Chapter 23- Urinary System

The function of the Urinary system includes.

Kidney, urethra, ureter, urinary bladder.

Kidneys filters and excrete what.

Blood and toxic metabolic waste.

Kidneys regulate what?

Blood volume, base-acid, pressure, osmolarity, and electrolytes.

Kidneys secrets erythropoietin, what is that?

Stimulation production of red blood cells.

Kidneys participates in calcitriol, what is that?

Regulating calcium levels.

Kidneys does what to hormones?

Clears it from blood.

What do kidneys do to free radicals?

Detoxify them.

What are kidney’s role in starvation?

Synthesize glucose from amino acids.

How many steps are there within the renal circulation. Write them out.

6

What percentage of nephrons considered Juxtamedullary nephrons?

15%

What does the structure of Juxtamedullary nephron look like and what does it do.

Is very long, maintains salinity gradient in the medulla and helps conserve water, efferent arterioles branch into vasa recta around long nephron loop.

What percentage of nephrons considered Cortical nephrons?

85%.

What does the structure of Cortical nephron look like and what does it do.

Short nephron loops, efferent arterioles branch into perpendicular capillaries around PCT and DCT h

How many steps are there when blood enters the 2nd capillaries; basic stages of urine formation. Write out the stages.

4

What is the direction of filtration within the glomerular?

From bloodstream to capsule space

Most molecules that are > 8nm in diameter gets turn back or passed through filter?

Turn back.

How many barriers are there when it comes to filtration

3

The 3 Filtration Barriers (write it out before-hand)

Fenestrated Endothelium Of Glomerular Capillaries, Basement Membrane, Filtration Slits

Fenestrated Endothelium of Glomerular Capillaries

70 to 90 filtration pores

Highly permeable

Basement Membrane

Proteoglycan gel, negative charge, exclude molecules >8nm

Albumin is repelled by neg charge

Blood plasma is 7 % protein, filtrate is only 0.03% protein

How much blood plasma is protein

7%Ho

How much filtrate is protein

0.03%

Filtration Slit

Podocyte cell extension (pedicels) wraps around the capillaries to form a barrier layer with 30 nm

Negative charge (additional charge for large anions)

How many forces are involved in the Glomerular filtration

3

What Pressure(s) within the Glomerular leads outwards

Blood Hydrostatic Pressure (BHP) and Net Filtration Pressure (NFP)

What Pressure(s) within the Glomerular Filtration leads outwards?

Colloid Osmotic Pressure (COP) and Capsular Pressure (CP)

Equation for Net Filtration Pressure

BHP-COP-CP

Which pressure is the largest within the Glomerular Filtraton

BHP

Why does filtration happen

Pressure pushing out of the glomerulus is stronger than pressure pushing fluids in