AS Biology F212 Smoking

• Combination of chemicals (carinogens)

Short term effects:

• settles on lining of the airways increasing diffusion distance for the oxygen entering the blood, decreasing CO2 diffusion out of the blood
• may cause allergic reaction (smooth muscle contracts restricting airflow to alveoli)
• can paralyse/destroy cilia - can't move mucus away and up the mouth
• stimulate goblet cells produce more mucus-collecting in airways
• leads to bacteria and viruses becoming trapped in mucus, multipling and may block bronchioles
• Making smokers more suspectible to infections such as influenza and pneumonia

Smokers cough

• attempting to move mucus up the throat (irritates airways)
• the cough causes damage to the airways, this gets replaced with scar tissue
• this is thicker and less flexible-reducing lumen airway/permanently restricted

Infections

• inflame the lining of the airways-damaging the epithelium lining
• this will attract WBC to deal with pathogenic organisms-making way out of the blood/airways by releasing enzymes
• these digest the linings of the lungs (e.g. sometimes the enzyme elastase is released and damages elastic tissue in the lungs)
• greatly effect the bronchioles + alveoli as the walls can't recoil to push out air
• bronchioles can collapse preventing air out of the alveoli causing pressure on alveoli so they burst.

• Chemical causing addiction
• as the body becomes used to the effects, the smoker feels unwell unless they have nicotine in their blood
• mimics the action of transmitter substances at the synapses between nerves making nervous system more sensitive (making them feel more alert)
• Releases hormone adrenaline: increases heart rate/breathing rate, constricts the arterioles= raising blood pressure
• reduces blood flow and oxygen delivery
• makes platelets sticky, increasing risk of blood clot