Pbd 2 Renal Exam 3

Front 1

What are 5 fxns of the kidneys?

Back 1

Removal of metabolic waste products
Removal of foreign chemicals & bioactive substances
Regulation of water & electrolyte balance
Gluconeogenesis
Production of hormones & enzymes

Front 2

When is gluconeogenesis become a substantial amount in the kidneys? In this case where does glucose come from?

Back 2

During a fast. Whenever the intake of carbohydrate is stopped for much more than half a day, our body begins to synthesize new glucose (the process of gluconeogenesis) from noncarbohydrate sources (amino acids from protein and glycerol from triglycerides).

Front 3

What hormones & enzymes are produced in the kidneys?

Back 3

EPO, Renin, & 1,25 dihydroxyviatim D

Front 4

What is the indented surface of the kidney called?

Back 4

The hilum

Front 5

What penetrates the hilum?

Back 5

By renal artery, renal vein, nn, & ureter

Front 6

Fxn of the ureter?

Back 6

Carries urine out of the kidney to the bladder

Front 7

Each ureter w/n a kidney is formed from funnel like structures called ________ __________ w/c in turn, are formed from ___________ __________.

Back 7

Major calyces, minor calyces

Front 8

Cone shaped renal tissue where minor calyces fit over?

Back 8

Pyramids

Front 9

What is the tip of each pyramid called? This projects to what?

Back 9

Papilla w/c projects into a minor calyx

Front 10

What is the fxn of the calyces?

Back 10

They act as collecting cups for the urine formed by the renal tissue in the pyramids

Front 11

How are the pyramids arranged?

Back 11

Radially around the hilum w/ the pipillae pointing toward the hilum

Front 12

The _________ constitute the medulla of the kidney.

Back 12

Pyramids

Front 13

What covers the cortical tissue?

Back 13

A very external surface of CT called the capsule

Front 14

T/F: each kidney contains 1 million nephrons.

Back 14

True

Front 15

Each nephron consists of a spherical filtering component called the ___________ __________ and a long __________ w/c extends from the renal corpuscle.

Back 15

Renal corpuscle, tubule

Front 16

What constitutes the renal corpuscle?

Back 16

Glomerulus & bowman’s capsule

Front 17

The nephron is made up of what 3 things?

Back 17

Renal corpuscle, renal tubule, collecting duct

Front 18

What makes up the renal tubule?

Back 18

PCT, henle’s loop, DCT

Front 19

What is the primary job of the renal corpuscle?

Back 19

To create a filtrate from blood that is free of cells & large proteins

Front 20

What are the afferent & efferent arterioles?

Back 20

Afferent is where blood arrives from the vasculature & efferent is where blood leaves from the gloemrulus

Front 21

Juxtaglomerular apparatus or JGA is composed of what 3 things?

Back 21

MD - macular densa, GC - granule cells, EGM – extraglomerular mesangial cells

Front 22

The filtration barrier in the renal corpuscle through which all filtered substances must pass consists of 3 layers, what are they?

Back 22

the capillary endothelium of the glomerular capillaries, a rather thick basement membrane, and a single-celled layer of epithelial cells.

Front 23

Talk about the capillary endothelium & what is it composed of? What is it not permeable to?

Back 23

the endothelial cells of the capillaries, is perforated by many large fenestrae ("windows"), like a slice of Swiss cheese, and is freely permeable to everything in the blood except red blood cells and platelets.

Front 24

This is not not a membrane in the sense of a lipid bilayer membrane but is a gel-like acellular meshwork of glycoproteins and proteoglycans, with a structure like a kitchen sponge?

Back 24

Basement membrane of the capillary

Front 25

Describe the epithelial cell layer that makes up the filtration barrier? What are these epithelial cells called?

Back 25

epithelial cells that rest on the basement membrane and face Bowman's space. These cells are called podocytes.

Front 26

Describe the structure of the podocytes?

Back 26

have an unusual octopus-like structure. Small "fingers," called pedicels (or foot processes), extend from each arm of the podocyte and are embedded in the basement membrane.

Front 27

_______ from a given podocytes interdigitate w/ the pedicels from adjacent podocytes.

Back 27

Pedicels for both

Front 28

What is the fxn of spaces between adjacent pedicels?

Back 28

constitute the path through which the filtrate, once through the endothelial cells and basement membrane, travels to enter Bowman's space.

Front 29

The foot processes are coated by a _________ layer of _________ material, w/c partially occludes the slits, and extremely _______ process called _______ _______ bridge the slits between the pedicels.

Back 29

Thick, extracellular, thin, slit diaphragm

Front 30

These are widened versions of the tight jxn & adhering jxns that link all epithelial cells together?

Back 30

Slit diaphragms

Front 31

These are epithelial foot process that extend from each arm of the podocytes & are embedded in the glomerular BM.

Back 31

Pediciles

Front 32

Describe the make up of the tubule?

