Cellular Adaptation Flashcards
Examples of cellular adaptation
Thymus decrease Atrophy Weight lifting Hypertrophy Inadequate nutrition Atrophy Horizontal stimulation of prostate gland Hyperplasia
Describe cellular injury
A sequence of events which occur when the adaptive ability of a cell is exceeded.
Injury May be reversible up to a certain point
If the stimulus persist, irreversible injury may result
What causes cellular injury
Oxygen deprivation Physical agents Chemicals/drugs Infectious agents Immunologic reactions Genetic derangements Nutritional imbalances
Example of dysplasia
Cervical dysplasia
Changes in epithelial cells of cervix (hpv)
Examples of metaplasia
Smoker -Pseudostratified tissue Replaced with one mature tissue type stratified squamous
Metaplasia
Reversible replacement of one mature type for another sometimes less differentiated cell type
What are abnormal stimulus hypertrophy and Hyperplasia ?
Increased functional demand (myocardium)
increased work demand (muscles)
metabolic demand
excess endocrine stimulation
Examples of Hypertrophy
Hypertrophy increase in size of cells and consequently the organ.
Weight lifting
Uterus with pregnancy
Heart muscle (abnormal) - hypertrophic cardiomyopathy
Atrophy
decrease or shrinkage in cell size, resulting
in a reduced tissue mass
Hypoxia
Reduced oxygen in tissue
Ischemia
decreased supply of oxygenated blood to tissue or organ due to circulatory
obstruction
Examples of Hyperplasia
Hyperplasia increases number of cells resulting from increased rate of cellular division. Enlarged tissue mass.
Enlarged prostate
endometrial hyperplasia
Necrosis
Premature death of cells and living tissue
apoptosis
programmed cell death
ATP Depletion
a major component of the injury is the alternation of membrane permeability cause by decreased activity of ATP
- dependent iconic pumps
Main cellular mechanism of cell Injury
ATP Depletion
Loss of Calcium homeostasis
oxidative stress
damage to mitochondria increased permeability of membranes
Principles regarding cellular response to injury and consequences
response depends on nature of injury, duration & severity
consequences of injury depend on cell type
although different agents may have different initial cellular targets. The final pathways are often similar
Why does oxygen deprivation occur?
impaired energy production
intercellular accumulation of water and electrolytes
changes in structure & size of organelles
cells switch from aerobic and anaerobic metabolism
Hypoxic conditions
trauma, stroke, respiratory diseases, unstable angina, organ failure, cancer, hemorrhagic stroke, peripheral arterial disease, congestive heart failure & heart attack
Cellular Metabolism
sustains life and allows cells to grow develop, repair damage and respond to
environmental changes
Describe the concepts of cellular adaptation
changes in conditions or stressors
cell usus reserves to continue functioning
cell produces adaptive changes to continue functioning
If reserves insufficient cell injury or death occurs
Dham- Atrophy, hypertrophy, hyperplasia, dysplasia and metaplasia
Dysplasia
a pre-neoplastic condition resulting in a alteration on in size, shape & organization of
cellular components of tissue.
What are 5 causes of Atrophy?
Reduced use of the tissue Inadequate nutrition loss of endocrine /hormonal stimulation loss of nerve supply aging
Describe the etiology (cause of disease) and pathogenesis (development of disease) process involving alteration in cellular function and growth
Disease may develop when cells and structure, function change, homeostasis cannot be maintained as a result.
Change in cell DNA
Cell damage or destroyed by changes in metabolic processes, reduced ATP, Altered PH of cells
Damage to cell membrane and receptors
Describe Pathologic Atrophy
Response to abnormal changes
Physiologic Atrophy
response to normal changes
What is oxygen deprivation?
Hypoxia - deficiency of oxygen
Ischemia - insufficient and blood flow, loss of blood supply.
(Arterial flow or reduced venous drainage)
How does hypoxia affect cell functioning?
Lack of oxygen in blood can cause the body not to function
Blood carries oxygen to the cells throughout your body to keep healthy and functioning.
Aerobic Metabolism
Energy metabolism known as cellular respiration
requires oxygen
Anaerobic
cellular process in which glucose is metabolized WITHOUT oxygen.
Passive membrane transport
No cellular energy (atp) required
substance moves down concentration gradient
Active membrane Transport
Energy (ATP) required
occurs only in living cell membrane
What are four types of tissue?
Epithelial tissue
connective tissue
Muscle Tissue
Nervous tissue
Epithelial Tissue
Comprised of sheets of cells found covering body surface, lining body cavities forming glands of the human body. Outer most or inner most tissue in an organ.
Connective tissue
binds things together, protection, support, fills space and repair
Muscle Tissue
A well vascularized and innervated tissue in which cells can physically shorten
Nervous Tissue
Tissue which makes up the brain, spinal cord, and nerves.
Cell differentiation
the process in which a stem cell alters from one type to differentiated one usually, the cell changes to more specialized type.
Genetics
Genetics is the study of heredity of traits of an organism and their variations within a population
Introduced by Mendel (1865)
Focus on behavior of genes
Genomics
is the study of genomes or the complete set of genetic material of an organism
Roderick in 1986
Focus on the entire genome of an organism
Hypertrophy
An increase in the size of cells and consequently the organ.
Example of Atrophy
Atrophy of the brain (Alzheimer)
Disuse Atrophy (inactive organ) arm in cast (shrinkage)
Endocrine atrophy - Lack of hormonal stimulation (menopause)
Aging and reduced Blood supply
Hyperplasia
Increase in the number of cells resulting from increased rate of cellular division
Cell function
Movement Conductivity Metabolic absorption Secretion Excretion Respiration Reproduction Communication
Cell communication
Autocrine
Paracrine
Endocrine
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