Module 6

Question 1

Glomerular filtration rate (GFR) is a measure of

Answer 1

blood filtered through the kidney each minute and is an important measure of renal function

Question 2

Tubular re-absorption

Answer 2

• H20 and other substances reabsorbed by the renal tubules and returned to the blood

Question 3

Failure of reabsorption in Tubular re-absorption can be due to

Answer 3

alterations in antidiuretic hormone (ADH), excessive diuretics, or a functional abnormality resulting in life-threatening sodium and volume depletion

Question 4

Tubular secretion

Answer 4

• Metabolic waste products (such as urea, nitrogen, creatinine phosphate and uric acid) electrolytes (such as K+) and certain drugs (such as penicillin) are removed during this process in the form of acids

Question 5

homeostasis.

Answer 5

Fluid around cells and its composition must be maintained at a constant level to support life

Question 6

Body fluid is divided into compartments:

Answer 6

• extracellular: consisting mainly of interstitial and intravascular compartments
• intracellular

Question 7

the dynamics of fluid movement between the intravascular and interstitial spaces

Answer 7

Infants’ and children’s higher body water content, along with their higher metabolic rates and increased body surface area to mass index, contribute to their higher turnover of fluids and solute. Therefore, infants and children require proportionally greater volumes of water than adults to maintain their fluid equilibrium and are more susceptible to volume depletion. Significant fluid losses may occur rapidly, leading to depletion of the intravascular volume.

Question 8

Osmosis

Answer 8

is the movement of water (solvent) across a semipermeable membrane from area of high solvent (low solute) concentration to an area of low solvent (high solute) concentration

Question 9

For osmosis to occur the membrane must be

Answer 9

more permeable to water than to solutes, and the concentration of solutes must be greater so that water moves more easily.

Question 10

Osmolality is

Answer 10

an estimation of the osmolar concentration of plasma and is proportional to the number of particles
(solute) per kilogram of solvent.

Question 11

Isotonic solutions

Answer 11

have equal concentrations of osmotically active particles in solution similar to the osmotic pressure of plasma. Because the ICF and ECF are similar, the cells will neither shrink nor swell. (0.9% sodium chloride, Hartmann’s solution, whole blood, 5% glucose)

Question 12

Hypotonic solutions

Answer 12

have a lower concentration of osmotically active particles than isotonic solutions (water, 0.45% sodium chloride)

Question 13

Hypertonic solutions

Answer 13

have a higher concentration of osmotically active particles than isotonic solutions (20% mannitol, 10% glucose, 20% albumin)

Question 14

Diffusion

Answer 14

is the movement of solutes across a semipermeable membrane from an area of higher solute concentration to an area of lower solute concentration – solutes will move until they are evenly dispersed throughout the solution.

Question 15

Filtration

Answer 15

is the transfer of water and dissolved substances through a semipermeable membrane from an area of
high pressure to an area of low pressure driven by hydrostatic pressure.

Question 16

Oncotic pressure, also called ‘colloid osmotic pressure’,

Answer 16

is the ‘pulling force’, pulling fluids from the surrounding tissue into the capillaries.

Question 17

compensatory mechanisms

Answer 17

One of the body’s physiological responses to this is the release of aldosterone to increases the reabsorption of sodium and water and facilitates the secretion of potassium in the kidneys to increase blood volume and, therefore, increase blood pressure.

Question 18

renin- angiotensin-aldosterone system.

Answer 18

The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating blood volume and systemic vascular resistance, which together influence cardiac output and arterial pressure. As the name implies, there are three important components to this system: 1) renin, 2) angiotensin, and 3) aldosterone. Renin, which is released primarily by the kidneys, stimulates the formation of angiotensin in blood and tissues, which in turn stimulates the release of aldosterone from the adrenal cortex.

Question 19

sodium functions

Answer 19

• maintenance of acid-base balance in combination with anions such as chloride and bicarbonate
• maintenance of water balance in the extracellular fluid through maintenance of osmotic pressure

Question 20

Potassium functions

Answer 20

K+ helps to maintain fluid volume in cells
When potassium ions move in and out of the cells they tend to be exchanged with hydrogen ions and therefore help to regulate pH

Question 21

• Isotonic

Answer 21

– a crystalloid solution that has similar concentration of electrolytes as body plasma → fluid stay in the extracellular space (vascular and interstitial space)

Question 22

• Hypotonic

Answer 22

a crystalloid solution that has a lower concentration of electrolytes than body plasma → fluid goes into the intracellular space

Question 23

• Hypertonic

Answer 23

a crystalloid solution that has a higher concentration of electrolytes than body plasma → fluid is pulled from the intracellular space