Pathophysiology - 1st exam Flashcards
What are the three levels of protection (immunity)
Physical/Chemical
(Innate, nonspecific)
Inflammatory
(Innate, nonspecific)
Acquired Immunity
(Adaptive: Specific antibodies)
T/F
Inflammatory response varies based on tissue type
False
response to an injury/antigen is the same in all tissues
Hallmark signs of inflammation
Swelling Heat Impaired Function Pain Redness
SHIPR
Goal of Inflammatory Response
To remove the causal agent and limit tissue damage
How long does an acute inflammatory response usually last?
8-10 days
Danger of chronic inflammation
Can lead to permanent cellular damage:
- fibrosis of affected tissue/organs
- narrowing of airways in asthma
- cancer
- chronic acid exposure (due to inflammatory response) mutates the DNA in chronic HPV infections of the throat and cervix.
What happens in chronic reactive airway disease?
Due to chronic inflammatory response:
Fibrotic scarring and narrowing of upper airways
What is the most important cell type in the inflammatory response?
Why?
Mast Cells
Upon activation, begin two separate processes.
- Degranulation
- release of histamine (vasodilation)
- release chemical factors that attract more WBCs (neutrophils and eosinophils) - Synthesis of substances for chemical defense
- Platelet Activating Factor
- activates prostaglandins
- activates leukotrienes (vascular effects)
What to prostaglandins do?
Vascular effects
Produce pain response
What do histamines do? Who produces them?
Increases permeability of capillaries
(Allows WBCs and some proteins in to fight invaders)
Produced by mast cells (and basophils)
What would happen to the number of receptors with chronic hyperinsulinemia
Downregulation of insulin receptors
How do you get hyperinsulinemia?
Healthy pancreas but defective receptors.
What would be the result if the insulin protein receptors in the phospholipid bilayer were dysfunctional?
You would end up with hyperglycemia (Type 2 diabetes)
What would be the result if there was an absolute deficiency of insulin (pancreatic beta cells not working)
Hyperglycemia (Type 1 Diabetes)
What is one of the biggest factors in insulin resistance?
A BMI of more than 30
This is because adipocytes release Resistin, which competes with insulin (binds faster to insulin protein receptors than insulin does).
Resistance is at the cellular level.
This leads to hyperglycemia.
What is a ligand?
Any kind of molecule that attaches to a protein receptor on a cell membrane.
Where is insulin made?
The beta cells of the pancreas.
What will the cell do if it doesn’t have enough glucose? (If there are low ligand levels)
It will send a chemical signal that travels through the bloodstream, stimulating the pancreas to send out more insulin.
It might also up-regulate the number of protein receptors so that it can take in more.
What types of cells are insulin-independent?
- Peripheral nerve cells
- Retinal cells
- Endothelial cells (lining arteries, veins, etc).
When is sorbitol produced?
When the cell has too much glucose.
Sorbitol is sticky and causes dysfunction in cells as well as H20 accumulation (behaves like sodium). Leads to problems in insulin-independent cells.
What is down-regulation? What precipitates it?
High ligand levels will cause a cell to protect itself from too much glucose. It does this by retracting its insulin protein receptors, thus stopping the inflow of glucose.
Who can protect themselves from too much glucose? Insulin-dependent cells or insulin independent cells?
Insulin-dependent cells can protect themselves with down-regulation.
What is diabetic neuropathy? What causes it? What does it feel like?
Too much glucose in insulin-independent cells of the peripheral nerves (fingers and toes) will lead to an accumulation of sorbitol (thru polyol pathway).
Sorbitol brings water with it. It will cause hydropic swelling and lysis.
It will start with burning/tingling and eventually lead to loss of sensation.
What is retinal neuropathy?
Buildup of sorbitol in cells (converted from excess glucose via polyol pathway) will lead to hydropic swelling and cell lysis in insulin-independent retinal cells.
First you will notice black spots, then changes in vision.
What is noncompliance? What causes it?
In vascular cells (insulin-independent), AGES (advanced glycated end products) bind glucose permanently with proteins.
Causes damage to endothelial cells.
Production of Nitric Oxide depleted. Arteries become stiff - arteriosclerosis.
Result: High BP, HTN
Does glucose follow insulin into the cell?
No. Insulin never enters the cell. It just activates the protein receptor that opens up a GLUT channel for glucose.
Which leads to hyperglycemia - Type 1 Diabetes or Type 2 Diabetes?
Both lead to hyperglycemia - it’s the reasons that differ.
Where is the dysfunction in Type 1 Diabetes?
In the pancreas/beta cells.
Due to genetic inheritance or, later in life, autoimmune problems.
Where is the causal dysfunction in Type 2 Diabetes?
Starts at the cell - the insulin receptors are dysfunctional.
Greatest risk factor is a BMI greater than 30.
What is Nephropathy? What causes it?
AGES (advanced glycated end products) permanently bind glucose to proteins.
Causes damage to the vascular tissue in the renal corpuscle.
Endothelial cell production of Nitric Oxide is depleted. Renal corpuscle tissue becomes stiff/non compliant - arteriosclerosis.
What are the 3 processes that might malfunction, causing glucose to be unable to enter a cell?
Reception (inability of insulin to attach to protein receptor)
Transduction (after insulin attaches, transmission malfunction inside the cell)
Response (failure of the glut channels to actually open)
Why does diabetes cause frequent urination and excessive thirst?
Hyperglycemia makes the kidneys try to excrete excess glucose that’s in the bloodstream.
Normally, the kidneys reabsorb all the glucose, but too much glucose in the blood will surpass the renal threshold and it will be detectable in the urine.
What is the primary job of the phospholipid bilayer?
To regulate the flow of substances into and out of the cell.
What do the pancreatic beta cells produce?
What about the alpha cells?
Beta: insulin
Alpha: Glucagon
What does glucagon do?
It travels to the liver, telling special cells there to release glycogen.
(Glycogen tells the cells to release ATP).
What is cardiac output?
How do you calculate it?
The volume of blood your heart pumps per minute.
HR x Stroke Volume = cardiac output.
What is an average Stroke Volume?
60-80 ml/Stroke
What physiological response will occur with a decreased stroke volume?
Decrease in Blood Pressure
(Decrease in cardiac output)
Heart will pump faster - Increase in heart rate.
What hormone do the adrenals release in a stressful event? What is its effect?
Epinephrine
It will attach to beta receptors in the SA node of the heart and increase heart rate.
What is a normal Serum K+ range?
3.5-5.0
What is hydropic swelling? What are some causes of it?
Cell swells due to increased water in the cell. (Can lead to cell lysis).
Can occur from:
Sodium entering the cell
-failure of sodium-potassium pump due to hypoxia
-hyperkalemia with serum potassium levels of 7+
-hypoparathyroidism with hypocalcemia
Sorbitol entering the cell
maybe Calcium entering the cell (contributing factor with hypoxia)
What would you expect to happen with a patient who has serum potassium levels of 5.9?
Cell membrane polarity in excitable cells will move closer to threshold.
-APs will be quick to generate and repolarize - cardiac dysrhythmias
-huge T-waves in EKG
(Possibly twitching, tetany, irritability)
What is the p-wave?
Little bump in EKG before the QRS complex.
Signifies atrial depolarization