Kidneys
balance water intake with water excretionbalance electrolyte intake with electrolyte excretion
Insensible Water Output
evaporation from respiratory tract and from skin (700 ml/day, 300-400 ml/day)
Sweat Water Output
highly variable, usually about 100ml1-2L/Hr during exercise
Feces Water Output
normally 100 ml/day or less
Cellular Membrane
separates ICF from ECF
Capillary Membrane
separates plasma and interstitial fluid
ICF
fluid/cytoplasm inside the 750-100 trillion cells of the body40% of total body weight in malein RBCs
Plasma
non-cellular portion of bloodhas higher concentration of proteins than interstitial fluid
Protein
does not pass through, stays in blood capillaryBuffer of ICF
Polycythemia
High RBCs
Anemia
Low RBCs
Transcellular Fluid
Joint fluid, CSF, GI Fluids, makes up 1L of total body water
Passive Transport
DOWN Concentration gradientDIFFUSION (simple or facilitated)
Active Transport
needs energy, whether by ATP or otherwise
Primary Active Transport
needs ATP
Secondary Active Transport
Not via ATP
Co-Transport
Symport
Counter-Transport
Antiport
Osmosis
concentration gradient of water# of particles matters most
Hydrostatic Pressure
water pushing on watercauses fluid to leave the plasma
Osmotic Pressure (Oncotic)
water pulling on water, tonicitycell vs solutionpulls fluid into the plasma
Isosmotic
2 solutions with the same osmolatiry
Hyperosmotic
solution with > osmolarity than the reference solution
Hypo-osmotic
a solution with < osmolarity than the reference
When to Use Hypertonic
increased intracranial pressureuse Saline
Hypovolemic Shock
hemorrhage triggers release of vasopressin from Posterior Pituitaey Glandwidespread vasoconstriction
Extracellular
more Na+ and Cl-in plasma
Intracellular
2/3 of body water
Mechanisms Manage Salt Levels
1. Hypothalamus and ADH2. Adrenal Cortex and Aldosterone
Sodium
primary cation of extracellular Fluid
Potassium
Primary cation of intracellular fluid
Bicarbonate
primary buffer of plasma
Hypernatremia
blood levels of sodium are too highrelease of ADH to stimulate thirstdistal convoluted tubule opens aquaporins so water can be reabsorbed and dilute sodium
ADH
opens aquaporins for water reabsorption
Hyponatremia
excess water or loss of Na+will cause cell swellingdecrease in ADH from pituitaryDistal Convoluted Tubule used to reabsorb Na and excrete K
Baroreceptor Reflex
second by second management of BP
Decreased BP
CN IX to brainstemsympathetic stimulaitonincreased CO Vasconstriction
Inxcreased BP
CN IX to brainstemCN X to parasympatheticdecrease CO
Juxtaglomerular Cells
make and release renin when BP drops
Filtration
movement of water and solutes from capillary into the interstitial spacedriven by hydrostratic pressure
Reabsorption
movement of water and solutes back into blood from interstitial spacedriven by oncotic pressure
Renin
in Liver, converts angiotensinogen to angiotensin I
Angiotensin I
goes to lung for ACE
ACE
angiotensin-converting enzyme, from lungs converts angiotensin I to angiotensin II
Causes of Edema
1. Increase capillary hydrostatic pressure2. decrease plasma proteins3. Increase capillary permeability4. Blockage of lymph return
Kwashiorkor
Malnutrition produced by a severely inadequate amount of protein in the diet.
Pre-eclampsia
When a pregnant woman develops high blood pressure and protein in the urine after the 20th week (late 2nd or 3rd trimester) of pregnancy.
Angiotensin II
goes to adrenals, Hypothalamus, and the Sympathetic NS