Topic 1 - CVD 1.5 - 1.11 Flashcards
What is CVD
Any disease that effects the heart and blood vessels
What is atherosclerosis
A process where a plaque builds up in the artery
Describe the process of atherosclerosis
-High blood pressure damages the endothelium
- Inflamatory response is triggered and white blood cells move into arterial walls
- Cholesterol builds up under the arterial wall forming an atheroma
- Ca2+ salts in the blood + fibrous tissue cause the atheroma to harden into an atherosclerotic plaque
- The hardening of a plaque causes the arterial wall to lose elastcity (reducing stretch and recoil)
-The lumen is also narrowed by the plaque
-Blood pressure increases further
What is a positive feedback loop
Where increasing one factor results in a change that increases the factor further
What is thrombosis
The process of forming a blood clot
What is the blood clotting cascade
A series of steps that must happen in a specific order to form a blood clot after injury
Why does blood clot
To prevent blood loss
Toprevent pathogens from entering the body
What are platelets
Tiny fragments of cells (with no nucleus) which are activated when blood vessels are damaged / ruptured
What happens in the blood clotting cascade
The arterial wall is damaged.
Platelets stick to the ruptured site and are exposed to collagen
This causes thromboplastin to be released.
In the presense of ca2+ and vitamin K, thromboplastin converts prothrombin into thrombin.
Thrombin then acts as a catalyst to convert (abundant and insoluble) fibrinogen into (soluble) fibrin.
Strands of fibrin form a mesh which trap platelets and red blood cells
This forms a blood clot.
The blood clot CAN harden to form a scab
What is Prothrombin
A soluble plasma protein used in the blood clotting cascade.
It is converted into thrombin by Thromboplastin
What is thromboplastin
A chemical found in platelets and a tissue factor
It converts prothrombin in thrombin when in the pressence of ca2+ and vitamin K
What is thrombin
A globular enzyme that acts as a catalyst
It converts thrombin to fibrinogen
What is fibrinogen
An abundant plasma protein. It is soluble and always readily available
It is converted into fibrin by thrombin
What is fibrin
An insoluble, long stranded protein.
It forms a mesh to trap platelets and RBC’s
It is made when thrombin catalyses fibrinogen into fibrin
What are coronary heart diseases (CHD)
Diseases which affect coronary circulartion and the heart
(vessels that suppy the caridac muscle with oxygen)
What is angina
The partial blockage / narrowing of coronary arteries.
It causes mild discomfort /chest pain
How does angina cause heart / chest pain
During exercises the herat requires more o2 as it contracts more
The partial blockage reduces the amount of o2 supplied to cardiac muscle
This means there is less aerobic respiration and less ATP
This means more anaeronbic respiration will occur
This means there is an increase in lactic acid produced
Lactic acid causes heart pain.
What is a stroke - (Ischemic stroke)
Sudden loss of brain function due to a blockage in arteries
-strokes can be fatal depending on where oxygen is blocked from
How does blockage in arteries cause a stroke
Less oxygen is supplide to the brain, so less aerobic respiration occurs
Anaerobic respiration increases, and more lactic acid is produced.
this decreases the pH and causes vital enzymes to denature
What is a heart attack (Myocardial infraction)
Complete blockage of coronary arteries
Caused by blood clots or atheromas
Can lead to cardiac muscle or heart failure (as the blood stops no oxygen is delivered to the cardiac muscle, and the muscle dies)
How do Heart attack occur
Cessation of blood flow (it stops)
Less / no oxygen is supplied to cardiac muscle
Aerobic respiration decreases, so ATP decreaes
The heart muscle cant contratct (its dead)
What does Ischemic mean
The stoppage / restriction of blood flow
What is an anneurysm
The swelling / buldging of blood vessels
How do anneurysms occur
When the arterial wall is damaged, elasticity is damages, so it cannot stretch to accommodate blood volume.
as the blood volume increases the artery buldges
What is a haemorrhage
The ruputure of blood vessels
Can lead to internal bleeding
What are Multifactorial disease
Different factors that affect risk of developing diseases interacting together
What are modifiable factors
Factors that can change over time.
E.g lifestyle and environmental factors
What are non modifiable factors
Factors outside of your control
E.g Genetics, biological sex, age
What is risk
Statistical chance or probability that an unwanted event will occur
Why is risk overestimated
Misleading information
Personal Experience
Unfamiliar scenario
Harm is immediated
Why is risk underestimated
Lack of information
Misunderstanding
Lack of personal experience
Harm is not immediate
What is correlation
Association / between two variables
What is causation
When a change in one variable directly causes a change in another
What is a cohort (longitudinal) studies
A study where:
- Participants tracked over a long period of time
- Groups are either exposed to a factor or not exposed.
These studies look at how something developes over time
What is a case control study
A study where people with a disease are compared to thoes that are not
The data collected is from the individuals had the disease
How do you evaluate a good study. (7 things)
1) Sample Size - The sample size needs to be large enough
2) Sample selection - must represent the whole population
3) Reliabilty - It must be both repetable, and valid
There should be and expremental control
4) Reproducibility - Do others obtain the same results when repeated
5) Bias - Are they looking for a specific outcome
6) Time - Was the study long enough to obtain enough data to make a conclusion
7) Statistical significance - Is the data due to chance
How can you tell if data is statistically significant
If the error bars / data overlap the differnence between data is not statistically significant .
