Organisation and Disease Flashcards
(299 cards)
1
Q
Define digestion
A
The breaking down of large food molecules into smaller water soluble molecules both chemically and physically, occurring in certain organs e.g the pancreas
2
Q
Why is digestion important?
A
Large insoluble food molecules cannot get into the blood which need to be used by our cells for vital processes e.g respiration and proteinsynthesis
3
Q
What is the alimentary canal?
A
A muscular tube running through the body fork the mouth to anus
4
Q
What is the function of bile? (3 points)
A
Breaks down large globules of fat into smaller ones (emulsifies them), increases the surface area of fat droplets, neutralises hydrochloric acid from the stomach as it’s alkaline
5
Q
What concentration of oxygen does blood going into the stomach have?
A
High
6
Q
What concentration of oxygen do cells lining the stomach have?
A
Low
7
Q
By which process does oxygen move from the blood to the cells lining the stomach?
A
Diffusion
8
Q
What other substance moves from the blood to the cells lining the stomach so that respiration can take place?
A
Glucose
9
Q
In which part of a cell does aerobic respiration take place?
A
Mitochondria
10
Q
How many alveoli does a human lung have?
A
About 80 million
11
Q
Give three features of the alveoli which allow large amount of oxygen to enter the blood
A
Large surface area, lots of capillaries, thin walls
12
Q
Name the process by which oxygen passes from the air into the blood
A
Diffusion
13
Q
How does breathing allow large amounts of oxygen to enter the blood?
A
More oxygen enters the alveoli and carbon dioxide passes out into the air, the alveoli maintains a higher concentration of oxygen
14
Q
How are the villi adapted to maximise the rate of absorption of the products of digestion? (3 ways)
A
Lots of microvilli provides a large surface area, lots of capillaries meaning they maintain concentration gradient, they have lots of mitochondria which allows for respiration and energy release
15
Q
Function of the small intestine?
A
digested food is absorbed out of the digestive system into the blood
16
Q
Function of the large intestine?
A
absorption of excess water from food into the blood
17
Q
2 functions of the stomach?
A
Production of hydrochloric acid to kill bacteria and give the right pH for protease (pH 2). Pummel food with its muscular walls
18
Q
How does the glucose concentration in the blood compare to that of the small intestine?
A
The concentration in the blood is lower
19
Q
Which three organs produce amylase?
A
Salivary glands, pancreas, small intestine
20
Q
Which two organs produce lipase?
A
Pancreas, small intestine
21
Q
Which three organs produce protease?
A
Stomach, pancreas, small intestine
22
Q
How does acid help digestion?
A
This is the optimum pH for the enzymes
23
Q
Amylase breaks down starch into…
A
Sugars
24
Q
Lipase breaks down fats into…
A
Fatty acids and glycerol
25
Protease breaks down proteins into...
Amino acids
26
Where is bile produced and released into?
Produced in the liver, released into the small intestine
27
Optimum pH of amylase?
pH7
28
optimum pH of protease?
pH2
29
Optimum pH of lipase?
pH8
30
Function of the rectum?
Stores faeces
31
Function of the salivary glands?
Produces saliva containing the enzyme amylase
32
Function of the mouth?
Mechanical digestion
33
What is the oesophagus?
A tube connecting the mouth to the stomach
34
Function of the anus?
Faeces leaves the body here
35
Function of the pancreas?
Produce enzymes and release them into the small intestine
36
Function of the gall bladder?
Stores bile
37
Function of the liver?
Produces bile
38
Oxygen moves from the lungs into the blood through the walls of what?
The capillaries
39
Two adaptions of the lungs that help rapid absorption of oxygen into the blood?
Large surface area, thin membrane
40
How do you test for reducing sugars in a food sample? 5 steps
Prepare food sample and transfer 5cm^3 to a test tube, prepare a water bath set to 75 degrees Celsius, add 10 drops of benedict's solution to test tube using pipette, place test tube pointing away from you in water bath for 5 minutes, if food sample contains a reducing sugar the solution will change from normal blue colour to green, yellow or brick red depending on sugar concentration (red is highest)
41
How do you test for starch in a food sample? 3 steps
Make food sample and transfer 5cm^3 to a test tube, add a few drops of iodine solution and gently shake tube to mix contents, if sample contains starch the colour of solution will change from browny orange to black or blue black
42
What is the function of enzymes?
Break down large insoluble food molecules into small soluble ones so they can diffuse into our cells
43
What are enzymes?
Biological catalysts, they are made of protein
44
Define metabolism
The sum of all reactions in a cell or in the body
45
Why are digestive enzymes different?
Work outside of your cells, are released from specialised cells in glands and the lining of the gut, secreted onto the food travelling through the digestive system
46
What happens in an enzyme reaction if the temperature/pH is too high/strong?
The active site becomes denatured therefore the are less collisions so the reaction decreases and stops
47
How do we test for lipids in a food sample? 3 steps
Prepare food sample and add 5cm^3 to test tube (don't need to filter it), add 3 drops of Sudan III stain solution to test tube and gently shake, solution stains lipids so if the mixture contains lipids it will separate into two layers -the top layer will be bright red
48
How do we test for protein in a food sample? 3 steps
Prepare food sample and add 2cm^3 of sample to test tube, add 2cm^3 biuret solution to the sample and mix contents by gently shaking, if food sample contains protein it will change from blue to pink or purple
49
Why do enzymes have an optimum temperature?
