Core concepts of patho-physiology Flashcards
Cell function is controlled in a coordinated fashion….describe how autocrine, paracrine and endocrine cells function
Autocrine- cell stimulates self (ex: mucous cells in airways will respond to the environment and will alter their secretions accordingly)
Paracrine- cell simulates other cell close by: eg: if a whole group of mucous cells act at the same time they will communicate and work as a unite
Endocrine- cells stimulate distant cells
what is in charge of higher control?
CNS, ANS, PNS
what is homeostasis?
static/balance
cells perform normal functions
what happens when a cell is injured?
they are driven away from homeostatic state
when does a cell become injured? (as a broad contexts)
when there is a disturbance in the balance between external and internal forces
cells will either adapt to the new situation or die
what does the outcome of cell response to injury depend on?
- injury type, duration and severity
- cell type, state and adaptability
what are the two types of cell death?
Necrosis: premature death of cells and living tissues: unprogrammed cell death; always detrimental,
Apoptosis: cell sends out signals and macrophages come and eat it; programmed cell death; usual beneficial
what are some ways cells respond to the disease process?
- cells adapt to changes in their environment (cells stay alive)
- inability to adapt may result in non-functioning or dead cells
- tissue response to injury is healing
- abnormal cell growth
what factors play a role in ho the cell responds to disease processes?
- genetic and immune factors
- adverse environmental factors causing the disease
What are some ways that cells adapt?
- modifying metabolic function (eg: if decreased calcium in blood, calcium will be mobilized from bones)
- alter their structure
What are the 3 types of structural change in cell adaptation?
- increased cellular activity (due to increased # of cells via mitosis, increased size of cells, or both)
- decreased cellular activity (due to decreased number, size or both of cells)
- change in morphology of cell from one type to another
What is a pathological stimuli?
environmental changes that exceed the acceptable and normal range of adaptation
What is a physiological stimuli?
stimuli that cause change that is within the normal range of adaptation
what are examples of external and internal pathological stimuli?
external: Oxygen deprivation, physical agents, chemical agents, infectious agents
internal: immunology, genetics, metabolic
Name 4 Pathological External Forces to Cell Injury
- Lack of Oxygen
- physical agents (trauma, freezing, burn, radiation etc.)
- chemical agents (drugs, poisons, heavy metals)
- Infectious agents (bacteria, virus, parasite)
What is wound healing by first intention?
healing that occurs after a surgical incision/clean cut
- acute inflam response> scab formation> PMN enter and scavenge debris> formulation of granulation tissue> replacement from fibrous scar
what is healing by second intent
healing that occurs after something like grating
> takes longer to heal, will cause a bigger blood clot
Name 3 Pathological Internal Factors to Cell Injury
- Immunologic
- Genetic
- Metabolic
4 Types of Cell Adaptation That Can Either be Physiologic or Pathologic
- Hyperplasia= increase number of cells (only affects cells that divide)
- Hypertrophy= increase cell size causes, which also increase in organ size
- Atrophy= decrease in cell size
- Metaplasia= change of epithelium type to another.
different cells have differing ability to regenerate…how do epithelial cells vs liver cells vs neurons regenerate as compared to one another
epithelial: continually dividing
liver cells: able to divide if required
neurons: no ability to divide
What is wound healing by first intention?
healing that occurs after a surgical incision/clean cut
- acute inflam response> scab formation> PMN enter and scavange debris> formulation of granulation tissue> replacement from fibrous scar
name two types of cell injury due to a lack of oxygen
myocardia infarct, stroke
List 7 Causes Of Cell Injury
- Hypoxia (decrease oxygen, thus decrease in ATP)
- Ischemia (decrease in blood flow, also involves hypoxia)
- Environment factors
- Metabolic abnormalities
- Immune dysfunction
- aging
- Nutritional imbalance
What are some cellular systems/structures that are most vulnerable?
- DNA
- Cell membrane
- protein generation
- ATP production
What are some hallmark factors to irreversible cell damage?
Loss of mitochondria, damage to plasma or lysosomal membrane
describe how skin wounds heal
by filling in the defect with granulation tissue and then replaing the granulation tissue with stronger fibrous tissue- with time the wound contracts and closes due to the contraction of myofibroblasts
name two examples of cell injury due to infectious agents
ebola virus, toxin released by bacteria
name two examples of cell injury due to physical agents
burn, frost bite
name two examples of cell injury due to chemical agents
overuse of alcohol, water contamination by arsenic
What is hyperplasia
an increase in tissue size due to an increase in the number of cells
ex: enlarged female breast during pregnancy
Describe wound healing of the skin
they heal by fitting in the defect with granulation tissue and then replacing it with stronger fibrous tissue. with time the wound contracts due to contraction of the myofibroblasts