Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

B3 CTB > Ageing > Flashcards

Ageing Flashcards

1
Q

What are the criteria for hallmarks of ageing?

A
  1. The hallmark should occur during normal ageing
  2. Its aggravation should accelerate ageing
  3. Its amelioration should reduce ageing and increase healthy lifespan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the consequence of genomic instability?

A

Increased DNA damange/mutation and lack of repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the consequence of Telomere attrition?

A

Lack of chromosome replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the consequence of Epigenetic alteration?

A

Loss of tanslation/transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the consequence of Loss of proteostasis?

A

Misfolding/structural changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the consequence of mitochondrial dysfunction?

A

Impaired energy release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the consequence of deregulated nutrient sensing?

A

Reduced nutrient uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the consequence of cellular senescence?

A

Cells no longer growing and dividing according to the cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the consequence of stem cell exhaustion?

A

Lack of new cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the consequence of altered communication?

A

Lack of cellular coordination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are primary hallmarks of ageing?

A

The initial causes of damage at the molecular level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are antagonistic hallmarks of ageing?

A

Cellular responses to damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are integrative hallmarks of ageing?

A

The combined effects of primary and antagonistic hallmarks, which leads to functional decline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the three epigenetic mechanisms of relevance to ageing?

A
  • DNA methylation: addition of methyl groups to cytosine bases in the DNA.
  • Histone modification: modifications (e.g. addition of acetyle groups) to the histone proteins associated with DNA in chromatin.
  • Chromatin remodelling: remodelling of the chromatin architecture, such as changes in the degree of packaging with histone proteins .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

During loss of proteostasis, what two mechanisms are used to degrade misfolded proteins?

A
  • Autophagy-lysosomal pathway (ALP), misfolded proteins are imported into a lysosome, where they are enzymatically digested.
  • Ubiquitin-proteasome system (UPS), misfolded proteins are marked for degradation by ubiquitin. The polyubiquitin tag is then recognised by the proteasome, within which the mis-folded protein is enzymatically broken down by proteases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of proteins refold misfolded proteins?

A

Chaperone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are senescent cells?

A

Cells that have exited the cell cycle and no longer divide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the ‘Senescence-associated secretory phenotype (SASP)?

A

Senescent cells secrete a range of signalling molecules, including chemokines, cytokines, proteases and growth factors. This collective secretion is referred to as SASP. It is associated in ageing tissues with chronic low grade inflammation that has been termed ‘sterile inflammation’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Can senescent cells become cancer cells?

A

No, because they cannot divide. The SASP secretion may actually promote cancerous changes in surrounding cells however

20
Q

List some of the key features of apoptosis

A
  • Activation of proteolytics caspases
  • Activation of a large number of enzymes
  • Breakup of nucleus
  • Some cell membrane blebbing, initially small but then larger blebs and membrane protrusions attract macrophages which phagocytose the apoptotic fragments
  • Cytosolic enzymes are segregated in vesicles
  • No local inflammation
  • Decreased cell volume
21
Q

What are the key features of necrotic cells?

A
  • Inability to maintain cellular composition due to damage or change in conditions
  • Uptake of extracellular fluid, leading to swelling
  • Influx of Ca2+ results in calcium uptake by mitochondria at the expense of their ATP production
  • Decreased energy production furthers swelling and damage
  • Blebbing (initially with no cellular organelles) becomes more pronounced until membrane rupture
  • Rupture releases enzymes and often results in acute inflammatory reaction
22
Q

What happens to the tunica intima and tunica media in arteries as we age?

A

There is a gradual thickening of the tunica intima and tunica media.

23
Q

What contributes to the thickening of the tunica intima?

A

In part the tunica intima thickening results from smooth muscle cells migrating into it from the tunica media

Endothelial dysfunction results in decreased production of NO which affects the capacity for vasodilation

24
Q

What contributes to the thickening of the tunica media?

A

There is a loss of elastic fibers and increased collagen fibres. There is also some cross-linking of the collagen fibres. These increases in collagen contribute to the thickening of this layer

25
Q

What is the general change in blood pressure in ageing individuals?

A

There is a gradual increase in systolic BP, a gradual decrease in diastolic BP and a widening of the pulse pressure

26
Q

Why does systolic blood pressure increase in ageing adults?

A

The systolic pressure rises because the arteries are less distensible. This results in less of the force of the ejected blood being accommodated by distension of the arterial wall

27
Q

What causes the gradual decrease in diastolic blood pressure in ageing adults?

A

The diastolic pressure decreases because the decreased stretching of the arterial wall during systole results in less pressure being ‘stored’ in the arterial wall during systole and so less pressure to drive blood flow during diastole.