They work best at this temperature and enzyme-substrate complexes form more quickly
50
Function of the heart?
To pump blood around the body
51
In which direction does an artery pump blood?
Away from the heart
52
In what direction does a vein pump blood?
Into the heart
53
Function of the veins?
To carry blood from the capillaries back to the heart and lungs
54
Function of skeletal muscles?
To push the blood up the body and back to heart
55
Is the blood carried by the veins oxygenated or deoxygenated?
Deoxygenated
56
Function of the arteries?
Carry blood away from the heart and to body cells
57
What pressure do veins carry blood under and how are they adapted for this?
Low so they do not need thick muscle layers or thick elastic layers like the arteries, they have a bigger lumen (hold down the middle of the tube) to help blood flow, they have valves to keep blood flowing in the right direction
58
What pressure do arteries carry blood under and how are they adapted for this?
High because the heart pumps blood out at high pressure so they contain thick layers of muscle to make them strong and thick elastic fibres to make them spring back, have a small lumen
59
What is the lumen lined with?
Endothelial cells
60
Is the blood carried by the arteries oxygenated or deoxygenated?
Oxygenated
61
Function of the capillaries?
Involved in exchange of materials at the tissues -they carry blood really close to every cell in the body to exchange substances with them. They supply food and oxygen but take away wastes like CO2
62
Is the blood carried by the capillaries oxygenated or deoxygenated?
Both
63
What are platelets?
Small cell fragments with no nucleus essential to blood clotting, they stop blood pouring out of a wound and stop microorganisms getting in
64
Function of white blood cells?
Defend the body against disease. They do contain a nucleus
65
Function of the red blood cells and 3 ways they are adapted?
Transport oxygen from the lungs to all the cells in the body. They have no nucleus to make more room, they are shaped like a biconcave disc which gives a large surface area for absorbing oxygen, contain a red pigment called haemoglobin which binds to oxygen in lungs to become oxyhaemoglobin but in body tissues the reverse happens
66
What is cardiac output?
The amount of blood the heart pumps in a minute
67
What is heart rate?
How often the heart beats
68
What is stroke volume?
How much blood is pumped out of the heart with each beat
69
What is the relationship between those three things?
CO = HR x SV
70
Four features of a good exchange surface?
Thin walls, good ventilation, lots of capillaries, large surface area
71
What is ventilation?
The process of inspiration and expiration
72
What happens during inspiration?(7 parts)
Ribs pull up and out, volume in chest increases, diaphragm contracts, further volume increase inside the chest, lower pressure in chest (less than atmospheric pressure), air drawn into the lungs from outside, lungs deflate
73
What happens during expiration? (6 parts)
Ribs pulled down and in, volume in thorax decreases, decrease in chest volume, pressure greater than atmospheric pressure, air forged out of lungs, lungs deflate
74
What is the relationship between pressure and volume?
Low pressure = high volume
75
What is health?
A state of physical and mental well-being
76
What is a risk factor?
Any factor, attribute, characteristic that increases the risk of developing a disease
77
What is a correlation?
A change in one variable is reflected by a change in another variable
78
What is cancer?
A group of diseases involving cells in a specific part of the body growing and reproducing uncontrollably
79
How does a tumour form?
Sometimes damaged cells pass through checkpoints which allows them to divide
80
4 characteristics of a benign tumour?
Not cancerous, cannot spread, inside a membrane, cause damage to other organs
81
6 characteristics of a malignant tumour?
Cancerous, can spread, can invade healthy tissue, cells can travel in the blood or lymph system, can form secondary tumours in other organs, destroys organs
82
What is the name for cell division?
Mitosis
83
4 risk factors of lung cancer?
Smoking, lack of exercise, unhealthy diet, air pollution
84
Risk factor of skin cancer?
Exposure to UV radiation
85
4 risk factors of cervical cancer?
Obesity, multiple pregnancies, smoking, STIs
86
3 risk factors of breast cancer?
Inherited genes, lack of exercise, unhealthy diet
87
4 risk factors of testicular cancer?
Smoking, unsafe sex, STIs, infertility
88
4 risk factors of brain tumours?
Radiation, smoking, drinking, being overweight
89
What is coronary heart disease?
Coronary arteries that supply the blood to the heart muscle get blocked by layers of fatty material building up which causes the arteries to become narrow and restricts blood flow so there is a lack of oxygen to the heart muscle so the heart cells cannot respire. This can cause a heart attack
90
What happens with a faulty heart valve?
Pressure cannot build up in the chambers, heart must work harder to build up enough pressure, blood may back flow or clot
91
What do statins do?
Drugs which reduce the amount of bad cholesterol (which can cause fatty deposits to form inside arteries which can lead to CHD) in the bloodstream therefore slow down rate of fatty deposits forming
92
What 2 things do stents do and how?
Keep coronary arteries open and reduce the chance of a heart attack by holding coronary arteries open and allowing blood to flow more freely
93
What is a communicable disease?
An infectious disease transmissible by direct or indirect contact with an affected individual or their discharges, caused by a pathogen like bacteria, funghi, viruses and parasites
94
What is a non communicable disease?
A disease which is non infectious and non transmissible among people, not caused by a pathogen. Generally they last for a long time and get worse slowly
95
6 ways disease is spread?
