T12 Flashcards
What are the 2 main theories on ageing?
Clonal senescence (inbuilt genetic mechanisms) Replication senescence (wear and tear)
Explain clonal senescence
In-built genetic factor and interactions with environment
Explain replication senescence
- Wear and tear
- Free radicals
- Defective repair
- Frailty syndrome
What is wear and tear?
Suggests normal daily loss of cells and sub lethal damage eventually leads to failure of tissue or organism
What are free radicals?
Highly reactive molecules created in neutrophils and macrophages to kill ingested organisms, if not neutralized - severe damage
What is defective healing/repair?
DNA damage
List the main characteristics of ageing
- Ageing of skin
- Osteo-articular ageing
- Impaired immunity
- Brown atrophy of liver and the heart
- Cardiovascular changes
- Neoplasms
Describe ageing of the skin
Wrinkles, hair loss, solar elastosis
Describe Osteo-articular ageing
Bones and joints: osteopenia (bone loss) , osteoporosis (thin bone trabecular) , fractures
Describe impaired immunity in ageing
Impaired with age, ↑autoimmune disease
Describe brown atrophy of liver and heart
Lipofuscin pigment in atrophic cells
Describe the cardiovascular changes in ageing
Developed world: MI, strokes, hypertension, atherosclerosis
What happens with ageing in terms of neoplasia?
becomes more frequent
Define death
Absence of vital signs e.g. respiration, pulse, response to pain
Define death
Absence of vital signs e.g. respiration, pulse, response to pain
What are possible problems with such a definition of death?
Even without these features it is possible that a person is still alive but very cold or suffering from a drug-induced coma
List common modes of death
- Cardiac arrest/dysrhythmia
- Shock
- Respiratory failure
- Stroke
- Renal failure
- Liver failure
Describe and discuss the differences between natural and unnatural causes of death
- Natural or old age
- Unnatural – accident , homicide, suicide, SIDS, SUDI, cot
death
List and briefly discuss the terminal events
- Bed sores
- Venous thrombosis
- Osteoporosis and muscle wasting
- Hypostatic pneumonia
How can bedsores contribute to death?
Occur over pressure points, can become infected
How can venous thrombosis contribute to death?
Immobile patients develop this, oedema of leg and risk for pulmonary emboli
How can osteoporosis and muscle wasting contribute to death?
- Reduction in bone mass
- Associated with bed rest
- Skeleton weakens and liberates calcium -> renal stones
- Immobilisation: skeletal muscle relaxation
