Flashcards in Topic 1 Deck (119):
1
What processes cause CHD
Athlerosclerosis and blood clots. (due to high blood pressure, toxins and fat deposits)
2
What is a stroke
A stroke is a blood clot in the brain that cuts off blood circulation
3
Why is a circulatory system or a mass transport system needed
For mass flow, to overcome the limitations of diffusion
4
Who uses open cirulatory systems
Insects
5
How does an open circulatory system work
Oxygenated blood is pumped into cavities around vital organs for diffusion. Blood circulates in large cavities
6
Who has closed circulatory systems
Many animals and all vertibrates
7
What does a closed circulatory system contain
Tubes for the blood often vessels, high blood pressure with no cavities for faster transport of blood, either a single or double circulatory system and (in this order) arteries -> arterioles -> capilaries -> venules -> veins.
8
How does a single circulatory system work
Deoxygenated blood is pumped from the heart to the gils, diffusion of substances takes place and the blood oxygenates, the oxygenated blood flows through the body and back to the heart
9
How many atriums and ventricles do single and double circulatory systems have
Double = two of each
Single = one of each
10
How does a double circulatory system work, and what components of the heart does the blood travel through
Deoxygenated blood from the right side of the heart is pumped from the heart to the lungs via Pulmanory artaries. The blood becomes oxygnated in the lungs and returns to the left side of the heart via the pulmanory veins. This oxygenated blood is sent to the body via the aorta, and returns to the right side of the heart via the inferior and superior vena cava.
11
What are the charge properties of water
It is a dipole because it has two equally charged polls. It is also a polar molecule because it has a uneven distribution of charge. Its negative ends are attracted to the positive ends allowing hydrogen bonds to form.
12
What are the solvent properties of water
Many chemicals can dissolve into it due to its dipole nature, this allows vital chemical reactions to take place inside the cytoplasm and allows for the transport of substances.
13
What are the thermal properties of water
Has a high specific heat capacity, therefore a lot of energy is needed to break the hydrogen bonds. This causes water to warm up and cool down slowly.
14
What causes the lub and dub sounds
Lub = atrioventricular valves
Dub = semi-lunar valves
15
What does myogenic mean
It means that something can generate its own impulse
16
What do all vessels contain
Collagen, Elastic fibres, smooth muscle and endothelium
17
What is collagen
Collagen is fibreous proteins which make blood vessels stronger and durable
18
What are the properties of arteries and arterioles
Narrow lumen, thick muscle wall, no valves
19
What are the properties of capillaries
Lumen only allows blood cells through in single file, wall is only one cell thick for higher rates of diffusion. No valves.
20
How does blood flow through the arteries and arterioles
When blood flows into these vessels due to systole, the vessels dilate due to the infulx of blood, this is possible because of the elastic fibres. During diastole pressure is maintained due to the vessels constricting, this also smoothens the flow of blood, this is so there is a steady flow of blood in the smaller arterioles and capillaries.
21
How does the blood flow through the capillaries
The flow of blood is steady in the capillaries for more diffusion of substances, there is also high friction in the capillaries which reduces the rate of the flow. There is one close to every cell in the body.
22
How does the blood flow through the venules and veins
There is a low pressure, and blood flows steadily with no pulses, the flow is assisted by the skeletal muscle pump and breathing. Any backflow of blood is prevented by the semilunar valves.
23
What happens during atrial systole (phase 1)
Blood arrives in the atriums via the inferior and superior vena cavas (right), and the pulmonary veins (left) due to the skeletal muscle pump and breathing. The atriums start to fill with blood and pressure increases forcing some blood through the atrioventricular valves into the ventricles. When systole occurs the atriums contract to force more blood into the ventricles.
24
What happens during ventricular systole (phase 2)
There is a slight delay after atrial systole before ventricular systole takes place. Ventricles contract from the base of the heart upwards increasing pressure on the semilunar valves which open allowing blood into the aorta and the pulmonary arteries. This pressure causes the atrioventricular valves to close preventing the backflow of blood into the atriums.
25
What happens during cardiac diastole (phase 3)
The atriums and ventricles relax, elastic recoil of the heart allow for a decrease in pressure. Due to a higher pressure in the aorta and the pulmonary veins the semilunar valves close. The coronary arteries fill up with blood. Low pressure in the atria helps draw in blood for the next contraction.
26
What is atherosclerosis
It is a disease process that leads to coronary heart disease, creates a fatty deposit in arteries that can block them or increase the chance of a blood clot
27
What happens in the first stage of atherosclerosis
The endothelium layer lining the artery gets damaged due to high blood pressure or toxins in the blood.
28
What happens in the second stage of atherosclerosis
There is an inflammatory response once the inner lining of the artery has been breached. White blood cells leave the blood and enter the artery wall. These cells accumulate
29
What happens in the third stage of atherosclerosis
Calcium salts and fibrous tissue also build up at the site, this results in hard swelling creating a plaque on the inner wall.
