Histology Urinary System

Front 1

The kidney has what two endocrine functions?

Back 1

Renin angiotensin system - Blood pressure control

Erythropoietin - stimulates RBC production

Front 2

What is Epogen and who gets it?

Back 2

Exogenous Erythropoietin

Pts with renal failure

Front 3

How often must renal failure patients be dialyzed?

Back 3

A few times a week

Front 4

What three things are kept in balance by the kidneys?

Back 4

Fluids
Electrolytes
pH

Front 5

Two of the three major functions of the renal system are maintaining electrochemical balance and endocrine functions. What is the third?

Back 5

Degrading and eliminating metabolic and pharmacotherapeutic molecules

All of the above would be toxins

Front 6

In chronic disease, which functions would we want to monitor?

Back 6

All of them! Malfunction of any of the functions indicate a problem.

Front 7

Toxins are eliminated through what two renal processes?

Back 7

Filtration (180 L/day)
Secretion (penicillin and asparagus)

Front 8

The conservation of salts, aminos, glucose and water is accomplished through what process?

Back 8

Reabsorption

Amazingly efficient: 99% reabsorbed

Front 9

The kidneys receive what percent of cardiac output?

Back 9

25%

Lungs get the most, roughly equal to everything else. Brain is next.

Front 10

How long does it take for all of the blood in the body to pass through the kidneys?

Back 10

5 mins!

Dang, that's fast.

Front 11

The kidney is divided into the __ and the __.

Back 11

Cortex and Medulla

Front 12

The renal cortex is covered by how many tissue layers?

Back 12

Two: Inner and Outer Layer of Capsule

Inner is myofibrils
Outer is dense CT

Front 13

The __ contains renal artery, vein, lymph vessels and ureter.

Back 13

Hilum.

This is the "input/output" portion of the kidney.

Front 14

The cortex contains _-__ renal pyramids.

Back 14

6-12 pyramids.

Front 15

What connects medulla with the cortex?

Back 15

Medullary rays

Front 16

The parts of the kidney that collect urine from the renal papilla and form the pelvis are called what?

Back 16

Calyces

Front 17

Renal __ is continuous with the ureter.

Back 17

Pelvis

Front 18

Define what is included in a renal lobe.

Back 18

Renal pyramid and the underlying papilla with its minor calix.

Front 19

A nephron and collecting duct are (together) called what?

Back 19

Uriniferous tubule

Front 20

The nephron begins with what structure?

Back 20

Bowman's Capsule within the (renal) corpuscle

Front 21

What is the sequence of specializations within a nephron

Back 21

Proximal convoluted tubule
Thin loop of Henle
Thick loop of Henle
Distal convoluted tubule

Front 22

What are the two types of nephrons and what are their jobs?

Back 22

Juxtamedullary (15%) - Maintain osmolarity gradient.

Cortical (85%) - Actual kidney functions.

Their locations and the depths of their loops are described by their names, juxtamedullary = "close to the middle," and functions:
Long, thin loops maintain salt gradient
Short, thicker loops perform actual filtration.
Don't memorize this stuff. Think about it!

Front 23

Renal arteries branch to

Back 23

Interlobar arteries

Front 24

Afferent and Efferent arterioles enter/exit the renal corpuscle where?

Back 24

Vascular pole

Front 25

Cortical and Juxtamedullary nephrons both give rise to capillary networks. What are they?

Back 25

Cortical → peritubular networks
Juxtamedullary → vasa recta

Recall that vasa recta surround Henle loops and play a role in maintaining the osmo. gradient.
Recta = "straight," or if you like, "erect"

Front 26

What is the pathway of blood through the kidneys?

Back 26

In: Renal artery → Interlobar artery → Arcuate artery → Interlobular artery →
→ peritubular networks, or
→ vasa recta

Out: same way (backwards) -
pn/vr → interlobular veins → arcuate veins → interlobar veins → Renal vein

Note: InterLOBAR > InterLOBULAR

Front 27

The renal corpuscle is composed of what?

