What is the body water content of females?
~50% water (higher fat content, less skeletal muscle mass).
What are the distinctive pattern of electrolytes in ECF?
Major Cation: Na+, Major anion: Cl- (chloride).
What are the distinctive pattern of electrolytes in ICF?
Low Na+ and Cl-. Major Cation: K+, Major anion: HPO42- (hydrogen phosphate).
Why are sodium and potassium nealry opposite in ECF and ICF?
Reflects the activity of cellular ATP- dependent sodium -potassium pumps.
What are the hypothalamic thirst center osmoreceptors stimulated by?
Declined plasma osmolality of 2 - 3%, Angiotension II or Baroreceptor input, Dry Mouth, Substantial decrease in blood volume or pressure.
What are the inhibitory feedback signals of water intake?
Relief of dry mouth, activation of stomach and intestinal stretch receptors.
What is Obligatory water losses?
Insensible water loss from lungs and skin, feces, and minimum daily sensible water loss of 500 ml in urine to excrete wastes.
What other facts may trigger ADH release via large changes in blood volume or pressure?
Fever, sweating, vomiting, dirrhea, blood loss, and traumatic burns.
What is a Negative Fluid Balance: Dehydration?
ECF water loss due to hemmorrpahge severe burns, prologned vomiting or diarrhea, profuse sweating, water deprivation, diurectic abuse.
What are the signs and symptoms of Dehydration?
Thirst, dry flushed skin, oliguria (decreased production of urine).
What can dehydration lead too?
Weight loss, fever, mental confusion, hypovolemic shock, and loss of electrolytes.
What happens if the ECF is diluted?
Hyponatremia (no enough sodium in the body fluids outside the cells).
What does swelling of cells lead too?
Severe metabolic disturbancea such as nausea, vomiting, muscular cramping, cerebral edema - possible death.
What is Edema due too?
Anything that increases flow of fluids out of the blood or hinders its return - high blood pressure, capillary permeability (usually due to inflammatory chemicals), incompletant venous valves, localized blood vessel blockage, congestive heart failure, hypertension, high blood volume.
What does hindered fluid return occur with in Edema?
An imbalance in colloid osmotic pressures - hypoporteinemia (decreased plasma proteins).
How can blocked (or surgically removed) lymph vessesl result in Edema?
Cause leaked proteins to accumulate in IF, increased colloid osmotic pressure of IF draws fluid from the blood, results in low blood pressure and severly imparied circulation.
What are salts important for?
Neuromuscular excitability, secretory activity, membrane permeability, controlling fluid movements.
What does JGA secrete Renin in response too?
Sympathetic nervous system stimulation - decreased filtrate osmolality, decrease stretch due to low blood pressure.
What does renin do to angiotensin II?
Catalyzes it, which prompts aldosterone release from the adrenal cortex.
What are the effects of ANP?
Decreases blood pressure and blood volume. Decreases ADH, Renin and Aldosterone production. Increases excretion of Na+ and water. Promotes vasodilation directly and also by decreasing production of angitensin II.
What is Calcium ion Ca2+ in ECF important for?
Neuromuscular excitability, blood clotting, cell membrane permeability, secretory activities.
What does PTH do to Small Intestines?
Enhances intestinal absorption of calcium (indirect through vitamin D).
What does inhibited PTH secretion result in?
Release of calcium from bone is inhibited, larger amounts of calcium are lost in feces are urine, more phosphate is retained.
What is H+ produced by?
Metabolism. - Phosphoric acid from breakdown of phosphorous containing proteins, lactic acid from anaerobic respiration of glucose, fatty acids and ketone bodies from fat metabolism, H+ liberated with C02 is converted to HC03 in blood.
What is the concentration of hydrogen ions regulated by?
Chemical buffer systems, respiratory centers, and renal mechanisms.
What is a Chemical Buffer?
System of one or more compounds that act to resist pH changes when strong acid or base is added.
What is Bicarbonate Buffer System?
Mixture of H2C03 (weak acid) [carbonic acid] and salts of HC03- (e.g., NaHC03, a weak base) [sodium bicarbonate]. Buffers ICF and ECF.
What happens to bicarbonate buffer system if a strong acid is added?
Bicarbonate ties up Hydrogen and froms carbonic acid. pH of solution decerases only slightly.
What happens if a strong base is added to Bicarbonate buffer system?
Causes Carbonic Acid to dissociate and donate Hydrogen, pH of the solution rises only slightly.
What are the components of Phosphate Buffer System?
Sodium salts of Dihydrogen phosphate (H2P04-) [weak acid], Monohydrogen phosphate (HP042-) [weak base].
What is an effective buffer in urine and ICF where phosphate concentrations are high?
Phosphate Buffer System.
What do Kidneys eliminate?
Other fixed metabolic acids (phosphoric, uric, lactic acids, and ketones) and prevent metabolic acidosis.
What are the most important renal mechanisms?
Conserving (reabsoring) or generating new HC03-, Excreting HC03-.
What is Respiratory Acidosis?
Most common cause of acid-base imbalance. Occurs when a person breathes shallowly, or gas exchange is hampered by diseases such as pneumonia, cystic fibrosis, or emphysema. - HYPOVENTILATION.