30
What is the first thing that happens in the clotting cascade
Platelets and damaged tissue release the protein thromboplastin
31
What is the second thing that happens in the clotting cascade, and what must be present in the blood
Thromboplastin activates the enzyme that catalyses the conversion of the protien prothrombin to the enzyme thrombin. vitamine K and calcium ions must be in the blood.
32
What is the order and names of the proteins and enzymes that are in the clotting cascade
Thromboplastin --> protein
(enzyme activates)
Prothrombin --> protein
(Converts to)
Thrombin --> enzyme
(acts as catalyst for next conversion)
Fibrinogen --> soluble plasma protein
(conversion)
Fibrin --> insoluble protein
33
What is the third thing that happens in the clotting cascade
Thrombin catalyses the conversion of the soluble plasma protein fibrinogen into the insoluble protein fibrin
34
What is the fourth thing that happens in the clotting cascade
Fibrin creates a mesh that traps more platelets and red blood cells
35
What is CHD (coronary heat disease)
Due to narrowing of the coronary arteries, O2 rich blood reaching the cardiac muscle is limited resulting in aerobic respiration and a pain known as angina. If blood supply is cut off (ischaemic) this causes cells to become permanently damaged causing a myocardial infraction
36
What are the symptoms of CHD
• Shortness of breath
• Increases pain, ache or discomfort in chest, left arm or shoulder (women may not get chest pain)
• Similar indigestion symptoms
• Arrhythmia irregular heart beat
Angina
37
What is a stroke
If blood supply is only briefly interrupted = mini stroke (all symptoms of a stroke but for a shorter time) can recover quickly. Blood clot = a full stroke if cells are starved of O2 it can be fatal
38
What are the symptoms of a stroke
• Numbness
• Dizziness
• Confusion
• Slurred speech
• Blurred vision or one eye vision
39
What is an Aneurysm
A narrowed artery becomes less flexible and blood clot builds most commonly in the aorta. As it grows aorta walls are stretched to 6-7cm in diameter and rupture. A bulge can be felt
40
What are the symptoms of an aneurysm
Bulge in chest
41
What are the risk factors of CVD
• Age --> old have higher risk
• Sex --> males have higher risk
• Heredity (genetic inheritance)
• Physical environment --> drugs, diet and exercise
• Social environment --> what people around you do and tell you to do
• Life style and behaviour --> drugs, diet and exercise
• high bp
• obesity
• high blood cholesterol
• smoking
• inactivity
42
Why do people over estimate and underestimate
Because it is either involuntary, not natural, unfamiliar, dreaded, unfair or has a very small risk
43
Why are null hypothesis and control variables used
To find if the causation and correlation is linked
44
What types of studies can be used
Cohort and case control studies
45
What is a cohort study
• Follow a large group of people and looks to see who develops the disease and who doesn’t, they find a causation and correlation.
• Prospective --> no one starts with the disease
OR
• Follow two groups one exposed to possible risk factor, the other is not exposed to the possible risk factor. This is to determine the causation and correlation.
46
What is a case control study
• People with the disease are compared with people who don’t
• Info on key factors are collected
47
Give an example of cohort study
In 1948 the Framingham heart study, the aim was to identify factors that contribute to the disease
• 5209 men + women ages 30-62 with no symptoms
• 2nd generation joined the study to the 3rd generation joined to this day
Every two years they provide medical history, physical examination and answer questions about lifestyle
AND
World health organisation
• 10 million people 25-64, in 21 countries for 10 years
• Finished in 1990s
48
Give an example of a control study
Global case-control study called INTERHEART this study Screened patients who got a heart attack from 262 hospitals in 52 countries, got 15152 causes and 14820 controls
49
What are the main features of a good study
Clear aim, Representative sample, valid and reliable results, sample size and controlling variables.
50
What is a calorie
A calorie is the quantity of heat energy required to raise 1cm³ of H2O by 1°C or K, C=calorie
1000c = 1kc 1C = 4.18J, 1kc=0.00418J
51
Where does energy come from
Carbohydrates, lipids and protein
52
What reverses a condensation reaction and what is required
Hydrolysis, water is needed
53
What are the three types of carbohydrates
Monosaccharides, Disaccharides and Polysaccharides
54
Name three types of Monosaccharides, and what typess of sugar they are.
Glucose, Galactose and Fructose. They are 6 carbon hexose sugars and monomers
55
Name three Disaccharides
Maltose, Sucrose and Lactose
56
Name three Polysaccharides
Starch, Glycogen and Cellulose
57
What are the main things about glucose
It is the main sugar in cell membranes, makes starch and glycogen.
