T9 gas exchange and smoking Flashcards
respiratory system consists of
nasal and mouth passages
epithelial tubes and tissues of the lungs
muscles of diaphragm and ribcage
goblet cells
produce mucus which traps dust and microorganisms
ciliated epithelial cells
sweep mucus towards throat to be swallowed
rings of cartilage
support the trachea, bronchi and bronchioles
what happens as airway size increases
less cartilage and smooth muscle lines the airways
alveolar epithelial cells
site for gas exchange in the lungs
trachea
transfers air to the lungs
strengthened with cartilage
bronchioles
branch from the bronchi and divide into smaller branches as cartilage decreases.
bronchi
trachea division into two, supported by the cartilage
are both lungs the same size?
no, right is larger than the left
alveoli adaptations
large surface area
deflate after each breath out
phospholipid surfactant decreases surface tension and so prevents collapse
surfactant
phospholipid produced by type 2 pneumocytyes
gas exchange membrane
layered junction between alveolar epithelial cells, capillary endothelial cells, alveolar epithelial cells and basement membranes. gases move freely across this via diffusion
why does the epithelium become thinner in the respiratory zone
because the diffusion pathway must narrow in order to increase efficiency of gas exchange.
why is the alveoli and lung tissue made out of elastic tissue
as the alveoli requires recoil and expansion in order to assist breathing.
how does ventilation occur
antagonistic muscle pairs provide opposing actions in the generation of movement through that of alternate contraction and relaxation
examples of antagonistic muscle pairs
external and internal intercostal muscles
diaphragm and abdominals
inspiration
increasing thoracic volume, decreasing lung pressure, drawing air into the lungs
external intercostal muscles and diaphragm contract
ribcage expands and moves up
expiration
passive process in which external intercostal and diaphragm relax, decreasing thoracic volume and increasing pressure, leads to recoil of lung tissue
which muscles assist forced breathing
abdominals and internal intercostal muscles
COPD
chronic obstructive pulmonary disease
persistent inflammatory disease causing obstructed airflow
what is COPD
permanent damage to the airways, resulting in chronic symptoms and limited treatment
leads to higher risk of heart failure due to lack of oxygen, requires long-term oxygen therapy
economic impact of COPD
many lost working days
strain on health services
personal impact of COPD
shortened lifespan, stress on you and family, chronic symptoms require a change in lifestyle
risks associated with tobacco smoking
COPD nicotine addiction cancer chronic CV and respiratory diseases heart disease increased risk of mouth, throat, lip and lung cancer decreased lung capacity
lung cancer
uncontrolled growth of epithelial cells
chronic bronchitis
symptoms?
excess mucus blocking airways, causing inflammation and infection
persistent cough
emphysema
narrowing of small airways and lung tissue/ capillary breakdown
leads to air pocket formation which decreases gas exchange
tar effects
damages teeth and gums
desensitises taste buds
accumulates in lung tissue
dna mutations in the epithelial lung cells»_space; cell proliferation and tumour formation
chronic
having persisted for a long time or constantly recurrent
symptoms of COPD
shortness of breath, cough, chronic bronchitis, emphysema,
nicotine effects
addictive constricts arteries increased BP and HR mobilises fat stores increased metabolic rate
carbon monoxide effects
toxic
displaces oxygen from haemoglobin
decreased oxygen content of the blood
short-term effects of nicotine
enters bloodstream and reaches brain, stimulating release of messengers that stimulate the reward centre and raises HR/BP
brain cell death due to impaired blood flow can result
blood vessel constriction drops skin temp
rise in CO levels in lungs contributes to breathlessness
long term effects of nicotine
increase viscosity of the blood
increased risk of fatty plaque build-up in the coronary and carotid arteries
increased risk of heart attack/stroke
