the effect of lung disease

Question 1

PULMONARY TUBERCULOSIS (TB)

Answer 1

• tuberculosis bacteria causes the immune system to build a wall around the bacteria in the lungs
• forms small, hard lumps called tubercles
• infected tissues within the tubercles dies which damages the gaseous exchange surface so tidal volume is DECREASED
• tuberculosis also causes fibrosis

Question 2

what is the effect of having a REDUCED TIDAL VOLUME?

Answer 2

• less air can be inhaled with each breath
• people have to breathe faster
• ventilation rate is INCREASED

Question 3

symptoms of PULMONARY TUBERCULOSIS

Answer 3

• persistent cough
• coughing up blood and mucus
• chest pains
• shortness of breath
• fatigue

Question 4

FIBROSIS

Answer 4

• fibrosis is the formation of SCAR TISSUE in the lungs
• asbestos and dust can lead to infection
• scar tissue is THICKER and LESS ELASTIC than normal lung tissue
• lungs are less able to expand and so cant hold as much air
• tidal volume is REDUCED
• FVC is REDUCED = a smaller volume of air can be forcefully breathed out
• reduction in rate of gaseous exchange - diffusion is slower across thicker scarred membrane

Question 5

symptoms of FIBROSIS

Answer 5

• shortness of breath
• dry cough
• chest pain
• fatigue
• weakness
• faster ventilation rate to get enough oxygen into the lungs to oxygenate the blood

Question 6

ASTHMA

Answer 6

• airways become inflamed and irritated
• caused by an allergic reaction to pollen and dust
• during an asthma attack, the smooth muscles lining the bronchioles contracts and large amount of mucus is produced
• this causes constriction in the airways making it difficult to breathe
• air flow in and out the lungs is SEVERELY REDUCED
• FEV 1 is SEVERELY REDUCED (less air can be breathed out in 1 second)

Question 7

symptoms of ASTHMA

Answer 7

• wheezing
• tight chest
• shortness of breath
• symptoms come on very suddenly during asthma attacks
• symptoms can be relieved by drugs (inhalers) which cause the muscle in the bronchioles to relax

Question 8

EMPHYSEMA

Answer 8

• lung disease caused by smoking or long-term exposure to air pollution
• foreign particles in the smoke become trapped in the alveoli
• this causes inflammation which attracts phagocytes
• phagocytes produces an enzyme that breaks down elastin
• elastin is found in the walls of the alveoli
• elastin is elastic and helps alveoli return to their normal shape after inhaling and exhaling
• loss of elastin means alveoli cant recoil to expel air (air remains trapped in the alveoli)
• leads to destruction of alveoli walls which reduces the surface area of the alveoli so rate of gaseous exchange DECREASES

Question 9

symptoms of EMPHYSEMA

Answer 9

• shortness of breath
• wheezing
• increased ventilation rate to try to increase the amount of air reaching their lungs

Question 10

what is the effect of lung disease on the rate gaseous exchange?

Answer 10

• TB, fibrosis, asthma, and emphysema all reduce the rate of gas exchange in the alveoli
• less oxygen diffuses into the bloodstream
• body cells receive less oxygen
• rate of aerobic respiration is REDUCED
• less energy is released
• leads to tiredness and weakness