Back 27

Glomerulus
Bowman's Capsule

Front 28

The renal corpuscle has two poles. What are they?

Back 28

Vascular pole
Urinary pole

Front 29

What happens at the vascular pole?

Back 29

Afferent arteriole carries blood into the glomerulus. Efferent arteriole carries blood away from the glomerulus.

Front 30

Where is renal filtrate first collected?

Back 30

Bowman's Space (Urinary Space) between Bowman's capsule and the glomerular tuft.

Front 31

From the Bowman's Space, what is the next stop for the filtrate?

Back 31

Proximal convoluted tubule

Front 32

__ cells support the glomerulus and act as phagocytes.

Back 32

Mesangial cells

Front 33

Filtration occurs primarily in the basal lamina between the endothelium and __

Back 33

Podocytes

Front 34

Extensions of podocytes around the glomerular capillaries are called __

Back 34

Pedicels

Front 35

The basal lamina of the renal corpuscle consists of what four components?

Back 35

Collagen IV
Laminin
Fibronectin
Polyanionic proteoglycan*

*rich in heparin sulfate

Front 36

Describe the basal laminar filtration process of the renal corpuscles.

Back 36

Collagen network traps molecules >60kD
Polyanions impede (-) charged particlesW

Front 37

What role do mesangial cells play in the filtration process?

Back 37

Continuously reabsorb the basal lamina

Front 38

What are filtration slits?

Back 38

Spaces between pedicels

Front 39

Filtrate passes through what three layers?

Back 39

Capillary Fenestrae
Basal Lamina
Filtration Slits

Front 40

What is the main site for reabsorption in the nephron?

Back 40

Proximal tubules are not only the longest segment, but also possess large epi cells with prominent apical brush border.

Front 41

O'Don says, "If there's crap in it, it's a __ tubule."

That's a quote referring to distinguishing this structure in lab.

Back 41

Proximal Tubule

Front 42

What is the juxtaglomerular apparatus?

Back 42

A key regulator of hormones involved with fluid balance including ADH.

Front 43

What types of cellular elements are included in the juxtaglomerular apparatus and how are they interconnected?

Back 43

Macula densa
Juxtaglomerular cells
Extraglomerular mesangial cells

These elements communicate via gap junctions

Front 44

What is renin?

Back 44

Renin is an endocrine hormone released by the kidney.

It acts on adrenal medulla to release aldosterone
- Increases resorption of Na

Also converts Angiotensinogen to Angiotensin I

Front 45

Where does renin come from?

Back 45

Juxtaglomerular cells release it. These are specialized smooth muscle cells in the walls of afferent (some efferent) arterioles.

Front 46

What are medullary rays?

Back 46

Aggregates of Henle loops, distal tubules and collecting ducts running between cortex and medulla.

"Ducts of a feather run together."
- Infinite Wisdom of O'Don

Front 47

What is the primary job of Collecting tubules?

Back 47

Reabsorption of H₂O.

ADH influences the permeability of these ducts, which steadily increase in diameter:

Collecting ducts → Ducts of Bellini → Calyces

Front 48

Where do the collecting ducts end?

Back 48

Renal papilla

Front 49

What is the tip of the renal papilla called?

Back 49

Area Cribrosa

Front 50

The tissues from calyces on out to the bladder are lined with what type of epithelial cell?

Back 50

All lined with transitional epi:

Calyces → r. pelvis → ureter → bladder

Front 51

Compare the muscles of the ureter to those found in the gut.

Back 51

Upper ureter has only two layers.
Lower ureter has three layers:
Long-Circular-Long like the gut tube, but unlike the gut the middle layer is longitudinally oriented.

Front 52

Back 52

Ureter

Front 53

Back 53

Transitional Epithelium

Front 54

Back 54

Transitional Epi, stretched

Note "junk" in the lumen, probably urine

Front 55

Back 55

Bladder

Front 56

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