aging Flashcards
factors the influence change
nutrition air pollution and smoking habits sleep disorder development of age and/ or lifestyle related pathology (asthma, COPD) changes in immune response fitness level socioeconomic factors
lung development
Lung size grows until around age 10-12
Further maturation and subdivision until 20’s
Females~20 years of age
Males ~25 years of age
After which lung function declines
what is senile emphysema
increasing size of bronchioles, air sacs and alveoli. reducing surface area for diffusion
what are the changes in morphology and functions of the lung?
decrease in alveolar surface area. (70-60 cm2) at the age of 70.
loss of elastin and collagen reducing recoil of the lung and tethering of airways.
loss of capillaries (reduction in VEGF)
changes in lung-obstructive
limited flow
trapped air
breathing pattern of faster RR, smaller Vt
perfusion of the lung
less total blood flow due to increasing pulmonary artery pressures.
changes in diffusion- increases in A-a gradient
PaCO2 levels remain normal however, in the absence of pathology
More deadspace but decreased metabolism
Increasing minute ventilation (if required)
Poorer VQ matching
how does PaO2 decreases every year
Normal PaO2 decreases around 0.33 mmHg/year – plateaus around 70- 75
thoracic cage/chest wall changes
Chest wall compliance decreases
In the young rib cage expansion accounts for 40% of lung volume change this drops to 30% in the elderly
Changes in rib-vertebral and sternal articulation mean the chest wall recoil would amount to about 30-40% of full inflation
- Your rib cage as you age is always in the expanded state - Less mobility
chest wall
Chest wall compliance decreases
Decreased mobility of costovertebral joints
Calcification of intercostal cartilage
Decalcification of ribs
Narrowing of intervertebral discs
Tendency towards kyphoscoliosis (forward hunch)
Tendency towards barrel chest
respiratory pump
Diaphragmatic mass seems to be preserved however with emphysematous changes may be mechanically disadvantaged
Intercostals decline in area with age
With changes in chest wall compliance intercostals contribute less to inspiratory efforts
Muscule function is highly correlated with cardiovascular function and as cardiac output declines and vessels become stiff with age muscles lose ability to generate maximal effort
Maximal inspiratory pressure with age
MIP is used a general proxy for respiratory muscle function
-force breath out following by clipping you nose and then force inspiration.
exercise capacity with age
Declines from the age of 25 at about 1% per year
Accelerates with poor lifestyle
Aging is also associated with
Weight gain
Increase Fat mass
Loss of muscle
respiratory centers
when young MV should match metabolic demands
when you get old the respond for metabolic changes are decreased. for hypercapnia and hypoxia.
response to hypercapnia
sensation of SOB (dyspnea) is exaggerated compared to younger controls even as response was blunted
immune response with age
Bronchial samples show increasing numbers of WBC
However peripheral WBC in the blood may be reduced overall
Overall response appears to be blunted to new pathogens while general inflammatory markers remain high.
