Chapter 4 Altered Cell Biology Flashcards
Atrophy
decrease in size
Hypertrophy
increase in size
Hyperplasias
increase in number
Dysplasia
disarranged cell; abnormal cell growth
Metaplasia
replacement of mature cells for less mature cells- lining of lungs in a smoker
Atrophy example
in a cast, bed bound, etc
Hypertrophy example
one kidney fails, heart working hard, muscles working hard
Hyperplasia example
preparing for birth, the uterus enlarges, regeneration of the liver with partial removal, even up to 70% will regenerate in about 2 weeks
Metaplasia Simplified
the original cells are not robust enough to withstand the new environment, and so they change into another type more suited to the new environment
Dysplasia Example
. Often are encountered in epithelial tissue of the cervix and respiratory tract
Reversible
Cellular Injury
Injured cells may recover
Irreversible
Cellular Injury
Injured cells die
most common cause of cellular injury
Lack of sufficient oxygen
Hypoxic injury types
-Ischemia
-Anoxia
-Cellular responses (Decrease ATP, vacuolation, cell swelling)
-Reperfusion injury
Ischemia
Reduced blood supply
Anoxia
Total lack of oxygen
Cellular responses
- Decrease in ATP (failure of sodium-potassium pump and sodium-calcium exchange)
-Cellular swelling
-Vacuolation (formation of vacuoles causing swelling)
Reperfusion injury
Reoxygenation causing more injury because of the formation of reactive oxygen radicals that can cause cell necrosis
Free radicals and reactive oxygen species
Electrically uncharged atom or group of atoms having an unpaired electron that damage
-Lipid peroxidation
-Alteration of proteins
-Alteration of DNA
-Mitochondrial damage
Cellular Death (Necrosis)
-Necrosis
Later Stages:
-Karyolysis
-Pyknosis
-Karyorrhexis
Necrosis
Sum of cellular changes
after local cell death and the process of cellular autodigestion
Karyolysis
Nuclear dissolution and chromatin lysis
Pyknosis
-Clumping of the nucleus
-Dissolves by karyolysis
Karyorrhexis
-Fragmentation of the nucleus
-“nuclear dust”
Coagulative Necrosis
-Kidneys, heart, and adrenal glands
-Protein denaturation
Coagulation is caused by
protein denaturation
protein denaturation
causes the protein albumin to change from a gelatinous, transparent state to a firm, opaque state
Liquefactive necrosis
-Neurons and glial cells of the brain
-Brain is rich in digestive hydrolytic enzymes
-Bacterial infection
(Staphylococci, streptococci, and Escherichia coli)
Caseous Necrosis
-Tuberculous pulmonary infection
-Combination of coagulative and liquefactive necrosis
Fat necrosis
-Breast, pancreas, and other abdominal organs
-Action of lipases
Lipases break down
triglycerides
triglycerides
release free fatty acids
free fatty acids
combine with calcium, magnesium, and sodium ions, creating soaps
Fat necrotic tissue appears
opaque and chalk-white.
Gangrenous necrosis
Death of tissue from severe hypoxic injury
-commonly occurring because of arteriosclerosis, or blockage of major arteries, particularly those in the lower leg
Dry gangrene
result of coagulative necrosis,
- skin is very dry, wrinkles, turns brown or black
-(gangrenous foot)
Wet gangrene
result of liquefactive necrosis,
- occurs in internal organs causing the site to become cold, swollen, and black.
- A foul odor is present
-severe, death can ensue
Gas gangrene
special type of gangrene caused by infection of injured tissue by one of many species of clostridium (difficile).
-These anaerobic bacteria produce hydrolytic enzymes and toxins
-destroy connective tissue and cellular membranes and cause bubbles of gas to form in muscle cells.
- This can be fatal if enzymes lyse the membranes of RBCs destroying their oxygen-carrying capacity. Death is caused by shock
Apoptosis
Programmed cellular death
-Active process of cellular self-destruction. Cells need to die; otherwise, endless proliferation would lead to gigantic bodies. The average adult can create 10 billion new cells every day and so we must destroy the same amount.
Aging is
“normal”
Disease is
“abnormal”
Life expectancy is
the number of years remaining at a given age
Normal life span and life expectancy
80-100
Degenerative extracellular changes
-Dehydration
-Wrinkles of the skin
-Cataracts
-Skeletal muscle alterations
Theories of Aging
-Genetic and environmental lifestyle factors
-Alterations of cellular control mechanisms
-Degenerative extracellular and vascular changes
Aging Types
-Cellular aging
-Tissue and systemic aging
-Frailty
Cellular aging
Atrophy, decreased function, and loss of cells
Tissue and systemic aging
-Progressive stiffness and rigidity
-Sarcopenia (loss of muscle mass and strength)
Frailty
Mobility, balance, muscle strength, motor activity, cognition, nutrition, endurance, falls, fractures, and bone density
