Edema and Effusions

Circulatory System

Delivers oxygen, collects wastes, important

for the health of cells

Ischemia

reduced blood flow

Infarction

localized coagulation necrosis

Edema

Excess fluid in tissues (e.g., swollen legs in

heart failure).

Effusion

Fluid buildup in body cavities (e.g., pleural

effusion in lung disease, ascites in liver failure).

(High) Hydrostatic pressure

More fluid pushed out

(Low) Colloid osmotic pressure

Less fluid pulled back in

Plasma Oncotic pressure

maintains fluid inside the

vasculature

Capillary Hydrostatic Pressure

pushes fluid from the blood

outside of the vasculature

Two types of EDEMA:

IN

• INFLAMMATORY

• NON-INFLAMMATORY

INFLAMMATORY

secondary to an inflammatory

response

exudate

due to increase vascular permeability

transudate

produces protein-poor fluid

INCREASED HYDROSTATIC PRESSURE

Mainly caused by disorders that impair venous return

Systemic

widespread

REDUCED PLASMA ONCOTIC PRESSURE

Albumin accounts for almost half of the total plasma protein

SODIUM AND WATER RETENTION

Where sodium goes, water will follow

Aldosterone

responsible for sodium retention

ADH

responsible for water retention

Water retention

increases hydrostatic pressure due to

increase in circulating blood volume

dilution

decreases oncotic

pressure due to ______

Salt retention

occurs due to renal (primary kidney disorders)

and cardiovascular disorders - decrease renal perfusion

LYMPHATIC OBSTRUCTION

Causes increase in hydrostatic

pressure due to obstruction

Parasitic filariasis

Elephantiasis

Hyperemia

an active process where arteriolar dilatation leads to increased blood flow

erythema (redness)

increased blood flow leads to ________ because of increased delivery of oxygenated blood.

Congestion

passive process resulting

from reduced venous outflow of blood

from a tissue.

Cyanosis

congested tissues have abnormal blue-red

color

Acute Pulmonary Congestion

engorged alveolar capillaries, alveolar septal

edema, focal intra-alveolar hemorrhage.

Chronic Pulmonary Congestion

often caused by congestive heart failure, the

septa are thickened and fibrotic, the alveoli often contain macrophages laden

with hemosiderin (heart failure cells).

Acute hepatic Congestion

the central vein and sinusoids are distended.

Chronic Passive Congestion

the centrilobular regions are grossly red-brown and slightly depressed and are accentuated against surrounding zones of uncongested tan (nutmeg liver).