58
What are the key things about Galactose
Its the main sugar in Lactose
59
What are the key things about fructose
Naturally in fruit and some vedge, sweetness attracts animals and is absorbed rapidly by the blood
60
What are the key things about Sucrose
Is made of a glucose + fructose, is the usual form of sugar for transport in plants
61
What are the key things about Maltose
Made of two glucose molecules, produced when amylase breaks down and can be found in germinating seeds
62
What are they key things about Lactose
Made of glucose + galactose and is the main sugar in milk
63
What are monosaccharides
Single sugar units that have 3-7 carbon atoms and are rapidly absorbed by the blood
64
What are Disaccharides
Made from two single sugar units (monosaccarides), forms 1-4 glycosidic bonds and has to be digested into monosaccarides for absorption
65
What are Polysaccharides
Is a long chain of monomers = polymer, all joined together with 1-4 glyocidic bonds and are not very soluble
66
What are the key things about starch
Main storage molecule in cells, it is a compact molecule with low solubility in water and thus does not extract water into the cell via osmosis
67
What are the two types of Polysaccharides that make up a starch molecule
Made of Amylose (20-30%, straight helix, chains 200-5000 glucose with 1,4 glycosidic bonds) and Amylopectin (70-80%, same as amylose but has side branches with 1,6 glycosidic bonds) which is more soluble in water
68
What are the key things about Glycogen
• Used by bacteria, fungi and animals instead (or in combination with) of starch as a storage molecule
• Has numerous side branches
• Can be rapidly hydrolysed
• Humans store it in the liver and muscles
69
What are the key things about Cellulose
• Is a dietary fibre
• Non-starch polysaccharide
• 10000 glucose joined together to form a straight chain with 1,4 glycosidic bonds
• Indigestible to humans but helps movement in the digestive tract
70
What are some key things about fats
• Supply over double the energy as carbs (37Jk g⁻¹)
• Insoluble in water but soluble in organic solvents such as ethanol
• Provide energy and essential fatty acids that the body cannot produce
71
What is the general structure of a lipid
Most of them are triglycerides which are made from three fatty acids and one glycerol connected by an ester bond which is formed in a condensation reaction (one for each fatty acid)
72
What are saturated fats
• If the fatty acid chain is a lipid containing the max amount of hydrogens it is saturated
• No carbon to carbon=straight chain
• Pack closely together and have strong intermolecular bonds
73
What are unsaturated fats
• Are not straight, have double carbon – carbon bonds cause kinks in the chain
• Monounsaturated has one double bond in each chain
• Polyunsaturated has a large number of double bonds
• Both can’t pack closely together and are liquid at room temperature
• Can be hydrated and made saturated = hydronated or trans fats
74
What is cholesterol
• Short molecule essential for good health
• Vital in cell membranes
• Makes some sex hormones such as progesterone and testosterone
• Forms bile salts for digestion
• Obtained from saturated fats
75
What is DRVs
Dietary reference values
• Essential average requirements
• Lower reference nutrient intake (the least amount of nutrients required)
• Higher reference nutrient intake (the most nutrients required)
76
What is BMR
Basel metabolic rate
• Is the energy required for essential body processes
• Higher in, males, fat, younger and more active people
77
What is BMI and how is it measured
Body mass index
• A method for classifying body weight
• Kg/m²=BMI
78
What is waist to hip ratio and how is it measuresd
• Better measure than BMI, due to its better correlation with heart attacks
• Waist circumference (narrow point between hip bone and rib cage)/hip circumference (widest point around the glutes)
• Men should be over 0.9
• Women should be over 0.85
79
What are the consequences of obesity
• Increases the risk CHD, stokes and type 2 diabetes
• Elevated bp, lipid levels = CVD
80
What is type 2 diabetes
Can’t produce sufficient insulin or body fats (type 1 is unable to take in insulin). Insulin is a hormone that regulated blood glucose levels, it is produced by the pancreas, and causes cells to absorb glucose.
81
What are lipoproteins
Insoluble cholesterol combined with proteins to make it soluble
82
What are the two main types of lipoprotein, and which are good or bad
LDL (bad) and HDL (good)
83
What are LDLs
• Triglycerides + cholesterol + protein
• Circulates the blood stream, binds to cell receptors to be absorbed
• Excess can overload the cells receptors and cause deposits on the artery wall as atheroma’s (part of atherosclerosis)
84
What are the HDLs
• More protein less cholesterol (semi triglyceride) = more dense
• Transports cholesterol from tissues to liver and breaks down
• Causes cholesterol levels to decrease and remove plaques
85
What is the difference between saturated and unsaturated
• Saturated = more LDL and HDL but significantly more LDL
• Polyunsaturated fat = decrease in LDL and HDL but significantly more LDL is decreased
86
What why is smoking bad
• CHD is 60% higher in smokers
• CO binds to haemoglobin instead of O2 meaning less gets to the cells and increases the risk of a myocardial infraction (aerobic respiration)
• Nicotine produces adrenaline which increases heart rate and vasconstricts arteries and arterioles which increases blood pressure
• Chemicals damage the lining of the arteries atherosclerosis
• Reduction of HDL cholesterol
87
Why is inactivity bad
• Moderate exercise prevents high bp and can lower resting bp
• Help maintain a healthy weight
• Increase HDL but has no effect on LDL
• Reduces risk of type 2 diabetes
• More likely to survive a myocardial infraction
88
What negatives to inheriting
Can be more likely to develop a disease, can get defective alleles.
