Cell Adaptations- (Exam 1) Flashcards
Define atrophy
decrease in size and/or number of the cells and their metabolic activity after normal growth has been reached
Define hypertrophy
- increased size of cells and their functions
- more common in cells with little replication
Define hyperplasia
- increase in the number of cells of an organ
- cells capable of replication
What is metaplasia?
- change in phenotype of a differentiated cell
- reversible if cause is removed
- most often in epithelial cells
What is dysplasia?
- refers to abnormal development
- mostly of epithelial cells
What is etiology?
- the study or theory of the factors that cause disease and the method of their introduction to the host
- the causes or origin of a disease or disorder
What is acute swelling?
early, sub-lethal manifestation of cell damage, characterized by increased cell size and volume due to water overload
What is the etiology of acute swelling?
- loss of ionic and fluid homeostasis
- failure of cell energy production
- cell membrane damage
- injury to enzymes regulating ion channels of membranes
- hypoxia, toxic agents
Describe the gross appearance of acute cell swelling
- slightly swollen organ with rounded edges
- pallor compared to normal
- in cut surface: tissue bulges and cannot be easily put in correct apposition
- slightly heavy (wet organ)
What is fatty change?
sub-lethal cell damage characterized by intracytoplasmic fatty vacuolation
What are the main causes of fatty change?
hypoxia, toxicity, metabolic disorders
Describe the gross appearance of fatty change
- diffuse yellow
- edges rounded and bulge on section
- tissue is soft, friable, greasy texture
Irreversible injury is associated morphologically with:
- severe swelling of mitochondria
- extensive damage to plasma membranes, giving rise to myelin figures
- swelling of lysosomes
Describe the gross appearance of necrosis
pale, soft, friable, and sharply demarcated from viable tissue by a zone of inflammation
Describe coagulative necrosis
- architecture of dead tissues is preserved
- necrotic cells removed by phagocytosis or digestion by lysosomal enzymes
Describe liquefactive necrosis
- architecture is liquified
- dead cells are digested and transformed into a liquid viscous mass
- occurs in tissues with high lipid content, high neutrophil recruitment, and high enzymatic release
Describe an abscess
a localized collection of pus in a cavity formed by disintegration of tissues surrounded by fibrous connective tissue
What is fibrinoid necrosis?
- usually seen in immune reactions involving blood vessels
- occurs when Ag-Ab complexes are deposited in walls of arteries
What can happen when there is too little apoptosis?
- mutations in p53 give rise to neoplasia
- lymphocytes react against self antigens
- failure to eliminate dead cells
What can happen when there is too much apoptosis?
- neurodegenerative disease
- ischemic injury
- death of virus-infected cells
Describe Phosphatidylserine and its actions
- phospholipid on inner membrane
- carries a negative charge
- flips to outer membrane to signal macrophages
What are the two types of endocytosis?
- potocytosis: caveolae mediated
- pinocytosis: receptor mediated
What are 3 causes of cell injury?
- oxygen deficiency
- infectious agents
- immunologic dysfunction
What are the 6 mechanisms of cell injury?
- depletion of ATP
- mitochondrial damage
- entry of calcium
- increased ROS
- membrane damage
- protein misfolding, DNA damage
What is the fundamental cause of necrotic cell death?
depletion of ATP
What are the 3 major consequences of mitochondrial damage?
- formation of the mitochondrial permeability transition pore
- increased production of ROS
- activation of apoptotic pathways
What are the 3 major forms of damage resulting from accumulation of calcium?
- membrane damage
- nuclear damage
- ATP depletion
How are ROS formed?
- normal metabolic processes
- absorption of radiant energy
- inflammation
- transition metals
- nitric oxide
How are ROS removed?
- spontaneous decay
- antioxidants
- storage and transport proteins
- enzymes
What types of cells can undergo hypertrophy?
- cardiomyocytes
- skeletal muscle cells
- neurons
What is the order of injury you will see?
- biochemical alterations
- ultrastructural changes
- light microscope changes
- gross changes
Describe the histological appearance of cellular swelling
- dilated cytoplasm from water uptake
- enlarge cells with pale cytoplasm
- increased cytoplasmic eosinophilia
- nucleus in normal position
Describe the ultrastructural changes of cellular swelling
- blebbing and blunting of plasma membrane, and loss of microvilli
- swelling and appearance of small densities in mitochondria
- dilation of ER with detachment of ribosomes
- nuclear alterations such as clumping of chromatin