How does age effect the risk of CVD
Age:
- risk increases with age since, the factors accumulate other time
E.g The older you are the more atherosclerotic plaques you will have
How does Biolgical sex effect the risk of CVD
- Men are 3x more likely to have CVD than pre-menopausal woman
- Oestrogen increases HDLs which removes cholesterol from blood
-Men also have more testosterone - so more adrenaline, which increases BP
How does smoking / vaping effect the risk of CVD
1) Nicotine causes vasoconstriction. (narrowing the lumen)
It also promotes the release of adrenaline (the heart will beat faster and BP will increase)
It also increases blood viscosity (platelets join together more = more clots)
2) Carbon monoxide has a greater binding affinity to haemoglobin.
This means less oxygen is carried in the blood. (so the heart pumps faster and BP increases)
3) It reduces the number of antioxidants - There are more free radicals so more damage to cells
How does drinking alcohol effect the risk of CVD
It causes blood vessles to become narrower which reduces blood flow and increases blood pressure
It also causes the heart to contract with more force
It increases blood volume
How does your diet effect your risk of developing CVD
Excess energy intake causes wight gain + excess carbohydrates are stored as fats (causing diabetes which increases BP)
- Excess saturated fats mean you will have more LDLs in blood
- Excess salt itake causes more blood to be retained by the kidneys ( increase in blood volume)
- Lack of antioxidants (free radicals are not neutralised )
What are high density lipoproteins (HDLs)
Proteins that transported unsaturated fats (cholesterol) From body tissue to the liver
They decrease the amount of Blood cholesterol
What are Low Density Lipoproteins (LDLs)
They transport saturated fats from the liver to cells
They move cholesterol into the blood stream
Why is having a high ratio of LDLs to HDls bad
LDLs bind to cell receptors to be taken into cells by endocytosis
If there are too many LDLs the receptors become saturated (full) then the cholesterol remains in the blood.
WHat happens when there is a high HDL: LDL ratio
More cholesterol is removed from the blood stream so there is a protective effect from CVD
When is someone obese
When they have a high excess in body fat compared to lean body tissue
What causes obesity / what is it most commoly a risk factor for
It is caused by having a poor diet or sedenatry lifestyle
It is greatly increases the risk for type two diabetes
What is an energy budget
Energy budget =The energy input —- energy output
What happens when energy input > enregy output
There will be wight gain (due to excess energy being stored as fats)
What happens when energy input =energy output
Weight is maintained
What happens when energy input < energy output
Weight is lost
This caun resut in people being underweight and having nutrient defficiencies
What is Basal metabolic rate
The energy required to keep the body functioning at rest
What effects Basal metabolic rate
Age
biological sex
Genetics
Fitness
Muscle mass
What is the Body mass index (BMI)
A meassure of body weight in comparrison of height
It is used to determine whether someone is overweigh or underweight
How is bmi calculated
Weight (kg) / height ^2 (m)
What is the main issue with BMI
It does not take weight distribution + body composition into account
What is the waist : hip
The waist to hip ratio is commonly used alongside BMI
It takes into account a persons distribution of fat
What should a mans waist : hip be
less than 1
What should a womans waist : hip be
less than 0.85
How is waist : hip calculated
Waist circumfrence (cm) / Hip circumfrence
What changes in lifestyle can be made to reduce blood pressure
Reducing salt intake
Excercising often
Reducing alcohol intake
Losing weight
Having a healthier diet
Stop smoking
What are antihypertensives
- Made to control hypertension
(blood pressure)
What do diuretics do? (type of antihypertensives)
Drugs that increase the volume of water in urine + reduces salt reabsorption
-This reduces blood volume (ant therefore Blood pressure)
What do vasodialtors do (type of antihypertensive)
Drugs that increase the lumen of blood vessels (can accomodate a greater blood volume, so blood pressure is lower)
It commonly blocks a hormone (angiotensin) that controls the constriction of blood vessels
What do beta blockers do (type of antihypertensive)
They reduce arterial constriction and reduce the strength of heart beats ( by making cardiac muscle contrsct weaker.
They can also block adrenaline
What are anticoagulants
Drugs that increase blood clotting time - making it take longer for blood clots to form
They interfere with blood clotting factors
What does Warfarin do?
An anticoagulant that reduces the amount of vitamin k produced by the body (Affecting the blood clotting cascade)
What are platelet inhibtory drugs
Drugs that prevent platelet formation
This reduces the formation of blood clots
What is asprin
A platelet inhibitorty drug that affects the part of the blood clotting cascade where platelets become sticky
What are statins
Drugs which lower blood cholesterol levels - blocks enzymes that control cholesterol synthesis
Low3ers LDL production and increases HDL production
What are the side effects of antihypertensives
Arrythmias
fainting
Headaches
Drausiness
Palpataions
Nausea
What are the side effects of Anticoagulants
Internal bleeding
Bruising
Nosebleeds
What are the side effects of Platelets inhibitory drugs
Nausea
Excessive bleeding
What are the side effects of Statins
Muscle pain
Headaches
Increased risk of diabetes
What is an aneurysm
The bulging of a blood vessel
