Pathophysiology of Smoking Flashcards
What is largely affected by smoking?
Mostly affects the respiratory system
Mostly affects breathing and gas exchange
What are other effects of smoking that are not directly related to the airways?
Atherosclerosis (build-up of plaque)
Cancers around the body
The entire body can be affected by smoking
How can smoking create physiological changes?
Direct physical damage to the lungs/airways
Physical accumulation of smoke-products
Inducing cellular responses
Toxic effects of chemicals in smoke
[Downstream effects of all mentioned]
What is the purpose of the lungs?
To get chemicals (i.e., oxygen but potentially anything else that is inhaled) into the body and distributed rapidly
How can the respiratory system be directly affected by smoking?
Direct damage to the lungs as of the hazardous chemicals
Accumulation of smoke products (tar, particulates, etc.) increases diffusion pathway as air cannot travel to blood efficiently–> can potentially contribute to physical blockages in the bronchioles
Can also exacerbate existing respiratory conditions such as asthma
What is the effect of tar on the bronchioles?
Tar can block the microtubules of the alveoli and cause the alveoli lining to thicken- blocks oxygen from being absorbed into the bloodstream
What occurs when you inhale smoke?
Inhaling gas and small solids/viscous liquids into the lungs
How can the airway clear itself?
Cilia
Cilia are projections from cells which push materials upwards out of the lungs
What is the effect of smoke on cilia?
Deposits from smoke cause inflammation and damage the cilia
What happens when smoke, and the relevant particulates/viscous liquids, become stuck in the mucus lining?
Will potentially accumulate
What occurs due to the cilia being damaged?
Results in the build-up of material that should be expelled, resulting in obstruction and increased risk of infection
What is significant about second hand smoking?
Depends on the scale and is not as bad but doesn’t detrimentally increase the likelihood of smoking associated risks
What is the name of a condition that the presence of smoke-products can cause?
Emphysema- reduction in the surface area of the alveoli
What can cause emphysema and other lung conditions?
Both direct damage and inflammation cause the breakdown of tissues in the lungs
How is emphysema caused?
Smoking damages the separations between alveoli
The walls within and between alveoli break down, converting the many small air sacs into a smaller number of large ones
What occurs due to emphysema?
Alveoli balloons up therefore decreasing the surface area of the alveoli
However, the alveoli contain more oxygen, therefore oxygen uptake decreases
What is bronchitis and what does it result in?
Bronchitis is inflammation of the bronchi
Directly results in an accumulation of mucus, reducing flow through the airways and a persistent cough to try to clear it
What is COPD and what is its relation with emphysema and bronchitis?
COPD stands for Chronic Obstructive Pulmonary Disorder
Bronchitis and emphysema are two common aspects of COPD
These cause difficulty in breathing, breathlessness, chronic cough, etc.
What does the body do when it is damaged?
Body repairs to seal wound quickly as to prevent excess pathogens
Won’t do it neatly as it is an emergency, so loads of extracellular matrix and messy area of cells will result in a scar
What is the effect of minor damage in relation to scarring?
There will be less scarring
What is the link between smoke particles and scarring?
Smoke particles in the lungs can contribute to development of scar tissue within the lungs, known as interstitial fibrosis
Smoking causes large scale scarring of the lungs as smoking reopens scars, leading to the tissue thickening and so causing fibrosis
Why are fibrotic lungs problematic?
In fibrotic lungs, the scar tissue replaces a lot of the lung tissue so the respiratory system has less space to function
The scar tissue takes up space and so reduces the functional lung volume which is irreversible, but symptoms may be managed by treatment and lifestyle changes
What occurs as a result of pulmonary fibrosis?
The reduced lung function results in breathlessness, low blood oxygen and various related health problems as a result
Finger clubbing is a distinctive symptom of pulmonary fibrosis
What is the relation between smoking and cancer?
Smoking contributes to lung cancer due to exposure to physical damage and carcinogenic chemicals
Although smoking is the leading cause of lung cancer, what other cancers can smoking contribute to?
Airways (oral, pharyngeal, laryngeal, oesophageal, etc.)
Other parts of the body include: pancreas, liver, kidneys, bladder, colorectal, etc.
Caused due to carcinogenic chemicals being absorbed into the bloodstream and so travels to other organs/areas of the body
How does lung cancer occur?
Cells are damaged, leading to uncontrollable mitosis to heal, resulting in the formation of a tumour
How can carcinogenic factors lead to cancer?
Carcinogenic factors cause DNA damage resulting in the DNA mutating
DNA mutations then result in the control of cell division being lost resulting in cancer
What other conditions can smoking lead to?
Cardiovascular diseases
How does smoking lead to CVD?
Affects cardiac function and blood pressure
Causes the heart to abnormally grow
How does smoking lead to atherosclerosis?
Smoking increases LDL and reduces HDL levels, which can promote plaques in arteries
Can contribute to coronary heart disease and peripheral artery disease, depending on the location
How can smoking impact cardiac function and blood pressure?
Components of smoke (e.g., nicotine) can increase heart volume and blood pressure
What occurs due to atherosclerosis in the coronary arteries?
