MOD 3 Integrative body functions Flashcards
What are the forces that move fluid to different body compartments
Osmosis
Hydrostatic Pressure
Osmotic (oncotic) pressure
Osmosis
The movement of fluid through a semipermeable membrane from an area of low solute concentration to a high solute concentration to reach equilibrium
Hydrostatic pressure
PUSHES fluid out of the blood vessel into the tissue on the arterial side of the capillaries
Osmotic (oncotic) pressure
the PULL that attracts fluid out of the tissue back into the blood vessel on the venous side of the capillaries
Molecules with pulling power:
Protein
Glucose
Sodium
Tonicity of IV fluids
Number/ size of molecules in a solution determines which direction fluid flows
Isotonic solutions
MOST COMMONLY USED
this fluid moves equally back and forth across a membrane without increasing or decreasing the cell size.
(preferred for fluid replacement since the tonicity (sodium concentration) is similar to blood)
*I SO perfect to remember isotonic fluids are used for almost all situations
EX: 0.9% normal saline, NS, and LR
Hypertonic solutions
HyperErtonic: the E reminds you that fluid ENTERS the bloodstream. Fluid is attracted from the tissue into the bloodstream by the high concentration of solutes in hypertonic fluid.
-Large molecules like protein and glucose attract water
-SALT SUCKS (sodium attracts water)
-Given in IV when RAPID TISSUE REPLACEMENT is needed
-or when TISSUE IS OVER HYDRATED as edema or third spacing
EX: 3% saline, 6% Saline, etc.
Hypotonic Solution
HypOtonic solution: O reminds that fluid goes OUT of bloodstream
Given in IV when TISSUE IS DEHYDRATED (diabetic ketoacidosis)
EX: D5W
Fluid overload
Too much fluid of any tonicity or giving fluids too fast.
It happens primarily in the lungs (because the excess fluid in the blood vessels pushes into interstitial lung tissue) - drowning the patient
*assess lungs frequently listen for rhonchi, rales, & crackles
Fluid Challenge = 500ml
Iv fluid is given in increments of 500ml at a time and the patient is assessed (bp and lungs auscultated)
before more fluid is given. if bp is normalized then 500ml can be given. If irregular or wet sounds in the lung then no more can be given and you need to alert the provider.
Edema
Swelling in interstitial tissue
damaging effects of edema
-impaired blood flow (and O2 delivery)
-reduced local healing of tissue
-metabolic wastes cannot easily leave cells so toxins build-up
-increases the workload on the heart as it tries to move fluid through the veins. More pressure is required to push the excess fluid which raises B/P
leads to CHRONIC HYPERTENSION
Life-threatening edema
-Laryngeal edema (causes airway blockage)
-Pleural edema (Breathing impaired)
-Cerebral edema (fluid squashes the brain inside the skull)
Third spacing
too much fluid moves from the intravascular space (blood vessels) into the interstitial third space. (the nonfunctional area between cells where the fluid becomes trapped)
causes: edema, reduced cardiac output, hypotension (because fluid moved out of the blood vessels which results in low bp and cannot get back into the blood stream.
Dependent edema (measuring edema changes)
in legs, is a common finding in congestive heart failure
not precise, but gives nurses a general method of monitoring the changing condition of edema in a patient
Daily weights (measuring edema changes)
Done at the same time every day (after voiding with the same weight clothing on, i.e, hospital gown)
gives an indication of water gain/loss.
-everyone usually weighs 2 lbs less in the morning than at bedtime
Water is lost through respiration and skin evaporation during the night along with the collected urine that is voided in the morning OR to with 2lbs more after eating more than usual the day before
Treatment to reduce edema
diuretic medications (triggers kidneys to release more water) and hypertonic fluids (pulls fluid out of th tissue to be excreted by the kidneys)
Mechanisms of water and sodium regulation *thirst
Controlled by thirst center in hypothalamus and triggered by
-cellular dehydration (caused by ECF osmolality, i.e., blood is thicker than normal)
-hypovolemia (low blood volume) thirst is one of the earliest s/s of hemorrhage
Mechanisms of water and sodium regulation * Antidiretic hormone (ADH)
also called vasopressin
-secreted by the posterior pituitary gland
-released in response to increased osmolality (higher blood concentration)
-regulates water in the body by signaling the kidney to retain water and sodium
-excretion of ADH is caused by LOW BLOOD VOLUME; low sodium; high osmolality of body fluids (i.e. dehydration - ADH will cause fluid retention to relieve the dehydration)
Electrolyte imbalance
4 major cations: Na+, K+, Ca++, Mg+
What is the normal range of each?
Function of each electrolyte: Excites or calms
What tissue do they effect
S/S of imbalance wither each cation (hyper or Hypo)
Fill out Functions of the 4 major cations chart
do it
Ph is balanced by 3 mechanisms
Chemical buffers
respiratory systems
renal system
Chemical buffers
Bicarbonate buffer, phosphate buffer, and protein buffers
functions almost instantaneously
Respiratory system
uses respiration to blow off excess carbon dioxide (an acid) to normalize low ph
respiratory mechanisms take several minutes to hours
Renal system
controls excretion of hydrogen ions (acid control) and bicarbonate (base control)
take several hours or days
Respiratory regulation FIRST RESPONSE BY LUNGS
if ACIDOTIC the lungs try and compensate - RAISES ph by blowing off CO2 (which creates weak acid carbonic acid) Resulting in KUSSMAUL breathing patter - deep rapid breathing
if ALKALOTIC the body will try to compensate by reducing ventilations to conserve CO2. hyperventilation (which causes respiratory alkalosis) can occur with fever, anxiety, pain, or as a result of ventilator providing too much oxygen
Metabolic regulation SLOWER RESPONSE BY KIDNEYS
if ACIDOTIC the kidneys will excrete hydrogen ions (H+) to get rid of acid and retain bicarbonate (a base) to neutralize acid
If ALKALOTIC the kidneys will retain H+ excrete bicarb
Respiratory causes of acid/base imbalance
Acidosis = RETAINED CO2 (lung insult, illness, injury, infection, COPD, trauma to lungs, etc.)
