Cells Flashcards
cell injury, cell growth and cellular disorder
Define growth in the context of cell biology.
Growth is the process of increase in size resulting from the synthesis of specific tissue components.
It applies to populations, individuals, organs, cells, or even cell organelles, such as mitochondria.
What is differentiation?
Differentiation is the process whereby a cell develops a specialized function and morphology.
It involves the coordinated and selective expression/repression of specific genes to produce a cell with specialized functions.
For example, tissue-specific stem cells only produce cell types needed to renew specific tissues.
Describe morphogenesis.
Morphogenesis is the complex process of development of the structure and form of organs, limbs, facial features, etc.
It is formed from cell masses during embryogenesis.
What is cell regeneration and why is it important?
Cell regeneration is key to the continued functioning of the body.
It allows cells or tissues destroyed by injury or disease to be replaced by functionally identical cells.
The replaced ‘daughter’ cells come from tissue-specific ‘parent’ stem cells.
What are the three types of cells based on their regenerative ability?
1.Labile cells - Very high regenerative ability and rate of turnover.
2.Stable cells - Good regenerative ability but low rate of turnover.
3.Permanent cells - No regenerative ability.
Explain the difference between hypertrophy and hyperplasia.
Hypertrophy is the increase in the ‘size’ of a cell without cell replication.
Hyperplasia is the increase in the ‘number of cells’ by cell division.
Both are responses to increased demand to increase tissue or organ size.
What is atrophy and give an example
Atrophy is the decrease in size of an organ or cell by reduction in cell size and/or reduction in cell number
An example is muscle atrophy in an immobilized limb due to a fracture, which results from a decrease in muscle fiber size.
What are labile cells and their characteristics?
Labile cells have a short lifespan, high turnover time, and high regenerative potential, meaning lost cells are rapidly replaced.
What are stable cells and their characteristics?
Stable cells divide infrequently under normal conditions but can rapidly divide when needed. Their regeneration depends on the type and extent of injury.
What causes cell injury?
Causes of cell injury include thermal injury (hot or cold)
poisons (e.g., organophosphates)
drugs (e.g., paracetamol overdose)
infectious organisms
ischemia (oxygen deprivation)
plasma membrane failure
DNA damage
loss of growth factors.
What are permanent cells and their characteristics?
Permanent cells normally divide only during fetal life and cannot be replaced when lost.
What is the cell cycle?
The cell cycle is the sequence of events that a cell goes through as it grows and divides to produce new cells.
What is hypoplasia and give an example.
Hypoplasia is the failure of development of an organ or tissue. An example is severe spina bifida causing hypoplasia, leading to failure in the development of the legs.
How do anti-cancer drugs affect the cell cycle?
Many anti-cancer drugs affect stages of the cell cycle to stop the rapid division of cancer cells. However, they also stop other rapidly dividing cells, such as those in the bone marrow and lymphoid tissues, and hair.
What are the most vulnerable systems in cell injury?
The most vulnerable systems in cell injury are cell membrane integrity, ATP generation, protein synthesis, and the integrity of the genetic apparatus.
