-principle cation excerting intercelullar osmotic pressure, required for neuromuscular activities and controlling heart rhythm.
Hyperkalemina- too much potassium, caused by aldosterone hyposecretion, renal failure, decreased insulin, extensive cellular trauma. interferes with action potential
Hypokalemia- too little potassium, cells become hyperpolarized interfere with neuron and muscle function
- 85% is stored in extracellular matrix of bone and teeth as calcium phosphate, also a component of DNA nucleotide and RNA, common buffer in urine
- found in the lumen of the stomach as hydrochloric acid, participates in the chlorine shift within erythrocytes for transport of carbon dioxide
-most abundant electrolyte in bone and teeth, harden bones and teeth, needed to initiate muscle contraction, participates in blood clotting
Hypercalcemia- too much calcium, interferes with normal muscle and nerve function and causes underexcitability of muscle and nerves
Hypocalcemia- too little calcium, overexcitability of muscles and nerves
- major function in physiological processes in muscles, brain, neurons, etc, need for action potentials. 2g per ay
Hypernatremina- too much sodium/ dehydration, causes high blood pressure, action potential imbalance, edema
Hyponatremia- too little sodium excessive water intake causes cell swelling , decrease in blood volume and blood pressure
acidosis/acidemia-buildup of acid in the bloodstream and body tissues, low blood pH
alkalosis/alkalemia- high blood pH caused by different factors (a lot of bicarbonate, loss of acid, low levels of carbon dioxide)
- substances move from tubule into blood
is the movement of substances between epithelial cells.
is the movement of substances across an epithelial cell crossing the luminal membrane (in contact with tubular fluid) and the basolateral membrane ( rests on the basement membrane
Transport maximum Tm- maximum amount of substance that can be absorbed or secreted across the tubule epithelium in a given period of time.
reabsorbed: nutrients are reabsorbed completely in the proximal convoluted tubule. sodium along the entire length of the nephron tuble, water reabsorbed by osmosis through paracellular or transcellular transport (through aquaporins)
phosphate reabsorption is inhibited by PTH, calcium reabsorption is increased by PTH
- substances move from blood to tuble
renal threshold- the maximum plasma concentration of a substance that can be carried in the blood without eventually appearing in urine
some drugs and nitrogenous waste are moved from the blood into the proximal convoluted tubule
Nitrogenous waste: Metabolic waste that contains nitrogen.
-small water soluble molecule produced from protein breaking down in liver,
-produced from nucleic acid breakdown in liver,
-produced from metabolism of creating in muscle tissue
- separates some water and dissolved solutes from the blood plasma in the glomerular capillaries
filtration membrane- porous, 0.1 micrometer thin, negative charge, formed by the glomerulus and visceral layer of capsule
Basement membrane-composed of glycoproteins and proteoglycan molecules, blocks large plasma proteins
Visceral layer- composed of cells called
that have long foot like projections (pedicels) that wrap around the capillaries. filtrations slits in between podocytes restrict passage of most small proteins.
Endothelium of glomerulus-closest to lumen, fenestrated, blocks formed elements from passing
blood enters through the afferent arteriole and exits through the efferent arteriole
Net filtration pressure- occurs if the pressure that promotes filtration (HPg) is greater than the sum of the pressures that oppose filtration (OPg and HPc)
Blood colloid osmotic pressure (OPg)- osmotic pressure exerted by the blood due to the dissolved solutes it contains
Glomerular hydrostatic blood pressure (HPg)-promotes filtration, driving force that "pushes" water and some dissolved solutes out of he glomerulus and into the capsular space
Capsular hydrostatic pressure (HPc)- pressure in the glomerular capsule due to the amount of filtrate already within the capsular space
Filtrate-includes water, sugars, ions, very small amounts of tiny proteins, nutrients, ketones, and hormones.
are erythrocytes, leukocytes, platelets, and proteins.
amount of potassium secreted in urine is dependent upon both intercalated cells and principal cells
average daily urine 1-1.5L. contents include ions, water, nitrogenous waste, and some hormones
materials that need to be extreted in urine are both filtered at the glomerulus and secreted along the tubule pathway to ensure elimination
ADH increases water reabsorption from the filtrate into the blood resulting in the production of a smaller volume of a more concentrated urine
urine is drained into the renal sinus of the kidney to be extreted by the urinary tract
Major fluid compartments
ECF / Extracellular fluid
- fluid outside of cells, (cerebrospinal fluid, synovial fluid, aqueous & vitrous humor, inner ear, and serous fluid)
interstitial fluid surrounds the cells, 2/3 of the ecf
blood plasma is the fluid within the blood vessels, protein is present
both ECF's have a high concentration in sodium(94%) & calcium (2%) cations, and chloride(69-77%) & bicarbonate (16-18%) anions.
ICF / Intracellular fluid
- fluid within our cells. 2/3 of our fluids are within our cells. enclosed by semipermeable plasma membrane.
contains more potassium(75%) & magnesium(17%) cations, phosphate(20%) anion and negatively charged proteins that ECF
Fluid movement between compartments happens by osmosis. when hydrated- water moves from ECF to ICF, when dehydrated- water moves from ICF to CF