Circulatory 1

Front 1

3 fluid compartments

Back 1

interstitial (between cells)

intravascular

intracellular (inside cells)

Front 2

Edema definition

Back 2

an accumulation of excess fluid in either the interstitial space or the body cavities

Front 3

2 sites of fluid imbalance

Which one manifests as edema?

Back 3

1. Imbalance between the intracellular and interstitial compartments (leads to cell shrinking or swelling)

2. Imbalance between the interstitial and intravascular compartments. Usually manifests as edema.

Front 4

Forces that move fluids between blood vessels and extravascular tissue

Back 4

hydrostatic pressure - fluid is forced out of blood and into tissues

intravascular osmotic pressure - plasma proteins pull fluid back into bloodstream

lymphatic absorption - excess interstitial fluid is absorbed and returned to systemic circulation via a large vein

Front 5

Causes of Edema (4)

Back 5

1. Increased Vascular Permeability

2. Increased Intravascular Hydrostatic Pressure

3. Decreased Plasma Osmotic Pressure

4. Decreased Lymphatic Drainage

Front 6

mechanism and edema location of Increased Vascular Permeability

Back 6

- general mechanism is endothelial reaction to inflammation.

- many inflammatory mediators are vasoactive. This causes endothelial cell contraction, creating wider inter-endothelial gaps. This increases vessel permeability and allows fluid leakage

- can be localized or generalized

Front 7

mechanism and edema location of increased intravascular hydrostatic pressure edema

Back 7

- mechanism is increased blood in the microcirculation. Due to congestion of blood either by venous obstruction or heart failure

- venous obstruction = localized edema

- heart failure = generalized edema

Front 8

mechanism and edema location of decreased plasma osmotic pressure edema

Back 8

- mechanism is decreased albumin in the circulation. albumin is the most abundant plasma protein and when it's lacking there's not a lot of "pull" to bring fluid back into bloodstream

- albumin shortage either due to reduced synthesis in the liver caused by malnutrition, liver disease, or intestinal malabsorption of protein; or because of increased albumin loss from the gut, kidney, or skin

- generalized only, never localized

Front 9

mechanism and edema location of decreased lymphatic drainage causing edema

Back 9

- mechanism is blockage or compression of lymphatic vessels.

- compression from tumors, nearby inflammatory swelling

- blockage by lymphatic vessel inflammation and fibrosis, tumours, or clots

- localized

Front 10

appearance of edema fluid

Back 10

clear or slightly yellow fluid with a small amount of protein (transudate)

Front 11

gross appearance of edema in the interstitium, lung, peritoneal cavity, and pleural cavity

Back 11

interstitium - gelatinous expansion of organ. If in subcutis there can be "pitting edema"

lung - pulmonary edema. lungs are heavy, wet, ooze fluid when squeezed

peritoneal cavity - ascites or hydroperitoneum

pleural cavity - hydrothorax

Front 12

what kind of edema is this?

Back 12

pitting edema

Front 13

what kind of edema is this? how can you tell?

Back 13

subcutaneous edema.

has gelatinous expansion of the subcutaneous tissues/subcutis.

Front 14

which one of the 4 causes of edema made this?

Back 14

decreased lymphatic drainage.

Filarial parasites from mosquitoes damage the lymphatic system so it can't drain properly. Causes what's called "lymphatic filariasis" aka elephantiasis.

Front 15

what kind of edema is this?

Back 15

pulmonary edema

Front 16

what's does this dog have? (had?)

Back 16

Ascites

- slightly yellow fluid (transudate) in the peritoneal cavity.

Front 17

what does this dog have?

Back 17

hydrothorax.

yellow transudate in the pleural cavity.

Front 18

Hyperemia vs. Congestion

Back 18

both mean increased volume of blood at a site

hyperemia = active. more blood delivered because of arteriolar dilation due to exercise or inflammation

congestion = passive. blood flow from a tissue is impaired due to venous obstruction or heart failure. Blood backs up

Front 19

which colour do tissues turn with hyperemia vs tissues with congestion?

Back 19

hyperemia = red

congestion = red-blue

Front 20

2 phases of congestion

Back 20

Acute - tissues are red and swollen. may be edematous

Chronic - more common. Capillaries may rupture, creating multifocal hemorrhage. Parenchymal cells undergo atrophy or death, creating contraction and scarring. Lungs and liver most commonly affected

Front 21

what type of congestion is this?

Back 21

acute congestion.

lung is red because of congestion of pulmonary vasculature

Front 22

what kind of congestion is this one?

Back 22

chronic