28
Q

Give rationale behind why the maximum heart rate might decrease with age

A

With aging, there is a loss of cells in the bundle of His and also fibrosis there. This impairment of conduction is thought to explain why the maximum heart rate falls with age

29
Q

Give examples of what happens to the chest wall and lung mechanics as an individual ages

A
  • Calcification of rib cartilage at the sternal and posteriorly at the articulation with the vertebrae, limits chest movement
  • Respiratory muscles lose mass and strength with age
  • Lung tissue loses elastic elements
  • As people age, closure of airways during expiration limits active expiration
30
Q

How does dead space change with age?

A

There is a significant increase in the dead space over the years. In a young adult it is around 150ml. In an 80 year old it is around 250ml. This increase decreases the amount of new air reaching the alveoli with each breath

31
Q

What happens to PaO2 as an individual ages?

A

It gradually declines

32
Q

What is the main cause of decreasing PaO2 with aging?

A

Results mostly from a combination of loss of alveolar surface area and increasing V/Q mismatching

33
Q

What happens to diffusing capacity with age?

A

Decreases with age - this results from a loss of total alveolar area with age

34
Q

What is responsible for the decline in exercise capacity as we age?

A

Maximal heart rate decreases with age. This reduces the ability to increase cardiac output during exercise and so reduces the ability to supply exercising muscles with O2
In addition, the ability to fully saturate blood in the lungs with O2

35
Q

Give examples of changes that occur in the kidneys with age

A
  • Renal blood flow decreases appreciably
  • There is a progressive loss of cortical glomeruli
  • The mass of the kidney can decrease by about 25% by age 80
36
Q

What are the 9 hallmarks of ageing?

A

Primary:

  1. Genomic instability
  2. Telomere attrition
  3. Epigenetic alteration
  4. Loss of proteostasis

Antagonistic:

  1. Mitochondrial dysfunction
  2. Deregulated nutrient sensing
  3. Cellular senescence

Integrative:

  1. Stem cell exhaustion
  2. Altered communication
37
Q

How is genomic instability caused?

A
38
Q

What are some changes in lung volumes with age?

A

Decreased vital capacity.

Increaed residual volume.

39
Q

What are some changes in FVC and FEV1 with age?

A

Reduced FVC and FEV1.

40
Q

What are some changes in gas exchange with age?

A

Reduced PaO2.

Increased PaCO2.

41
Q

What are some changes in the urinary system with age?

A

Reduced renal plasma flow.

Increased filtration fraction.

Reduced glomerular filtration rate.

42
Q

What is a consequence of decreased renal function?

A

They face a greater risk of dehydration.

43
Q

What are the effects of ageing on digestive system functions?

A

Saliva:

There are reductions in secretion of mucus, immunoglobulins, and enzymes in the elderly. The reduction in the immunoglobulin secretion decreases the protection that saliva provides against GI and respiratory diseases.

Swallowing:

Swallowing becomes a slower process. This reflects a combination of some laryngeal and pharyngeal sensory loss, muscle weakness, and poorer coordination between the oral and pharyngeal phases of swallowing.

Oesophagus:

The primary oesophageal peristaltic wave is less forceful and lasts longer. Seconday peristalsis is less frequent. The LOS generates less force so reflux of gastric contents becomes more common and the elderly suffer more from heartburn.

Stomach:

Decreased wall elasticity resulting in decreased stomach capacity. Gastric emptying slows with age. Goblet cell numbers fall with age and the secretion of HCO3- by surface cells decreases, resulting in reduction in the effectiveness of the mucus layer in protecting the underlying cells from acid and enzymatic damage.

Small intestine:

Loss of Peyer’s patches and lymphoid follicles in older people, reflecting the general decline in immune function with age.

Large intestine:

Constipation becomes more common. Microbiota becomes less varied with age.

Pancreas:

From age 60, there is a gradual decline in pancreatic exocrine function and by age 80, it is estimated that 10% of people have limited enzyme secretion that can impair digestion.

Liver:

From age 65, there is a gradual reduction in liver size. The liver’s ability to detoxify compounds declines.

44
Q

What happens to microglia with age?

A

They become less effective.

45
Q

What happens to astrocytes with age?

A

They can become senescent with secretion of SASP resulting in local chronic inflammatory responses.

46
Q

What happens to oligodendrocytes with age?

A

Decreased ability for re-myelination of damaged axons.

47
Q

What happens to neurons with age?

A

They decrease in volume, retract their dendrites and lose dendritic spines.

B3 CTB (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions