The Kidney

Where are the kidneys located? Point to them. Palpate that area of the back, the one that will make you jump if someone pokes you there. Why is that area sensitive? –The kidneys are in a vulnerable, superficial location. Do you remember which type of epithelial tissue lines the urinary tract including the bladder? –Transitional epithelium, which has stretch

What is the main job of the kidneys? Rid the blood of acid, urea and toxins.

Kidney business _____ of blood flow through the kidneys per day. Blood makes _______ circuits per day. 200 liters 200

Kidney terms Find definitions for the major kidney structures –Nephron- –Renal Tubule- –Glomerulus- –Bowman’s capsule- Locate these on your diagram.

Kidney terms Find definitions for the major kidney structures –Nephron- structural and functonal unit of kidney which forms the urine –Glomerulus- structural part of nephron forming a knot where circulatory system meets kidney. –Renal tubule-duct in which formed urine collects –Bowman’s capsule- cup into which blood filtrate enters renal tubule (like a funnel)

Kidney processes The two main transport mechanisms that produce urine in the proper concentration of salts and water are –________________ How are these different?

Kidney processes The two main transport mechanisms that produce urine in the proper concentration of salts and water are –Osmosis –Active Transport How are these different?

Kidney processes Three overall processes occur –_______________ –________________

Kidney processes Four overall processes occur –Filtration –Reabsorption –Secretion –Excretion

Filtration Water and small molecules (ie: glucose, salts, urea) forced into ___________________________________ ___________________________________ ___________________________________. –Draw a red arrow on your diagram to represent filtration (see page 486)

Filtration Water and small molecules (ie: glucose, salts, urea) forced into Bowman’s capsule from blood capillaries by force of blood pressure. –Draw a purple arrow on your diagram to represent filtration (see page 486)

Reabsorption While 200 liters of water flow through the kidneys, some of this, and other valuable molecules (glucose, amino acids) are _____________________________. (Natural recycling) Urea- a waste product of cellular metabolism -is poorly reabsorbed

Reabsorption While 200 liters of water flow through the kidneys, some of this, and other valuable molecules (glucose, amino acids) are returned to the blood. (Natural recycling) Urea- a waste product of cellular metabolism -is poorly reabsorbed

…reabsorption Reabsorption depends on active transport of molecules, and water follows passively by osmosis. Yellow color of urine comes from bile pigments that were released into blood. Draw orange arrows showing reabsorption.

…reabsorption What would happen if this water were not reabsorbed?

Secretion Substances that enter the renal tubule to leave the body are considered _________ –______________________________________ __________________________________ –Helps maintain blood pH and rid the body of toxins. –Draw a blue arrow showing secretion

Secretion Substances that enter the renal tubule to leave the body are considered “secretions” –Hydrogen, potassium, some drugs and poisons are secreted. –Helps maintain blood pH and rid the body of toxins. –Draw a blue arrow showing secretion

Renal Failure and the Artificial Kidney After reading “Renal Failure and the Artificial Kidney” (page 483) answer the following… –List the signs and symptoms of uremia. –List 4 possible causes of renal failure. –Describe the basis of how hemodialysis works. –Name and describe an alternative for hemodialysis. –If dialysis is not effective, what may be a patient’s next chance?

Development of Kidneys As embryos, we develop 3 pairs of kidneys. –First are non-functional and fish-like, then they degenerate –Second may function for several days, then they also degenerate. –Third set are the form that will stick with us.

Coming up... What happens after you give a urine sample? What are they looking for?

Urinalysis Diseases that may be indicated by urinalysis –Diabetes –Anemia –Renal damage –Jaundice –Melanoma –Liver infection, urinary tract infection Also –Diet problems –Some drugs –Pregnancy