Ctb 14: Kidney

Front 1

what are the three general functions of the kidney

Back 1

1. excretory 2. homeostatic 3. endocrine

Front 2

Describe the macroscopic structure of the kidney

Back 2

Solid organ mostly parenchyma, little stroma. Cortex= granular, hoomgenous w/ medullary rays, Medulla=striated, 6-18 renal pyramids

Front 3

What is included in a dney lobe

Back 3

macroscopic subdivision= renal pyramid+ surronding cortex

Front 4

What is included in a kidney lobule

Back 4

microscopic=medullary ray+cortical tissue (nephrons)

Front 5

Describe the blood supply to the kidney (CO, filtration volume)

Back 5

20-25% OF CO, 125 ML of fluid extracted from blood/min, 124ml reabs.

Front 6

Describe the aterial supply to the kidney

Back 6

renal=>lobar=>interlobar=>arcuate=>interlobular=> afferent arteriole/ subscapular a.

Front 7

Deseribe the flow of blood around the nephron

Back 7

into the glomerulus via the afferent arteriole, exit via the efferent arteriole to the peritubular capillarys (vasa recta for juxtamedullary nephrons)

Front 8

How do cortical and juxtamedullary nephrons differ

Back 8

juxtamedulary have longer think segments of LOH, vasa recta maintain osmotic gradients in interstitium of medulla

Front 9

what properties of the vasa recta facilitate the maintenece of interstitial osmotic gradient

Back 9

countercurrent multiplier, descending loops is lined with continuous epithelium, ascending loop is fenestrated

Front 10

how does the structure of the afferent and efferent arterioles contribute to glomerular filtration

Back 10

the afferent is larger in diameter than the efferent, the size difference creates a pressure differences that drives filtration

Front 11

Describe the structure of the epithelium of Bowman's capsule

Back 11

double layered parietal and visceral. Parietal is simple squamous, reflects onto golmerular capillaries to become visceral which is also simple epithelium. Visceral is composed of podocytes which have pedicles. Space between the two layers=urinary space, continous with PT

Front 12

What are the three components of the glomerular filtration barrier

Back 12

1. Glomerular capilllary endothelium 2. Glomerular basement membrane 3. Visceral Layer of Bowman's capsule (podocytes)

Front 13

Describe the structure of the glomerular capilllary endothelium

Back 13

discontinuous, freely permeable to water and solutes, luminal surface has negative charge b/c coated with glycocalyx w/ negativley charged proteoglycan molecules

Front 14

Describe the structure of the glomerular basement membrane

Back 14

2-3 x thicker than normal BM, physical and charge barrier to proteins, three layers 1. lucent (lamina rara interna) rich in polyanions 2. basal lamina (type IV collagen) 3 lucent (lamina rara externa), rich in polyanions

Front 15

Which part of the glomerular filtration barrier is the primary barrier that prevents protein from entering the glomerular filtrate

Back 15

glomerular basement membrane

Front 16

Describe the structure of the visceral layer of bowman's capusle, the third layer of the glomerular filtration barrier

Back 16

podocytes w/ pedicles that interdigitate along GBM, spaces between pedicles= filtration slit,

Front 17

describe the structure of the filtration slits foubetween pedicles of podocytes

Back 17

bridged by electron dense filtration slit diaphgragm, modified adherens junction w/ nephrin, coverd with podocalyxin

Front 18

Describe the structure of the renal mesangium

Back 18

cells and ECM that abut the inner surface of the GBM, modified pericyte/ smooth muscles cells that have receptors for ANP and AGII, secerte enodthelin, cytokines, prostaglandins

Front 19

What are the three functions of the renal mesangium

Back 19

1. physical support of glomerus 2. regulation of glomerular blood flow 3. regulation of turnover of GBM

Front 20

Describe glomerulonephritis

Back 20

injury to glomerulus via inflammation, mediated by immune complexes, compromised filtration= proteinuria, hematuria, oliguria, edema, hypertension, rapidly progressing forms can be fatal

Front 21

What type of epithelium lines the convoluted portion of the proxmial tuble

Back 21

cuboidal to columnar, brush border at apex caoted with glycocalyx

Front 22

Describe the unqiue features of the proximal tubule convoluted protion that faciltate reabs.

