Ageing Flashcards
What 3 categories can the hallmarks of ageing be divided into?
Primary hallmarks - causes of damage
Antagonistic hallmarks - responses to damage
Integrative hallmarks - consequence of damage
What are the 4 primary hallmarks of ageing?
Genomic instability
Telomere attrition
Epigenetic alterations
Loss of proteostasis
What are the 3 antagonistic hallmarks of ageing?
Mitochondrial dysfunction
Deregulated nutrient sensing
Cellular senescence
What are the 2 integrative hallmarks of ageing?
Stem cell exhaustion
Altered communication
What is meant by genomic instability as a hallmark of ageing?
Accumulation of DNA damage and mutations
Which 3 kinds of cells have the telomerase enzyme? What does it do?
Telomerase extends telomeres
Found in germ cells, stem cells, and cancerous cells
What are the 3 main epigenetic alterations in ageing?
DNA methylation
Histone modifications
Chromatin remodelling
What are the 4 fates of mis-folded proteins?
Refolded by chaperone proteins
Degraded by
- Autophagy-lysosomal pathway
- Ubiquitin-proteasome system
Aggregation
What effect does ageing have on the tunica intima of blood vessels and how?
Reduced lumen diameter - due to migration of smooth muscle cells into the tunica intima
What effect does ageing have on the tunica media of blood vessels and how?
Decrease in compliance - due to loss of elastin and increase in collagen
In what way does ageing affect systolic and diastolic blood pressure?
Increases systolic BP
Decreases diastolic BP
Why does ageing reduce diastolic BP?
Due to the loss of elastic recoil by the arterial vessels due to increased stiffness (loss of elastin, increase in collagen)
What is pulse pressure?
The difference between systolic and diastolic pressure
How does ageing affect pulse pressure?
Increases pulse pressure
In cardiac function, what is afterload?
The resistance the left ventricle must overcome to eject blood
What affect does ageing have on afterload and why?
Increased afterload due to decreased aortic compliance
Increased afterload causes what changes to the left ventricle? How does this affect diastolic volume?
Left ventricle hypertrophy, which leads to decreased diastolic volume
What effect does ageing have on the baseline levels of catecholamines? What causes this change?
Increased catecholamines
Reduced receptor sensitivity (B-adrenergic receptors)
Why are older people more susceptible to postural hypotension?
Blunting of arterial baroreceptor response
Which 2 factors cause a lower resting heart rate / bradycardia in older adults?
Loss of SAN cells
Fibrosis of the conduction system
In what way does chest wall compliance change in older people and why?
Chest wall compliance decreases - due to the calcification of ribs, kyphosis
In what way does lung compliance change in older people and why?
Lung compliance increases - due to loss of elastic recoil
In what way does overall respiratory compliance change in older people?
Decreased overall compliance - breathing is less efficient
In what way does residual volume (RV) and functional residual capacity (FRC) change in older adults?
Increased RV & FRC
In what way does forced vital capacity (FVC) and forced expiratory volume (FEV1) change in older adults?
Decreased FVC & FEV1
In general, how will V/Q ratio change as we age and how does this affect PaO2?
Low V/Q (not enough ventilation but adequate perfusion) - this leads to lower oxygen levels in arterial blood
As we age, which 2 factors cause a reduction in GFR?
Decreased renal plasma flow
Loss of glomeruli
What happens to the size of the liver as we age?
Reduces in size
As we age, which 2 types of memory decline first?
Working memory
Episodic memory
As we age, which 2 types of memory are better preserved?
Semantic memory
Procedural memory
