SHANGES in gwoth

Question 1

Describe what hypertrophy and hyperplasia need

Answer 1

• Requires stimulus to cell division (usually increase in work)

Question 2

Where does hypertrophy occur

Answer 2

• Occurs in tissue/organ where cells cannot divide

Question 3

What sort of growth normally happens in permanent tissue

Answer 3

Hypertrophy

Question 4

What sort of growth in renewing tissue

Answer 4

Hyperplasia

Question 5

Where can hyperplasia be seen

Answer 5

Renewing tissue, where cells can divide.

Also in resting tissue (e.g liver regeneration)

Question 6

What is neoplasia

Answer 6

• Excessive proliferation of one cell type
• Results from cumulative genetic/epigenetic changes  loss of cell cycle checkpoint control points
• Abnormal ,unbalanced histology
• No useful function
• Progressive, spantaneous regression is rare

Question 7

Differnece between hyperplasia and neoplasia

Answer 7

-hyperplasia is increase in the size of a tissue or organ due to increased number of cells, neoplasia is formation of new tissue. -hyperplasia is a physiological response to a stimulus that leads to normal cell proliferation and enlargement of a tissue while neoplasia is an abnormal cell proliferation in a non-physiological manner, which is unresponsive to a stimulus.

Question 8

Describe benign tumours

Answer 8

grow by local expansion
• do not invade adjacent tissue, traverse basement membrane or spread to distant sites
• differentiation usually resembles that seen in normal tissue
• may cause harm through pressure, obstruction or secretion of hormones
• may progress to malignancy

Question 9

Describe malignant tumours

Answer 9

• grow by invasion of adjacent tissue, traverse basement membrane and spread to distant sites
• differentiation is incomplete to some extent (pleomorphism, anaplasia)
• nuclei are often large, aneuploid; mitotic abnormalities
• cause harm through destruction of normal tissue function (may also induce cachexia)

Question 10

Example of agenesis

Answer 10

renal agenesis (in Potter’s syndrome)

Question 11

What is hypoplasia

Answer 11

Partial failure to develop

Question 12

2 broad categories of atrophy

Answer 12

Physiological and pathological

Question 13

Describe examples of physiological atrophy

Answer 13

• Remnant structures – during development (thyroglossal duct usually atrophies and closes off before birth)
• Organs – after physiological stimulus to hyperplasia/hypertrophy has been removed (e.g. Uterus after birth, skeletal muscles after retiring from weight training, thymic involution, the shrinking of the thymus with age,

Question 14

Describe different types of pathological atrophy

Answer 14

General
Tissue specific
Local

Question 15

Describe 4 types of local atrophy

Answer 15

1) Disuse e.g. bone and muscle of immobilised limb
2) Ischaemic – cells decrease in size to reduce their metabolic needs and to maintain survival e.g. cerebral atrophy
3) Neuropathic e.g. muscle wasting after nerve injury or poliomyelitis
4) Idiopathic (i.e. arises spontaneously) e.g. Parkinsons