So what does a regular cigarette
- tar
- butane
- ammonia
- methanol
- formoladehyde
- cadmium
- radon
- hydrogen Cyanide
- arsenic
- acetone
- nicotine
- carbon monoxide
- carbon monoxide enters the blood and combines with the red blood cells haemoglobin to form carboxyhemoglobin
- reduces the oxygen capacity of RBC
- smokers feel this when they exercise
- also damages the endothelium of the arteries
Damaged arteries can lead to artherosclerosis
- damage is repaired by the phagocytes
- this encourages the growth of smooth muscle
- this leads to deposition of fatty substances (plaque)
- these deposits develop into atheromas
The build up of Artheroma’s results in tears and restriction of the lumen and the blood flow
This can lead to many conditions such as Thrombosis, coronary heart disease and strokes. These are all types of cardiovascular disease.
thrombosis
- blood flowing past a built up plaque cannot flow smoothly
- this can lead to a blood clot forming, which increases the risk of sticky platelets
- blood clot is a thrombus
- it can block arteries
when the lumen of the coronary arteries is narrowed by plaque, it can reduce the blood flow to the heart, which can result in:
- Heart attack, where part of the heart muscle dies
- Angina: Severe pain in chest as heart does not receive enough O2
- heart failure: where the heart cannot pump due to blockage of CA
So what factors increase the risk of CHD?
- Death of brain tissue
- caused by either thrombus blocks an artery leading to the brain
- artery leading to brain burst (haemorrhage)
cardiovascular diseases are those diseases that affects the heart and circulatory system.
- Atherosclerosis
- Coronary heart disease (CHD)
- stroke
- arteriosclerosis
This disease is the most common that affects the economically developed countries.
Symptoms of Cardiovascular disease:
High blood pressure and hypertension are usually the first signs, they result from the narrowing of the artery lumen caused by the deposition of atheroma. The narrowing lumen increases the friction between the blood and the artery wall. The heart pumps against this increase friction between the blood and the artery wall. The heart pumps against this increased friction which raises the blood pressure. The atheroma makes the artery wall less elastic. WHich means that they cannot recoil and dilate as easily.
Coronary heart disease (CHD)
A person with CHD may find it more harder to exercise. They may feel out of breath after only a small amount of exertion. This is because of the atherosclerosis in the coronary arteries. The atheroma narrows the lumen of the artery, reducing blood flow to the cardiac muscle. When exercising the heart increases its output. The heart muscle does not receive enough oxygen for aerobic respiration and is put under strain in an effort to pump more blood. As it does not have enough oxygen it cannot pump sufficient blood to the rest of the body.
stroke
The symptoms of stroke are always sudden, it results from part of the brain receiving not enough oxygen
- sudden numbness or weakness of the face, especially on one side of the body
- sudden confusion and difficulty in speaking or understanding
- sudden difficulty in seeing
- sudden trouble in walking
- sudden severe headache, unknown causes
Nicotine mimics the action of transmitter substances between nerves, making the nervous system more sensitive, Nicotine causes adrenaline to be release, this increased Adrenaline can cause:
- increased heart rate
- breathing
- arterioles constrict
- raise blood pressure
Nicotine causes the arterioles to constrict. It can make platelets sticky which can contribute to the formation of clots and thrombus. and also causes the build up of plaque. A clot or thrombus can stop blood flow. Or move in blood until it reaches a narrow artery.
Short term affects that result from TAR
- Because it settles on the lining of the airways and the alveoli, it increases the diffusion distance for oxygen entering the blood and for carbon dioxide leaving the blood.
- Results in smooth muscles in the walls of the airways to contract
- the lumen of the airway gets smaller and this restricts the flow of air to the alveoli
- cilia are unable to move the mucus
- tar also stimulates goblet cells to enlarge and secrete more mucus
- mucus collects in airways, pathogens are not removed, so multiply
- bronchioles become blocked and more susceptible to infections
Long term effects of tar
Smokers cough is an attempt to move the bacteria laden mucus that collects on the lungs. A constant cough can lead to the delicate lining of the airways and the alveoli becoming damaged. This lining will eventually be replaced by scar tissue, which is thicker and less flexible. More smooth muscle grows on the bronchioles which reduces the lumen of the airway and the flow of air is permanently restricted.
Due to the build up of the pathogens in the bronchioles, means that the linings of the airways may become inflamed, this will damage the lining of the epithelium in particular. Also this then attracts white bloods cells which attempt to deal with the pathogenic micro-organisms. They have to make their way into the airway from the blood, so therefore they release enzymes which digest part of the linings of the lungs in order to get into the airways. The enzyme used is elastase. This damages the elastic tissue in the alveoli, so they alveoli can no longer contract and expel air as there is a loss of elasticity in the alveolus walls. As we exhale, the alveolus walls do not recoil to push air out. Which increases pressure in the alveoli as air gets trapped. The bronchioles collapse which cause the alveoli to burst and therefore reduce the surface area of the lungs.
Diseases associated with smoking
Emphysema
- loss of elasticity in the alveoli, which causes it to burst
- reduction in surface area, so less surface for gaseous exchange
- shortness of breath which leads to more shallow and rapid breathing
- blood is less well oxygenated which leads to fatigue
- carcinogenic compounds line the lungs
- these chemicals (mutagens) enter nucleus and cause mutation of DNA which can effect cell division
- Cancer often starts at the entrance of the bronchi and takes 20-30 years to develop and grows for years before it develops
Chronic bronchitis
inflammation of the lining of the airways and damage to the cilia and over production of mucus by goblet cells
- irritation of the lungs
- coughing
- coughing up bacteria-laden mucus that will also contain white blood cells
- can lead to infections
Chronic obstructive pulmonary disease
this is a combination of all the diseases mentioned above
sahiljhamb 