Water&food, animals, insects, bodily fluids, the aid, direct contact
96
8 ways to decrease your risk of disease?
Get vaccinated, wash hands often, use antibiotics safely, disinfect hot zones in your residence, don’t share personal items, travel wisely, safe sex, be smart about food prep
97
What is phagocytosis?
The process by which a cell (often a phagocyte or protist) engulfs a solid particle to form an internal compartment (a phagosome)
98
What is a phagocyte?
A type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles
99
What is a lymphocyte?
A small white blood cell which plays a large role in defending the body against disease
100
How do white blood cells recognise pathogens?
Pathogens have antigens (protein markers) on them
101
How do white blood cells break down pathogens?
White blood cells make antibodies of a specific shape to fit antigens perfectly which bind together and the pathogen gets broken down
102
What is an independent variable?
The variable you change
103
What is a dependent variable?
The factor you measure
104
What is a control variable?
The variable you keep the same
105
What happens to the body’s antibody concentration after the second infection and why?
The number of antibodies is greater because they are created quicker after being recognised
106
Why do communicable diseases spread faster after a natural disaster? (4 ways)
Disease can spread through water as a result of flooding, air becomes contaminated with gases, people are within close proximity of eachother in hospital, pathogens enter the body through cuts and wounds
107
Which are smaller viruses or bacteria?
Viruses because they are not cells like bacterium
108
What is the viruses DNA like?
Small section of genetic material in a protein coat
109
How do viruses infect the body? (6 steps)
The virus has antigens of a specific shape to fit the receptors of a host cell which allows is to enter, virus releases its DNA in order for replication to occur, the virus takes over the host cells organelle, the virus makes hundreds of thousands of copies, the virus copies fill the cell and burst it open, viruses enter the blood and may attach to a new cell
110
How is tobacco mosaic virus spread? (3 ways)
Plant wounds, tobacco on hands, contaminated seeds
111
What are three symptoms of tobacco mosaic virus?
Mosaic pattern on leaves, stunted growth, areas of leaf die
112
How is measles spread? (2 ways)
Inflation or droplets from coughs and sneezes, contact with infected individuals
113
What are 6 symptoms of measles?
High fever, runny nose, cough, red watery eyes, white spots on cheeks, red skin rash
114
How is HIV spread? (4 ways)
Bodily fluids like blood, sexual contact, breast milk, placenta
115
What are 3 symptoms of HIV?
Rash, joint pain, swollen glands
116
How do bacteria multiply?
By binary fission
117
How frequently can binary fission occur?
Every 20 mins
118
What does bacteria need for binary fission?
Correct temperature and nutrients
119
What temperature are bacteria kept at in school labs to control their growth?
25 degrees Celsius
120
Is bacterial replication sexual or asexual reproduction?
Asexual because it requires one parent to produce identical copies
121
How do bacteria make us ill? (4 ways)
Release poisons or toxins, bodies provide favourable conditions for bacteria, they multiply rapidly, damage our tissues
122
What are 3 differences between viruses and bacteria?
Viruses are much smaller than bacteria, viruses contain DNA in a protein coat whereas bacteria have free flowing DNA, viruses need a living cell to invade unlike bacteria
123
What is gonorrhoea?
A sexually transmitted disease caused by a bacterium called Neisseria gonorrhoeac or gonoccus
124
How is gonorrhoea spread? (2 ways)
By sexual contact, can be passed from a pregnant women to a newborn baby
125
What 5 areas does gonorrhoea cause harm to?
Cervix, urethra, rectum, throat, eyes
126
What are three typical symptoms of gonorrhoea?
Green or yellow discharge from the vagina or penis, pain when urinating, bleeding between periods
127
How many infected men and women don’t experience symptoms of gonorrhoea?
1 in 10 men and almost half of infected women
128
How can gonorrhoea be treated?
Used to be treated with penicillin but now some strains of bacteria are resistant so it is now treated with a different single antibiotic injection and tablet
129
How can STIs be prevented?
Using appropriate contraception and condoms
130
Why is HIV so dangerous when it infects a pregnant women?
It can cause permanent blindness to a newborn baby
131
What does rose black spot disease do?
Causes holes and black/purple pigmentation to form on the leaves of a plant. The leaves can then turn yellow and fall off
132
Why does rose black spot disease stunt plant growth?
Plants cannot absorb light through chlorophyll to carry out photosynthesis, plants need sugar to grow
133
How is rose black spot disease caused and spread?
Caused by a fungus called rose black spot. Spreads through wind and water
134
How can rose black spot be treated? (2 ways)
Fungicides, remove the diseases area and destroy it so the fungus can't be spread to other rose plants
135
What four places do fungi live in?
Water, air, plants, soil
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What is a protist?
A single celled eukaryote that grows on and contaminates food, they can be parasites
137
What is a parasite?
Lives on or inside another organism, relies on host for survival and causes it harm. Often transferred to the organism by a vector which doesn't get the disease itself
138
What is malaria?
A serious tropical disease caused by a type of parasite called Plasmodium, passed person to person by an insect vector (mosquito)
139
What is a vector?
Something which spreads disease rather than causing it
140
When do malaria symptoms appear?
Between 7 and 18 days after becoming infected
141
What are 6 symptoms of malaria?
Sweats and chills, high temp, headaches, vomiting, muscle pains and diarrhoea
142
What happens after you are bitten by a mosquito infected with the parasite?
