02 Cellular Adaptation Flashcards
Basic parts of a cell:
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▪️cell membrane ▪️ER ▪️Nucleus ▪️ribosome ▪️golgi apparatus ▪️mitichondria ▪️lysosome
The structural and functional unit of all living organisms
Building block of life
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Cell
Cell adaptayion is Normally confined to a fairly narrow range of function and structure by:
Genetic programs of metabolism
Differentiation
Specialization
Steady state
Homeostasis
Factors that determine whether injury or death would occur:
Strength of stimulus Duration of stimulus Health of the cell Type of cell Adaptability of cell
Causes of cell injury and Death:
Ischemia/ Hypoxia Infection Chemical/drugs Physical Immunologic Genetic Nutritional
Primary Targets in Cell Injury and death:
Cell Membrane
️Mitochondria
Cytoskeleton
Cellular DNA
Mechanisms of cell death and injury:
Depletion of ATP Mitochondrial Damage Influx of intracellular Calcium Accumulation of Free Radicals Defects in Membrane Permeability
Cell Injury manifested as Cytoplasmic changes:
▪️Fatty change
▪️Inclusions (e.g. Pigments)
▪️Cell swelling
Common causes of Fatty Change:
Malnutrition
Alcohols
Drugs
Pigments found as inclusions during cell injury:
Carbon Hemosiderin Bilirubin Lipofuscin Melanin
Examples of Inclusions found during cell injury:
Pigments
Proteins
Carbohydrates
TYPES OF CELL ADAPTATION:
Atrophy Hypertrophy Hyperplasia Metaplasia Dysplasia
Mechanisms of Adaptation:
Increasing cellular activity
Decreasing cellular activity
Altering cellular structure
Loss of maturation
Increase in size
Hypertrophy
Increase in number
Hyperplasia
Altering cell structure
Metaplasia
Loss of maturation
Dysplasia
Shrinkage in the size of the cell by loss of cell substance and may lead to cell death
Atrophy
Classifications of atrophy:
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Physiologic
Pathologic
Atrophy Due to decreased workload (e.g. Decreased size of uterus following childbirth, or disease)
Physiologic atrophy
Atrophy primarily due to the denervation of muscle, diminished blood supply and nutritional deficiency
Pathologic atrophy
Causes of cellular adapatation:
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Reduced functional demand or disuse In adequate supply of oxygen Lack of trophic hormones Malnutrition loss of innervation diminished blood supply aging Pressure
Increase in the size of cells which results in an increase in the size of the organs
▪️No new cells, just larger ones
▪️Synthesis more structural components
▪️can be physiologic or pathologic
▪️caused by the increased functional demand or specific hormonal stimulation
Hypertrophy
Adaptation Mostly seen in cells that cannot divide (skeletal muscle and cardiac muscle)
These changes usually Revert to normal if the cause is removed
Hypertrophy
Increase in the number of cells in an organ or tissue leading to increased organ or tissue size
Occurs if the cellular population is capable of synthesizing DNA, permitting mitotic division
Hyperplasia
Classification of Hyperplasia in which there is Increased in local production of growth factor receptors on the responding cells activating transcription factors and leading to cell proliferation
▪️Hormonal (breast and uterus during pregnancy)
▪️Compensatory (regeneration of liver following partial hepatectomy)
Physiologic Hyperplasia
Classification of hyperplasia in which there is:
stimulation of growth factors (hormonal or Viral infection- papilloma viruses)
and it may also give rise to neoplasms
Pathologic hyperplasia
Also called as GRAVES DISEASE
Hyperthyroidism
An autoimmune disorder correct arise by diffuse goiter, hyperthyroidism, and exophthalmos
Hyperthyroidism
Immune mechanism of hyperthyroidism which increases thyroid hormone secretion:
IgG antibodies vs. TSH receptor (agonists)
Pathology of hyperthyroidism
Dark red, meaty; tall columnar epithelium with intra-luminal papillae
Proliferation of prostatic glands and stroma resulting in enlargement of the gland with obstruction of Urine flow through the bladder outlet
Nodular Hyperplasia, Prostate Gland
Gross pathology of prostate in NODULAR HYPERPLASIA
Nodular, enlarged, rubbery
Pathogenesis of NODULAR HYPERPLASIA
Unknown; altered normal testosterone:estrogen ratio that develops in the elderly
Microscopic pathology of nodular HYPERPLASIA
Fibromuscular and Glandular Hyperplasia
Hyperplasia usually secondary to chronic stimulation by corticotropin due to:
- Cushing disease
- ectopic corticotropin production by nonpituitary tumor
Adrenal cortical hyperplasia
Bilateral diffuse or nodular hyperplasia of adrenal glands
Adrenal cortical hyperplasia
Primary hypersecretion of corticotropin by pituitary tumor
Cushing disease
Primary aldosteronism seen in adrenal cortical hyperplasia
Conn Syndrome
Obesity, moon facies, osteoporosis HPN, amenorrhea, virilization seen in adrenal cortical hyperplasia
Cushing syndrome
Proliferative lesions of the endometrium usually resulting from hyperestrinism
Endometrial hyperplasia
REVERSIBLE Transformation for replacement of one adult cell type to another adult cell type
Metaplasia
Thought to arise from reprogramming of stem or undifferentiated cells that are present in adult tissue
Metaplasia
Most common transformation or replacement seen in metaplasia
Columnar to squamous cells
Metaplastic Transformation seen in respiratory tract among smokers
Columnar to squamous cells
Metaplastic Transformation seen in Barrett esophagitis
Squamous to columnar cells
Metaplasia of endocervical glandular epithelium due to chronic infection
Squamous metaplasia
Also occurs in mesenchymal tissue (e.g. formation of bone in skeletal muscle)
Metaplasia
Change from one type of mature another type of mature epithelium;
persistence of stimulus may lead to dysplasia
Metaplasia
REVERSIBLE Abnormal growth and differentiation
(Variations n size & shape, enlargement, irregularity, and hyperchromasia of nuclei, disorderly arrangement of cells within the epithelium)
Dysplasia
A pre-neoplastic lesion (A stage in the cellular evolution of cancer)
Dysplasia
Dysplasia in minor degree are associated with:
Chronic irritation or inflammation
Dysplasia is most frequently encountered in:
▪️Metaplastic squamous epithelium of the respiratory tract
▪uterine cervix
Strongly implicated as a precursor of cancer; however it doesnt necessarily lead to cancer, due to its adaptive characteristics
Dysplasia