Back 22

1. brush border on apex 2. infoldings of apical cell mebrane 3. lysoscomes and apical vesicles 4 numerous mitocondria at base

Front 23

What type of epithelium lines the straight portion of the proximal tubule (thick descending limb)

Back 23

cuboidal

Front 24

What is the relative concentration of the fluid leaving the proximal tubule

Back 24

isosmotic, sodium and water reabs. isosotically

Front 25

How do cortical and jutxamedullary nephrons differ in terms of length of the LOH

Back 25

cotrical nephron have short loops and only a descending thin limb, juxtamedulr have asceing and descending thin limbs and are much longer

Front 26

How does the type of epithelium difer between the thick and thin segements of the LOH

Back 26

thick=cuboidal , thin= simple squamous, note also that in the thin ascending limb the cell membranes are interdigitated making them impereable to water

Front 27

what type of epithelium lines the straight portion (thick ascending limb) of the distal tubule

Back 27

simple cuboidal

Front 28

What are the special features of the cells lining the straight portion (thick ascending limb) of the distal tubule

Back 28

simple cuboidal, apical surface has few microvilli and efficient tight junctions at the lateral border, extensive interdigitations of lateral and basal cell membranes, abundant mitochondria

Front 29

What type of epithelium lines the convolut portion of the distal tubule

Back 29

simple cuboidal

Front 30

What are the unique features of the cells that line the convoluted portion of the distal tubule

Back 30

few microvilli, fewer mitochondria and basal interdigitations than straight portion

Front 31

What type of epithelial cellls line the collecting duct

Back 31

cuboidal to columnar, brush border at apex caoted with glycocalyx

Front 32

Describe the structure and function of principle cells

Back 32

found in collecting duct, have one primary cilium (acts as flow sensor) and ADH sensitive AQP-2 cahnnels

Front 33

Describe the structure and purpose of the primary cilium of the priniciple cells of the collecting duct

Back 33

Acts as flow sensor, function mediated by polycystin 1 and 2, defects in these proteins relt in polycystic kindey disease

Front 34

Describe the structure and function of intercalated cells of the collecting duct epithelium

Back 34

apical fold, microvilli, apical vesicles, basal membrane infoldings, numerous mitochondria, function to maintain acid-base balance

Front 35

What are some of the results of tubular disease

Back 35

affects reabs and secretory fxns, can result in polyuria or oligo/anuria, renal failure, acidosis

Front 36

How does the countercurrent multiplier effect produced a hypotonic fluid in the distal tubule

Back 36

The asecnding limb of the LOH is impermeable to water while the descending limb is somewhat permeable. The solutes that are pumped out of the ascending limb "draw out" water from the descending limb

Front 37

How does structure of the vasa recta maintain the ionic gradient established by the countercurent multiplier system of the tubules

Back 37

countercurrent exhange. The arterioels around the decending limb (which is permeable to water) have a continuous epitheilum whereas those around the ascending limb (which is impermable to water) have fenestrated epithelium. This ensures that water is quickly pulled out of the interstitum when it is diffusing out of the decensding loops but the solutes being pumped out of the ascending limb are not removed. This mantains the osmotic gradient

Front 38

What are the three components of the juxtaglomerular apparatus

Back 38

1. renin producing JG cells 2. Extraglomerular mesangial cells 3. macula densa

Front 39

Describe the structure and function of renin producing JG cells of the juxtaglomerular apparatus

Back 39

Modified smooth muscles cells in the walls of the afferent arteriole, secrete REnin leading to the production of AG II, results in vasocostriction and incase in aldoesterone secretion leading to increase Na and H2O reabs==>increase BP and blood volume

Front 40

What is the function of the extraglomerular mesangial (lacis) cells

Back 40

connected to JG and extraglomerular mesangial cells by gap junctions ,may be invovoled in erythorpoietin production

Front 41

Where is the macula densa located? What does it do

Back 41

part othe JGA, consists of columnar cells of the distal convoluted tubule adjacent to the afferent arteriole, detect Na and Cl concentation and pass information to JG cells to contorl renin secretion so as to control filtration rate and autoregulate blood volume

Front 42

which cells secrete erythropoietin? What does it do

Back 42

secreted by intersitital cells of renal cortex, simulates divison of RBC precursors, increases release of RBCs from bone marrow. stimulated by hypoxia

Front 43

Acute kidney injury can result from prerenal (vascular), intrinsic (kidney tissue) or post renal (obstructive) injury. What are some consequences of acute renal failure

Back 43

GRF decreases, azotemia, oligouria, ischemia, incrase of toxins in blood

Front 44

ESRD is irreversible and can be caused by gomerular inury, autosomal donmina polycystic kidney disease and other issues. what are some consequences of ESRD

Back 44

uremia, hematuria

Front 45

What type of epithelium makes up the mucosal lining of the calyces, pelivs, and ureters

Back 45

transitional

Front 46

the transitional epithelial cells that line the excretory passages of the renal system contain plaques in their apical membranes. What is the function of these plaques

Back 46

plaques are associated with actin filaments in the cell cortex. in the relaxed state, the plaques form infoldings (fusiform vesicles) whose lumen is continous with the tubule lumen. In the distended state, the plaques can unfold allowing the apical membrane to expand.

