Renal - Nephron Orientation

Front 1

What is the tubular structure and function part of the kidneys?

Back 1

The nephron.

It has polarity within the kidney.

Front 2

Bowman's Capsule - Function

Back 2

It receives filtrate from the glomerular capillaries

Front 3

Bowman's Capsule - Type of Pressure

Back 3

Hydrostatic pressure

Front 4

Bowman's Capsule - Is the pressure high or low here?

What is the pressure?

Back 4

High hydrostatic pressure - 60

Front 5

Proximal tubule - Function

Back 5

Reabsorption

Front 6

What is reabsorbed in the proximal tubule?

Back 6

Reabsorption of water and solutes

Front 7

Loop of Henle regulates....

Back 7

The concentration of urine

Front 8

Distal tubule reabsorbs....

5 substances.

Back 8

• Water
• Electrolytes
• ADH
• Aldosterone
• ANP
• Tubular secretions

Front 9

Collecting ducts - Function

And which are they similar to?

Back 9

Collect almost all urine on way to the ureter.

Functions similar to the distal tubule.

Front 10

Filtered fluid enters through [........] and starts chugging its way through hollow tube which is one single cell layer thick.

Back 10

Bowman’s capsule

Front 11

How are nephrons coiled?

Back 11

All nephrons coil upon themselves so that the distal tubule from every single nephron is coming back from the Loop of Henle

Front 12

Afferent arterioles

Back 12

Blood vessels that come into glomerular capillary

Front 13

Efferent arterioles

Back 13

Blood vessels that leaves glomerular capillary

Front 14

The size of the tubules are the same size as...

What are the walls of the tubules made up of? How many layers?

Back 14

Capillaries

Tubules have a single layer of renal epithelium making up their walls

Front 15

Describe the flow...

Back 15

o Proximal tubules- fluid filtering decreases in volume, reabsorbing large amounts of it (blue arrows)
o Goes to Loop of Henle (pink arrows) where fluid descends and then ascends
o Switch to distal tubule (green arrows)- the distal tubule comes snaking between the afferent and efferent arterioles making up the glomerular capillary
o Then moves to the collecting duct

Front 16

Review:

What % of CO is delivered to the kidneys each minute?

Back 16

20-25%

Front 17

What is the most abundant cation of ECF?

Back 17

Sodium

Front 18

What is the most abundant anion of ICF?

Back 18

Chloride

Front 19

Vasculature

Back 19

Afferent & efferent arterioles (High resistance)

Glomerular & peritubular capillaries (Highly fenestrated)

Vasa recta (Subset of peritubular)

Lies side by side with Loops of Henle - Low perfusion 2% reduced blood flow – Has role in concentrated urine - Vulnerable to ischemia and hypoxia

Front 20

Juxtamedullary nephron contains....

(3 parts)

Back 20

o Vasa recta
o Thin loop of henle
o Thick loop of henle

Front 21

Cortical nephron contains....

Back 21

o Efferent arteriole
o Afferent arteriole

Front 22

Describe the afferent arterioles...

Back 22

Arteries come into the kidneys from an inner zone then move out and give off branches- each of these structures is called an afferent arteriole

Front 23

Describe the efferent arterioles...

Back 23

The efferent arteriole gives rise to another set of capillaries and loops all around the nephrons- peritubular capillaries

Front 24

[..........] capillary system joins together and go back to a branch that will turn into the renal vein and leave the kidney and go to the vena cava?

Back 24

Peritubular capillary system

Front 25

Every nephron has a meshwork of [.........] surrounding the tubular structure.

Back 25

Peritubular capillaries

Front 26

How are the juxtamedullary types of nephrons different?

Back 26

They have an afferent and efferent arteriole (still have glomerular capillary) but have capillary loops of peritubular tubules that surround proximal and distal tubules

o Loops that surround the Loop of Henle are the vasa recta which are a subset of pertitubular capillaries that lie side by side to the loop of Henle of ONLY the juxtamedullary nephrons

Front 27

Processes in Urine Formation: Glomerular Filtration, Tubular Reabsorption, and Tubular Secretion

Back 27

1. A large amount of fluid free of protein and blood cellular components is filtered from the glomerular capillaries into Bowman’s capsule

2. The concentration in the glomerular filtrate in Bowman’s capsule is almost the same as in the plasma

3. In tubules, filtered fluid is modified by reabsorption of water and specific solutes back into the blood and includes secretion of other substances from the peritubular capillaries into the tubules

Front 28

Urinary excretion involves what three parts?

Back 28

Filtration
-
Reabsorption
+
Secretion

Front 29

Describe filtration..

Back 29

fluid leaving glomerular capillaries and goes into Bowman’s capsule by Starling forces. The fluid is flowing through the thin tubule right next to the peritubular capillary

Much of what is filtered gets reabsorbed

Substances passing from tubular space transported across the epithelial cells and then across the endothelial cells of peritubular capillaries to go back to the blood stream

Front 30

What does reabsorption of filtrate depend on?

Back 30

Processes of reabsorption of filtrate back to the circulation has specific transport proteins that deal with Na and Cl because they deal with large amounts of Na and Cl (they are main anion and cation of blood plasma)

If there is a loss of Na or Cl from the urine, hypovolemia results because water will follow

Front 31

What is secretion?

Back 31

Secretion is the transport of unwanted substances (waste products) from peritubular blood into tubular fluid in order to get rid of it from the body at a much faster rate

Front 32

At what time are products excreted?

Back 32

Whatever is left at the end of the collecting ducts will go to the calyces and ureters and will ultimately be excreted

Front 33

What is the most significant function of the tubules?

Back 33

Reclaiming Na and Cl-

It has specific transporters to do so.

Front 34

Concentration in Bowman’s capsule is similar to that in the plasma except there should be NO [..........] at all. Should only have H20, glucose, urea, Na, creatinine.

Back 34

Proteins