Patho exam 1- Fluid/pH

Starling forces

forces that determine the movement of fluid between capillaries and the interstitial space

What are starling forces

hydrostatic and oncotic pressure

Hydrostatic pressure

push fluid against blood vessel wall

This happens from the heart squeezing the arteries

Oncotic/osmotic pressure

concentration of solutes mainly Albumin(non permeable) and sodium

This Pulls water to where it is

capillary hydrostatic pressure

pushes fluid out of capillary

filtration

high at the arteriole end

interstitial hydrostatic pressure

pushes fluid against the capillary wall into the capillary

reabsorption

capillary oncotic pressure

attracts water from the interstitial space back into the capillary

reabsoprton

interstitial oncotic pressure

attracts water from the capillary into the interstitial space

filtration

Fluid enters/stays in the interstitial space

edema

Causes of edema

increased capillary hydrostatic pressure,

decreased plasma oncotic pressure,

increased capillary membrane,

lymphatic channel obstruction

Causes of edema- Increased capillary hydrostatic pressure

something is causing the fluid to be forced out of the vascular and into the interstitial areas; increase in net filtration

Causes of edema- Increased capillary hydrostatic pressure example

hypertension, blood clot/venous obstruction. too much IV hydration

Causes of edema- decreased plasma oncotic pressure

less proteins inside the blood vessel will cause the net movement of fluid to leave the capillary because now there are more proteins out of the vessel than in

filtration> absoprtion

Causes of edema- decreased plasma oncotic pressure example

liver disease(less proteins made), malnutrition (decrease in albumin)

What is one cause of edema related to capillary membrane permeability?

Leaky blood vessel

more fluid leaves plasma as well as proteins which draw more fluid out

How does increased capillary membrane permeability affect hydrostatic pressure in edema?

Decrease in resistance for hydrostatic pressure

overall decrease over time because proteins and fluid are leaving easier

What happens to proteins in edema due to capillary membrane permeability?

Proteins may leak out of the vessel, causing decreased pulling of oncotic pressure into the capillary and increased pushing of oncotic pressure out of the capillary

Causes of edema- increased capillary membrane permeability example

inflammation causes blood vessel to dilate

Causes of edema- lymphatic channel obstruction

lymph fluid will build up behind a blockage, increasing interstital hydrostatic pressure, but having a greater effect on interstital oncotic pressure

so the net is a filtration with more fluid in the interstitial

Causes of edema- lymphatic channel obstruction example

removal of lymph node, infection, tumor

Pitting edema

we can push into the edema, and it will leave an indentation

Pitting edema example

heart failure

Localized edema

one single body region (effusion is localized edema within a body cavity or space)

Localized edema example

sprained ankle, pleural/pericardial effusions

Generalized edema

swelling throughout the entire body

Severe swelling throughout the entire body

anasarca

(gravity) dependent edema

what people have when they sit for a long time

(gravity) dependent edema example

feet swelling

The term spacing is used to describe

where fluid is located

First spacing

normal distribution of fluid

Second spacing

edema, fluid accumulating in interstitial spaces

Third spacing

when fluid goes to location it is not located or is limited

Examples of third spacing

pleural and pericardial effusion

aldosterone

released by adrenal cortex which increases sodium reabsorption into kidneys

____ and _____ are responsible for sodium and water retention (less urine output) when there is _____ _______

ADH and RAAS; volume depletion(also hypovolemia)

RAAS

JG cells on kidney detect low pressure(low osmolarity or low fluids) which cause kidneys release renin, renin(enzyme) converts angiotensinogen to angiotensin 1, angiotensin 1 is converted to angiotensin 2 because of the ACE enzyme released from lungs, angiotensin 2 is the stimulus for release of aldosterone and constriction of arteries

Angiotensin 2 does what to BV

vasoconstricts → increases BP

aldosterone stimulates the reabsorbtion of

Na+ (fluid follows)

Angiotensin 2 stimulates secretion of

aldosterone (Na retention in kidneys)

What also stimulates aldosterone secretion

high potassium

Angiotensin 2 also secretes

ADH(vasopressin) (water retention in kidneys)

What else stimulates aldosterone release?

high potassium

ADH

hormone released by the posterior pituitary that is responsible for reabsorbing water which increase BP, BV

_____ responds when there is EXCESS volume to increase urinary output

ANP

What secretes ANP

atria in the form of ANH and ventricle released in form of BNP

when BP and BV are elevated to tell kidneys to excrete fluid

ANP function

causes excretion of fluids and reduction of Na reabsorption

ANP inhibits

renin secretion which leads to increased urine output and decreased BP and BV

isotonic concentration

equal outside and inside the cell, no fluid shifts

Isotonic size of cell

normal

Isotonic fluid excess

causes hypervolemia (caused by IV fluid, hypersecretion of aldosterone, medication) leads to weight gain, increased BP, edema

Isotonic fluid loss

causes hypovolemia (caused by hemorrhage), leads to weight loss, decreased urine output, dry skin, decreased BP

Hypertonic concentration

More Na out of the cell

Hypertonic fluid shift

water moves out of cell to follow sodium → leads to cell dysfunction → cell death(organ failure)

Hypertonic size of cell

shrinks

Hypertonic clinical manifestations

caused by: hypernatremia/ECF water deficit

Hypotonic concentration

more Na inside the cell = higher osmolarity inside

Hypotonic fluid shifts

Into cell to follow the high osmolarity inside the cell

Hypotonic size of cell

swells

Hypotonic clinical manifestations

caused by: hyponatremia, water excess

Hypervolemia and clinical signs

Increased water which causes edema

clinical signs include tight skin and bounding pulse

Taunt skin(hard to pinch because of excess fluid)

Hypovolemia

also known as dehydration

clinical signs include skin being dry, scaly, tenting(when pulling on skin it stays in stretched postion)