Unit 1 - Altered Cellular and Tissue Biology Flashcards
normal function of the plasma membrane
act as a semi permeable barrier between the I CF and the ECF
which type of transport allows water and small uncharged molecules to cross the plasma membrane?
passive transport. large complex molecules move across the membrane through active transport which requires energy.
list the three mechanisms discussed in class that are affected when the plasma membrane sustains injury
- The nucleus and its genetic information
- Organelles and their function
- Altered cellular physiology and pathology
when faced with stress, why do cells adapt by changing structure and function?
to survive and maintain homeostasis
list the five cellular alterations discussed in class
- Atrophy
- Hypertrophy
- Hyperplasia
- Dysplasia
- Metaplasia
decreases cell substances and results in cell shrinkage
cellular atrophy
causes of cellular atrophy
- physiological (associated with normal development)
- pathological (accompanying disease)
- disuse (due to lack of use or stimulation)
causes a cellular atrophy may result in…
decreased protein synthesis and or protein catabolism
pathway that degrades proteins
ubiquitin-proteosome pathway
small protein used in the destruction of damaged or unneeded proteins
ubiquitin
protein complex in the cells containing proteases
proteosomes
increase in cell size
hypertrophy
general cause of hypertrophy
increased rate of protein synthesis
list the three mechanical signals of hypertrophy
- Stretch
- Growth factors and hormones
- Vasoactive agents
an increase in the number of cells of a tissue or organ
hyperplasia
name into tissues that are examples of cells that go through hyperplasia
breast and uterine tissue during pregnancy. Hyperplasia occurs in these tissues due to their ability to go through mitotic division
how is physiological hyperplasia regulated?
hormonal and compensatory
which organs are most affected with hormonal hyperplasia
?mostly estrogen dependent organs such as the uterus and breast tissue during ovulation and pregnancy
what is compensatory hyperplasia?
an adaptive mechanism that allows certain organs such as the liver to regenerate
an abnormal proliferation of normal cells usually in response to excess hormonal stimulation of growth factors
pathologic hyperplasia
deranged growth that results in cells that lose their uniformity
dysplasia
what is the mitigating cause of dysplasia?
chronic irritation or inflammation
susceptible organs include the uterus and cervix oral cavity gallbladder and respiratory tract
dysplasia is potentially reversible when irritating cause is removed
the reversible conversion from one adult cell type to another cell type better suited for the environmental stressors
metaplasia
cell injury occurs when…
the cell is unable to maintain homeostasis
what are the two consequences of cellular injury
- Cellular recovery (reversible injury)
2. Cellular gas (irreversible injury)
derive cell of oxygen and interrupts oxidative metabolism and the generation of ATP
hypoxia
what are the potential causes of hypoxia?
Can result from inadequate oxygen in the air, respiratory disease, decreased blood flow due to circulatory disease, anemia, the inability of the cell to use oxygen
tissue damage caused when blood supply returns to the tissue after a period of ischemia or lack of oxygen
reprofusion injury
reactive oxygen compounds caused by an atom or group of atoms with unpaired electrons
free radicals
includes hydroxyl radicals, super oxides, hydrogen peroxide’s
free radicals, or reactive oxygen species, cause injury by:
- Lipid peroxidation (destroys unsaturated fatty acids causing damage to the plasma membrane)
- Fragmentation of polypeptide chains within proteins (teenagers membrane transport proteins)
- Alteration of DNA (causes breakage a single strands)
list the four mechanisms that initiate production of free radicals that were discussed in class
- Absorption of UV light
- X-rays
- Oxidative reactions of normal metabolism
- Enzymatic metabolism of exogenous chemicals or drugs
tissue injury can result from exposure to toxic chemical agents, what are the four cellular mechanisms must affected?
- Injury to the cell membrane and cellular structures
- Blockage of enzymatic pathways
- Coagulation of cellular proteins
- Disrupt osmotic anionic balance within the cell
tissue injury occurs during metabolism or elimination of the toxic chemical. What is the result of the metabolism of carbon tetrachloride by the liver?
carbon tetrachloride is metabolized to highly reactive free radicals
the liver metabolizes alcohol, list the cellular conditions to the liver from alcohol abuse
- Leads to fatty deposits in the liver
- Increased intracellular water
- Depression a fatty acid oxidation
what is the disease that afflicts unborn children to women who abuse alcohol?
fetal alcohol syndrome
be sure to read over the bullet points of this disease in the lecture notes
injury resulting from mechanical energy applied to the body
blunt force trauma
bleeding under the skin or underlying tissues
contusions
removal of skin
abrasions
caused by a failure of cells to receive or use oxygen
asphyxial injuries
agents that survive and potentially produce toxin or cause injury to the cell
infectious agents
cellular accumulations or infiltrates may result in cellular injury, this occurs when:
- normal substances are produced in excess
- abnormal substances are ineffectively broken down
- harmful exogenous materials accumulate inside the cell
cellular injury that results in premature death of cells in living tissue by autolysis
necrosis
what are the four types of cellular necrosis?
- Coagulative
- Liquifactive
- Caseous
- Fatty
usually results from hypoxia caused by severe ischemia, resulting in denaturation of tissue proteins.
primarily found in the kidneys, heart, and adrenal glands
coagulative necrosis
brain cells are digested by their own hydrolase enzymes, this injury generally found after ischemic injury
liquefactive of necrosis
necrotic debris is not digested completely by cellular hydrolase enzymes, commonly seen in tuberculosis, necrotic tissue can be enclosed by a membrane called the tubercle
caseous necrosis
caused by lipase enzymes breaking down triglycerides and releasing fatty acids, this necrosis generally found in breast and pancreatic and abnormal tissues
fatty new process
in fatty necrosis, fatty acids combined with calcium magnesium and sodium to produce soaps, this is called…
saponification
this necrosis results from severe hypoxic injury caused by blockage to major arteries followed by bacterial invasion
gangrenous necrosis
gangrene usually caused by quite a lot of necrosis
dry gangrene
gangrene develops when neutrophils invade and cause liquefaction necrosis
wet gangrene
special type of gangrene resulting from bacterial infection
gas gangrene
regulated programmed cell death
apoptosis (please go over bullet points concerning apoptosis in the class notes)
self-destructive and survival mechanism literally turned “self eating”, which occurs during nutrient deprivation
autophagy
a wasting syndrome of a gene which causes changes in the musculoskeletal system
frailty
what is the cause of frailty?
endocrine- immune dysregulation resulting from a decline in hormones and an increase in pro-inflammatory cytokines
list the three mechanisms of frailty
- Cellular changes produced by genetic, environmental, and behavioral factors
- Changes in regulatory mechanisms, especially in cells of the integrated, immune, and central nervous systems
- Degenerative extracellular and vascular alterations
cellular changes or alterations of cellular control seen in frailty include…
increase degrading of hormone synthesis and hormone secretion
rejection of hormone receptors and neuromodulators leading to decreased cell signaling
decline in immune function seen in frailty includes…
autoantibodies attacking self tissues
degenerative extracellular changes in frailty include…
depletion of collagen linking which leads to decreases in sale permeability to nutrients and release of waste
other issues of frailty include…
reduced insulin signaling causing glucose intolerance resulting in type II diabetes myelitis
oxidative stress which damages the DNA altering gene expression
reactive oxygen species causing modification of lipids, proteins, and nucleic acid potentially leading to autophagy
list the characteristics of somatic death
- Death of the entire organism
- Diffuse over entire tissues and organs systems
- Does not involve inflammatory response
- Complete cessation of respiration and circulation
- Skin surface becomes discolored due to lack of circulation
- Body temperature drops gradually