The parasite enters the bloodstream and travels to the liver where the infection develops before invading red blood cells
143
What two things do vaccinations do?
Help your immune system and protect you from disease like measles
144
How were vaccines discovered?
Edward Jenner recognised that milkmaids and shepherdesses did not have smallpox scars which meant they were immune to the disease however they had all had cowpox which meant that infecting an individual with cowpox prevents them catching smallpox
145
What is a vaccine?
A dead or inactive form of a pathogen injected into the body carrying antigens which the body produces antibodies to attack so if live pathogens of the same type appear in the body the cells can mass produce antibodies rapidly to kill off the pathogen
146
What are three arguments for vaccines?
Plants do not need to be used in medicines, vaccines provide economic benefits for society, controlled lots of communicable diseases that were once common in the UK like mumps and rubella, smallpox no longer occurs due to vaccines, polio infections have fallen by 99%, epidemics can be prevented if large percentage of population is vaccinated
147
What are three arguments against vaccines?
Sometimes people have bad reactions like swelling or a fever or seizure, tested on animals, are expensive, don't always give you immunity
148
What happens in pre-inoculation of preparing an uncontaminated culture of bacterium in a Petri dish? (2 steps)
Petri dish and agar sterilised before use to kill unwanted bacteria, inoculating loop passes through flame/sterile swab to kill/sterilise other bacteria
149
What happens during inoculation of preparing an uncontaminated culture of bacterium in a Petri dish? (2 steps)
loop/swab used to spread bacterium onto agar, lid of Petri dish opened as little as possible to prevent microbes from the air entering
150
What happens in post-inoculation of preparing an uncontaminated culture of bacterium in a Petri dish? (2 steps)
Sealed with tape to prevent microbes from air entering, incubate to allow growth of bacteria
151
What is a medicine?
A chemical substance used in the diagnosis, cure, treatment or prevention of a disease
152
What do painkillers and antiseptics do?
Relieve symptoms of a disease but do not kill pathogens
153
What are antibiotics used for?
Treating bacterial infections by preventing the cell wall forming or binary fission, they do this without killing body cells
154
Why do antibiotics not attack our own cells? (2 reasons)
We do not have cell walls and they may use specific enzymes
155
Why can’t antibiotics treat viral infections?
Viruses are inside of our cells so it’s difficult to develop drugs which kill viruses without damaging body tissues
156
How does bacteria become resistant to antibiotics?
Bacteria is killed by a specific antibiotic but one bacteria may have a mutation making it resistant, all mutated bacteria survive and reproduce rapidly so a large number of antibiotic resistant bacteria exist
157
What is a drug?
A substance taken into the body which modifies and affects chemical reactions in the body
158
What does aspirin originate from?
Willow
159
What does penicillin originate from?
Penicillium mould
160
How was penicillin discovered?
Some of Alexander Fleming ‘s bacteria samples had died after becoming contaminated with a particular fungus so he used this to treat bacteria infections in soldiers, he knew it worked because there were zones of inhibition
161
What was the problem with the discovery of penicillin?
Some strains of bacteria were resistant which resulted in MRSA
162
What six things need to be checked when developing a drug?
Effectiveness, toxicity, safety, ability to be taken in and out of the body, side effects, dosage
163
Why was thalidomide developed and what did it cause?
Developed as a sleeping pill but caused major defects such as shortened limbs
164
How long does drug development take and cost?
12 years, £600 million per drug
165
What happens in the research stage of developing drugs?
Researchers target a disease and make possible drugs using computer models
166
What happens in the pre clinic trials stage of drug development?
Drugs are tested on cells, tissues and sometimes whole organs but most are rejected. However you cannot use human cells and tissues to test a drug that affects whole or multiple body systems, you must use an animal with an intact system
167
What happens in the pre clinical trials part two?
Involves animal testing which tests efficacy (whether the drug works and produces the effect you are looking for), and toxicity (how harmful it is). The law in Britain states any new drug must be tested on two different live mammals
168
What happens in the clinical trials of drug development phase one?
Involves a very low dose in the first human tests which is gradually increased. Tested on healthy volunteers to check for side effects when the body is working normally
169
What happens in clinical trials phase two?
Tested on people suffering from the illness to find the optimum dosage (the dose which is most effective and has the fewest side effects) To test how well the drug works patients are randomly put in two groups- one is given the drug and the other a placebo to allow for the placebo effect
170
What are three arguments for drug development?
Provides jobs, people have a right to be treated, cures many disease
171
What are three arguments against drug development?
Costs £600 million to develop a single drug, involves animal testing, can have side effects
172
What are monoclonal antibodies?
Proteins that are produced to target particular cells or chemicals in the body
173
Why is a child more likely to get a disease when they start school?
Come into contact with infected people and the immune system is not fully developed
174
How does a child catch an illness when they start school?
The virus enters the child’s body and has antigens of a specific shape to fit the host cell but the body has not created antibodies to fit these yet
175
How does blood flow through the body? 11 stages
Enters right atrium through vena cava, tricuspid valve forced open, enters right ventricle, semi-lunar valve closes, blood goes to lungs, at the same time: bloody in the pulmonary vein enters left atrium, bicuspid valve opens, enters left ventricle, semi lunar valve opens, bicuspid valve closes, blood goes into aorta to the body
176
What must she the air do to allow gases to diffuse into the blood?
