RENAL FUNCTION: WHAT'S WRONG WITH THIS PATIENT?
Text Assignment: Human Kidney & Function Ch.42, pp 798-808; Pancreatic Hormones & Serum Glucose Regulation - Table 37.2 (p.708), pp 711-713, Figure 37.15 p.714; Pregnancy & Hormones pp 817-821 (Note Figure 43.17, p821); and Digestive System & Liver Function pp 729-731.
PREPARE AHEAD OF TIME! Read through the tests you will be doing. I suggest listing possible disorders that might show up in a specific test next to its heading.
EXCRETORY SYSTEM: All the systems of your body have one fundamental purpose in common -- to maintain a steady state known as homeostasis for your body.
Figure 42.3 - Pieces Parts: kidneys, ureters, urinary bladder, and urethra.
Specific Functions (of excretory systems in general!) 1)Regulation of water balance 2)Maintain blood pH by controlling your electrolyte balance. 3)Excretion of nitrogenous wastes produced from body metabolism. In our case this is urea. 4)Remove toxic substances from blood.
KIDNEYS - homeostasis = #1 job functional unit of kidney = nephron (See Figure 42.12) Kidney structure - cortex and medulla
Cortex - outer region, top halves of nephrons . Medulla - inner region; loops of Henle, bottoms of collecting ducts .
NEPHRON STRUCTURE - See Handout Available in BLC
URINE FORMATION 3 Steps: 1)filtration 2)secretion 3)reabsorption
1)Filtration - cortical region of kidney - blood is filtered through glomerular filtration slits located within Bowman's Capsule.
Filtrate = blood plasma proteins, electrolytes (Na+, Cl-,
K+, Ca++), and urea. {Metabolic wastes are actually generated as
ammonia, but we convert it to the non-toxic form of urea}
What doesn't make it through? Large molecules such as RBC, proteins, drugs, and toxins.
Table 1 in lab manual (p.138) - Illustrates what makes it into the filtrate. **Notice that the major component in urine ends up being water.**
2)Secretion - substances are removed from blood in peritubular capillaries and added to filtrate "peri" = around "tubular" = convoluted tubules
Which substances? All those molecules that were too large to filter through the glomerular slits (penicillin, drugs, proteins, etc.).
3)Reabsorption - occurs in limbs and loop of Henle, distal convoluted tubules - See Figure 42.11, p.806 a)Water is removed from the filtrate in the descending limb of Henle. b)Salts are lost from ascending limb of Henle. c)Water is lost from distal convoluted tubule and collecting duct.
**We talked about the importance of water conservation for both plants and invertebrates as they left the water and moved onto land. The nephron (particularly the loop of Henle) is the mammalian solution to this problem.**
Example = Kangaroo rats in the desert - the longer the loop of Henle, the more water conserved.
LAB PROCEDURE 1)Six teams of physicians
2)You'll be given a case file with added information from what you see in the lab manual. YOU NEED TO RUN ONLY TESTS THAT ARE APPROPRIATE FOR YOUR PATIENT! YOU NEED TO TEST EVERY SYMPTOM. TA'S NEED TO SEE EVERYONE PARTICIPATING!!!
3) You'll present results at the end of lab including which tests you ran and why, what the results were, what you prescribe as treatment, and future outlook for your patient.
HOMEOSTATIC IMBALANCES OF KIDNEYS Testing method = urinalysis
What can show up? RBC - kidney infections (better known as glomerular nephritis) - filtration slits are swollen/irritated, often allowing larger substances to pass through. Can also be present in urine due to autoimmune diseases (which have an inflammatory response). drugs - remember drugs are added to the filtrate through secretion. proteins - (excess) heavy dieting and exercise leads to the burning of muscle tissue - can also be present due to other kidney and liver disorders. pregnancy - hormone HCG (human chorionic gonadotropin) shows up in urine - This is what home pregnancy kits are testing for.