Chapter 20- Combined Set

The nephron is the functional unit of the kidney because

the nephron filters the plasma, reabsorbs critical molecules and excretes the rest

The renal filtrate is formed in the kidney's outer shell, called the

Renal cortex

The renal corpuscle is the site where

Plasma is filtered from the glomerulus into Bowman’s capsule

The filtrate is subject to no further modification and is therefore first called urine at the end of the

Collecting duct

The urine of an individual will contain glucose when

plasma glucose concentration has reached the renal threshold

The proximal tubule is where

Reabsorption of solutes and water takes place

Secretion differs from filtration in that

Secretion is more selective

Substances secreted into the filtrate as it moves along the nephron tubule include all of the following

Hydrogen ions, Anions and Potassium Ions

Glucose reabsorption from the renal filtrate is due to

sequential active transport and facilitated diffusion by the cells of the proximal tubule

A poison that inhibits the Na⁺-K⁺-ATPase in the proximal tubule would likely __________ in this segment

Decrease glucose reabsorption

If clearance of a substance is greater than GFR, the substance is

Net secreted by the kidney

Secretion

-Moves substances from the plasma into the lumen of the nephron

-It is selective because it is carrier-mediated

Filtration Coefficient

Rate of filtration across the glomerular capillary membrane

Hydrostatic Pressure

Pressure exerted by blood in the glomerular capillaries

Glomerular Filtration Rate (GFR)

Amount of fluid that filters into the nephron per unit time

Colloid osmotic pressure

Pressure due to proteins in plasma but not in Bowman’s space

Fluid Pressure

Pressure created by filtrate in Bowman’s space

Filtration fraction

Percentage of total plasma volume that filters at the glomerulus

Macula densa cells

Specialized cells in the distal tubule wall the monitor flow through the tubule

Mesangial Cells

Contractile cells in the renal corpuscle that alter glomerular blood flow

Podocyte

Specialized cells of Bowman’s capsule that surround each glomerular capillary

Juxtaglomerular Apparatus

Region where the distal tubule of the nephron passes between afferent and efferent arterioles

Myogenic response

Intrinsic ability of vascular smooth to respond to pressure changes

Tubuloglomerular feedback

Process by which changes in fluid flow through the distal tubule influence glomerular filtration rate

Granular cells

Specialized cells in the walls of the afferent arterioles that synthesize and release renin

Filtered load

Rate of which substance is filtered

Clearance

Rate at which a solute disappears from the body by excretion or metabolism

Glomerular filtration rate

Amount of fluid filtered into the nephron per unit time

Renal handling

Overall nephron processing of a substance, including filtration, reabsorption and secretion

What is the ability of the nephron to filter substances based on size and charge due to?

• Capillary endothelium

• Glomerular basement membrane

• Epithelium of the Bowman’s capsule (podocytes)

Substances actively secreted into the renal tubule

-Hydrogen ions

-Xenobiotics

-Potassium ions

-Organic metabolites

Put the following in the appropriate sequence to indicate the pathway a substance must travel to be reabsorbed:

• basolateral membrane of the tubular epithelial cells,

• capillary pore of the peritubular capillary,

• luminal membrane of the tubular epithelial cell,

• peritubular space.

1. Luminal membrane of the tubular epithelial cell

2. Basolateral membrane of the tubular epithelial cell

3. Peritubular space

4. Capillary pore of the peritubular capilllary

Glucose in the kidney

• Is 100% reabsorbed in the nephron

• Is freely filtered at the glomerulus

Processes in which glucose is reabsorbed

• Facilitated diffusion

• Secondary active transport

Renal cortex

Outer portion of the kidney containing nephrons

Renal medulla

Inner portion of the kidney containing nephrons

Bowman’s capsule

Initial segment of the renal tubule that receives filtered fluid from the glomerular capillaries

Renal pelvis

Area at the center of the kidney, where urine collects before being funneled into the ureter

Renal corpsule

Glomerulus plus Bowman’s capsule

The filtrate is subject to no further modification and is therefore first called urine at the end of the

Collecting duct

Proximal tubule is where

reabsorption of solutes and water takes place