Alkalosis = CO2 is too low (caused by hyperventilation)
Sodium lab value
135-145
EXCITES
EXtracellular cation
Affects brain and nervous system = changes in LOC/ seizures
Potassium lab values
3.5-5.0
EXCITES
Intracellular cation
Affects heart (either high or low values)
Calcium lab values
8.5-10.5
CALMS
Extracellular cation
Affects nerves and muscles
Magnesium lab values
1.5-3.0
Calms
Intracellular cation
Affects deep tendon reflexes and smooth muscle (I.e. uterus, lungs, heart, and intestines)
Acidosis effect
DEPRESSION of the central nervous system (decreases synaptic transmission
-severe acidosis causes:
disorientation
coma
death
Alkalosis effect
EXCITATION of the central nervous system
severe alkalosis causes:
muscle spasms or tetany
convulsions
death
Normal CO2 measure
42
CO2 = acid
normal HCO3 measure
32
HCO3 = base
Acidosis ph =
below 7.35
Alkalosis ph =
above 7.45
Normal ph
7.35 - 7.45
Respiratory means what with an ABG analysis
the CO2 measurement is out of wack
Metabolic means what with an ABG analysis
the HCO3 is out of whack
Compensated
pH is NORMAL and other two values are abnormal
Uncompensated
pH AND ONE other value is abnormal
partially compensated
ALL values are abnormal
What is the stress response?
Alarm stage
resistance/ adaptation
stage of exhaustion
Alarm stage
aware of the stress
CNS aroused
Body defenses mobilized
cortisol response = SNS or fight or flight phenomena
release catecholamine and cortisol
Resistance/ adaptation
full mobilization of all body resources allows the individual to cope (maintain homeostasis) despite being in a stressed condition
stage of exhaustion
continuous stress causes the progressive breakdown of compensatory mechanisms and homeostasis. this stage marks the onset of certain diseases
When stress happens what is released in the body?
catecholamines
cortisol
antidiuretic hormone (ADH)
Catechomalines
epinephrine
norepinephrine
epinephrine
exerts its chief effects on the cardiovascular system
-vasodilation
- increase cardiac output to maintain blood pressure
-increases blood flow to the brain
-increases blood flow to the skeletal muscles
-dilation of the airways, increases delivery of O2 to the bloodstream
Norepinephrine
effects complement those of epinephrine
-vasoconstriction
-constricts blood vessels of the viscera and skin, this shifts blood flow to the vessels dilated by epinephrine
-also increases mental alertness
Cortisol
acts as mediator and inhibitor
-prevents over-activation of the Sympathetic nervous system (fight or flight)
-mobilizes GLUCOSE, amino acids, lipids, and fatty acids, and delivers them to the bloodstream
-suppresses immune inflammatory function
-blocks the effects of insulin
-enhances effects of catecholamines
-glucose increases with stress. prolonged and unrelenting stress causes a chronic ELEVATION OF GLUCOSE levels that leads to diabetes mellitus.
antidiuretic hormone (ADH)
excreted from the pituitary gland, stimulates kidneys to RETAIN fluid thereby increasing blood pressure
-causes VASOCONSTRICTION which helps to increase bp
-participates in renin-angiotensin-aldosterone pathway
What are the bad effects of prolonged stressed
cardiovascular effects
immune system effects
gastrointestinal system effects
endocrine system effects
CNS effects
cancer
autoimmune disorders
prolonged stress effects on the cardiovascular system
SNS increases heart rate and bp. prolonged stress can cause chronic HYPERTENSION and cardiovascular disease
prolonged stress effects on the immune system
decreased lymphocyte production - decreased T-cell activity which leads to PRONE TO INFECTIONS
increase in proinflammatory processes (via cytokines)
suppressed NK cells (responsible for killing tumors)
reactivates latent viruses
prolonged stress effects on the gastrointestinal system
Is deactivated by the SNS because the GI tract is not needed for “fight or flight” activities
-slow peristalsis
-ULCERS
-constipation
-serious bowel problems
prolonged stress effects on the endocrine system
release cortisol from the adrenal glands increases blood sugar for energy needs
HYPERGLYCEMIA (diabetes mellitus type 2)
hypothalamic/ pituitary axis affects the reproductive system (female)
hypothalamic amenorrhea of stress
depression
eating disorders
hypogonadism of Cushing’s syndrome affects lipid alteration OBESITY
prolonged stress effects on the CNS
fatigue and lethargy ; protein catabolism
depression, anxiety,
INSOMNIA : activity of neurotransmitters and neurohormones
prolonged stress causes cancer because
decreased nk cell activity
poor repair of damaged DNA
alterations int he rates of apoptosis of immune and cancer cells
psychosocial interventions to reduce stress extended the lives of women with breast cancer