Constantly move in and out of the lungs
177
What happens in a valve replacement?
Surgeon reaches your heart by making an incision down the middle of your breastbone then uses a heart-lung machine to circulate blood around your body during the operation before opening your heart to reach the affected valve. The replacement is then performed using mechanical or biological valves
178
Give 3 advantages of valve replacement
Biological valves do not damage red flood cells as they pass through open valves, mechanical valves last a lifetime, improved symptoms and quality of life
179
Give 5 disadvantages of valve replacement?
Patient has to take anti blood clotting drugs for the rest of their life, mechanical valves damage red blood cells, chance of further operations to replace them, biological valves are prone to becoming hardened over the course of several years, endocarditis is a risk
180
What is endocarditis?
A rare but serious condition where the inner lining of the heart becomes infected
181
How do stents work?
Inserted into clogged artery with a balloon catheter. The balloon is then inflated and the stent expands and locks in place, pushing the artery wall out and squashing the fatty deposit in the centre of the artery
182
Give 5 advantages of stents
Improve blood flow, prevent further damage to heart, prevent symptoms of heart disease such as chest pain or shortness of breath, effective for a long time, recovery time is relatively quick after surgery
183
Give 3 disadvantages of stents
Small risk of bleeding from the site where the catheter was inserted, blood clots can occur near the stent -called thombrosis, allergic reaction
184
What does a pacemaker do?
Helps monitor your heartbeat, the electrodes detect your hearts electrical activity and send data through wires to the computer in the generator. If your heart rhythm is abnormal the computer directs the generator to send electrical impulses to your heart
185
Give 3 advantages of pacemakers
Eliminate systems Of bradycardia, less shortness of breath, more energy
186
Give a disadvantage of pacemakers
Risk of developing an infection with these symptoms :high temperature of 38 degrees Celsius or above, pain, swelling and redness at the side of the pacemaker
187
Give a disadvantage of transplants
Immunosuppressants must be taken
188
Give 3 factors which cause ill health
Diet, stress, life situations
189
Why is diffusion important for respiration?
Diffusion gives oxygen to the places which need it and respiration refers to movement between cells
190
What happens if an enzyme doesn’t fit the active site (is the wrong shape)?
The body has to work harder and will use more energy
191
Name 4 main blood vessels of the heart
Vena cava, pulmonary vein, pulmonary artery, aorta
192
What does the superior vena cava do?
Returns blood to the heart from the upper body
193
What does the inferior vena cava do?
Carries deoxygenated blood from the lower half of the body to the right atrium of the heart
194
What does the pulmonary artery do?
Carries deoxygenated blood from the right ventricle to the lungs
195
What does the pulmonary vein do?
Carries oxygenated blood from the lungs back to the left atrium of the heart
196
What does the aorta do?
Distribute oxygenated blood to all parts of the body
197
How could improve reliability/validity of the potato experiment? 4 things
Make sure they are all the same mass at the beginning, make sure the balance is accurate, do the test multiple times, make sure solutions do not exaporate
198
How is malaria passed on?
If a mosquito bites a person who is infected by malaria, it can become infected so when it bites another person they become infected
199
Give 2 advantages of using monoclonal antibodies in medicine
Can be used to diagnose and treat diseases, used to mark and identify molecules in cells
200
Give 4 disadvantages of using monoclonal antibodies in medicine
Costs, risks, take a long time to produce, use of animals
201
What is the function of valves?
Stop backflow of blood
202
What happens in blood clotting?
When the heart must work harder to build up enough pressure, blood may back flow or clot due to platelets releasing an enzyme fibrinogen to form a mesh work
203
Give 5 medical risk factors of coronary heart disease
High blood pressure, high cholesterol, diabetes, genetic factors, medicine
204
Give 9 lifestyle risk factors of CHD
Obesity, high fat diet, lack of exercise, smoking, consumption of drugs, exposure to air pollution, eating insufficient fruit and veg, high salt intake, alcohol
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How does high blood pressure cause CHD?
Puts added pressure on walls of arteries and over time this extra pressure damages the arteries which makes them vulnerable to narrowing
206
How does high cholesterol cause CHD?
LDL, known as bad cholesterol, clings to the walls of your arteries if there is too much of it in your blood stream which can eventually clog your arteries
207
How does diabetes cause CHD?
High blood glucose can damage your blood vessels and the nerves that control your heart and blood vessels
208
How does smoking (lifestyle risk factor of CHD) link to the medical risk factors?
Leads to high blood pressure, cholesterol and fatty deposition
209
How does obesity (lifestyle risk factor of CHD) link to the medical risk factors?
Can cause high blood pressure, cholesterol, fatty deposition and diabetes
210
How can genetic factors cause CHD?
Could cause high blood pressure or high cholesterol, diabetes or obesity
211
How does alcohol (lifestyle risk factor of CHD) link to the medical risk factors?
Could lead to high blood pressure or cholesterol
212
How does high salt intake (lifestyle risk factor of CHD) link to the medical risk factors?
Leads to high blood pressure
213
How does the use of medication/medicine cause CHD?
It can affect blood and blood vessels and metabolism
214
Why is the human heart referred to as part of a dual circulatory system (two circuits joined together)?
