7 December 2009Renal Physiology

Lab this week: Urinalysis

Review website for instructions.

Abstracts

How to address an unsatisfactory grade: see which sections most points were lost, and concentrate on improving those sections.

Revised abstract due Wednesday Exam Day at 9:00 am.Submit revised abstract, original abstract, original stats report, and 1st Grading rubric all paper-clipped in this order, with revised abstract on top, signed only on the backside.

Overall abstract grade proportion to be determined.

Goal is to master the skill of writing a good abstract.

Renal Physiology

• Structures of the kidney• Three fundamental renal mechanisms

– Filtration– Reabsorption– Secretion

• Functions of the kidneys– Homeostasis

• Fluid balance (blood pressure)• Electrolyte balance (blood pressure, membrane excitability)• Acid-base balance (in concert with lungs)

Kidneys are source of 3 hormones: Renin, EPO, and Vit D.Kidneys are targets of 3 hormones: ADH, Aldosterone, ANH

Topics discussed: cortex, medulla, kidney stones, micturition (detrussor, internal and external urethra sphincters and innervation), incidence of bladder infections by gender, urethral sphincters

Renal artery = One way in. Two ways out of kidney (renal vein or ureter)

Distinction between urine and tubular fluid.

Fig. 14.04

Cortex and medulla

Fig. 14.02a

Renalcorpuscle

Juxtamedullary and Cortical Nephrons

Peritubular Capillaraies and branch thereof called vasa recta

The nephron

Figure 14.10

Membrane proteins are segregated into apical (luminal) and basolateral membranes.

Special terms• Filtration: movement of fluid from blood into

the lumen of the nephron

• Reabsorption: the movement of specific compounds from the lumen back into the blood (peritubular capillaries)

• Secretion: the transport of specific compounds from blood into the lumen

• Excretion: elimination from the body in urine

Fig. 14.03a

Fig. 14.05Glomerular Filtration Rate is 180 L/day

Three stimuli for secretion of renin from JGC

Fig. 14.03b

Figure 14.03Ultrafiltrate of plasma enters Bowman’s space

Composition same as plasma except no formed elements and no proteins

Fig. 14.08

variable

Fig. 14.09

Ways to alter GFR

Fig. 14.06

Table 14.02

Lab this week:Extra 800 ml intake!

Sidebar: some desert animals never drink and must obtain all their water in the diet.

Table 14.04

Lab this week:Extra 7 g intake!

Figure 14.07

Net Secretion Net Reabsorption

Ex: Sodium

Complete Reabsorption

Ex: Glucose