophyll - lower epidermis - stomata.
- diffuse and evaporate out - high water conc in cells - low in air - moves down conc gradient
what are the factors affecting rate of transpiration?
light intensity, temperature, humidity, wind speed
how does light intensity affect the rate of transpiration?
- makes stomata open if brighter - lower LI, stomata close
- if stomata open - transpiration is faster as water can diffuse out of leaves
how does wind speed affect the rate of transpiration?
higher wind speed - faster transpiration - will blow air with high water concentration away - becomes dilute - steeper concentration gradient - diffuse faster
how does humidity affect the rate of transpiration?
- high humidity - slow transpiration
- if air is concentrated with water (humid) - shallow concentration gradient
how does temperature affect the rate of transpiration?
high temperature - particles have higher kinetic energy - evaporate faster as molecules break apart and become gas - as particles move faster
what are the adaptations of plants to reduce water loss?
- rolled leaves
- sunken stomata
- spikes not leaves
- hairs on leaves
- fewer stomata
- shallow, widespread roots
- thick waxy cuticle
how do rolled leaves reduce water loss?
reduce exposure of stomata to air, reducing evaporative water loss.
how do sunken stomata reduce water loss?
reduces air movement over stomata, creating humid microclimate, reducing evaporation rate.
how do spikes reduce water loss?
- prevent animals from eating plant
- spines break up airflow - reduces evaporation - trapped air can create a buffer zone with slightly more moist air
- spines also help collect water from fog.
how do hairs on leaves reduce water loss?
trap air close to leaf - creates microclimate around leaf - as leaf loses water microclimate becomes humid - hairs prevent this from being blown away - humidity - slower transpiration rate
how do shallow and widespread roots reduce water loss?
spread wide to collect surface water from wide area of land
how does fewer stomata reduce water loss?
less places for water to evaporate/diffuse out of leaf
how does thick waxy cuticle reduce water loss?
stops vapour escaping through epidermis - shiny to reflect heat - lower temperature - slower transpiration
define translocation
transportation of food substances produced in photosynthesis, to places where they are needed eg storage organs (bulbs and tubers), developing seeds, growing parts of a plant
what is the cause of 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 heart’s muscle
what are some symptoms of reduced blood flow?
- breathlessness
- harder to do exercise
- pain (cell distress signals from lack of o2)
- lethargy
- higher heart rate and bp
what are non-modifiable risk factors for CHD?
genetic predisposition - inheriting genes that increase the risk of chd
What are modifiable risk factors for CHD?
- stress (lower work load)
- fatty/sugary diet (change diet)
- lack of exercise
- smoking
how do statins work?
- tablets taken 1 per day
- reduce production of cholesterol in liver
- lower levels in blood
what are some pros of treating CHD with statins?
- prevents formulation of plaques (prevents blocking of arteries - heart attacks)
- easy to take
what are some cons of treating CHD with statins?
- 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)
what are some pros of having a mechanical valve replacement?
- not biological tissue (less religious objections)
- more durable (last longer)
what are some cons of having a mechanical valve replacement?
- tendency for blood clots to form metal surface (heart attacks)
- may not work as effectively
what are some pros of having a biological valve replacement?
work naturally (no blood thinning needed)
what are some cons of having a biological valve replacement?
- less durable
- religious objections
- Immunosupressents (may get rejected)
how does heart valve replacement work?
removing a damaged valve in surgery under anaesthetic and replacing it with a new one
what are some pros of heart valve replacement?
- 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)
what are some cons of heart valve replacement?
- anaesthetic (dangerous - allergic reaction - potentially fatal)
- surgery (potential for infection)
how does a heart transplant work?
- surgery under general anaesthetic
- use a heart-lung bypass machine
- remove patient’s heart and replace it with a donor
what are some pros of a heart transplant?
survive (new heart - work more efficiently)
what are some cons of a heart transplant?
- 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?
- stent placed in artery (guided round body using x-ray)
- inflated via balloon
- flattens fatty deposits against artery wall
- widens artery
what are some pros of stents?
decreases risk of heart attack (greater blood flow - easier to supply blood to body)
what are some cons of stents?
- open wound (risk of infection)
- anaesthetic
- can cause an aneurysm (cause bulge - rupture - internal bleeding)
how can CHD cause a heart attack?
- coronary arteries on surface of heart get a tiny deposit of fat & cholesterol (plaque)
- grows & reduces flow of blood
- high blood pressure
- rbc smash against plaques damaging them so the plaques open
- rbc stick to damaged plaque creating a 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
what kind of medical intervention is there for heart attacks?
- ecg to locate dying patch of cells & blocked artery
- TPA medicine - clot-busting drug which destroys plaque/blockage to return blood flow to normal - only works once
- cell may beat out of sync, creating own electrical signals - clashes with SAN - defibrillator shocks heart and stops beating and makes it reset
what happens to 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
what can immune reactions caused by pathogens also trigger?
allergies ie skin rash, asthma
what can viruses in cells be the trigger for?
certain cancers
what can severe physical ill health can lead to?
depression and other mental illness
what is cancer?
the uncontrolled growth of cells which can spread around the body
what is a benign tumour?
a cancer that does not spread, as it is surrounded by a membrane and grows slowly as it is trapped in its membrane but can create pressure on surrounding tissues which can cause numbness
what is the treatment for a benign tumour?
usually left alone, unless causing pain, when surgery is undergone to remove it
what is a malignant tumour?
a cancer that spreads, as cancerous cells break away and travel through capillaries and grows quickly
what is the treatment for a malignant tumour?
kill cancerous cells with radiotherapy (can only work on top few cms) or chemotherapy