Blood passes through the heart twice. In the first circuit, the right ventricle pumps deoxygenated blood to lungs to take in oxygen then blood returns to the heart. In the second one the left ventricle pumps oxygenated blood all around the organs of the body, blood gives up oxygen to body cells and deoxygenated blood returns to the heart to be pumped into the lungs again
215
Where is the right atrium located on a diagram of the heart?
Top left corner
216
Where is the left atrium located on a diagram of the heart?
Top right corner
217
Where is the right ventricle located on a diagram of the heart?
Bottom left
218
Where is the left ventricle located on a diagram of the heart?
Bottom right
219
Where is the pulmonary vein located on a diagram of the heart?
Furthest to the right at the top
220
Where is the vena cava located on a diagram of the heart?
Furthest to the left at the top
221
Where is the pulmonary artery located on a diagram of the heart?
Second from the left at the top
222
Where is the aorta located on a diagram of the heart?
Second from the right at the top
223
Function of coronary arteries
Deliver oxygen to the capillaries in the heart muscle
224
What do pacemaker cells do?
This group of cells in the right atrium wall control heart rate by producing a small electrical impulse which spreads to surrounding muscle cells causing them to contract
225
How does bile help digestion of lipid in milk?
The enzymes in the small intestine work best in alkaline conditions, but the food is acidic after being in the stomach. Bile is an alkaline substance produced by the liver and stored in the gall bladder. It is secreted into the small intestine, where it emulsifies fats. This is important, because it provides a larger surface area in which the lipases can work.
226
What are tissues?
A group of similar cells which work together to carry out a particular function. Can include more than one type of cell
227
What is the function if the glandular tissue?
Make and secrete chemicals like enzymes and hormones
228
What is an organ?
A group of different tissues that work together to perform a certain function
229
What 3 tissues is the stomach made up of and what do they do?
Muscular tissue moves stomach wall to churn up food, glandular tissue which makes digestive juices to digest food, epithelial tissue covers outside and inside of stomach
230
What is an organ system?
Group of organs working together to perform a certain function
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Which 6 organs is the digestive system made up of and what do they do?
Glands produce digestive juices, stomach and small intestine digest food, liver produces bile, small intestine absorbs soluble food molecules, large intestine absorbs water from undigested food leaving faeces
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What are enzymes?
Catalysts produced by living things; they carefully control chemical reactions (only catalyse one specific reaction though) to get the right amount of substances. They are large proteins made up of chains of amino acids, chains fold into unique shapes to form active sites
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What are catalysts?
Substances which increase speed of a reaction without being changed or used up by the reaction
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What does the 'induced fit' model of enzyme action show?
The active site changes shape a little as the substrate binds to it to get a tighter fit
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What effect does pH have on enzyme controlled reactions?
If it is too high or low the pH interferes with bonds holding the enzyme together which changes the shape of the active site and denatures the enzyme
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How can you investigate how pH affects amylase activity? 8 steps
Put a drop of iodine solution into every well of a spotting tile, place a Bunsen burner on a heat proof mat and a tripod and gauze over the Bunsen burner which you place a beaker of water on top and heat until it is 35 degrees Celsius, using syringe add 1cm^3 amylase solution and 1cm^3 buffer solution pH5 to a boiling tube and put this boiling tube into the water and wait for five minutes, using syringe add 5cm^3 starch solution to boiling tube, mix contents of boiling tube and start stop clock, sample mixture every 30 seconds with a dropping pipette into a well in the spotting tile (when the iodine solution remains browny orange starch has been broken down), repeat whole experiment with buffer solutions of different pH values, control concentration and volume of amylase solution for fair test
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How to calculate rate of reaction?
How much something changes (e.g amount of product formed) divided by time
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What are the 2 functions of bile?
Neutralises hydrochloric acid in the stomach and makes conditions alkaline because the hydrochloric acid makes the pH too acidic for enzymes in the small intestine to work, enzymes work best in these conditions. Emulsifies fat (breaks it into tiny droplets) which gives a much bigger surface area of fat for the enzyme lipase to work on, making digestion faster
239
Identify 10 parts of the thorax
Oesophagus, trachea (wind pipe), intercostal muscles (between ribs), alveoli (air sacs on end of bronchioles), heart, ribs, pleural membranes around lungs, bronchus on end of trachea, bronchioles which stem off the bronchus, diaphragm
240
What is the thorax?
Top part of your body which is separated from the lower part by the diaphragm
241
How is the thorax structured? 4 points
Lungs like pink sponges are protected by the ribcage and surrounded by pleural membranes, air that you breathe in goes through the trachea which splits into two tubes called bronchi -one goes to each lung, bronchi split progressively into smaller tubes called bronchioles, bronchioles end at small air bags called alveoli where gas exchange occurs
242
How does gas exchange occur in the lungs? 6 points
Millions of air sacs called alveoli surrounded by a network of blood capillaries, blood passing next to the alveoli has just returned to the lungs from the rest of the body so it contains lots of carbon dioxide and very little oxygen, oxygen diffuses out of the alveolus (high conc) into the blood (low conc), carbon dioxide diffuses out of the blood (high conc) into the alveolus (low conc) to be breathed out, when blood reaches body cells oxygen is released from red blood cells (higher conc) and diffuses into the body cells (low conc), at the same time carbon dioxide diffuses out of body cells (high conc) into blood (low conc) and is carried back to lungs
243
What is the equation for breathing rate?
