Exam 1 Cell injury/alterations Flashcards
Atrophy
Ex.
The cell reverts to a smaller size
An adaptation in response to change in metabolic requirement
Ex: patient who had surgery and did not eat for a few days. The stomach will get smaller from not eating so it cannot accommodate large foods yet. Start with liquids then move to larger meals.
requires less metabolic requirement
Body builder works out gets big muscles .. the muscles turn into fat or revert to smaller size
Causes of Atrophy
Pathologic and Physiological changes
- Disuse or diminish work load ex. stomach (physiologic)
- Lack of nerve stimulation ex: paralyzed (Pathologic)
- Lack or loss of hormonal stimulation ex: remove of ovary due to cancer (Pathologic) Menopause/breast reduce (Physiological)
- Decrease blood flow; Diabetics- pathologic
- Poor nutrition(stunted growth)- pathologic
- Aging-Physiological
Ischemia
Diminished blood supply to the area: cells will starve to death
hypertrophy
Increase in individual cell size
Can either be physiologic or pathologic
Ex: Exercise ->angiogenesis->increase perfusion to the area->good affect (Physiological) muscles are getting bigger
Ex: Chronic Hypertension->Hypertrophy of the heart (no corresponding angiogenesis) -> cells need more oxygen but no sufficient supply-> Ischemia (Pathological) -heart muscles have gotten bigger
so, cells get bigger but they dont get enough nutrients
What is the Hallmark of physiologic and pathologic in hypertrophy?
Angiogenesis; formation of new blood vessels more perfusion to the area
Hyperplasia
Increase in the number of cells in a tissue
Can either be physiologic or pathologic
Ex. pathologic hyperplasia: Begnin Prostatic Hyperplasia which is increase in the number of prostate cells and can cause cancer/ obstruct flow of urine
Ex. pathologic: Keloids; maladaptive hyperplastic accumulation of cells
Ex. physiologic: Increase in the size of breast during pregnancy
Metaplasia
- Pathologic
- Due to genetic change in response to environmental or chronic inflammation
- The replacement of one cell type with another type
chronic inflammation-> change in cell structure for tissue survival
Ex: GERD , Squamous cells in throat changing to columnar cells because stomach acid is present which is not good
Dysplasia
- Pathologic
- Disorganized cellular growth with in a tissue (not all of the cells are the same in one tissue or area
- The cells vary in sizes and shapes
- This is seen in chronic inflammation or precancerous conditions
- without treatment can become Neoplasia
uncontrolled growth
Neoplasia
- Pathologic
- the new and abnormal development of cells that may be benign or malignant
- can be controlled if caught early on
Cellular injury: What causes the dysfunction of sodium potassium pump?
No sufficient ATP -> Active Transport fails ->impaired osmotic balance -> Na not removed from the cell -> attracts water -> swelling -> cell death
No ATP (energy) can be caused from lack of oxygen or blood clot
What are 4 causes of cellular injury ?
- Dysfunction of Sodium Potassium pump
- Defects in protein synthesis
- Intracellular accumulations
- Genetic damage
What are intracellular accumulations?
- Either from environment (ex:dust) or cell waste products (ex: creatine kinase, lactic acid)
- When cells are destroyed they produce creatinine kinase ex:chest pain from exercise which causes over excursion
Ex: Neighbor fell and was left there for 8 hours which can cause CK to be elevated, muscle cells are exerted and destroyed
- It can be reversible or irreversible. Irreversible ex: coal miner from the age of 16 ; Reversible ex: A person exercising temporarily
What is genetic damage?
IMAGE
Injury to cells DNA -> Mutation -> change in cell structure -> not compatible to like
Genetically programmed Mutation can cause immediate cell death (apoptosis) or non immediate cell death (ex.s spontaneous abortion) . The non immediate cell death can lead to cancer.
Free radical injury
- Reactive oxygens that can create instability with adjacent molecules ; oxidative stress: development of chronic and degenerative diseases ( caused by an imbalance between antioxidants and oxidation generators)
- They react to plasma membranes and organelle membranes as well as the nucleus and its DNA which causes –> cell destruction
Hypoxic cell injury
- Most common cause of cellular injury
- Hypoxia is oxygen deprivation which is the most common cause of cellular injury ex: stroke (not enough oxygen to the brain-stroke)
no O2 to the heart leads to MI
- This happens when blood is unable to deliver sufficient oxygen to cells
