aging + Atrophy, Hypertrophy, Hyperplasia, Metaplasia

Question 1

what are the 4 types of cellualr adaption

Answer 1

Atrophy, Hypertrophy, Hyperplasia, Metaplasia

Question 2

size of cell population depends on

Answer 2

• cell proliferation
• cell differentiation
• cell death via apoptosis

Question 3

Describe atrophy

Answer 3

• decrease in size causes shrinkage of organ size
• hypotrophy and/or hypoplasia

Question 4

Describe Hypertrophy

Answer 4

• increase in tissue/organ size due to increased cell size

*** does not **increase cell number

• often based on increased demand
• hypertrophy the increased cellular size is caused by an increased accumulation of protein in cellular components

Question 5

Give an example of hypertrophy

Answer 5

• in pregnancy, the size of each muscle cell in uterus increased by up 15x pre-pregnancy size
• Muscles get bigger via
  
  • Myofibril hypertrophied muscles
  • Sarcoplasmic hypotrophied muscle

Question 6

what is the following an example of:
* in pregnancy, the size of each muscle cell in uterus increased by up 15x pre-pregnancy size
* Muscles get bigger via
* Myofibril hypertrophied muscles
* Sarcoplasmic hypotrophied muscle

Answer 6

Hypertrophy

Question 7

Give an example of atrophy

Answer 7

• muscles of uterus enlarge in pregnancy and atrophy post delivery

Question 8

what is the following an example of :
* muscles of uterus enlarge in pregnancy and atrophy post delivery

Answer 8

atrophy

Question 9

Describe hyperplasia

Answer 9

• Increase in tissue/organ due to increased cell number
• does not increase cell size
• response to severe/prolonged injury/hormones/compensatory mechanism for dysfunctional cells in same tissue
• reversible

Question 10

Give an example of hyperplasia

Answer 10

1)* a pregnancy uterus hypertrophy due to cell enlargement causing organ enlargements, cell numbers also increase which is hyperplasia

2)* enlarged prostate is an example
* smooth muscles cells have divided producing prostatic hyperplasia

3)* Neuronal hyperplasia
* Hyperplasia of peripheral nerves (central cannot divide)

Question 11

what cell adaption are the following presenting:

1)* a pregnancy uterus hypertrophy due to cell enlargement causing organ enlargements, cell numbers also increase which is hyperplasia

2)* enlarged prostate is an example
* smooth muscles cells have divided producing prostatic hyperplasia

3)* Neuronal hyperplasia
* Hyperplasia of peripheral nerves (central cannot divide)

Answer 11

Hyperplasia

Question 12

Describe metaplasia

Answer 12

• adaptation so one cell can convert to another cell based on changing stimulus

Question 13

Give an example of metaplasia

Answer 13

• vaginal pH can cause cells to convert from glandular —> squamous
• Barrett’s esophagus

Question 14

The following are examplse of which cell adaption:
* vaginal pH can cause cells to convert from glandular —> squamous
* Barrett’s esophagus

Answer 14

metaplasia

Question 15

State the difference between myofibril hypertrophy vs sarcoplasmic hypertrophy

Answer 15

Myofibril hypertrophy
* Microtears to individual muscle fibres –> inceased volume + density of myofibrils

**Sarcoplasmic hypertrophy **
* Increased volume of sarcoplasmic fluid –> increased muscle volume w/o increase in no. of fibres

Question 16

Give an example of combined hyperplasia + hypertrophy

Answer 16

During prenancy, in utero

Question 17

Define dysplasia

Answer 17

Morphological changes seen in cells in progression to becoming cancer (neoplasia)

Question 18

Give examples of where dysplasia may occur

Answer 18

Occurs in bronchi (due to continued carnogen exposure makes metaplastic cells –> dysplastic)

Question 19

What is the Hayflick limit?

Answer 19

There is a limit to human cell division due to telomere shortening; therefore, in culture, fetal cells will divide faster than young adult cells, which will divide faster than elderly adult cells

Question 20

What are telomeres? What is their relation with aging?

Answer 20

• Telomeres are caps of non coding DNA at the ends of chromosomes
• Shorten at every cell division
• Eventually becoming too short + cell x divide
• The initial lenght is inherited paternally

Question 21

Describe progeria. What does this prove about current theory about aging?

Answer 21

Condition that causes accelerated aging in children due to cell x to divide
Cell membrane defects –> x cell division –> accelerated aging
Adds evidence that cell division is associated w/ aging

Question 22

Describe osteoperosis. State the role of oestrogen in this condition

Answer 22

• Loss of bone mass w/thinner bone matrix
• Increases fragility of bone –> increases incidence of fractures
• Caused by lack of oestrogen post menopause –> increased bone resporption + decreased bone formation –> wedge fractures