Number of breaths divided by number of minutes
244
What are the 2 functions of the circulatory system?
Carry food and oxygen to every cell in the body, carry waste products to where they can be removed from the body
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How is the heart adapted to keep blood flowing around the body? 2 ways
Walls of the heart mostly made of muscle tissue, heart has valves to prevent blood flowing backwards (make sure it flows in one direction only)
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How does the heart use its four chambers to pump blood around the body? 5 points
Blood flows into the two atria from the vena cava and pulmonary vein, atria contract which pushes blood into the ventricles, ventricles contract which forces blood into the pulmonary artery and the aorta and out of the heart, blood flows to organs through arteries and returns through veins, atria fill again and the whole cycle starts over
247
How does the heart have its own supply of oxygenated blood?
Coronary arteries branch off the aorta and surround the heart making sure it gets all the oxygenated blood it needs
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Identify 2 ways capillaries are adapted for their function
Permeable walls so substances can diffuse in and out, walls only one cell thick which increases diffusion rate by decreasing distance over which it occurs
249
What do arteries branch into?
Capillaries which eventually join up to form veins
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Equation for blood flow?
Volume of blood divided by number of minutes
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What 9 things does plasma (a liquid) carry in blood?
Red blood cells, white blood cells, platelets, nutrients like glucose and amino acids (soluble products of digestion), carbon dioxide from organs to lungs, urea from the liver to kidneys, hormones, proteins, antibodies/antitoxins produced by white blood cells
252
What does haemoglobin do in red blood cells?
Binds to oxygen in the lungs to become oxyhaemoglobin, in the body tissues the reverse happens (oxyhaemoglobin splits up into oxygen and haemoglobin to release oxygen into cells)
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What are the 4 main things in blood?
Red blood cells, white blood cells, platelets, plasma
254
How do you produce a food sample for food tests? 4 steps
Break up a piece of food using a pestle and mortar, transfer ground up food to a beaker and add distilled water, give mixture a good stir with a glass rod to dissolve some food, filter solution using a funnel lined with filter paper to get rid of solid bits of food
255
What is cholesterol?
An essential lipid your body produces and needs to function properly however too much 'bad/LDL' cholesterol can cause health problems
256
Give 5 advantages of statins
Reduce amount of bad cholesterol therefore reduce risk of strokes, CHD and heart attacks. increase the amount of a beneficial type of cholesterol (HDL) in your bloodstream, some studies show statins may help prevent some other diseases
257
Identify 6 disadvantages of statins
Long term drugs which must be taken regularly but someone might forget, cause negative side effects like headaches, kidney failure, liver damage, memory loss. Effect isn't instant it takes time to kick in
258
What are the two options of treatment if a patient has heart failure?
Heart transplant from people who have recently died, if they are not available or aren't the best option an artificial heart may be fitted
259
What are artificial hearts?
Mechanical devices that pump blood for a person whose own heart has failed, a temporary fix to keep a person alive until a donor is found or help them recover by allowing the heart to rest and heal. I some cases they are used as a permanent fix which reduces need for donor hearts
260
What is the main advantage of artificial hearts?
Less likely to be rejected from a patient's immune system than a donor heart because they are made from metals or plastics so the body doesn't recognise them as foreign and attack in the way it does with living tissue
261
Identify 4 disadvantages of artificial hearts
Surgery to fit one (as well as with transplant surgery) can lead to bleeding and infection, don't work as well as healthy natural hearts because parts of the heart could wear out or the electrical motor could fail, blood doesn't flow through artificial hearts as smoothly which can cause blood clots and strokes, patient has to take drugs to thin their blood to make prevent blood clotting which can cause problems with bleeding if they're hurt in an accident
262
How can heart valves be weakened or damaged (3 ways) and what does the damage cause (2 things)?
Heart attacks, infection, old age. Causes valve tissue to stiffen so it won't open properly or valve may become leaky allowing blood to flow in both directions so it does not circulate as effectively as normal
263
How can artificial blood keep you alive in an emergency?
When someone loses a lot of blood in an accident, their heart can still pump remaining red blood cells around to get oxygen to their organs as long as the volume of blood can be topped up. Artificial blood is a salt solution (saline) which is used to replace lost volume of blood. Its safe if no air bubbles get into the blood and can keep people alive even if they lose 2/3 of red blood cells
264
What advantages would an artificial blood product have?
Would replace the function of red blood cells so there is no need for a blood transfusion which would therefore decrease the number of diseases being passed on
265
Give 4 examples of how diseases can interact and cause other physical and mental issues
People who have problems with their immune system are more likely to suffer from communicable diseases as their body is less likely to defend itself from the pathogen, some types of hepatitis virus cause infections which cause long-term infections in the liver which can lead to increased chance of liver cancer, infection with HPV can cause cervical cancer, immune system reactions in the body caused by infections by a pathogen can sometimes trigger allergic reactions such as skin rashes or worsen symptoms of asthma
266
What are 7 costs of non communicable diseases?
death, shorter lifespan, lower quality of life for sufferer and their family, huge cost for NHS to research and treat these diseases, families may have to move or adapt their home to help a family member which can be costly, family's income will be reduced if the sufferer has to give up work or dies, reduction in number of people able to work affects country's economy
267
Why are non communicable diseases more common in developed countries?
People have higher income and buy high fat food
268
How do lifestyle factors have different impacts on health nationally?
