What is Apoptosis?
A programmed cell death
What is necrosis?
Death of most or all of the cells in an organ or tissue due to disease, injury, or
... [Show More] failure of the blood supply.
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Characteristics of tissue necrosis
1) Rapid loss of of the plasma membrane structure
2) Organelle swelling
3) Mitochondrial dysfunction
Hypoxia
What is the #1 major cause of cellular injury leading to necrosis. (especially the kidney and heart)
What is hypertrophy?
Is an increase in the size of cells
Physiologic hypertrophy
Hypertrophy of myocardial cells such as in endurance training
Pathologic hypertrophy
Occurs secondary to HTN
What is Hyperplasia
Increase in the number of cells
Pathological hyperplasia
Endometrial hyperplasia
Compensatory hyperplasia
Removal of 70% of the liver- can regenerate in about 2 weeks
What is Metaplasia
Replacement of cells
Example of Metaplasia
Normal columnar ciliated epithelial cells of the brohchial lining have been replaced by stratified squamous epithelial cells
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During ischemia, what effect does the loss of the ATP levels have on cells?
Reduction in ATP levels causes the plasma membrane's sodium-potassium pump and sodium-calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. Sodium and water then can enter the cell freely, and cellular swelling results.
Free radicals play a major role in the initiation and progression of which diseases?
These reactive oxygen species play major roles in the initiation and progression of cardiovascular alterations associated with hyperlipidemia, diabetes mellitus, hypertension, ischemic heart diseases, and chronic heart failure.
What are free radicals?
Electrically uncharged atom or group of atoms having an unpaired electron.
How are free radicals formed?
Having one unpaired electron makes the molecule unstable; thus to stabilize, it gives up an electron to another molecule or steals one.
Free radical species
Are capable of injurious chemical bond formation with proteins, lipids, carbohydrates - key molecules in membranes and nucleic acids.
What are the Lysosomes?
Enzymatic digestion of cellular organelles, including the nucleus and nucleolus, halting synthesis of DNA and RNA
What are peroxisomes?
membrane-bound organelles in most Eukaryotic cells, primarily involved in lipid metabolism and the conversion of reactive oxygen species such as hydrogen peroxide into safer molecules like water and oxygen
How does the body metabolize Ethanol
Liver enzymes metabolize ethanol to acetaldehyde which causes hepatic cellular dysfunction. Peroxisomes help detoxify ethanol.
Which cell component is the most vulnerable target of radiation?
DNA
What is Sarcopenia
Muscular atrophy
What are some example of aging of cell/tissues
- Increased peripheral vascular resistance
- Decreased production of HCL and delayed emptying of the stomach
- Decreased immune response
What are indications of dehydration?
Headache, thirst, dry skin, and mucous membranes, elevated temperature, weight loss, and decreased or concentrated urine. Skin turgor may be normal or decreased. S/sx of hypovolemia, including tachycardia, weak pulses, dizziness, and postural hypotension.
Oncotic pressure
A form of osmotic pressure exerted by proteins, notably albumin, in a blood vessel's plasma (blood/liquid) that usually tends to pull water into the circulatory system.
What activates osmoreceptors?
An increase in osmotic pressure of the plasma
Low plasma albumin causes edema as a result of what?
A reduction in plasma oncotic pressure
Atrial natriuretic peptide (ANP)
Produced by the myocardial atria
Brain natriuretic peptide
Produced by the myocardial ventricles
What are the antagonists of the Renin-Angiotensin-Aldosterone System (RAAS)
Natriuretic Peptides: ANP, BNP, and urodilation with the kidney
What are the effects of natriuretic peptides?
Decrease blood pressure and increase sodium and water excretion.
What is the Renin-Angiotensin-Aldosterone System (RAAS)?
Is a hormone system that regulates blood pressure and fluid balance.
How does the Renin-Angiotensin-Aldosterone System (RAAS) function?
When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the precursor - prorenin, already present in the blood into renin and secrete it directly into the circulation. Plasma renin then carries out the conversion of angiotensinogen, released by the liver, to angiotensin I.
[2] Angiotensin I is subsequently converted to angiotensin II by the angiotensin-converting enzyme (ACE) found in the lungs. Angiotensin II is a potent vasoconstrictive peptide that causes blood vessels to narrow, resulting in increased blood pressure.
[3] Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the renal tubules to increase the reabsorption of sodium and water into the blood, while at the same time causing the excretion of potassium (to maintain electrolyte balance). This increases the volume of extracellular fluid in the body, which also increases blood pressure.
Increased plasma osmolality
Secretion of antidiuretic hormone (ADH) and the perception of thirst are stimulated by __________
Normal Na+ levels
135-145 meq/L
Clinical manifestations of severe hypernatremia
confusion, convulsions, cerebral hemorrhage, and coma [Show Less]