Pathophysiology Oral Topics Flashcards
Cellular Phase of Acute Inflammation
It involes the delivery of leukocytes, mainly neutrophil, to the site of injury so they can use their host defence function. This phase is devided into margination, adhesion, transmigration, chemotaxis and phagocytosis.
First the leukocyte will marginate to the vessel surface. Then it will adhere to the surface and transmigrate from the vascular space to the extravascular space which is facilitated by complementary adhesion molecules such as selectins and integrins. After the extravasation, the neutrophil will undergo chemotaxis which is a process of guiding the transmigrated leukocytes to the site of cell injury.
Pathophysiology of Cardiac Insufficiency
- Definition of Heart Failure
- Causes of Heart Failure
- Forms of Heart Failure
- Symptoms of Heart Failure
Pathophysiological compensatory mechanisms in heart failure
- Increases in left ventricular volume and pressure
- Ventricular remodeling
- Neurohormonal activation
What are the different type of hyperlipidemias in Fredrickson/WHO classification called?
Type I - Familial lipoprotein lipase deficiency
Type IIA - Familial hypercholesterolemia
Type IIB - Familial hyperbetalipoproteinemia
Type III - Familial dysbetalipoproteinemia
Type IV - Familial combined hyperlipidemia
Type V - Mixed hyperlipoproteinemia
Myocardial stunning
Refers to a prolonged period (hours, days) of reversible myocardial dysfunction after an ishemic event.
Hibernation
Occurs in the setting of chronic ischemia when oxygen delivery is adequate to maintain myocardial viability but inadequate to maintain normal function. The clinical importance of the hibernating states is that restoration of blood flow to the involved myocardium results in improved mechanical function
Regional myocardial hypoxia causes
Anaerobic glycolysis, lactate production, intracellular acidosis, and disordered calcium homeostasis. These intracellular changes induce abnormalities in myocardial relaxation, leading to reduced compliance and contraction, which cause regional wall abnormalities. Finally, ECG evidence of ischemia occurs, and angina pectoris ensues.
The size and pattern of an infarct depends on
- Location and extent of occlusion
- Amount of heart tisse supplied by the vessel
- Duration of the occlusion
- Metabolic needs of the affected tissue
- Extent of collateral circulation
- Heart rate, blood pressure, and cardiac rhythm
Arrhytmias are generally produced by one of three mechanisms
Enhanced automaticity
Triggered activity
Reentry
Delayed afterdepolarizations (DADs)
The presence of increased Calcium in the sarcoplasmic reticulum and cytosol leads to induction of DADs
Digitalis toxicity, catecholamines and reperfusion ventricular tachycardia (ischemia) can lead to increased calcium –> Thus, the formation of DADs
Early afterdepolarizations (EADs)
Arise from action potential prolongation and reactivation of depolarizing currents.
Hypokalemia, Hypomagnesemia, Bradycardia and drugs can predispose to generation of EADs.
Arrhythmias from abnormal automaticity
Sinus bradycardia
Sinus tachycardia
Atrial tachycardia
Ventricular fibrillation
Arrhythmias from triggered automaticity
Due to EADs:
Polymorphic ventricular tachycardia
Atrial tachycardia
Torsades de pointes
Arrhythmias from reentry
AVNRT AVRT Atrial fibrillation Atrial flutter Ventricular fibrillation
Most common complications of PUD
Hemorrhage
Perforation
Penetration
Gastric outlet obstruction
Four major causes of chronic diarrhea
Presence of hyperosmotic luminal contents
Increased intestinal secretory processes
Inflammatory conditions, and infectious processes
Factitious diarrhea
What is ulcerative proctitis, proctosigmoiditis, and pancolitis
It’s the length of lesion in ulcerative colitis. Ulcerative proctitis involve the rectum alone, proctosigmoiditis involves the rectum and sigmoid colon and pancolitis involves the entire colon.
Three factors that contribute to the formation of gallstones
Abnormalities in the composition of bile
Stasis of blie
Inflammation of the gallbladder
Causes of Ascites
Cirrhosis Portal hypertension Right-sided heart failure Nephrotic syndrome Hypoalbuminemia
GERD complications
Strictures of the esophagus
Barret’s esophagus
Hemorrhage
Erosive esophagitis
Release of Kallikrein and Chymotrypsin results in
increased capillary membrane permeability, leading to the leakage of fluid into the interstitum and development of edema and relative hypovolemia.
Release of Elastase results in
leads to dissolution of the elastic fibers of the blood vessels and cuts, leading to hemorrhage.
