SFP: hemodynamic disorders I Flashcards
define homeostasis
a state of equilibrium in the body with respect to chemical compositions of fluids and tissues
define edema
excess water in the interstitial space
define anasarca
extreme generalized edema of subcutaneous tissues, cavities, and organs
define hydrothorax
edema in the pleural cavity
define hydropericardium
edema in the pericardial cavity
define ascites
edema in the peritoneal cavity
differentiate between transudate and exudate
transudate: protein-poor fluid resulting from non-inflammatory mechanisms
exudate: protein rich fluid resulting from increased vascular permeability during inflammation
what are the 4 noninflammatory causes of edema
- increased arterial hydrostatic pressure; lots of fluid leaving the arterial end of a capillary
- decreased osmotic pressure; not as much fluid returning to the blood on the venous end of the capillary
- lymphatic obstruction
- sodium and water retention by the body
what causes local edema
increased hydrostatic pressure caused by impaired venous return due to obstruction; the edema will be present distal to the obstruction
deep vein thrombosis is an example of…
local edema
what causes systemic edema
impaired venous return leads to a general increase in venous pressure
congestive heart failure is a cause of ____ edema
systemic edema
describe how congestive heart failure leads to systemic edema
- heart failure reduces cardiac output
- decreased output leads to less blood flow to the kidney. as a result, kidneys release renin
- renin leads to the formation of angiotensin and the release of aldosterone
- aldosterone causes the kidneys to reabsorb sodium and water, which increases plasma volume
- more blood is formed as a result of these effort, but the heart still isn’t capable of pushing out more blood. the increased blood with still limited pumping capacity causes systemic edema.
describe pulmonary edema
a local edema caused by left ventricular failure. the left ventricle fails to pump, causing blood backup in the left atrium. this creates pressure in the lungs. there will be air, fluid, and RBC’s in the alveolar spaces.
describe general systemic edema
caused by right ventricular failure. the right ventricle fails, causing blood to backup in the right atrium. this causes blood to back up in the inflow vessels, namely the inferior and superior vena cava. this leads to systemic edema.
what is a primary cause of reduced plasma osmotic pressure
lowered levels of protein causing less fluid to be drawn back into the blood
describe the mechanism of edema caused by reduced osmotic pressure
- a decrease in plasma volume due to lack of protein decreases cardiac output
- decreased output leads to less blood flow to the kidney. as a result, kidneys release renin
- renin leads to the formation of angiotensin and the release of aldosterone
- aldosterone causes the kidneys to reabsorb sodium and water, which increases plasma volume
- more blood is formed as a result of these effort, but there is still not enough protein. this will lead to edema
describe the patterns of edema seen in reduced osmotic pressure
generalized edema, periorbital edema, ascites (belly full of fluid)
what is kwashiorker?
a severe dietary protein deficiency that can cause edema via reduced osmotic pressure
what are some causes of reduced protein that leads to reduced osmotic pressure
- nephrotic syndrome: loss of albumin at the glomerulus
- liver disease: reduced synthesis of albumin
- protein malnutrition: reduced synthesis of albumin
describe the connection between alcoholic liver disease and edema
portal hypertension increases due to the blood struggling to travel through the liver as a result of scarring. this
coupled with reduced albumin synthesis in the liver increases hydrostatic pressure and causes edema
describe lymphatic obstruction
is if often a response to filarial worms (elephantiasis). it occurs due to an inflammatory response to the parasite resulting in fibrosis/scar tissue
what is a common cause of upper limb edema?
axillary node blockage or removal due to breast cancer
describe sodium retention in relation to edema
it is often secondary to activation of aldosterone in response to a lowered volume reduction.