Back 32

It’s made up of a single layer of epithelial cells resting on a BM

Front 33

What is a common feature of the tubule epithelial cells?

Back 33

The presence of tight jxns between adjacent cells that physically link them together like the plastic that holds a 6 pack together

Front 34

What is the blood supply to the nephrons?

Back 34

Renal artery -> arcuate artery -> interlobular artery -> afferent arteriole -> Bowman’s capsule -> efferent arteriole -> peritubular arteries (cortical glomeruli)-> interbundle plexus and descending/ascending vasa recta(juxtamedullary glomeruli

Front 35

The 3 different names of nephrons according to position of their renal corpuscle?

Back 35

Juxtamedullary, midcortical, & superficial nephrons.

Front 36

Position of corpuscle often determines loop _________.

Back 36

Length

Front 37

What can be said about the anatomy of each nephron?

Back 37

Each nephron is anatomically distinct until we get to the collecting ducts

Front 38

Where do the peritublar capillaries come from in the kidneys & what happens to them?

Back 38

Efferent arterioles subdivide to them. They are profusely distributed thruout the cortex then rejoin to form the veins by w/c blood ultimately leaves the kidney

Front 39

w/c area of the kidneys receives less blood, medulla or cortex?

Back 39

Medulla

Front 40

T/F: gloumeruli can be found in both cortex & medulla?

Back 40

False, medulla does not contain any glomeruli

Front 41

What is special about the arterioles in the juxtameduallry glomeruli?

Back 41

They do not branch into peritubular capillaries but descend downward into the outer medulla and form vasa recta

Front 42

These vessels come from the juxtamedullary glomeruli, descend into medulla, divide many times to form bundles of parallel vessels that penetrate deep into the medulla?

Back 42

Descending vasa recta

Front 43

These are differentiated smooth mm cells in the walls of the afferent arterioles?

Back 43

Granule cells or juxtaglomerular cells

Front 44

Granule cells release what?

Back 44

Renin

Front 45

These cells are part of the JGA & they are continuous w/ those of Bowman’s capsule?

Back 45

Extraglomerular mesangial cells

Front 46

These cells are specialized thick ascending limb epithelial cells?

Back 46

Macular densa cells

Front 47

Function of macular densa cells?

Back 47

Detect luminal content of the nephron at the very end of the tubule and contribute to the control of filtration rate and renin secretion. They are good Na sensors.

Front 48

Describe the renal innervations?

Back 48

sympathetic innervations of the kidneys is distributed between afferent and efferent arterioles, the JGA, and many portions of the tubule. In contrast to many systems, there is no significant parasympathetic innervations.

Front 49

process by which water and solutes in the blood leave the vascular system through the filtration barrier and enter Bowman’s space.

Back 49

Glomerular filtration

Front 50

process of moving substances into the tubular lumen from the peritubular capillaries

Back 50

Tubular Secretion

Front 51

process of moving substances from the tubular lumen into the peritubular capillaries

Back 51

tubular reabsorption

Front 52

% of plasma that gets filtered thru the glomerulus?

Back 52

20%

Front 53

w/ the 3 renal processes for any substance, what is the formula?

Back 53

Amount excreted = amount filtered + amount secreted – amount reabsorbed.

Front 54

How many renal processes are there? What are they?

Back 54

5 total. The major ones are filtration, secretion, & reabsorption. The other 2 are metabolism by tubular cells & production of substances by tubular cells

Front 55

fraction of the blood volume composed of red blood cells.

Back 55

Hematocrit:

Front 56

total blood flow to the kidneys per unit time.

Back 56

Renal blood flow:

Front 57

amount of filtrate that enters the tubule system through Bowman’s space per unit time.

Back 57

Glomerular filtration rate (GFR):

Front 58

Typical hematocrit is about how much?

Back 58

0.45 (or 45%).

Front 59

Typical renal blood flow is

Back 59

~1.1 L/min

Front 60

what is the plasma flow to the glomeruli?

Back 60

From these values we can calculate typical plasma flow to the glomeruli per unit time as
RBF * 0.55 = ~605 mL/min.

Front 61

how much is GFR?

Back 61

~125ml/min

Front 62

Two primary factors set RBF (~1.1 L/min under normal conditions); what are they?

Back 62

Mean pressure in the renal artery vs. mean pressure in the renal vein.
Resistance of the renal arterioles. This is the sum of the afferent & efferent arterioles of the 1 million nephrons in the kidney

Front 63

since afferent and efferent arterioles of each glomerulus are in_________ , a given change in either arteriole will have an identical effect. When radius of both arterioles changes simultaneously, the effect on RBF is ___________

Back 63

series, additive

Front 64

Two main characteristics of molecules effect their ability to cross the filtration barrier and enter Bowman’s space, what are they?

Back 64

molecular radius & shape, and electrical charge

Front 65

Compare between molecular radius & shape of molecule to its filtration?

