CHAPTER 18 1) Know the difference between, diffusion, osmosis, filtration and active transport (TB Q#1) • Osmosis: movement of water across a semipermeable membrane from a compartment of lower particle concentration to one that has a higher particle concentration. • Diffusion: a passive movement of electrolytes or other particles from an area of higher concentration to one of lower concentration. • Filtration: The net effect of several forces that tend to move fluid across a membrane. • Active Transport: The energy-requiring movement of electrolytes or other substances across cell membranes against a concentration gradient (from an area of low concentration to one of higher concentration). A nurse is caring for a patient who is suffering from kidney failure and is receiving peritoneal dialysis. The nurse explains that peritoneal dialysis works by instilling a solution into the abdomen that contains dextrose that will pull extra fluid into the abdominal cavity. What is the name of this process? a. Diffusion b. Osmosis c. Filtration d. Active transport 2) Be able to describe and give rationale with examples of isotonic, hypertonic and hypotonic fluids (TB Q#2, #3) a. Isotonic: Fluids that have the same osmolality as normal blood. 0.9% sodium chloride is an example of an isotonic solution. It expands the body’s extracellular fluid volume without causing water to shift in or out of cells. b. Hypertonic: more concentrated than normal blood, pulls fluid by osmosis causing them to shrink. 3% sodium chloride is an example. c. Hypotonic: Less concentrated than normal blood after they are infused. They move water from extracellular compartment into the cells by osmosis causing them to swell. A patient has been admitted to the postsurgical nursing unit after surgery. The health care provider has ordered the patient to have an IV of 0.9% sodium chloride. The nurse who is caring for the patient recognizes this as what type of solution? a. Hypotonic b. Isotonic c. Hypertonic d. Hypnotic 3) Be able to describe the mechanism behind thirst (TB Q#4) a. Thirst is a conscious desire of water. It regulates fluid intake when plasma osmolality increases (osmoreceptor-mediated thirst) or the blood volume decreases. The thirstcontrol mechanism is in the hypothalamus of the brain. Osmoreceptors there continually monitor plasma osmolarity; when osmolality increases, the hypothalamus stimulates thirst. Two nursing students were having pizza one evening as they were studying. One student remarked that whenever she ate pizza, she was incredibly thirsty. The second student explained that this thirst was caused by: a. colloid osmotic pressure. b. osmoreceptors. c. oncotic pressure. d. hydrostatic pressure. 4) Describe insensible water loss and the effects on particular organs (TB Q#5) a. Fluid output occurs through 4 organs: the skin, GI tract, lungs and kidneys (Insensible water loss is not visible). It is continuous and occurs through the skin and lungs. Insensible water output increases with fever. A 7-year-old patient was admitted to the hospital with a high fever. The nurse caring for the child knows that the child has increased insensible water loss resulting from the fever and should receive additional water to prevent hypernatremia. Insensible water loss occurs through which organ? a. Kidneys b. GI tract c. Skin d. Stomach 5) Be able to describe the mechanism in which fluid and electrolyte balance is maintained or regulated partially by hormones (TB Q#7) a. The hypothalamus controls release of ADG from the posterior pituitary gland. Antidiuretic hormone circulates to the kidneys, where it acts on the collecting ducts causing them to reabsorb water. The bodys fluid and electrolyte balance is maintained partially by hormonal regulation. The nurse conveys an understanding of this mechanism in which statement? a. The pituitary gland secretes aldosterone. b. The kidney secretes antidiuretic hormone. c. The adrenal cortex secretes antidiuretic hormone. d. The pituitary gland secretes antidiuretic hormone. 6) Educations for clients at risk for hyperthermia.ie; (hypothalamus injury) Any injury to the hypothalamus impairs heat loss mechanisms. Educate patients at risk for hyperthermia to do which of the following? (Select all that apply.) a. Avoid strenuous exercise in hot, humid weather. b. Avoid exercising in areas with poor ventilation