Aging Session 36

Question 1

What is Gerontology ?

Answer 1

• The study of aging

Question 2

What are the different hallmarks of aging and what do each of them do ?

Answer 2

• Primary Hallmarks : Causes of damage
• Antagonistic Hallmarks : Responses to damage
• Integrative hallmarks : Culprtis of the phenotype

Question 3

When does genomic instability occur ?

Answer 3

• This occurs because endogenous or exogenous agents can stimulate a variety of damage on the DNA on a single chromosome which exceed DNA repairs and that’s when genomic instability occurs

Question 4

What is the telomere attrition ?

Answer 4

• Cells can divide between 50-70 times before cell death, so at one point when the telomeres becomes very short , the division is inhibited and the cell enters senescence (aging)

Question 5

What are some things that can cause epigenetic alterations and therefore lead to aging ?

Answer 5

• Alterations in the methylation of DNA or acetylation and methylation of histones, and also other chromatin associated proteins can cause epigenetic changes that contribute to aging

Question 6

what happens when proteins unfold and are unable to be refolded ?

Answer 6

• failure to refold or degrade unfolded proteins can lead to their accumulation and aggregation , resulting in proteotoxic effects

Question 7

What happens when there is mitochondrial dysfunction ?

Answer 7

• At a higher level It can effect aging

Question 8

What are some things that may occur because of altered intercellular communication ?

Answer 8

• Neuroendocrine dysfunction
• Inflammaging
• Immunosenescence
• Bystander effects

Question 9

What effect does aging have on the integumentary system ?

Answer 9

• Skin becomes thinner and less elastic
• Less adipose tissue in the subcutaneous layer
• sagging and wrinkling of the skin
• sweat glands become less active
• fewer hair follicle and a decrease in melanocytes

Question 10

What effect does aging have on the cardiovascular system ?

Answer 10

• Heart muscle weakens
• The elasticity of arteries decreases : raising bp

Question 11

What effect does aging have on the digestive system ?

Answer 11

• Secretion of saliva decreases : so more bacteria adhere to the teeth causing decay
• blood flow to the liver is reduced

Question 12

What effect does aging have on the immune system ?

Answer 12

• Function declines with age
• The thymus shrinks to less than 5% of its original size
• Antibody production decreases

Question 13

What effect does aging have on the respiratory system ?

Answer 13

• cardiovascular problems are often accompanied by respiratory disorders
• Decrease elasticity of lung tissues reduces ventilation

Question 14

What effect does aging have on the urinary system ?

Answer 14

• Blood supply to kidneys is reduced
• kidney becomes smaller and less efficient at filtering waste
• Salt and water balance is difficult to maintain , dehydrate faster
• urinary incontinence (lack of bladder control)
• enlarged prostate gland may cause difficult urination

Question 15

What effect does aging have on the musculoskeletal system ?

Answer 15

• decrease in both size and number of muscle fibres
• bones shrink in size and density

Question 16

What effect does aging have on the reproductive system for males ?

Answer 16

• low testosterone levels which lead too decreased sex drive , excessive weight gain , loss of muscle mass
• But males are still fertile

Question 17

What effect does aging have on the reproductive system for females ?

Answer 17

• Menopause occurs at age 45-55
• Ovaires dont respond to gonadotropic hormones
• physical symptoms : dizziness , depression , headaches
• females live longer than men as estrogen protects against cardiovascular disorders
• But females no longer fertile

Question 18

What effect does aging have on the endocrine system ?

Answer 18

• Activity of thyroid gland declines , resulting in a lower basal metabolic rate
• Cells become less sensitive to insulin

Question 19

What effect does Aging have on the nervous systems ?

Answer 19

• declines in cardiovascular function may impair cerebral blood flow regulation

Question 20

how is Alzheimer disease characterized ?

Answer 20

• abnormally structured neurons and reduced acetylcholine in the hippocampus

Question 21

What two features do the affected neurons have ?

Answer 21

• Bundles of neurofibrillary tangles extend from the axon to surround the nucleus of the neuron
• Protein rich accumulations called amyloid plaques envelop branches of the axon

Question 22

What are the risk factors of the Alzheimer disease ?

Answer 22

• Elevated blood cholesterol and blood pressure , smoking , obesity , sedentary lifestyle and diabetes mellitus

Question 23

What are the treatments of Alzheimer disease ?

Answer 23

• Cholinesterase inhibitors
• Drugs that block excitotoxicity : tendency of diseased neurons to self destruct
• but none of these are cures , they just slow the progress of symptoms

Question 24

What effect does Aging have on the sensory systems ?

Answer 24

• smell senses decrease and about 15% suffer from anosmia ( total inability to smell )
• after age 50 , most begin to lose hearing
• starting at age 40 , presbyopia is common ( difficulty focusing on near objects )
• cataracts and other eye disorders are much more common