Release of Phospholipase A results in
in the presence of bile, destroys phospholipids of cell membranes causing severe pancreatic and adipose tissue necrosis.
Release of Lipase results in
flows into damaged tissue and is absorbed into systemic circulation, resulting in fat necrosis of the pancreas and surrounding tissue.
Pulmonary complications of Pancreatitis
Atelectasis
Pleural effusion
ARDS
Cardiovascular complications of Pancreatitis
Cardiogenic shock
Neurological complications of Pancreatitis
Pancreatic encephalopathy
Metabolic complications of Pancreatitis
Metabolic acidosis
Hypocalcemia
Hyperglycemia
Hematologic complications of Pancreatitis
DIC
GI bleeding
Renal complications of Pancreatitis
Prerenal failure
Subacute Granulomatous (De Quervain) Thyroiditis is caused by
Viral infections
Subacute Lymphocytic Thyroidits (Hashimotos) (Chronic) is caused by
Destruction of the normal thyroid architecture by lymphocytic infiltration result in hypothyroidism and goiter
Manifestations of hypoparathyroidism
Tetany with muscle cramps
Paresthesias
Prolonged QT
Hypotension
How can hyperparathyroidism lead to kidney stones
Because of elevation in ionized calcium, and increased urinary excretion of both calcium and phosphorus
In hypopituitarism, which hormones are lost first
GH, LH and FSH followed by TSH, then ACTH, and finally prolaction
Dopamine beta hydroxylase deficiency
is a condition involving inadequate dopamine beta-hydroxylase. It is characterized by increased amounts of serum dopamine and the absence of norepinephrine (NE) and epinephrine. Dopamine is released, as a false neurotransmitter, in place of norepinephrine
Types of hormonal hypofunction
Hypothyroidism
Hypoparathyroidism
Addison’s disease
Types of hormonal hyperfunction
Hyperthyroidism Hyperparathyroidism Acromegaly Prolactinoma Conn's syndrome Cushing syndrome
Hormones associated with the stress response
Catecholamines (norepinephrine, epinephrine)
CRH –> ACTH –> Cortisol
Aldosterone
ADH
Coordinated release of the neurohormones in stress results in
- Mobilization of energy
- A sharpened focus and awareness
- Increased cerebral blood flow and glucose utilization
- Enhanced cardiovascular and respiratory functioning
- Redistribution of blood flow to the brain and muscles
- Modulation of the immune response
- Inhibition of reproductive function, and a decrease in appetite
Hypoxia can result from
- Inadequate amount of oxygen in the air
- Respiratory disease
- Ischemia
- Anemia
- Edema
- Inability of the cells to use oxygen
ARDS is a clinical syndrome characterised by
Acute onset of severe dyspnea
Hypoxemia
Pulmonary infiltrates
Causes of hypoxemic respiratory failure
- COPD
- Restrictive lung disease
- ARDS
Cause of hypercapnic respiratory failure
- Weakness or paralysis of respiratory muscles
- Muscular dystrophy
- Brain injury
Primary causes of nephrotic syndrome
Minimal change disease
Focal segmental glomerulosclerosis
Membranous glomerulonephritis
Secondary cause of nephrotic syndrome
Diabetes mellitus
SLE
Minimal change disease is characterized by
Diffuse loss of podocytes or foot processes of the visceral epithelial cells of the glomeruli
Membranous nephropathy is characterized by
Diffuse thickening of the glomerular basement membrane due to deposition of immune complexes
Focal segmental glomerulosclerosis is characterized by
Sclerosis (increased collagen deposition) in some but not all glomeruli
Acute renal failure is a syndrome characterized by
Abrupt decrease in GFR, increased BUN, disturbed regulation of ECF volume, acid base homeostasis and impaired drug excretion
Intrinsic kidney injury can be divided into
Vasculature
Glomerulus
Tubules
Interstitium
Complications of Acute kidney injury
Hyperkalemia Metabolic acidosis Hypocalcemia Hyperphosphatemia Anemia
Metabolic syndrome is characterized by
- Hyperglycemia
- Intra-abdominal obesity
- High triglycerides, low HDL
- Hypertension
- Systemic inflammation
- Abnormal fibrinogen
- Abnormal function of vascular endothelium
- Macrovascular disease (CHD, cerebrovascular and peripheral artery disease)
Acute complications of Diabetes Mellitus
Hypoglycemia
Lactic acidosis
Diabetic ketoacidosis
Chronic complications of Diabetes Mellitus
Microvascular -Nephropathy -Retinopathy -Neuropathy Diabetic foot Macrovascular
