7. Edema And Effusion

Question 1

Edema

Answer 1

Swelling caused by excess fluid in interstitial space

Intracellular - low blood flow - tissue death
Ionic pump fails - sodium in - water in cell bursts

Extracellular - filtration, lymphedema, increase BP

Question 2

Mechanisms of systemic edema

Answer 2

Major causes of systemic edema

Heart failure: Increase capillary hydrostatic pressure - edema

Renal failure: decrease renal blood flow - activation of renin-angiotensin system, retention of Na H20 (renal failure), increase blood volume - edema

Reduced plasma osmotic pressure- extra filtration, malnutrition, decrease hepatic synthesis, nephrotic syndrome, decrease plasma albumin - edema

Question 3

Three factors protect against edema foramtion

Answer 3

Lymphatic flow increases

Fluid entry into the interstitial will eventually raise the interstitial pressure = more reabsorption

Fluid entry into interstitium also lowers the interstitial oncotic pressure both by dilation and lymphatic-mediated removal of interstitial proteins

Question 4

Peripheral edema

Answer 4

Pitting edema: more common
Movement of excess interstitial water in response to pressure - press finger and takes time for fluid to move

Non-pitting edema: primarily due to one of Two disorders- lymphatic obstruction

Question 5

Pulmonary edema

Answer 5

Cardiac disease is the most common cause of pulmonary edema

Question 6

Other forms of edema

Answer 6

Lymphedema, periorbital edema, scrotal edema, ascites - extra fluid in perineal cavity of abdomen

Question 7

Effusion vs edema

Answer 7

effusion: Accumulation of fluid in the body cavities
EX: Aceties - increase fluid in abdominal cavity

Edema: accumulation of fluid in tissues

Question 8

Transudate protein-poor

Answer 8

Produces pitting edema and body cavity effusions

Less protein

Increase hydrostatic pressure (congestive HF, venous outflow obstruction) decrease colloid osmotic pressure (decrease protein synthesis, increase protein loss)

Question 9

Exudate protein-rich

Answer 9

Produces swelling of tissues but non pitting edema

Inflammation -
Vasodilation and stasis
Increase in inter endothelial spaces

Question 10

Three factors that protect against edema formation

Answer 10

1. Increase lymphatic flow
2. Fluid entry into interstitium will eventually raise interstitial pressure - more reabsorption
3. Fluid entry into interstitium, decrease oncotic pressure by: dilation (excess filtration) and lymphatic mediated removal or interstitial proteins