Chapter 6 Flashcards
where are capillaries
vessels between arteries and veins
how many layers do capillaries have
1 (tunica intima)
what is the role of capillaries
regulate fluids, electrolytes, and nutrient exchange between blood and extracellular space
can capillaries proliferate?
yes.
they help repair injured areas
hydrostatic pressure
pressure exerted by water
osmotic pressure
pressure exerted by differences in osmolarity
what determines osmotic pressure
amount of protein in fluid
albumin made by liver
integrity of endothelial cells
fluid can leak out of vessels
what is lymph
comes from blood, composed of water, proteins, WBCs, but NO RBCS
what happens to excess fluid that leaks out of a vessel
picked up by lymphatic vessels and brought back to blood
what happens if excess fluid that leaks out of a vessel is left outside of a vessel
too much fluid in interstitial space, blood volume gets too LOW
what are the fluid compartments of the body
intracellular fluid, plasma, interstitial fluid
imbalance of fluids
fluid may not be able to keep up (diarrhea=losing too much fluid)
may shift abnormally (goes into different compartment)
water in females
55% total body weight
water in males
60% total body weight
what does water balance depend on
lean body mass and muscle
what is water balance determined by
fluid intake and loss
fluid intake
LIQUIDS, food, metabolic water
fluid loss
URINE, stool, sweat, insensance water loss
what causes edema and effusion
alterations in pressures and/or vessels
edema
accumulation of fluid in tissues
interstitial space
effusion
accumulation of fluid in body cavities
pleural cavity
types of edema
exudate and transudate
exudate edema
high protein
inflammatory
NOT pitting
transudate edema
low protein, caused mainly by fluid
decreased osmotic pressure
increased hydrostatic pressure
pitting
what is pitting
push skin in and it remains indented
is edema pathological or physiological
pathological
why is edema a problem
results of underlying disease
mild-severe
can be fatal
fatal edemas
cerebral and pulmonary edema
cerebral edema
swelling of brain, skull limits swelling so the swelling goes inward and suppresses brain stem
pulmonary edema
impairs gas exchange
ascites-peritoneum
edema in abdominal cavity
anasarca
severe, generalized edema (all over body)
pericardial edema
fluid within pericardium preventing heart from expanding
EFFUSION
pleural edema
fluid in pleural cavity
EFFUSION
hydrostatic edema
caused by impaired venous return
where is hydrostatic edema most commonly observed
lower extremities = gravity
examples of hydrostatic edema
localized venous obstruction
thrombosis
osmotic edema
caused by low albumin
what causes low albumin
liver disease, poor nutrition (not enough protein), kidney disease
is osmotic edema transudate or exudate?
transudate
lymphedema
build up of fluid when lymphatics are damaged or blocked
is lymphedema exudate or transudate?
exudate, high protein edema
what is the most common cause of lymphedema
removal of lymph nodes, impairing lymph draining
secondary lymphedema
removal of lymph nodes due to cancer metastasizing
high protein edema
observed with inflammation
leaky capillaries releasing water and plasma proteins into interstitial space
dehydration
deficiency of body water
what causes dehydration
insufficient water intake vs. excess water loss
3 types of dehydration
dehydrated, euhydrated, overhydrated
how is dehydration categorized?
relative amount of lost body weight
symptoms of dehydration
headache, rapid pulse, thirst, low urine output, tenting
tenting
pinch skin, stays up
who is at risk for dehydration
babies, toddlers, elderly
normotonic
same tonicity thats in the body
sweat
hypotonic
low tonicity compared to body
urine
hypertonic
high tonicity compared to body
diarrhea
third spacing
moved into another space
edema or dehydrated, not both
characteristics of third spacing
low urine, low BP, increased weight, puffiness
what causes third spacing
shift of fluid from intravascular space into another body space or cavity; ascites, severe burns, low oncotic pressure (low albumin)
cations
sodium
potassium
calcium
magnesium
anions
bicarbonate
chloride
phosphate
potassium
primary intracellular cation
plays role in repolarization, action potentials
control of K+
intake, excretion (kidneys)
why is it important to keep ECF levels low
increase K+ then K+ stays inside cell
avoids leaking
hypokalemia
too low K+ in blood
hyperkalemia
too much K+ in blood
what does hypokalemia do to the membrane
hyperpolarizes it
cells fire less easily
inhibition of Na+/K+ pump
cardiac arrhythmias
what causes hypokalemia
diuretics (increases urine output to reduce body water)
eating disorders
what does HYPERkalemia do to membrane
decreases resting membrane potential closer to 0
effects of hyperkalemia
depolarizes membrane
cells fire more easily
creates ectopic beats from non-conducting myocardium
pH of extracellular fluid
7.4
blood pH
7.35-7.45
what pH levels does death occur at
<6.8 or >8.0
acidosis
pH below 7.35
increase H+ levels
alkalosis
pH above 7.45
decreases H+ levels
intracellular buffering system
phosphate buffer
what does the phosphate buffer do
minimizes changes in pH
plasma buffer
carbonic acid-bicarbonate pair
protein buffering (hemoglobin)
proteins have negative charge, serving as buffers for H+
renal buffering
major corrector of pH
secretion of H+ in urine and reabsorption of HCO3-
ion exchange buffer system
exchange of K+ for H+ in acidosis and alkalosis
acid-base imbalances
respiratory acidosis
respiratory alkalosis
metabolic acidosis
metabolic alkalosis
what is principal effect of acidosis
depression of CNS through decrease in synaptic transmission vcfc
what does acidosis lead to
disorientation
coma
death
respiratory acidosis
carbonic acid excess caused by elevated blood levels of CO2
hypercapnia
high CO2
what causes respiratory acidosis
depression of respiratory center in brain controlling breathing rate
drugs/head trauma
paralysis of respiratory or chest muscles (ALS)
emphysema (COPD)