People from deprived areas are more likely to smoke, have a poor diet and not exercise
269
What affects the 'local' incidence of a disease?
Your personal choices
270
How does alcohol cause liver disease?
Liver breaks down alcohol but the reaction can damage its cells, liver cells can also be damaged when toxic chemicals leak from the gut due to damage to intestines caused by alcohol
271
How does alcohol affect brain function?
Can damage nerve cells in the brain which causes thre brain to lose volume
272
How do smoking and alcohol affect an unborn baby?
Smoking reduces the amount of oxygen it receives and can cause lots of health problems, alcohol damages baby's cells affecting its development and causing a wide range of health issues
273
Why can't correlations always show cause of a disease?
Some risk factors aren't capable of causing a disease but they are related to another risk factor which is. For example, a lack of exercise and high fat diet are heavily linked to an increased chance of cardiovascular disease but they can't cause the disease directly; it is the high blood pressure and high 'bad' cholesterol levels that cause it
274
Identify 3 things which have improved cancer survival rates
Improved treatment, being able to diagnose cancer earlier, increased screening for the disease
275
Give an example of when inheriting faulty genes can make you more susceptible to cancer
Mutations in the BRCA genes have been linked to an increased likelihood of developing breast and ovarian cancer
276
What 2 infections can measles lead to?
Pneumonia (lung infection) or encephalitis (brain infection)
277
When do symptoms of HIV develop and how can the virus be controlled?
Flu like symptoms for a few weeks then no other symptoms for several years. During this time HIV can be controlled by antiretroviral drugs which stop the virus replicating in the body
278
How does the HIV virus attack the body?
Attacks immune cells and if a body's immune system is badly damaged it can't cope with other infections or cancers. By this stage the virus is known as AIDS
279
Describe the part of a malarial protist's life cycle which takes place inside a mosquito
Mosquitoes are vectors which pick up the malarial protist when they feed on an infected animal. Every time the mosquito feeds on an another animal it infects it by inserting the protist into the animal's blood vessels
280
What is salmonella?
A type of bacteria that causes food poisoning (eating food that has been contaminated e.g chicken which caught the disease when it was alive)
281
Identify 4 symptoms of salmonella -what are these symptoms produced by?
Fever, stomach cramps, vomiting, diarrhoea. Caused by the toxins bacteria produce
282
Identify 2 ways to protect people from mosquitoes and other vectors
Insecticides, mosquito nets, destroy mosquito habitat so they cannot breed
283
How does the skin defend against disease?
Acts as a barrier and also secretes antimicrobial substances which kill pathogens
284
How do the hair and nose defend against disease?
Hair and mucus inside your nose trap particles which could contain pathogens
285
How do the trachea and bronchi defend against disease?
Secrete mucus to trap pathogens. They are lined with cilia which are hair like structures that waft the mucus up the back of the throat where it can be swallowed
286
How does the stomach defend against disease?
Produces hydrochloric acid which kills pathogens that make it far from the mouth
287
What do antitoxins do?
Counteract toxins by invading bacteria
288
What is an advantage and 2 disadvantages of antibiotics?
Greatly reduced number of deaths from communicable diseases caused by bacteria. Cannot treat viral infections, bacteria can become resistant
289
Why do many drugs originally come from plants?
Plants produce a variety of chemicals to defend themselves against pests and pathogens. Some of these chemicals can be used to treat human diseases or relieve symptoms
290
Identify 2 current medicines which were discovered by studying plants
Aspirin is used as a painkiller and to lower fever, derived from a chemical found in willow. Digitalis is used to treat heart conditions, developed from a chemical found in foxgloves
291
When are the results of drug testing published?
After they've been through peer review (when other scientists check the work is valid and has been carried out rigorously) to prevent false claims
292
Why do children with cystic fibrosis grow more slowly than those without? 2 points
CF blocks the duct leading from the pancreas to the small intestine so the pancreas cannot create enzymes to break down large insoluble food molecules to smaller soluble ones meaning less nutrients are absorbed so less amino acids are produced to make protein, starch cannot be broken down into glucose for respiration so less aerobic respiration occurs and less energy is released
293
What molecule are genes made of?
DNA
294
Why is the median age for people with CF lower than the median age for a whole population?
People with CF have a shorter life span
295
What do you call the heart's natural pacemaker?
SAN node
296
Do capillaries carry blood under low or high pressure and how are they structured?
Low, they have no muscle wall or elastic layer present, small lumen
297
Why would someone with a higher cardiac output be more successful in a race?
Their heart is beating more times per minute and more blood is being pumped so the patient would get more oxygen and glucose to their cells and more aerobic respiration would occur, meaning more energy is released and more carbon dioxide removed
298
Identify 2 advantages of using a cow tissue heart valve as oppose to a living tissue heart valve
There are lots of cows being used for meat so there would be a shorter waiting time as you are not waiting for a donor like you would with a living heart valve, the operation is less invasive as it is attached to a stent and is inserted through your leg so open heart surgery is not required
299
Identify 4 disadvantages of using a cow tissue heart valve as oppose to a living tissue heart valve
Risks of using a stent (allergic reaction, blood clot, bleeding at site of insertion), higher chance of rejection from a cow valve as it is viewed as foreign, only been used since 2011 which is a shorter time than living heart valves so there may be unknown risks, people may be against the use of animals for religious reasons
