Summary of Urinary System Function and Fluid/Electrolyte Balance Concept Map By: Carol A. Gavareski, MS Bellingham Technical College 3028 Lindbergh Ave Bellingham, WA 98225 360-752-8431; cgavares@btc.ctc.edu Objective: Review processes of urine formation and fluid and electrolyte balance, and show how they inter-relate. Directions to student: You will work in groups of 2-4 students, without using books or notes. Your instructor will be available for input as needed. After you have submitted your concept map for instructor review, you may consult your notes (no textbook) to correct errors and complete the map. Most of the terms and phrases you will need are listed in the following table. You may select from these, or use your own words. Where appropriate, add your own wording to further describe something. Some terms and phrases will be used more than once, and possibly some not at all. Numbers in ( ) following some terms and phrases suggest how many times they may be used. Steps: 1. Fill in the boxes under NEPHRON STRUCTURES with the names of the various nephron parts and urinary structures (see Table- column 1). 2. Fill in the blanks numbered 1-3 with the 3 steps of urine formation. 3. Fill in the blanks under DESCRIPTIONS/FUNCTIONS with the proper substances involved (see Table- column 2) and/or phrases that further describe that structure or explain a process (see table column 3). 4. In the column under REGULATION/HOMEOSTASIS, fill in the proper terms or phrases that describe how that particular process is controlled (see Table- columns 2-3). 5. When you have finished step 4 above, add the following titles to the various sections you completed in step 4: a. Acid-base balance b. Potassium homeostasis c. Calcium homeostasis d. Maintenance of plasma volume and blood pressure homeostasis e. Osmoregulation
Structures Afferent arteriole Efferent arteriole Glomerulus Bowman s capsule Distal convoluted tubule Proximal convoluted tubule Collecting duct Loop of Henle Peritubular capillaries (2) Venule Renal artery Renal vein Principal cells Intercalated cells Juxtaglomerular cells Baroreceptors (intrarenal) Renal pelvis Ureter Urinary bladder Urethra Adrenal cortex (2) Posterior pituitary Parathyroid glands Solutes, fluids, hormones, other substances Water (4) Small solutes RBC s Protein Glucose Urea Na+ (2) K+ (2) Ca++ H+ (3) HCO 3 - (2) Cl- ADH (3) Aldosterone (3) PTH Renin Angiotensinogen Angiotensin I Angiotensin II Angiotensin-converting enzyme Filtrate Tubular fluid Urine Hypertonic urine Hypotonic urine Glomerular filtration (2) Tubular reabsorption (2) Tubular secretion (2) Descriptions/functions Return of substances from tubular fluid to blood Movement of substances from blood into tubular fluid Uses counter-current exchange to establish osmotic gradient in kidney medulla Glomerular blood pressure (2) Blood plasma osmotic pressure Capsular hydrostatic pressure Kidney self-regulation of glomerular blood flow to maintain relatively constant GFR Vasoconstriction of afferent arteriole to reduce GFR (Hypertonic or hypotonic?) blood plasma (Too high or too low?) blood Ca++ (Too high or too low?) blood pressure (Too high or too low?) blood K+ (Increases or decreases?) K+ secretion (Increases or decreases?) Na+ reabsorption Water follows Na+ by osmosis (2) (Increases or decreases?) Ca++ reabsorption (Increases or decreases?) water permeability of collecting duct cells (Increases or decreases?) water reabsorption by osmosis (Increase or decrease?) blood plasma Ca++ to normal (Increase or decrease?) blood plasma K+ to normal Restore blood plasma volume Restore blood plasma acid-base balance; ph = 7.35-7.45 Return blood plasma to isotonic condition
Blood enters kidney by way of (vessel) NEPHRON STRUCTURES DESCRIPTIONS/ FUNCTIONS REGULATION/ HOMEOSTASIS Blood enters nephron via afferent arteriole NFP determined by 3 forces: minus minus (1) (1) Process: GFR normally regulated by alterations of (one of the forces listed above). Fluid called: Consists of: and Does not contain: and Alterations accomplished in 2 ways: Autoregulation: Sympathetic stim: (3) (2) Fluid flows into renal tubule system Fluid now called: Exchange between blood in and fluid in renal tubules is 2-way
(2) Process: Describe: Consist of these regions: (3) Process: Describe: Reabsorption: 1. 6. 2. 7. (metabolic waste) 3. 8. other ions 4. 9. follows by osmosis 5. Secretion: 1. Function: Secreted by in response to (stimulus) Reabsorption: 1. Ca++ 2. Na+ and other ions 3. follows by osmosis Secretion: 1. 2. Has this effect:, which in turn helps to.
Stimulus: Receptors are located _ Stimulates secretion of: by juxtaglomerular cells of the kidney. Mediates conversion of: (plasma protein produced by the liver) to Consist of 2 cell types: (1) (2) Converted to: in presence of located in endothelium of pulmonary capillaries. Stimulates to produce Reabsorption of And this causes: Has this effect: which in turn causes which helpsto
Secreted by in response to (stimulus) Secretion of Has this effect: which in turn helps to Secreted by in response to (stimulus) Reabsorption of Has this effect on CD cells: which results in: Which in turn helps to Secrete either: if plasma ph <7.4; or if plasma ph > 7.4 Has this effect: helps to
It is now in its final form. Blood, its contents altered by these processes, now flows away from the nephron by way of (vessel type) Fluid is now at the end of the nephron tubule system. Consists of water and solutes added by processes of: and minus water and solutes removed by process of:. Concentration is: in presence of Or in absence of. It flows next into the (central collecting portion) of the kidney. Blood leaves kidney by way of (vessel) to re-enter general circulation into the inferior vena cava. Eliminated from body through other urinary structures: