How Cells Respond To Injury Flashcards
What are the four types of tissue
Epithelial, muscle, nervous, connective tissue
Types of cell growth
Multiplicative, auxetic, accretionary
Multiplicative
Increase in cell numbers, happens a lot in embryology
Auxetic
Increase in cell size
Accretionary
Increase of extracellular tissue e.g. bone tissue growth
Can labile cells regenerate
Yes
Can stable cells regenerate
Sometimes
Permanent sells can’t
Regenerate as they are terminally differentiated
Proliferation
Cells increase in number
Cell cycle before proliferation
G1, as phase, G2, mitosis
G0 have
Terminally differentiated cells
So proliferation is triggered through
Specific stimuli
Cell injury causes
Trauma, osmotic pressure, thermal, oxygen starvation, infection, membrane failure, DNA damage, loss of growth factors, metabolic disruption
Cell injury leads to
Apoptosis which is controlled cell death or necrosis which causes inflammation
Reversible injury
Cell morphology causes swelling due to failure of cell membrane Ion pumps
Apoptosis has no
Inflammatory stimulus and is triggered by car spaces which Cleeve other proteins to carry out apoptosis
In necrosis cells
Burst and pollute with cell debris which causes an inflammatory response
What is autophagy
Cellular self eating and is a response to lack of nutrients
Will neurons and muscles divide
No as they are terminally differentiated so will stay in G0
Do liver cells divide
Most liver cells stay in G0 so won’t divide
Do fibroblasts and lymphocytes divide
Periodically they divide
What are the four types of cell adaptation e.g. response to stress hormones or signalling
Hyper Trophy, hyperplasia, Atrophy, metaplasia
What is hypertrophy
Increase in cell size e.g. blood pressure causes hyperTrophy and injured myocyte
What is hyperplasia
Increase in cell numbers, it is tightly regulated but there is a risk of malignancy
Proliferation of differentiated cells which usually occurs after an injury
What is atrophy
Decrease in cell size, Cells don’t die which causes a decrease in organs and their functions
Atrophy causes
Lack of nutrients, low oxygen, ageing
What is metaplasia
Replacement of one cell type with another cell type, it is caused by stress
Reprogramming of stem cell differentiation, it has a high risk of malignancy
Example of metaplasia
Smoking causes columnar epithelium to change to squamous epithelium which are less affective and can’t produce mucus
