BIO 256 CHAMBERLAIN EXAM 3 2025

What is the most abundant component of body fluid? - -water (45-60% total body mass) Why do women and obese people have less body water? - -adipose tissue does not hold water New borns are ___% water - -75 How much water is in the ICF? - -65% How much water is in the ECF? - -35% How much water is in the tissues (interstitial fluid)? - -25% How much water is in the blood plasma and lymphatic tissue? - -8% How much water is in the transcellular fluid? - -2% Where is intracellular fluid found? - -inside the cells ____ fluid comprises the majority of all body fluids - -intracellular Intracellular fluid makes up __ total body fluid - -2/3 Where is extracellular fluid found? - -outside the cells Extracellular fluid makes up ___ total body fluid - -1/3 What categories are extracellular fluid divided into? - -interstitial fluid, blood plasma Where is interstitial fluid found? - -between the cells What are the functions of electrolytes? - -control osmosis, regulate body secretions, maintain acid-base balance, carry electric current, serve as cofactors What are electrolytes maintained by? - -kidneys reabsorbing/secreting electrolytes, oral/IV intake, secretion of hormones (ADH, aldosterone, PTH) What is natriuresis? - -excretion of sodium in the urine What hormone promotes natriuresis? - -ANP Bio 256 Bio 256 How does ANP promote natruiresis? - -increases excretion of Na+ by inhibiting Na+ pumps What is the most abundant cation in the ECF? - -Na+ What is the most abundant anion in the ECF? - -Cl- What is the most abundant cation in the ICF? - -K+ What is the most abundant anion in the ICF? - -phosphate What is aldosterone? - -salt retaining hormone Aldosterone plays a primary role in _____ - -adjusting sodium excretion What is hypotension - -low blood pressure What does hypotension stimulate? - -secretion of renin What does renin stimulate? - -secretion of angiotensin What does angiotensin stimulate? - -secretion of aldosterone What does aldosterone increase? - -Na+/H2O reabsorption and K+ secretion What stimulates secretion of aldosterone? - -low Na+, high K+, angiotensin (from low bp) How much sodium do adults need a day? - -0.5 g How much sodium does the average american diet contain? - -3-7 g/day What is alkalosis? - -ph above 7.45 What happens during alkalosis? - -H+ diffuses out of the cells and K+ diffuses in During alkalosis, membrane ____ occurs which leads to the nerves being overstimulated - -depolarization A person will not live if the ph is below ___ or ___ - -7.0, 7.7 What is acidosis? - -ph below 7.35 What happens during acidosis? - -H+ diffuses into cells and K+ diffuses out (elevates K+ in ECF) Bio 256 Bio 256 Bio 256 During acidosis, membrane ____ occurs which make nerves hard to stimualte - hyperpolarization What is normal ph? - -7.35-7.45 What is ph determined by? - -hydrogen ions What is a buffer? - -mechanisms that resist changes in ph Buffer convert ____ acids and bases to ___ ones - -strong, weak What do physiological buffers do? - -stabilizes ph by controlling the body's output of acids, bases, or CO2 How long does urinary compensation take? - -hours/days How long does respiratory compensation take? - -minutes Does urinary or respiratory compensation alter the ph more? - -urinary What is a chemical buffer? - -substance that binds H+ and removes it from solution as its concentration begins to rise How long does it take for chemical buffer systems to restore ph? - -fraction of a second What are the 3 major chemical buffers in the body? - -bicarbonate, phosphate, and protein What is the most abundant buffer in the ICF/blood plasma? - -protein buffer system What is respiratory acidosis? - -abnormally high CO2 in systemic art