No sufficient oxygen, which would increase the likelihood of angina, blood clot and myocardial infarction
What would happen if a plaque ruptures?
Plaque ruptures–> blood clot forms–> blocked arteries
Why are compromised CVS or respiratory systems dangerous?
Decreases survival
Where can carbon monoxide be found and why?
Smoke from smoking, due to carbon monoxide being a product of incomplete combustion as the carbon has not fully reacted with the oxygen
How can carbon monoxide result in less oxygen in the body?
Carbon monoxide has a greater affinity for haemoglobin than oxygen, therefore will bind with Hb more readily than oxygen resulting in less oxygen in the body
What is the affect of carbon monoxide on the lungs and the heart?
The heart and the lungs must work harder to compensate for the lack of oxygen (short term)
This puts stress on the heart and lungs leading to the development of health problems
What is significant about heavy smokers and carbon monoxide?
Heavy smokers have lungs that are too damaged for carbon monoxide poisoning, as the abundance of carbon monoxide won’t be sufficient
What are examples of other issues that smoking can lead to?
Stroke
Addiction (nicotine, psychological)
Reproductive issues (decreased fertility, erectile dysfunction, developmental abnormalities)
Diabetes
Deaths of tissues around the body (potential amputation)
Digestive problems
General ill health
How are nicotine and diabetes linked?
Promotes insulin resistance (contributing to blood sugar dysregulation and potentially Type II diabetes mellitus)
Is nicotine always seen as bad?
No, as in the short term can act as a cognitive enhancer
However, in the long term has been linked with mental health and neurological problems
Why are alternate nicotine products used to help quit smoking?
The adverse effects of nicotine are small compared to the other effects of smoking
What are the effects of nicotine on the CVS?
Increases heartrate and promotes vasoconstriction, reducing peripheral blood flow
How can insulin resistance due to nicotine be reversed?
If in early stages the nicotine addiction is helped
What occurs as a result of prolonged vasoconstriction?
Tissue death
What happens during frostbite?
Very cold for long periods of time therefor leading to tissues dying and digits dropping off
Can nicotine lead to digits dropping off?
In extremes, yes
How does nicotine lead to addiction?
Brain is enhanced cognitively, but brain expects more nicotine
What is done to combat cigarette cravings?
Nicotine patches and gum are used to satisfy cravings, but are not always effective
Can be done as [nicotine] fluctuates and some people are addicted to physical process of smoking and psychological effects
How do other tobacco sources compare to cigarettes and nicotine products?
Are worse
What are examples of other forms of smoking?
Cigars (not done as often): largely similar to cigarettes in risk, but there is a common misconception that they are (much) safer
Chewing tobacco: Still contributes to cancer development and oral disease- lower risk (but still present) of issues related directly to inhalation and throughout the wider body
Marijuana and other drugs: Health impacts of the drug itself will vary (marijuana’s effects are not well established), but smoking it results in the issues associated with smoking (CO poisoning, irritation of bronchi, etc.)
Why were modern vapes (e-cigarettes) developed?
Developed with the intent of being a healthier alternative to smoking
Deliver nicotine and address cravings
Why are vapes and e-cigarettes no longer seen as a safer alternative?
Appear to be mostly less harmful, but the full health effects are unknown (only 10 years in the market)
Opened up a market and so now directed at an irrelevant audience
Known to contribute to emphysema, bronchitis, asthma and COPD
Can exacerbate conditions
What are some of the long-term effects of vaping and using e-cigarettes that can be inferred?
Effects of nicotine
Effects of any other drug present
Reduced risk from aspects related directly to smoke
Observed to cause mutations, so may be carcinogenic
What are the two types of smoke given out when smoking?
Mainstream: deliberately inhaled by the smoker
Sidestream: released from the end of the lit cigarette
Which type of smoke is more dangerous than the other?
Sidestream smoke- leads to more risks
What is second hand smoke?
A mix of both mainstream and sidestream smoke
What is passive smoking?
The inhalation of smoke (sidestream and exhaled mainstream) without smoking
What are the risks associated with passive smoking?
Diseases and conditions associated with passive smoking are similar to those of smoking directly, but the risk is typically lower
Greater exposure to smoke (passive or not) increases the risk of disease
Why is passive smoking harmful during pregnancy?
Passive exposure to smoke during pregnancy can also cause developmental issues for the foetus
What is the relation of risks and exposure?
All risks correlate to the scale of exposure
What are examples of some of the effects of smoking that are reversible once smoking has stopped?
Heart rate and (transient effects on) blood pressure return to normal within 20 minutes
Carbon monoxide (and its effects) are removed within ~12 hours
Within two days the excess mucus and deposits in it are mostly being coughed up.
Lung function gradually improves over months and years
Risk of heart disease is halved within one year and gradually decreases back to normal
Risk of most cancers decreases to normal 5-10 years after quitting
What is the percentage of cancers that are caused due to smoking?
~80% of lung cancer cases
~15% of cancers overall
What was the number of hospital admissions, deaths and prescriptions that smoking attributed to in 2019/20?
Over 500,000 hospital admissions
74600 deaths
710000 prescriptions to stop smoking