89
What is sickle cell
Is inherited, and causes red some red blood cells to be a sickle or crescent shape, which can restrict blood vessels and also makes them unable to carry O2
90
Can gene disorders increase the chance of CHD
Yes
91
What is a Apolipoprotein gene cluster
• This is an example of where several genes can affect the likelihood of CVD
• This gene cluster has been linked with Alzheimer’s
• Apolipoprotein is a component for lipoproteins
92
What are the three types of Apolipoprotein
APOA
APOB
APOE
93
What is APOA
• major protein in HDLs and helps with removal
• mutations can cause a reduction of removal which will increases the chance of CVD
94
What is APOB
• Major protein in LDL
• Mutations result in higher LDL levels in blood = higher risk of CVD
95
What is APOE
• Major component in HDLs and VLDL (very-low density lipoprotein) which both remove excess cholesterol to the liver
• All are ok except for APOE4 which slows down the removal of cholesterol = increase the risk of CVD
96
Why is CHD multi-factorial
because there are multiple factors such as genes that effect it
97
How can salt contribute to CVD
causes kidneys to retain water = high fluid levels in blood = higher bp
98
How can stress contribute to CVD
release of adrenaline = arteries and arterioles to vasoconstrict = higher bp
99
How can alcohol contribute to CVD
• Raised bp
• Contributes to obesity
• Irregular heart beat (Arrhythmia)
• Damage liver = impaired ability to remove carbs, proteins and lipids from the blood, plus detoxification (removal of toxic substances)
• Alcohol is converted into ethanol = more VLDL = higher chance of plaque formation.
100
How can coffee contribute to CVD
It may or may not contribute
101
How to reduce risk of CVD
• No smoking
• Bp bellow 140/85 mmHg
• Low cholesterol
• Normal BMI and waist to hip ratio
• Regular physical exercise
• Moderate to no alcohol
• More polyunsaturated fats
102
How to control blood pressure
Change lifestyle, take drugs
103
What drugs are prescribed to people with high blood pressure
ACE inhibitors, Calcium channel blockers and Diuretics
104
What do ACE inhibitors do
• Effective antihypertensive drug reduces the synthesis of angiotensin 2, which causes the vasoconstriction in vessels
• The drug prevents the production of angiotensin 2 from the inactive angiotensin 1
105
What are the side effects of ACE inhibitors
• Dry cough
• Dizziness
• Arrhythmia
• Reduction in kidney function
106
What do calcium channel blockers do
• Antihypertensive drug
• Blocks Ca channels to muscles so vessels cant contract and constrict
107
What do diuretics do
• Increases the volume of urine produced by the kidneys and rid the body of excess fluids and salt
• Decreases the blood plasma volume and cardiac output
108
What are the side effects of calcium channel blockers
• Headaches
• Dizziness
• Swollen ankles
• Arrhythmia
• Red face
109
What are the side effects of diuretics
• Dizziness
• Nausea
• Muscle cramps
110
How can humans decrease there blood cholesterol
Diet and Drugs double D!
111
What drugs can be used to reduce blood cholesterol
Statins or anticoagulant and platelet inhibitory
112
What are the anticoagulant and platelet inhibitory drugs
Aspirin, Clopidogrel and Warfarin
113
What am i doing with my life
hitting lifts killing siths
114
What are the side effects of using statins
• Tiredness
• Disturbed sleep
• Feeling sick to actually vomiting
• Diarrhoea
• Headache
• Muscle weakness
• Cause of cancers such as gastrointestinal and respiratory
115
What elements of dieting can help reduce cholesterol levels
• Energy balance
• Reduced saturated fat
• More polyunsaturated fats
• Reduced cholesterol
• Reduced salt
• More non-starch polysaccharides e.g pectins
• More oily fish, fruit and vedge
116
What does aspirin and Clopidogrel do
reduces the stickiness of the platelets = reduce likely hood of clots (however some people are allergic to aspirin)
117
What does warfarin do
Interferes with the production of vitamin K = effects the conditions needed for a clot to form
118
What are the side effects of using anticoagulant and platelet inhibitory drugs
• Bleeding in the gastrointestinal tract, warfarin has the lowest probability of this, it is higher with aspirin and especially when aspirin is combined with Clopidogrel
119