TOPIC 6 & 11 HUMAN PHYSIOLOGY 11.3 The Kidney & Osmoregulation

Read & Consider Structure What do you know? What questions do you have? Compare the renal vein & artery based on previous knowledge.

Draw, label, & annotate a diagram of the kidney.  Cortex  Medulla  Pelvis  Ureter  Renal blood vessels

Annotate the Nephron  Malpighian body  Proximal convoluted tubule  Loop of Henle  Distal convoluted tubule  Collecting duct

Brainstorm: Blood from the renal artery:Blood from the renal vein:

Read & Consider – Filtration Process What do you know? What questions do you have?

Ultrafiltration Occurs in the Malpighian body and is powered by blood pressure. This process drives substances such as water and relatively small molecules of the blood plasma, including useful ions, glucose and amino acids through an extremely fine sieve-like structure to produce filtrate.

Malpighian Body  The glomerulus increases blood pressure by forming narrow branches; this also increases filtration surface area.  Pressure is also maintained by the narrow efferent artery that restricts outflow of blood from the glomerulus. NOTE: The efferent blood vessel is associated with other regions of the nephron for additional reabsorption.

Continued…  Fenstrations  Basement Membrane  Podocytes

Reabsorption & Regulation  Ultrafiltration – nondiscriminating filtration.  Selective Reabsorption – the kidney retrieves substances that the body still requires.  Regulation – the kidney can control how much of the substance is reabsorbed.

Reabsorption Specifics - The PCT is the longest section of the nephron and has a microvilli cell border to increase the SA for absorption from filtrate. There are also a large number of mitochondria which produce the extra ATP required for active transport.

Continued…  Glucose, amino acids, 85% mineral ions  Small proteins  pinocytosis  80% water  Some urea

Excretion Totals Substance Total Amount in Plasma Filtered (per day) Reabsorbed (per day) Urine (excreted per day) water 3 liters180 liters L1-2 liters glucose 2.7 g162.0 g 0.0 g urea 0.9 g54.0 g27.0 g Proteins / polypeptides g2.0 g1.9g0.1 g Na + ions 9.7 g579.0 g575.0 g4.0 g Cl - ions 10.7 g640.0 g633.7 g6.3 g

The Loop of Henle  The loop of Henle is of a descending and ascending limb associated with a parallel blood supply to pick up water that has been reabsorbed into the medulla.  This blood supply (vasa recta) will also deliver oxygen to, and remove carbon dioxide from metabolically active cells of the loop.

Water Balance -  Descending  “Hairpin” zone  Ascending  DCT  Collecting Ducts

Anti-diuretic Hormone (ADH)  Low blood water –ADH is release causing the collecting duct to become fully permeable to water for reabsorption into the blood stream.  High blood water – no ADH is released and walls are less permeable producing a large volume of more diluted urine.

Hydrate! … but not too much  The body loses more fluid than it takes in. Dehydration is common, but generally easy to prevent.  Rare, but results from dirking too much water without replenishing salts and other ions. DehydrationOverhydration

Read & Consider & – Species Variation What do you know? What questions do you have?

 Osmoregulation – is the maintenance of a proper balance of water and dissolved substances in the organism. Osmoregulation is controlled by the hypothalamus.  The hypothalamus responds to changing water concentration by initiating a thirst sensation and secretion of anti-diuretic hormone (ADH), allowing more water reabsorption into the blood. Osmoregulation

Osmoconformation  Osmoconformers are unable to regulate their internal environment and so conform to the osmolarity of the solution in which they live.  Most marine invertebrates are osmoconformers.  Fish are osmoregulators. Consider the salmon.

Insect Variation

Urine Testing  Diabetes results in erratic glucose levels, usually above the normal glucose level of 90mg/m 3. The outcome of this is failure of the kidney to reabsorb all glucose forced out during ultrafiltration. Consequently, the urine of a diabetic has raised and erratic levels of glucose in the urine.

Kidney Failure

Works Cited  De Neef, Steve. Clown Fish and Sea Anemone. Digital image. The Telegraph. Telegraph Media Group, 6 Sept Web. 04 Jan  Dialysis Diagram. Digital image. Kidney Dialysis. Gujarat Kidney Foundation, n.d. Web. 04 Jan  Kidney blood supply. Digital image. National Cancer Institute. National Cancer Institute, 24 June Web. 04 Jan  Human Kidney. Digital image. Kidney Function Checks. Walk in Clinic London, 13 Dec Web. 04 Jan  "Neurovascular Supply of the Kidney." Kidney. Ken Hub, n.d. Web. 04 Jan  Salmon Life Cycle. Digital image. IGFA. International Game Fish Association, n.d. Web. 04 Jan  Spry, Leslie Spry M.D., M.D. Human Kidney. Digital image. The Huffington Post. TheHuffingtonPost.com, 5 Mar Web. 03 Jan  Three Dimensional Nephron. Digital image. 3DAnatomy.JP. 3D Anatomy Japan, n.d. Web. 04 Jan