Front 47

Describe the muscularis layer of the excretory passages

Back 47

between mucosa and adventitia, consists of thin layers of smooth muscle, in upper 2/3 of ureter there are two layers (inner=longitudinal, outer= circular) in the lower 1/3 there are three layers (inner=longitudinal, middle= circular, outer= longitudinal)

Front 48

what are the three layers of coverings around the excretory passages

Back 48

from inside to out mucosa, muscularis, adventitia

Front 49

Describe the layers that cover the bladder

Back 49

inner mucosa is transitional epithelium, next is 3 layers of smooth muslce, the superior surface is then covered with peritoneum forming a serosa while the exterior layer of the sides and base is an adventita

Front 50

Describe the musculature of the bladder

Back 50

The mscularis (detrusor muslce) has three layers, at the neck of the bladder the smooth muscle forms the interna lsphincter.

Front 51

How is the bladder innervagted

Back 51

sympathetic for vascular control, parasympathetic for micturition control

Front 52

How does the epithelial lining of the male urethra change from proximal to distal

Back 52

prostatic portion=transitional epithelium, membranous and penile are stratified to pseudostratified columnar epithelium, navicular fossa at distal tip is lined with nonkeratinized stratified squamous

Front 53

Describe the differences between the male and female urethra

Back 53

male is longer (15-20cm) and has multiple functions, female is shorter (3-5cm) urinary function only

Front 54

Describe BPH

Back 54

affects males >45, hypertorphy of the glands of the prostate surronding the urethra,can cause urethral obstruction

Front 55

Describe renal calculi, causes

Back 55

common in sedentary men, hereditary, hypercalcemia, pH change, supersaturation of ions

Front 56

What are the components of a renal corpuscle

Back 56

glomerulus, mesangial cells, bowman's capsule

Front 57

what type of capillaries are found in a glomerulus

Back 57

fenestrated

Front 58

what type of epithelium makes up the parietal layer of Bowman's capsule

Back 58

simple squamous

Front 59

What are teh three types of cells within the glomerulus

Back 59

capillary endothelial, podocytes, mesangial cells

Front 60

What is the space between the glomerulus and the parietal layer of bowman's capsule

Back 60

urinary space

Front 61

What components make up the fitration barrier

Back 61

1. capillary endothelium (fenestrated) 2. glomerular basement membrane 3. podocytes (visceral layer of Bowman's capsulsle, simple epithelium)

Front 62

Plasma ultrafiltrate drains from the urinary space into...

Back 62

proximal tublue

Front 63

Discribe the difference in epithelium type between the PT, DT, and CD

Back 63

PT=high cuboidal, DT=low cuboidal, CD= cuboidal=>columnar

Front 64

Discribe the difference in lumen characteristics between the PT, DT, and CD

Back 64

PT=occluded, DT=open, wide, smooth contour, CD=open, "scalloped" edge b/c cells buldge inwards

Front 65

Discribe the difference in cell borders between the PT, DT, and CD

Back 65

PT=indistinct, DT=indistinch, CD= distinct

Front 66

Discribe the difference iin nuclei in a given plan of section between the PT, DT, and CD

Back 66

PT=few, basal, DT=many, central CD=many central

Front 67

Describe the differences in cytoplasmic staining between the PT, DT, and CD

Back 67

PT=eosinophilic, granular, DT and CD= pale

Front 68

why will PTs outnumber DTs in a given corss section

Back 68

DTs are shorter than PTs

Front 69

WHy does the lumen of the PT appear occulded

Back 69

brush border extends into the lumen

Front 70

why are the cell borders of the PT and DT indistinct

Back 70

extensive interdigitations of lateral plasma membranes

Front 71

how does the epithelium change as you move from PT to thin descending limb

Back 71

cuboidal to simple squamous

Front 72

How can you distinguish a CD from PTs and DTs

Back 72

CD has larger lumen and distinct borders between cells, cuboidal to columnar cells, scalloped edge because apical surfaces of cells buldge into lumen

Front 73

what substance makes up the kidney stroma

Back 73

reticular fibers

Front 74

what are the three tunics around the ureter

Back 74

mucosa (transitional epithelium), muscularis, adventitia

Front 75

How can the number of layers of muscular help you figure out where in the ureter a sample came from

Back 75

upper 2/3 has two layers longitudina and cicular, lower 1/3 has three longitudinal, circular, longitudinal

Front 76

what protein makes up the fibers in the lamina propria of the bladder

Back 76

elastin

Front 77

How many layers of smooth muscle does thate bladder have

Back 77

3

Front 78

the majority of blader cancers arise from what cell type

Back 78

urothelial

Front 79

how does the shape of a transitional epithelium change when the organ is relaxed or tense

Back 79

when relaxed, the cells are "cobblestoned" when stretched, they lay flat