Intro to Pathology Flashcards
Pathology
Study of suffering
- structural and functional things that go wrong and cause disease
4 aspects of disease
- Etiology
- Pathogenesis
- Morphological change
- Clinical significance
Etiology
Cause of the disease ; origin
Pathogenesis
The mechanism of development and progression of disease
Morphologic Change
Structural alterations induced first in the cells and then the organs
- have to see lots of death/sick cells before we see changes in organ
Clinical significance
Functional consequences of the morphologic changes
- what are the symptoms
- how are they affecting the patient
Idiopathic
We don’t know the cause of the disease
Cell injury
All disease starts out by this
Caused by injuries stimulus
When toxin is not removed can go to cell injury and go past adaptation
Cell injury can be reversible [when stressor is removed]
If persists [ then injury is irreversible -> cell dies]
Adaptation
All cells are put through some sort of stress
Ie. By eating things we shouldn’t, drink things we shouldn’t, medications etc.
So they adapt to that stress and when that toxin is removed go back to homeostatic normal cell
Apoptosis
= cell- suicide
Pre-programmed cell death
Occurs in some cells if they encounter a particular stimulus]
- can be triggered via intrinsic or extrinsic pathway [activate caspases]
Also a time frame in which injury goes through different phases
Ex. Heart - cardiac ischemia
[limited blood flow to heart - not getting enough oxygen
Cell function declines as they become more na more injured
- at some point reach point of no return
Reversible -> irreversible injury that cell will die. - as injury increases , more and more cell death
- as more and more cell dies- see ultra structural changes in heart [ cant see with naked eye, but with microscope]
- then can see at light microscopic level
- as we get to enough cells dying, then can see gross morphologic changes
Gross morphologic changes
Those that you can see with your naked eye
Hypoxia
Oxygen deprivation
4 cell symptoms that are vulnerable to injurious stimuli
Cell membrane : if breached, torn - then thrown off ionic balance [between intracellular and extracellular] -{mitochondria, lysosomes]
- cytoskeletal Damage can lead to this
Atp generation via mitochondrial aerobic respiration
Protein synthesis
Integrity of genetic machinery
Loss of calcium
Tight regular Intracellular vs, extracellular balance
- messes with cell membrane integrity
Muscle contraction is altered
ATP depletion and ATP synthesis
Associated with ischemia , hypoxia, and chemical injury [chemicals toxic to mitochondria]
Ie. Lack of oxygen delivery
Ischemia
Low blood leading to hypoxia
Mitochondria dysfunction
Can lead to necrosis
- increased cytoplasmic ca
- oxidative stress [low o2]
- decreased survival singles
Damage can be reversible in the early stages, but irreversible damage results in cell death via apoptosis and necrosis
What can cause low atp levels
Mitochondria[leads to cell death] , plasma membrane [ leads to loss of cellular components]and lysosomal damage [enzymatic digestion of cellular components]
NOTE cytoskeletal damage can also lead to membrane damage
All eventually lead to necrosis
Dna damage
Accumulation of misfolded proteins
- cell can trigger apoptosis
Hypoxia
Low oxygen
Physiologic adaptations
Cellular responses to normal stimulation by hormones, other endogenous chemicals, physical stresses or increased use
Pathological adaptations
Occur in order to escape injury
- also can occur as a result of hormones, stresses, etc. to prevent injury
Pathological and physiological response both involve
- Up or down regulation of specific cell receptors
- Induction of new protein synthesis by the target cell
- A switch from producing one specific Protein to a different one
Cellular adaptation to injury
Normal cells can adapt to increased stresses, suffer reversible injury, or under persistent insult they can be irreversibly damaged and die
Atrophy
Decrease in cell size
- when a lot of cells are involved the whole tissue/ organ goes down in size
- even though cells are smaller, they are not dead
Hypertrophy
Increase in cell size
-in pure hypertrophy, there re no new cells , but just bigger cells caused by an increase in the synthesis of structural proteins and organelles [skeletal muscle]
Hyperplasia
Increase in cell number
Metaplasia
Change in cell type
Reversible change in which one adult cell type is replaced by another adult cell type
- this occurs. With epithelial or mesenchymal cells
Causes of atrophy
Decreased workload
Loss of innervation
diminished blood supply
Inadequate nutrition
Enlargement of uterus during pregnancy
Hypertrophy and hyperplasia occur at the same time
Necrosis
Cell homicide
- results from an insult
Necrosis features
Swelling (enlarged cell size)
Pyknosis _> karyorrhexis __> karyolysis [nucleus]
Disrupted plasma membrane
Enzymatic digestion, cellular components may leak out of the cell
Frequent adjacent inflammation
Invariably pathological {irreversible cell injury}
Apoptosis features
Reduced cell size
Nucleus fragments into nucleosome size fragments
Plasma membrane is intact
Cellular components are interact, but may be released in apoptotic bodies
No adjacent inflammation
Often physiological - meaning removing unwanted cells only. Can be pathologic after some forms of cell injury, especially DNA damage
Inflammation
Protective response intended to elimate the initial cause of injury as well as necrotic cells and tissues associated with injury
Associated with the repair process that replaces the damaged tissue
It is beneficial and a necessary response to injury, but it can also be harmful