Back 65

<7000 Da will freely pass, >66,000 Da will be blocked. Anything in between those #s will depend on the size, filtration rate increases as size decreases

Front 66

What is the relationship between electrical charge & filtration rate?

Back 66

For a given size, filtration rate increases with positive charge, negatively charged molecules are filtered less than neutral ones, and positively charged molecules are filtered more than neutral ones

Front 67

What is the make up of each nephron?

Back 67

it consists of a gloerulus, a PCT, loop of henle, DCT, & CT

Front 68

where in the kidney is blood filtered?

Back 68

in the glomerulus

Front 69

what happens in the CT?

Back 69

This is where water, electrolytes, & other substances are reabsorbed into the bloodstream while other, unneeded materials are secreted into the tubular filtrate for elimination

Front 70

this is the functional unit of the kidney?

Back 70

nephron

Front 71

what is the vascular component of the nephron?

Back 71

it consists of 2 arterioles closely associated w/ 2 capillary beds: the glomerulus & the peritbular capillaries

Front 72

where do u find the peritubular capillaries?

Back 72

surround the tubular structures

Front 73

what happens in the tubular portion of the nephron?

Back 73

it processes the glomerular filtrate (urine), facilitating the rabsorption of substances from the tubular fluid into the peritubular capillaries & the secretion of substances from the peritbular capillaries into the urine filtrate.

Front 74

what are the 2 catergories of nephrons?

Back 74

85% are nephrons that originate in the superficial part of the cortex called cortical nephrons.
15% are juxtamedullary nephrons.

Front 75

these types of nephrons have short thick loops of henle that penetrate only a short distance into the medulla

Back 75

cortical nephrons

Front 76

these types of nephrons originate deeper in the cortex & have longer & thinner loops of henle that penetrate the entire length of the medulla

Back 76

juxtamedullary nephrons

Front 77

describe the pressure in the glomerulus? why is it this way?

Back 77

the glomerulus is a high pressure capillary filtration system. b/c the arterioles are high resistance vessels Y the afferent arteriole has a larger diameter than the efferent, the BP in the glomerulus is extremely high & therefore easily forces fluid & solutes out of the blood into the GC along its entire length.

Front 78

the peritubular capillaries originate from where?

Back 78

efferent arteriole

Front 79

describe the pressure of the peritubular capillaries?

Back 79

low pressure vessels that are adapted for reabsorption rather than filtration.

Front 80

in the deepest part o fthe renal cortex, the efferent arterioles serving the juxtaglomerular glomeruli continue into long thin walled looping vessels called __________?

Back 80

vasa recta

Front 81

along w/c part of the nephron do we see the vasa recta?

Back 81

they accompany the long loops of henle in the medullary portion to assist in exchange of substances flowing in & out of that portion of the kidney.

Front 82

blood flows into the glomerular capillaries from the ________ ________ & flows out of the glomerular capillaries into the _________ __________, w/c leads into the ___________ capillaries.

Back 82

afferent arteriole, efferent arteriole, peritubular capillaries

Front 83

fluid & particles from the blood are filtered through the capillary membrane into a fluid filled space in Bowman's capsule called __________ _________?

Back 83

Bowman's space

Front 84

T/F: the portion of the blood that is filtered into the capsule space is called the filtrate

Back 84

true

Front 85

what are the 3 layers of the glomerular capillary membrane?

Back 85

1) capillary endothelial layer
2) BM
3) single celled capsular epithelial layer

Front 86

In w/c of the 3 layers of the glomerular capillary memb do u find fenestrations?

Back 86

they are found in the endothelial layer

Front 87

These are small perforations found in the endothelial layer of the glomerular capillary?

Back 87

fenestrations

Front 88

this layer lines the glomerulus & interfaces w/ blood as it moves thru the capillary (fig 30-5)

Back 88

endothelial layer

Front 89

In w/c layer do u find the podocytes?

Back 89

in the epithelial layer

Front 90

The epithelial layer that covers the glomerulus is continuous w/ the ____________ that lines Bowman's capsule.

Back 90

epithlium

Front 91

Podocytes are embedded in what? what do they form?

Back 91

they are embedded in the BM & form slit pores thru w/c the glomerular filtrate passes

Front 92

what is the make up of the BM?

Back 92

acullular meshwork of collagen fibers, glycoproteins, & mucopolysaccharides

Front 93

what is primarily responsible for what gets filtered?

Back 93

the spaces between the fibers that make up the BM represent the pores of a filter & determine the size dependent permeability barrier of the glomerulus

Front 94

in some areas, the capillary endo thelium & the BM do not completely surround each capillary. What is there instead?

Back 94

the mesangial cells

Front 95

Two functions of mesangial cells?

Back 95

1) phagocytic properties where they remove macromolecular material that enter the intercapillary spaces
2) they also can exhibit contractile properties & contribute to the regulation of blood flow

Front 96

Describe the cells of the PCT?

Back 96

they have fine villous structure that increases the SA for reabsorption & they are also rich in mitochondria